Journal of Boron Cilt Vol 02 Sayi Issue 02 Yil Year 2017

e-ISSN: 2149-9020

BOR DERGİSİ JOURNAL OF BORON CİLT VOL 02 SAYI ISSUE 02 YIL YEAR 2017

Ulusal Bor Araştırma Enstitüsü Adına Sahibi Owner on Behalf of National Boron Research Institute Başkan/President Dr. Abdulkerim Yörükoğlu

Baş Editör/Editor in Chief Dr. Metin Gürü (Ankara, Türkiye)

Editörler/Editors Dr. Ali Rehber Türker (Ankara, Türkiye) Dr. Fatih Akkurt (Ankara, Türkiye) DANIŞMA KURULU ADVISORY BOARD

Dr. A. Nusret Bulutçu (İstanbul, Türkiye) Dr. Mehmet Sankır (Ankara, Türkiye) Dr. Ali Karaduman (Ankara, Türkiye) Dr. Mehmet Suat Somer (İstanbul, Türkiye) Dr. Atakan Peker (Washington, USA) Dr. Mehmet Sabri Çelik (İstanbul, Türkiye) Dr. Arun K. Chattopadhyay ( Pittsburgh, USA) Dr. Murat Bilen (Ankara, Türkiye) Dr. Ayhan Mergen (İstanbul, Türkiye) Dr. Mustafa Barış (Ankara, Türkiye) Dr. Bilal Demirel (Kayseri, Türkiye) Dr. Nuran Ay (Eskişehir, Türkiye) Dr. Cahit Helvacı (İzmir, Türkiye) Dr. Olcay Şendil (Ankara, Türkiye) Dr. Çetin Çakanyıldırım (Çorum, Türkiye) Dr. Osman Okur (Kocaeli, Türkiye) Dr. Duygu Ağaoğulları (İstanbul, Türkiye) Dr. Rasim Yarım (Friedrichshafen, Germany) Dr. Erol Pehlivan (Konya, Türkiye) Dr. Sait Gezgin (Konya, Türkiye) Dr. Gülhan Özbayoğlu (Ankara, Türkiye) Dr. Sedat Sürdem (Ankara, Türkiye) Dr. Hatem Akbulut (Sakarya, Türkiye) Dr. Şafak Gökhan Özkan (İstanbul, Türkiye) Dr. İhsan Efeoğlu (Erzurum, Türkiye) Dr. Şener Oktik (İstanbul, Türkiye) Dr. İsmail Çakmak (İstanbul, Türkiye) Dr. Şükrü Dursun (Konya, Türkiye) Dr. İsmail Duman (İstanbul, Türkiye) Dr. Yuri Grin (Dresden, Germany) Dr. İsmail Girgin (Ankara, Türkiye) Dr. Zafer Evis (Ankara, Türkiye) Dr. Zeynel Kılıç (Ankara, Türkiye) Sorumlu Yazı İşleri Müdürü Manager of Publication Yayıncı/Publisher Beyhan Sayın Ulusal Bor Araştırma Enstitüsü (BOREN) Bilgi Toplama, İdari ve Mali İşler Koordinatörü e-mail: [email protected] İletişim/Contact Dumlupınar Bulvarı (Eskişehir Yolu 7. km), Basım Tarihi/Publication Date: 30/09/2017 No:166 Kat:10, 06520, Ankara Matbaa/Printing: Aydili Tasarım & Tanıtım Tel: (0312) 219 81 50 Adres: Mebusevleri Mah. Turgut Reis Cad. No:16/1 Faks: (0312) 219 80 55 Çankaya /ANKARA e-mail: [email protected] Tel: 0312 221 06 38 Faks: 0312 221 06 99 web: http://dergipark.gov.tr/boron

BOR Dergisi uluslararası hakemli bir dergidir. BOR Dergisi ULAKBİM TR Dizin ve Google Scholar tarafından indekslenmektedir. Yılda iki defa yayımlanır. Derginin yazım kılavuzuna, telif hakkı devir formuna ve yayınlanan makalelere http://dergipark.gov.tr/boron adresinden ulaşabilirsiniz. / Journal of BORON is International refereed journal. Journal of BORON is indexed by ULAKBIM TR Indexed and Google Scholar. Published twice a year. Please visit the Journal website http://dergipark.gov.tr/boron for writing rules, copyright form and published articles.

ANKARA EYLÜL 2017 / SEPTEMBER 2017 e-ISSN: 2149-9020

ULUSAL BOR ARAŞTIRMA ENSTİTÜSÜ ISSN: 2149-9020 NATIONAL BORON RESEARCH INSTITUTE

BOR DE RGİSİ JOURNAL OF BORON

CİLT/VOL SAYI/ISSUE YIL/YEAR 02 02 20 17 BOR DERGİSİ JOURNAL OF BORON http://dergipark.gov.tr/boron

İÇİNDEKİLER/CONTENTS

Borate deposits: An overview and future forecast with regard to mineral deposits ...... Cahit Helvacı 59

Synthesis and characterization of multi-functional material MoBP3O12 ...... Gülşah Çelik Gül, Figen Kurtuluş, Halil Güler 71 Mikrodalga enerjisinin kolemanit cevherinin ufalanmasına ve flotasyonuna etkisi ...... İsmail Demir, Can Güngören, Şafak Gökhan Özkan 75

Borojipsin diamonyum hidrojen fosfat çözeltilerinde çözünürlüğünün incelenmesi ...... Havva Mumcu Şimşek, Rövşen Guliyev, Ayşe Vildan Beşe, Hacer İçen 82

Review on magnesium diboride (MgB2) as excellent superconductor: Effects of the production techniques on the superconducting properties ...... Mehran Rafieazad, Özge Balcı, Selçuk Acar, Mehmet Somer 87

In-situ formation of borides and enhancement of powder metallurgy properties ...... Arun K. Chattopadhyay, Mustafa Barış, Tuncay Şimşek, Murat Bilen 97

Alternating current electrophoretic deposition of HA and hBN nanoparticles on Ti substrate ...... Merve Geçgin, Yapıncak Göncü, Nuran Ay 102

BORON 2 (2), 59 - 70, 2017

ULUSAL BOR ARAŞTIRMA ENSTİTÜSÜ ISSN: 2149-9020 NATIONAL BORON RESEARCH INSTITUTE

BOR DE RGİSİ JOURNAL OF BORON

CİLT/VOL SAYI/ISSUE YIL/YEAR 02 02 20 17 BOR DERGİSİ JOURNAL OF BORON http://dergipark.gov.tr/boron

Borate deposits: An overview and future forecast with regard to mineral deposits Cahit Helvacı*

Dokuz Eylül Üniversitesi, Jeoloji Mühendisliği Bölümü, 35160 Buca/İzmir, Turkey, ORCID ID orcid.org/0000-0002-8659-1141

ARTICLE INFO ABSTRACT

Article history: The element boron does not exist freely by itself in nature, it occurs in combination Received 9 March 2017 with oxygen and other elements in salts, commonly called “borates”. Over 250 Received in revised form 23 June 2017 boron-bearing minerals have been identified, the most common being sodium, Accepted 29 June 2017 calcium, or magnesium salts. Boron is a rare element in the nature (average Available online 25 September 2017 content in the Earth’s crust is 10 ppm), but extraordinary concentrations can be Research Article found in certain places. The formation of borate deposits can be summarized as follows; (1) a skarn group associated with intrusive and consisting of silicates and Keywords: iron oxides; (2) a magnesium oxide group hosted by marine evaporitic sediments; Borate basins, (3) a sodium– and calcium–borate hydrates group associated with lacustrine Borate deposits, (playa lake) sediments and explosive volcanic activity. Borate formation,

Overview of deposits, Borate is defined as any compound that contains or supplies boric oxide (B2O3). A Future forecast large number of minerals contain boric oxide, but the four that are most important from a worldwide commercial standpoint which are borax, kernite, ulexite, and colemanite. These are produced in a limited number of countries, and Turkey has largest borax, ulexite and colemanite reserves in the world. All the countries are dependent upon colemanite and ulexite reserves of Turkey. Borate exploration consists of detailed prospecting of favorable areas followed by drilling, and uses all the tools available to the exploration geologist. Most of the world’s commercial borate deposits are mined by open pit methods. Brines from Searles Lake, and presumably the Chinese sources, are recovered by either controlled evaporation or carbonation. Boric acid is one of the final products produced from most of the processes. Detail mineralogical and advanced chemical data on the individual borate minerals and associated minerals (such as clay and lithium minerals) will increase the knowledge of borate end-products and their incomes as well as creating new gateways to the high technology and research on the borate minerals. These types studies will be extremely important for borate and related mineral industry. Very few modern industries can get by without borates, and very few people can get by without their products. When you consider the role boron plays in plant life, and by extension, all life, it’s hard to imagine our world without it. Therefore, borates and their products could be one of the main topics for sustainable development in whole world.

1. Introduction the formation of economically viable borate deposits in playa-lake volcano-sedimentary sediments: (1) for- Borates are an unusually large grouping of minerals, mation of playa-lake environment; (2) concentration but the number of commercially important borates is of boron in the playa lake, sourced from andesitic to limited, and their chemistry and crystal structure are both unusual and complex. The accounts of the early rhyolitic volcanic, direct ash fall into the basin, or hy- exploration, mining, and processing of borates are drothermal solutions along faults; (3) thermal springs fascinating, because their remote locations often led near the area of volcanism; (4) arid to semi-arid climat- to unusual difficulties, and hardships in recovering the ic conditions; and (5) lake water with a pH of between desired products. Specific conditions are essential for 8.5 and 12.

*corresponding author: [email protected] 59 Helvacı C. / BORON 2 (2), 59 - 70, 2017

Boron’s chemistry and reactivity are fascinating be- Tibet (Central Asia). Generally, the origin of borate cause they form a wide variety of oxygen compounds deposits is related with Cenozoic volcanism, hydro- that occur in an essentially unending variety of simple thermal spring activity, closed basins and arid climate. to exceedingly complex molecules. The borates are Borax is the major commercial source of boron, with among the most interesting of the world’s industrial major supplies coming from Turkey, USA and Argen- minerals, having been known and used since the earli- tina whereas kernite is main product from the Kramer est recorded history, first for precious metal working deposit in USA. Colemanite, large-scale production of and later in ceramics [1,2]. main calcium borate, is restricted to Turkey. Datolite and szaibelyite are confined to Russia and Chinese Borate deposits occur in a limited number of Neogene sources. Tincal (borax) deposits are present in the to Holocene non-marine evaporitic settings [3-5]. In world: one in Anatolia (Kırka), another one in California such areas, the subduction-related processes may (Boron), and two in the Andes (Tincalayu and Loma have played significant role in the formation of borate- Blanca). Kırka, Boron and Loma Blanca have similari- rich series [6-8]. ties in order to the chemical and mineralogical composition of the borate minerals with sequences coleman- Boron is enriched in continental crust, clastic sedi- ite and/or inyoite//ulexite//borax or kernite//ulexite// ments, and seawater- altered oceanic crust. Thus, the colemanite and/or inyoite. Colemanite deposits with initial source and enrichment of boron was probably in or without probertite and hydroboracite are present a subduction environment via metasomatism of litho- in Anatolia (Emet, Bigadiç, Kestelek), Death Valley, sphere by boron-rich fluids released from down-going California (Furnace Creek Fm.), and Argentina (Sijes). altered oceanic slabs and possibly boron-rich pelagic Quaternary borates are present in salars (Andes) and sediments [9-12]. playa-lakes and salt pans (USA and Tibet).

Boron is one of the rarer and more unevenly distribut- Known borate deposits of Turkey were formed in the ed elements in the Earth’s crust, but there are extraor- lacustrine sediments of Tertiary age during periods of dinary concentrations of boron on an industrial scale volcanic activity which commenced in the early Tertia- in some localized areas (Figure 1). Borate minerals ry period and continued at least to the beginning of the are formed in various environments and in very differ- Quaternary. The lithology of the borate deposits shows ent conditions. The most important economic deposits some differences from one deposit to another, but they are very closely related to the Tertiary volcanic activity are, generally, interbedded with conglomerate, sand- in orogenic belts. They are situated close to converg- stone, tuff, clay, marl and limestone. Sediments in the ing plate margins; characterized by andesitic-rhyolitic borate lakes often show clear evidence of cyclicity. Bo- magmas; arid or semiarid climates; and non-marine rate minerals were deposited in separate of possibly evaporitic environments. Turkish, United States, South interconnected lakes under arid or semi-arid climatic American and many other commercial borate depos- conditions within lake sediments. its are non-marine evaporites associated with volcanic activity [12-15]. Pyroclastic and volcanic rocks of rhyolitic, dacitic, tra- chytic, andesitic and basaltic composition are interca- Four main metallogenic borate provinces, with ex- lated with these lacustrine sediments. The existence ogenous deposits of continental environments, were of volcanic rocks in every borate district suggests that recognized in global scale. They are Anatolia (Turkey), volcanic activity may have been necessary for the for- California (USA), Central Andes (South America) and mation of borates.

Figure 1. World major borate mines.

60 Helvacı C. / BORON 2 (2), 59 - 70, 2017

2. Mineralogy Table 1. Composition of principal boron minerals (Garrett, [3]).

By at least 3.8 Ga (Geologic age), boron had been Mineral Empirical Formula B2O3 Content, Wt % concentrated sufficiently to form its own minerals, Sassolite B(OH)3 or B2O3.3H2O 56.4 which are thought to have stabilized ribose, an essen- Borax (Tincal) Na2B4O7.10H2O 36.5 tial component of ribonucleic acid and a precursor to Tincalconite Na2B4O7.5H2O 48.8 life [16]. Boron is the only light element with two abun- Kernite Na2B4O7.4H2O 51.0 dant isotopes, B10 and B11; the former has a large cap- UIexite NaCaB O .8H O 43.0 ture cross-section that makes it an excellent neutron 5 9 2 absorber. These two stable isotopes differ significantly Probertite NaCaB5O9.5H2O 49.6 in atomic weight so that boron isotopic compositions of Priceite (Pandermite) Ca4B10O19.7H2O 49.8 minerals and rocks retain signatures from their precur- Inyoite Ca2B6O11.13H2O 37.6 sors and the processes by which they formed. Boron Meyerhofferite Ca2B6O11.7H2O 46.7 compounds comprise a great diversity of crystal struc- Colemanite Ca2B6O11.5H2O 50.8 tures. Evaporites constitute the richest concentrations Hydroboracite CaMgB6 O11.6H2O 50.5 of boron on Earth, and thus are the main source of boron for its many applications in medicine, electron- Inderborite CaMgB6 O11.11H2O 41.5 ics and the nuclear industry. Kurnakovite Mg2B6O11.15H2O 37.3

Inderite Mg2B6O11.15H2O 37.3 Boron is a minor element in the Earth with an average Szaibelyite (Ascharite) Mg2B2O5.H2O 41.4* concentration of 10 ppm in the upper continental crust. Suanite Mg B O 46.3 It occurs in many metamorphic and acid plutonic rocks 2 2 5 in the mineral tourmaline. In sediments, it is present Kotoite Mg3B2O6 36.5 as detrital tourmaline and as a minor element in illitic Pinnoite MgB2O4.3H2O 42.5 clays. Boracite (Strassfurite) Mg3B7O13Cl 62.2

Datolite Ca2B2Si2O9.H2O 21.8 Boron is never found in the elemental form in nature. Cahnite Ca AsBO .2H O 11.7 Boron combines with oxygen and other elements to 2 6 2 Danburite CaB2Si2A8 28.3 form borates which contain the BO3 (triangular) or BO4 (tetrahedral) structural coordination units [17]. These Howlite Ca4Si2B10O23.5H2O 44.5 Vonsenite (Paigeite) (Fe,Mg) FeBO 10.3 borate units may be polymerized similarly to the SiO4 2 5 of the silicate minerals. This results in more than 230 Ludwigite (FeMg)4Fe2B2O7 17.8 naturally occurring borate minerals identified until 1996 Tunnellite Sr B6O10.4H2O 52.9 [3,4,18,19] but the new analytical techniques allow the continuous identification of new borate minerals. cium borate, is restricted to Turkey. Datolite and szai- Although borates can be formed with any cation, and belyite are confined to Russia and Chinese sources. form double salts with other anions, the most abundant minerals are formed with calcium, sodium or both ele- Sassolite, borax, kernite, ulexite, probertite, pander- ments. Borates are strongly ionic compounds, soluble mite, colemanite, hydroboracite and szaibelyite are in hot water, and as the cations are generally alkalis or economically operated boron mines that have com- alkaline earth elements, most of them are transparent mercial importance. and colourless having a glassy luster. Three different 3. Depositional setting and formation of borate chemical formulation systems (structural, empirical, deposits and oxide-like) are used in borate minerals. The main borate minerals present in evaporitic lacustrine depos- As one of the 92 elements that make up the planet, it’s its. Neogene ore deposits with boron concentrations not surprising that boron is all around us - in soil and allowing industrial exploitation are restricted to four water, plants and animals. Boron is one of the rarer groups of major borates: Ca-borates (inyoite, mey- and more unevenly distributed elements in the Earth’s erhofferite, colemanite and priceite), Na-Ca-borates crust, but there are extraordinary concentrations of (ulexite and probertite), Na-borates (borax, kernite) boron on an industrial scale in some localized areas. and Mg-Ca-borates (hydroboracite) (Table 1). Other Borate minerals are formed in various environments borates occur as minor phases and do not require the and in very different conditions (Figure 2). The most presence of the major ones [14,15,20,21]. important economic deposits are very closely related to the Tertiary volcanic activity in orogenic belts. They Over 250 boron-bearing minerals have been identi- are situated close to converging plate margins; char- fied, the most common being sodium, calcium, or acterized by andesitic-rhyolotic magmas; arid or semi- magnesium salts [22]. Borax is the major commercial arid climates; and non-marine evaporite environments. source of boron, with major supplies coming from Tur- Turkish, United States, South American and many oth- key, USA and Argentina, whereas kernite comes from er commercial borate deposits are non-marine evapo- USA. Colemanite, large-scale production of main cal- rites associated with volcanic activity [6,13,21].

61 Helvacı C. / BORON 2 (2), 59 - 70, 2017

Figure 2. Scheme for the cycle of boron. 1. Skarn Deposits; 2. Marine Deposits; 3. Playa-lake Deposits (Modified after Watanabe, [12]).

Arid to semiarid climatic conditions are required for the just below the surface; these are the marsh or playa deposition of economic amounts of the soluble borates deposits of early mining in California and Nevada and by evaporation. According to Muessig (1966), hydrat- some of the salar deposits of South America. Finally, ed borates may accumulate in several ways within a there are lake deposits, whose occurrence required nonmarine basin. They may be deposited in layers in much more than seasonal flooding; these are the bo- a spring apron around a borate spring, with ulexite, rax and kernite deposits such as in Boron, California borax, or inyoite as the primary borate mineral [18]. (USA) and Kırka (Turkey), formed by chemical precipi- Borates may also form in a pool dominantly fed by a tation in a closed basin [14]. borate spring, with borax crystals formed in bottom muds or at the intermittently-dried margins, as at Clear Borate minerals may be subdivided, for convenience, Lake, CA and at Salar de Surire, Chile [14]. into three broad groups with respect to their origin and geological environments. These are: A) Skarn mineral Papke (1976) concluded that if the spring flows are low group is associated with intrusives and consists of or intermittent, evaporation develops a surface efflo- silicates and iron oxides; B) Magnesium oxide group rescence or precipitate, or an accumulation of crystals hosted by marine sediments; C) Hydrates sodium and

Figure 3. Generalized playa lake depositional model showing the formation of borate deposits in Neogene basins of western Anatolia, Turkey (after Helvacı, [21]).

62 Helvacı C. / BORON 2 (2), 59 - 70, 2017 calcium borate group related to lacustrine sediments tools available to the exploration geologist. The recog- and volcanic activity. A large number of minerals con- nition of trends of favorable host rocks and structures tain boric oxide, but the six that are the most significant is an important guide to areas that are of possible from a worldwide commercial stanpoint are: coleman- interest. Satellite imagery, both real and false color, ite, ulexite, borax, kernite, pandermite and hyrobora- and standard photo interpretation can be successfully cite. used under certain conditions.

Borate deposits of Turkey, as of other countries, origi- In most parts of the world, the identification of a Ceno- nated as chemical precipitates and are found interbed- zoic suite of non-marine fine-grained sediments and ded with clays, mudstone, tuffs, limestones, and simi- tuffs is the usual starting point for the field geologist, lar lacustrine sediments. There is evidence that most because most commercial borates are found associ- of these deposits were closely related in time to active ated with these rocks. Because many borates are as- volcanism. Thermal springs and hydrothermal solu- sociated with volcanic rocks, volcanic centers, flows, tions associated with this volcanic activity are therefore ash deposits, and tuffs, particularly if zeolite-bearing, regarded as the most likely source of the boron (Figure may also be favorable guides to borate prospecting 3) [14,23-27]. [14,20,28].

Boron minerals are found in various geological envi- The skarn borates of Eastern Europe and Asia were ronment: found by careful prospecting in geologically preserved fold belts where limy sediments are in contact with po- 1. a skarn group associated with intrusives and con- tassic to alkaline volcanics. Datolite and danburite oc- sisting of silicates and iron oxides; cur in skarns where the limestone was originally rich 2. a magnesium oxide group hosted by marine evap- in calcium and silica; axinite, kotoite, and ludwigite skarns are hosted by dolomitic limestones. The mag- oritic sediments; nesium borates and those associated with iron ores 3. a sodium– and calcium–borate hydrates group are generally of low grade. Marine borates are sought associated with lacustrine (playa lake) sediments in tectonically stable areas with shallow to outcropping and explosive volcanic activity. salt structures, with gypsum caps, where near surface borate deposits are identified by whitish soil cover and The following conditions are essential for the formation scanty vegetation [23]. of economically viable borate deposits in playa-lake volcanosedimentary sediments: In arid regions, ulexite often accumulates at, or just beneath, the current surface of salt flats and playas, • formation of playa-lake environment; indicating that boron is moving in the system. These • concentration of boron in the playa lake, recent crusts may also indicate brine deposits containing boron values of interest. Springs and recent spring • sourced from andesitic to rhyolitic volcanics, direct deposits containing anomalous borates may also be ash fall into the basin, or hydrothermal solutions used as a guide to ore in certain areas. along graben-margin faults; Geochemical surveys [29] are useful methods of nar- • thermal springs near the area of volcanism; rowing down prospect areas to a drill target. Both soil and rock chip sampling techniques are utilized in ex- • arid to semi-arid climatic conditions; and ploration programs with boron, strontium, arsenic, and lithium as a common suite of elements. Beryllium is • lake water with a pH of between 8.5 and 12. also used in the search for skarn borates in Russia, as 4. Borate exploration are complex B-Mg-Ca-Cl ratios. Water sampling, both surface and well (subsurface), may be useful. Certain There are extraordinary concentrations of boron at plants are boron sensitive and vegetation surveys an industrial scale in some localized areas (Figure 1). might prove interesting, but only the Russians have Borate minerals are formed in various environments done much work in this area. and in very diverse conditions. The most important economic deposits are very closely associated with Geophysical surveys, particularly gravity and magnet- the Tertiary volcanic activity in extensional Neogene ics, are used to outline target basins or structures be- basins. In some instances they are situated close to neath sedimentary basin fill. Resistivity and seismic converging plate margins, characterised by andesitic- surveys have been used to define basin structures rhyolitic magmas, arid or semi-arid climates and non- and formations which may be associated with the bo- marine evaporite environments. rates in that area. Various downhole well logging techniques, including natural gamma and neutron probes Borate exploration consists of detailed prospecting of will indicate the approximate percentage of borates favorable areas followed by drilling and utilizes all the and clay in zones of special interest.

63 Helvacı C. / BORON 2 (2), 59 - 70, 2017

Geologic mapping followed by drilling is still the defini- • and evaporitic horizons or an indication of leach- tive test in most areas of the world. While rotary drill ing of them. methods may be used, cores are generally taken of When considering its geochemical behavior [3,6] bo- the most prospective zones. Assays of B2O3 and other associated elements (arsenic, lithium, strontium) are ron shows a very high mobility in the earth crust and then run on the horizons that appear favorable for bo- therefore, it is rather difficult to find unaltered borate rates. Because the saline borates are water soluble, minerals at or close to earth surface. Rapid alteration short core runs are used, but the common borates by the effect of water and CO2 calcite forms and boric generally core well with recoveries above 90%. acid is washed away according to the following reaction: Under current economic conditions, bedded deposits of borax, colemanite, and ulexite are not generally 2CaO.3B2O3.5H2O + 2CO2 + nH2O  2CaCO3 + 6H3BO3 + (n-4) H2O sought at depths greater than 500 m. Brines with a Colemanite Carbonic acid Calcite Boric acid high borate content, particularly those associated with 5. World resources of borates other salts of value, might be extracted from greater depths under certain circumstances. The skarn and A large number of minerals contain boric oxide, but magnesium borates are economical only from surface the three that are the most important from a world- and near surface excavations at this time. wide commercial standpoint are: borax, ulexite, and Borate exploration consists of detailed prospecting of colemanite. These are produced in a limited number favourable areas followed by drilling, and uses all the of countries, dominated by Turkey, the United States, tools available to the exploration geologist. and South America, which all together furnish about 90-95% of the world’s borate supplies [14,30]. Produc- • contribution of Miocene volcanics and volcano- tion in the United States originates in the Mojave Des- clastics interbedding within sediments; ert of California; borax and kernite are mined by US Borax from its large deposit at Boron, and a limited • to Neogene playa-lake basins; amount of colemanite is probably mined by Newport • formation of capping limestone; Mineral Ventures from Death Valley. There are over 40 borate deposits located along and 885 km trend in • claystone–limestone–marl intercalations; the high Andes near the common borders of Argen- • evidence of hot springs or hydrothermal solutions tina, Bolivia, Chile, and Peru, of which at least 14 are carrying boron into the playa lake; currently in production.

Figure 4. a) Borax and dolomitic clay alternations, Kırka opencast borax mine, Kırka deposit, Eskişehir. b) Borax layers and dolomitic clays alternating in Kırka borate deposit, Turkey. c) Massive crystalline borax lithofacies. The borax crystals show zone growth (matrix inclusions) at the top. Borax crystals are transparent and rectangular to equant. These crystals have variable size and are surrounded by an lutitic matrix. d) Colemanite is principal borate mineral and is interclated with green clay as nodular and lensoidal lenses, Espey open pit mine, Emet, Turkey.

64 Helvacı C. / BORON 2 (2), 59 - 70, 2017

canosedimentary sequences exceed over 1000 m in the deposits, and they are intensively dislocated by NE-SW and NW-SE-trending gravity faults (Figure 4, 5).

Turkey has an important share in the world markets with borax (tincal) production in Kırka; colemanite and ulexite production in Emet, Bigadiç and Kestelek regions. Turkey is the biggest colemanite producer of the world and the visible and potential reserves are greater compared to current production. The most pessimist observers even agree on the fact that these reserves may last longer than a couple of hundred years (Table 2) [36].

Eti Maden Works and the private sector should coop- erate in producing end products from boron minerals, thus follow marketing and industry oriented research policies. The country’s resources need to be evaluated in a planned and programmed manner.

Figure 5. Sequence of boron mineral formations in Turkish borate 6. Mining and mineral processing deposits (Helvacı, [15]). The sodium borates borax (tincal) and kernite, the calcium borate colemanite, and the sodium-calcium Neogene basins which spread on a wide scale in west borate ulexite make up 90% of the borates used by Anatolia, contain lignite, bituminous shale, uranium, industry worldwide. Most borates were extracted pri- borate deposits and several industrial raw materials. marily in California and Turkey and to a lesser extent in Considering that only boron mines of those mentioned Argentina, Bolivia, Chile, China, and Peru (Figure 6). above, include 80% of world reserves. The western Anatolia borate district contains five distinct areas. Boron compounds and minerals were produced by From the west to east they are: Bigadiç, Sultançayır, surface and underground mining and from brine. Com- Kestelek, Emet and Kırka [31,32]. This district contains mercial borate deposits in the world are mined by open the largest borate reserves in the world [14]. pit methods. The Kırka mine in Turkey are huge open pit mines utilizing large trucks and shovels and front Turkish borate deposits were formed in the Tertiary end loader methods for ore mining and overburden lacustrine sediments during periods of volcanic ac- removal similarly to the world’s major borate opera- tivity, forming in separate or possibly interconnected tions (Figure 7). Ores and overburden are drilled and lake basins under arid or semi-arid climatic conditions blasted for easier handling. Boron operation uses a [4,14,15,20-23,25,31,33-35]. Sediments in the borate belt conveyor to move ore from the in-pit crusher to lakes often show clear interconnected lakes, and vol- a coarse ore stockpile form which it is reclaimed by

Table 2. The reserve and life estimates of the world borate deposits (Helvacı, [21]).

Known economic Total reserve Estimated life of Estimated life of Country reserve (million tons (million tons of known reserve total reserve of B2O3) B2O3) (year) (year) Turkey 224.000 563.000 155 389 USA 40.000 80.000 28 55 Russia 40.000 60.000 28 69 China 27.000 36.000 19 25 Chile 8.000 41.000 6 28 Bolivia 4.000 19.000 3 13 Peru 4.000 22.000 3 15 Argentina 2.000 9.000 1 6 Kazakstan 14.000 15.000 10 10 TOTAL 363.000 885.000 253 610

65 Helvacı C. / BORON 2 (2), 59 - 70, 2017

Figure 6. a) Boron open pit mine, California, USA. b) Tincalayu open pit mine, Argentina. c) Salar de Pastos Grandes, Argentina. d) Exploration of borate distribution at Lake Salinas, Laguna Salinas, Peru.

Figure 7. a) Kırka opencast borax mine, Kırka deposit, Eskişehir. b) Simav opencast mine, Bigadiç area, Turkey. c) Tülü opencast mine, Bigadiç area, Turkey. d) Old mine adit, Simav mine, Bigadiç area, Turkey. a bucketwheel that blends the ore before it is fed to In terms of mining, operation of Turkish boron mines the refinery. Brines from Searles Lake, and presum- are immensely susceptible with respect to geography, ably the Chinese sources, are recovered by either transportation, energy, etc. compared to other coun- controlled evaporation or carbonation. Boric acid is tries (especially Latin America, USA and China) and one of the final products produced from most of the suitable for marketing. For instance, boron deposits in processes. South America are at an altitude of 4000 metres and

66 Helvacı C. / BORON 2 (2), 59 - 70, 2017

those in North America are located in the middle of the Table 3. Commercial refined borate productions. desert, hence it is difficult and problematic to mine the deposits. Product Formula % B203

Borax decahydrate, borax pentahydrate, anhydrous Borax decahydrate Na2B4O7 10H2O 30,5 borax, boric acid, sodium perborate tetrahydrate, sodi- Borax Na B O 5H O 47,8 um perborate monohydrate and anhydrous boric acid pentahydrate 2 4 7 2 are economically significant chemical boron compo- Boric Acid H BO 56,3 nents. Turkey, USA, Russia, China, Kazakhstan, Italy, 3 3

Argentine, Bolivia, Peru and Chile are prominent coun- Borax anhydrous B2O3 100,0 tries that produce boron minerals and products (Figure 8). Borax, kernite, colemanite, and ulexite are the main Sodium perborate NaBO3 4H2O 22,0 boron minerals, which provide the source for most of Raw borax Na B O 69,2 the world’s production from Turkey, South America, anhydrous 2 2 3 and the United States [3,4,12,14,15,19,21,37,39]. from hygiene to health, from durable materials to space industry. Boron minerals and products used in different branches of industry, compose of major industrial util- ity products such as; fibreglass, medical applications and pharmaceutical materials, for safety purposes in nuclear reactors, artificial fertilizers, in photography, glass and enamel. Used in several compound forms like borax and boric acid, boron creates multi-faceted and useful components. The subject compounds provide an advantage especially in strong soldering, in welding, in reducing friction and in processes of metal purification.

Borax and boric acid, with their property to diminish bacteria, to dissolve easily in water and to soften the water perfectly; are extensively used in the making of soaps, cleansing agents, detergents, officinal products, textile colouring, protection of different materials, low resistant alloys and agricultural industry. Some of boron products, because of their structure as a perfect melting matter, are irrevocable materials in metal purification and production of steel, atomic reactors, igni- Figure 8. World borate production (Helvacı, [21]). tion switch fuses, lamps in electronic tools and solar Processing techniques are related to both the scale of batteries. “Cubic boron nitride” its main raw material the operation and the ore type, with either the upgrad- a boron compound is used in production of commer- ed or refined mineral (borax, colemanite, and ulexite) cially named “borazon”, harder than diamond; “Boron or boric acid as the final product for most operations nitride” as a termic isolator used in producing durable (Table 3) [33]. Borax-kernite ores (Boron, Kırka, Tin- materials like“boron carbide”; “boron tricloride”, “boron calayu) are crushed to 2,5 cm and then dissolved in triflouride” and boron esters are used in the making of hot water/recycled borate liquor. The resultant strong durable industrial products like oil refineries as cata- liquor is clarified and concentrated in large counter- lyzers. Boron compounds; diborane (B2H6), pentabo- current thickeners, filtered, fed to vacuum crystalliz- rane (B5H9), decaborane (B10H14) and alkali borons ers, centrifuged, and then dried. The final product is are foreseen as the potential jet and rocket fuels of the refined borax decahydrate or pentahydrate or fused future [40,41]. anhydrous borax, or is used as feed for boric acid production. Colemanite concentrates are used directly in The principal uses of borates have not changed much specific glass melts or used as a feed for boric acid in the past decade and major markets include fiber- plants. The ulexite from most of the South American glass, insulation, textile or continuous-filament glass salars is air dried, screened, and bagged. It is then fibers, glass, detergents and bleaches, enamels and combined with locally available sulfuric acid to pro- frits, fertilizers, and fire retardants (Figure 9). duce a relatively low grade boric acid or exported as feed for boric acid plants elsewhere. In certain organisms, borates can inhibit metabolic processes. One of the key chemical effects is seen Boron mineral and its products are indispensable inin laundry detergents and other cleaning products, dustrial raw materials of today. They are widely used where borates are important components in bleaching

67 Helvacı C. / BORON 2 (2), 59 - 70, 2017

Figure 9. World borate end uses (after Helvacı, [21]). and stain removal. The chemical properties of borates Turkey’s potential of visible and prospective boron serve to balance acidity and alkalinity in many appli- mines is greater than its supply. Even the most pes- cations. Borates are able to bond with other particles simistic observers are unanimous on the opinion that to keep different ingredients dispersed evenly and are these reserves might meet demands for a couple of used to control viscosity in paints, adhesives and cos- hundred years. All countries in extensively using these metics. Borates modify the structure of glass to make minerals are dependent on Turkey’s boron supplies. it resistant to heat or chemical attack. Borates interact with surfaces containing iron to form a coating which Standard of living going up rapidly, advancement of protects the metal from corrosion. Combined with zinc, scientific and technological discoveries will eventually borates are used to retard flames and suppress smoke result in the demand and necessity for perfect boron in polymers that coat electrical cables. Borates also compounds. Production and marketing of boron min- act as a flame retardant in cellulose insulation. Borates erals should be directed towards end products with absorb neutrons in applications ranging from nuclear a high added-value, instead of raw or semi-finished containment shields to treatments for cancer. products, and related investments have to be real- ized. Boron products have a high added-value and 7. Conclusions they have a strategic role in the area they are used. Recently, boron products have been utilized in differ- Although some reports declare 72-73% in their annual ent fields of industry and shown an increase parallel to reports, approximately 75-80% of the world’s boron technological innovations as standard of living going reserves are located in Turkey (Table 2) [42]. Turkish up rapidly, advancement of scientific and technological borate deposits are the largest and highest grade (re- discoveries will eventually result in the demand and spectively 30, 29 and 25% B2O3) of colemanite, ulexite necessity for perfect boron compounds (Figure 10). and borax (tincal) deposits in the world and have sufficient potential to meet the demand for many years. Production policy should be grounded on a detailed

Figure 10. Present and future borate demand by key end use 2005-2013 (MT B2O3) (Rio Tinto Inc.,[40]).

68 Helvacı C. / BORON 2 (2), 59 - 70, 2017 and thorough market research. These important un- chim. and Anal. Chem. U.S.S.R. 2, 167-177, 1964. derground resources must be restructured and or- [13] Ozol A. A., Plate tectonics and the process of volcano- ganized to ensure maximum return for the country’s genic-sedimentary formation of boron, Int. Geol. Rev., economy. Further research on mineralogy and chem- 20, 692-698, 1977. istry with regard to borate minerals and associated [14] Kistler R. B., Helvacı C., Boron and Borates, In: Indus- minerals will increase the knowledge of borate end- trial Minerals and Rocks, (Donald D. Carr editor) 6th products. Research and technological development Edition, Society of Mining, Metalurgy and Exploration, towards production of end-products with a high add- Inc., 171-186, 1994. ed value, should take first place in the fundamental [15] Helvacı C., Geological features of Neogene basins restructuring, rather than the mineral boron raw and hosting borate deposits: An overview of deposits and semi-manufactured products. Borate and their prod- future forecast, Turkey, Bull. Min. Res. Exp., 151, 169- ucts could be one of the main topic for sustainable de- 215, 2015. velopments of the world. [16] Grew E. S., Boron: From cosmic scarcity to 300 minerals, Elements, 13, 225-229, 2017. References [17] Christ C. L., Clark J. R., A crystal-chemical classifica- [1] Helvacı C., Turkish borate deposits: geological position of borate structures with emphasison hydrated bo- tion, economic importance and boron policies. Turkish rates, Phys. Chem. Miner., 2, 59-87, 1977. Engineers’ and Architects’ Association, Chamber of [18] Muessig S., Recent South American Borate Deposits, Geological Engineers publications, Ankara, ISBN 975- 2nd Svmposium on Salt, J.L. Rau, ed., Vol. 1, Northern 395-582-0, No. 71, 34 s., 2003. Ohio Geological Society, Cleveland, OH, pp. 151-159, [2] Travis N. J., Cocks E. J., The Tincal Trail. A history of 1966. borax. Harrap, London, 311, 1984. [19] Grew E. S., Anovita L. M., Boron, Mineralogy, petrol- [3] Garrett D. E., Borates: Handbook of Deposits, Pro- ogy and geochemistry, Rev. Mineral., volume 33, Min- cessing, Properties, and Use, Academic Press, UK eralogical Society of America, Washington, D.C., 862, (ss.226), 1998. 1996. [4] Helvacı C., Federico O., Garcia-Veigas J., Rosell L., [20] Helvacı C., Alonso R. N., Borate deposits of Turkey Gündoğan İ., Yücel-Öztürk Y., Neogene borate depos- and Argentina: A summary and geological comparison, its: Mineralogy, petrology and sedimentology, A Work- Turkish J. Earth Sci., 24, 1-27, 2000. shop With Special Emphasis on the Anatolian Depos- [21] Helvacı C., Borates, In: Selley R. C., Cocks L. R. M, its. IESCA, İzmir (64 pp.), 2012. Plimer I. R., (editors) Encyclopedia of Geology, Else- [5] Helvacı C., Occurence of rare borate-minerals: Ve- vier, December 2005, vol.3, p. 510-522, 2005. atchite-A, tunellite, teruggite and cahnite in the Emet [22] Cooper M. A., Hawthorne F. C., Garcia-Veigas J., Al- borate deposits, Turkey, Mineralium Deposita 19, 217- cobé X., Helvacı C., Grew E. S., Ball N. A., Fontar- 226, 1984. nauite, (Na, K)2 (Sr,Ca) (SO4) [B5O8(OH)] (H2O)2, a [6] Floyd P. A, Helvacı C., Mittwede S. K., Geochemical new sulfate-borate from Doğanlar (Emet), Kütahya discrimination of volcanic rocks associated with borate Province, Western Anatolia, Turkey, Can. Mineral., deposits: An exploration tool, J. Geochem. Explor., 60, 2015. 185-20, 1998. [23] Helvacı C., Orti F., Sedimentology and diagenesis of [7] Jackson, J., McKenzie, D. 1984. Active tectonics of the Miocene colemanite-ulexite deposits (Western Ana- Alpine-Himalayan Belt between western Turkey and tolia, Turkey), J. Sediment. Res., 68 (5), 1021-1033, Pakistan. Geophysical Journal of the Royal Astronomi- 1998. cal Society, 77, 185-264. [24] Orti F., Helvacı C., Rosell L., Gündoğan İ., Sulphate- [8] You C. F., Spivack A. J., Smith J. H., Gieskes J. M., borate relations in an evaporitic lacustrine environmet: 1993. Mobilization of boron in convergent margins: The Sultançayır Gypsum (Miocene, Western Anatolia), implications for the boron geochemical cycle. Geology Sedimentolgy 45, 697-710, 1998. 21, 207–210. [25] Helvacı C., Orti F., Zoning in the Kırka borate deposit, [9] Palmer M. R., Boron-isotope systematics of Hahna- western Turkey: Primary evaporitic fractionation or hera arc (Indonesia) lavas: Evidence for involvement diagenetic modifications, Can. Mineral., 42 (4), 1179- of the subducted slab, Geology 19, 215–217, 1991. 1204, 2004. [10] Leeman W. P., Sisson V. B., Geochemistry of boron [26] García-Veigas J., Helvacı C., Mineralogy and sedi- and its implications for crustal and mantle processes, mentology of the Miocene Göcenoluk borate deposit, Rev. Mineral., 33. Mineral. Soc. Amer., pp. 645–707, Kırka district, western Anatolia, Turkey, Sediment. 1996. Geol., 290, 85–96, 2013. [11] Lisitsyn A. E., Pastushenko I. I., Prospecting, Explora- [27] Orti F., Rosell L., Garcia-Veigas J., Helvacı C., Sulfate- tion and Evaluation of Boron Occurrences, All-Union borate association (Glauberite-Probertite) in the Emet Scientific Research Institute of Geology, Moscow, 173 Basin: Implications for evaporite sedimentology (Mid- pp., 1983. dle Miocene, Turkey), J. Sediment. Res., 86, 448–475, 2016. [12] Watanebe T., Geochemical cycle and concentration of boron in the earth’s crust, V.I. Verdenskii Inst. Geo- [28] Barker J. M., Lefond S. J., Some Additional Borate

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and Zeolites from the Mesa Del Alamo Borate District, Turkey, Geochemica et Cosmochemica Acta, 61 (15), North Central Sonora, Mexico,Preprint 79-367, Society 3161-3169, 1997. of Mining Engineers, Littleton, co, 12 pp., 1979. [36] Tombal T. D., Özkan Ş. G., Kurşun Ünver İ., Osmanli- [29] Utekhin G. M., The problem of distribution features oğlu A. E., “Properties, production, uses of boron com- and conditions of boron concentration in skarns (Eng- pounds and their importance in nuclear reactor techno- lish abstract version of original 1964 paper in Russian), logy”, BORON, 1(2), 86-95, 2016. Economic Geology, 60, 1750-1751, 1965. [37] Muessig S., Primary borates in playa deposits: Mine- [30] Lyday P. A., Boron-1990, Mineral Commodify Summa- rals of high hydration, Economic Geology 54, 495-501, ries, US Bureau of Mines, 9 pp., 1991. 1959. [31] Meixner H., Borate deposits of Turkey, Bulletin of the [38] Aristarain L. F., Hurlbut C. S. J., Boron minarals and Mineral Research and Exploration Institute of Turkey, deposits, Mineral. Rec., 3 (165-172), 213-220, 1972. 125, 1-2, 1965. [39] Özkan Ş. G., Kuyumcu H. Z., Önal G., A recent outlook [32] Helvacı C., Geolgy, mineralogy and geochemistry for borates mining and industry in Turkey, World Min. of the borate deposits and associated rocks and the Surf. Underground, 60 (1), 43-47, 2008. Emet Valley, Turkey, PhD Thesis, University of Notting- [40] Rio Tinto Inc., Form 20–F - Annual report for the fiscal ham, England (unpublished), 1977. year ending December 31, 2010: Washington, DC, Se- [33] İnan K., Dunham A. C., Esson J., Mineralogy, che- curities and Exchange Commission, March 15 2011, mistry and origin of Kırka borate deposit, Eskişehir (Accessed September 27, 2012, at http: //www.secin- Province, Turkey, Trans. Inst. Min. Metall., Sect. B, 82, fo.com). 114-123, 1973. [41] Roskill Information Services Ltd., Boron – Global in- [34] Helvacı C., Stratigraphy, minerology and genesis of dustry markets and outlook: London, United Kingdom, the Bigadiç borate deposits, Western Turkey, Econ. 243 pp., 2010. Geol., 90, 1237-1260, 1995. [42] Helvacı C., Bor yataklarının genel değerlendirilmesi ve [35] Palmer M. R., Helvacı,C., The boron isotope geoc- gelecek öngörüsü. Madencilik ve Yerbilimleri Dergisi, hemistry of the Neogene borate deposits of Western sayı 47, sayfa 66-78, 2015.

70 BORON 2 (2), 71 - 74, 2017

ULUSAL BOR ARAŞTIRMA ENSTİTÜSÜ ISSN: 2149-9020 NATIONAL BORON RESEARCH INSTITUTE

BOR DE RGİSİ JOURNAL OF BORON

CİLT/VOL SAYI/ISSUE YIL/YEAR 02 02 20 17 BOR DERGİSİ JOURNAL OF BORON http://dergipark.gov.tr/boron

Synthesis and characterization of multi-functional material MoBP3O12 Gülşah Çelik Gül1*, Figen Kurtuluş2, Halil Güler3

1Balikesir University, Faculty of Science, Department of Chemistry, 10145 Balikesir, Turkey, ORCID ID orcd.org/0000-0001-7213-1657 2Balikesir University, Faculty of Science, Department of Chemistry, 10145 Balikesir, Turkey, ORCID ID orcd.org/0000-0001-7301-4698 3Balikesir University, Faculty of Science, Department of Chemistry, 10145 Balikesir, Turkey, ORCID ID orcd.org/0000-0001-5931-829X

ARTICLE INFO ABSTRACT

Article history: New metal borophosphate compound MoBP3O12, as a potential candidate of Received 16 January 2017 nonlinear optical material, was obtained by hydrothermal method. The title compound Received in revised form 23 June 2017 was synthesized from the mixture of MoO3, B2O3, and (NH4)2HPO4 with the molar Accepted 05 July 2016 ratio 1:0.5:3, by heating at 200 °C for 3 days. The powder X-ray diffraction data was Available online 25 September 2017 indexed in tetragonal system with the refined unit cell parameters, a = b = 5.302 (8), c = 21.538 (4) Å and Z = 1. Stoichiometric chemical analysis of molybdenum was Research Article done by inductively coupled plasma atomic emission spectroscopy (ICP-AES) and Keywords: boron content was analysed by spectrophotometric azomethine H method. The Borophosphate compounds, indexed powder X-ray diffraction (XRD) data with POWD program, fourier transform Hydrothermal synthesis, infrared spectroscopy (FTIR) spectrum and thermal analysis of MoBP3O12 are also X-ray diffraction, given in the paper. Nonlinear optic materials, POWD program

1. Introduction surfaces. Moreover, different types of metal borophosphates are being used as antioxidant, fire proofing In the last decades, metal borates have drawn world agent (sodium, potassium borophosphate) and also attention because of their excellent physical and as a binder (aluminium borophosphate as binder for unique optical nature [1-3]. On the other hand, phos- clays and phosphates) [13]. Strontium borophosphate phate compounds have been taken an interest due to is reported as light sensitive material and can be used their magnetic, optic and electro-optic properties [4-6]. in solar energy research [14]. As the other group, rare In the borate structure, boron atoms can connect with earth borophosphate compounds have found wide ap- oxygen atoms in two different ways; trigonal sp2 bonds plication area for laser and luminescence materials 3 or tetrahedral sp bonds to form BO3 and BO4, respec- and can be called “self-active lasers”. Borophosphate tively [7]. In addition to these two simple groups, bo- glass ceramic compositions are being used for seal- rates contain complex groups, such as symmetrical ing cathode ray tubes, plasma display panels and fluo-

B3O6 boroxol ring, unsymmetrical B3O7 ring and infinite rescent character display tubes [15]. Alkaline, alkaline chain (BO2)n [8, 9]. In the phosphate structure, rela- earth and rare earth metal borophosphate compounds tively simple tetrahedral PO4 and complex P2O7 are have been studied and investigated in detail in recent mainly available [9]. The diversity of linkage of boron years. But, to our knowledge, there is few reports deal and phosphorus atoms with oxygen atoms lead to the with transition metal borophosphates. formation of new compounds called ‘borophosphates’ with different partial anionic structures [10]. Borophos- Generally, conventional solid state synthesis is used to obtain metal borophosphates. Anhydrous borophosphates are described by the existence of “BPO7 group” including four-fold coordinated B and P, and bridging phates as M[BPO5] (M=Ca, Sr), M3[BP3O12] (M=Ba, Pb) oxygens occurring silica-like network [11]. Borophos- and Na5[B2P3O13] are the basic borophosphates syn- phate compounds are promising new class of func- thesized by high temperature furnaces at about 1100- tional materials, particularly nonlinear optics, because 1400 °C [16-19]. However, such high temperature of having a huge structural diversity [12]. can lead to glassy product not possible to get optical quality crystals [20]. Therefore, more mild applications There is much information for the industrial applica- like hydrothermal method must be explored. To syn- tions of metal borophosphate compounds. For exam- thesize single crystal and polycrystalline compounds, ple; alkaline earth metal borophosphates, especially hydrothermal synthesis is an excellent method. Lots

CaBPO5, are used for corrosion protection of metal of chromate, phosphate, borate, and borophosphate

*Corresponding author: [email protected] 71 Çelik Gül G. et al. / BORON 2 (2), 71 - 74, 2017 compounds are produced with hydrothermal synthe- the sample. Using standard kits, the boron concentra- sis [21]. The most common arrangement required for tion in the sample to be assayed was measured in a such crystallization is the temperature gradient that spectrophotometer against the previously prepared helps to transport the material from the zone of high peptide. Using mathematical transformations, it is de- solubility. This method has some significant advan- termined how many moles of boron are present in one tages over other chemical techniques. Many materi- molar product Mo content was also determined with als can be produced directly in the desired crystalline several necessary dilutions by using a PerkinElmer phase at relatively low temperatures (under 350 °C) Optima 3100-XL-ICP-OES by using molybdenum with eliminating any need for the calcination treatment standard. prior to sintering. 2.4 Indexing of the XRD pattern Herein, the hydrothermal synthesis and structural The refinement of the unit cell parameters were real- analysis of molybdenum borophosphate, MoBP3O12 ized by the POWD program (an interactive Powder is reported. This compound is characterized by pow- Diffraction Data Interpretation and Indexing Program der X-ray diffraction (XRD), fourier transform infra- Ver. 2.2.) [24]. red spectrophotometry (FTIR), inductively coupled plasma/optical emission spectroscopy (ICP/OES) and 3. Results and discussion azomethine H spectrophotometric method. 3.1 Powder X-ray diffraction results of MoBP3O12 2. Materials and methods The synthesized product was obtained as a white powder and stable at room temperature. Figure 1 shows 2.1 Synthesis of MoBP O 3 12 the powder X-ray diffraction pattern of the product. When we compared the “d” values with ICDD (Inter- The chemical reagents, MoO3, B2O3, (NH4)2HPO4 and H PO were analytical grade by Merck and Riedel. national Centre for Diffraction Data) crystal structure 3 4 database and literature, there was no coupling. There- MoO3, B2O3 and (NH4)2HPO4 were mixed in 1:0.5:3 molar ratio and 6 mL H PO (85 %) and 20 mL distilled fore, we indexed the pattern via POWD program and 3 4 decided that an original new XRD patterns were ob- water added to dissolve them (pH<2). The clear solu- tained with the product. In the indexing process, none tion was transferred into stainless steel Teflon auto- impurity was detected. So, all reflections are indexed clave and heated at 200 °C for 3 days. The products in the tetragonal system. After refinements, the lat- were filtered off, washed with distilled water and dried tice constants were calculated as a= b= 5.302(8) and at 60 °C. Experiment was repeated three times for re- c=21.538(4) Å. The experimental density of the prod- producibility. uct was obtained 1.124 g/cm3 and Z value was calculated as 1. The observed and calculated powder XRD 2.2 Characterization data of the product are listed in Table 1. So we could The XRD data were collected by using Brucker Axs- say high purity of this compound was obtained by hy- Advanced-Dx type of diffractometer with Cu-K radia- drothermal method. The basic chemical reaction of a synthesis of MoBP O can be suggested as follows: tion (40 kV, 20 mA, l=1.54056 Å). Infrared spectrum 3 12 was obtained using Perkin Elmer BX-2 FTIR spectro- MoO3 + 1/2B2O3 + 3(NH4)2HPO4  MoBP3O12 + 6NH3 + 9/2H2O (1) photometer in the 4000-400 cm-1 range. The thermal property was defined by Perkin Elmer Diamond ther- mogravimetric analysis (TGA). 3.2 The results of chemical analysis The mole ratio of boron was calculated 1.13 by azo- 2.3 Chemical analysis methine H method. The value was very close to the The elemental boron analysis was determined by us- theoretical stoichiometric value, resulting with a for- ing the azomethine H spectrophotometric method with mula MoBP3O12. The target compound was dissolved high and good sensitivity. Elemental boron analysis in warm nitric acid/water solution (1:1) to obtain 1 M was performed using the azomethine-H spectrochemi- solution of the compound to obtain stock solution. The solution was analysed with several necessary dilu- cal method with high detection power [22,23], Lange tions on PerkinElmer Optima 3100 XL ICP-OES with Cadas 2800 spectrophotometer. In this method borate software Winlab 32 and connected AS-90-TrayB auto anions form a yellow complex which is photometrically sampler. The instrumentation was equipped with perceptible with azomethine-H. A standard kit (LCK an echelle-based polychromator, a standard axi- 307 Bor, 0.05-2.5 mg/L, supplied by Hach Lange, ally viewed glass torch and a cross flow nebulizer GmbH Willstätterstr, 11, 40549 Düsseldorf, Germany) coupled to glass cyclonic spray chamber. Transport was used for this procedure. The sample to be as- of the solutions to the nebulizer was achieved us- sayed was weighed in appropriate quantities and the ing a peristaltic pump at 1.5 mL min-1. Plasma, appropriate dilution was carried out in the presence auxiliary and nebulization gas flows were 15.0, of a small amount (2-3 mL) of nitric acid, dissolved in 0.5 and 0.5 L.min-1, respectively. The wavelength water, with a boron concentration of 0.05-2.5 mg/L in has been used for the Mo element was at 202.031 nm.

72 Çelik Gül G. et al. / BORON 2 (2), 71 - 74, 2017

Figure 1. Powder X-ray diffraction pattern of MoBP3O12.

Table 1. List of diffraction intensities, d-values and the indexing results of MoBP3O12.

I/I0 dobs dcalc hkl 100 5.27 5.30 100 86 3.725 3.750 110 95 3.061 3.077 007 (114) 26 2.650 2.651 200 21 2.366 2.372 210 42 2.004 2.009 207 16 1.7687 1.7676 300 (224) 16 1.6836 1.6845 219 20 1.6002 1.6011 227 (314)

18 1.5365 1.5385 228 Figure 2. FTIR spectrum of MoBP3O12. 18 1.4697 1.4707 320 Table 2. The FTIR wavenumbers of MoBP O . 18 1.3722 1.3723 319 3 12 Experimental Band Locations 15 1.3281 1.3269 327 Assignments -1 -1 Wavenumbers (cm ) (cm ) 16 1.2526 1.2530 329 (P=O) 1241 1216 15 1.2166 1.2175 407 (334) 1370 (Broad) 1377

13 1.1842 1.1840 421 3 (BO3) 1241(Broad) 1200-1245 14 1.1610 1.1605 418 3 (BPO7) 1079 1079  1020 (Broad) 1051 3 (BO4) s (BOP) 718 749 The obtained Mo and B concentrations in mg/L were 4 (PO4) 467 467 converted to mol/L and the mole ratio of Mo/B was cal- 1 (BO4) 897 882 culated as 1:1 molar ratio.  (BOP) 668 655  (OPO) 548 561 3.3 FTIR and thermal studies

The FTIR spectrum of MoBP3O12 is illustrated in Fig- ure 2. The absorption bands around 3615, 3450 and 1670 cm-1 are due to the absorption of water from the air. Absorption bands at 1241 and 1377 cm-1 may be assigned to non-bridging P=O vibrations. Experimen- tal and referred stretching vibrations of BO4, BO3, PO4 and other functional groups have been given in Table 2 [25-27]. Since the borophosphates are consisting of simple or complex anionic structures like BO3, BO4,

PO4 and BOP, the IR bands support the presence of this coordination in the synthesized crystal structure.

The result of thermal analysis is displayed in Figure 3. The mass loss at about 200 °C is related to the hu- midity. Thermal changes at 708 and 990 °C represent Figure 3. The DTA curves of MoBP O . phase transformations in crystal structure. 3 12

73 Çelik Gül G. et al. / BORON 2 (2), 71 - 74, 2017

4. Conclusions [12] Shi Y., Liang J. K., Zhang H., Liu Q. L., Chen X. L., Yang J. L., Zhuang W. D. et al., Crystal structure and In this work, the synthesis of molybdenum borophos- thermal decomposition studies of barium borophosphate has been achieved by hydrothermal method for phate, BaBPO5, J. Solid State Chem., 135, 43‒51, the first time. The crystal structure and unit cellpa- 1998. rameters of MoBP3O12 were obtained by POWD index- [13] Goetzman K., Karlheinz D., Dieter H. N., Ralfh G., Pat- ing program as tetragonal system and a=b=5.302(8) ent CA C09K015, 1996. and c=21.538(4) Å, respectively. While indexing pro- [14] Bulur E., Goeksu H. Y., Wieser A., Figel M., Oezer A. cess, we used powder X-ray diffraction pattern. Also, M., Thermoluminescent properties of fluorescent ma- we benefit from FTIR spectrum, ICP-OES analyse re- terials used in commercial lamps, Rad. Pro. Dosi., 65, sults, spectrophotometric method results, and thermal 373‒379, 1996. analysis for supporting presence of borophosphate in [15] Tanabe R., Sugimato N., Ho S., Manabe T., Patent the crystal structure and mole ratio of the basic atoms. CA Section 57 (Ceramics) CODEN: JKXXXAF, ICS: Also, crystal system, unit cell parameters and chemi- C03C008-08; C03C008-14, 95-274456, 23 Oct., 1995. cal formula of molybdenum borophosphate were described for the first time with this paper. [16] Kniep R., Gozel G., Eisenmann B., Rohr C., Asbrand M., Kızılyallı M., Borophosphate - Eine stiefmütterlich behandelte verbindungsklasse: Die kristallstrukturen Acknowledgment II II von M [BPO5] (M =Ca, Sr) und Ba3[BP3O12], Ange. Authors would like to thank to Turkey Prime Ministry Chem. Inter. Ed., 33, 749‒750, 1994. State Planning Organization (DPT-2003-K-120-230), [17] Hauf C., Friedrich T., Kniep R., Crystal structure Balıkesir University with research project foundation of pentasodium catena-(diborato-triphosphate), and Scientific and Technological Research Council of Na5[B2P3O13], Crys. Mater., 210, 446-451, 1995. Turkey for financial support. [18] Petkova P., Boubaker K., Vasilev P., Mustafa M., Yu- mak A., Touihri H., Soltani M.T., Infrared Spectros- References copy of Undoped and Cu-doped (80-x)Sb2O3-20Li(2) [1] Becker P., Borate materials in nonlinear optics, Adv. O-xMoO(3) Glasses, AIP Conference Proceedings, Mater., 10, 979‒992, 1998. 1727, 0217, 2016. [2] Chen C., Lin Z., Wang Z., The development of new bo- [19] Zhu C., Wang J., Ren X., Zhang Y., Liu S., Shen J., Yue rate-based UV nonlinear optical crystals, Appl. Phys. Y., Sintering temperature and atmosphere modulated B, 80, 1‒25, 2005. evolution of structure and luminescence of 2CaO– P2O5–B2O3: Eu phosphors, J. Lum., 145, 110–113, [3] Aka G., Brenier A., Self-frequency conversion in non- 2014. linear laser crystals, Optic Mater., 22, 89‒94, 2003. [20] Byrappa K., Progress in Crystal Growth and Charac- [4] Chen C., Wu Y., Li R., Growth of large Mo18O52 single terization of Materials, Pergamon Press, Frankfurt, crystals by a vapor phase method, J. Crys. Growth, 99, 1991. 708‒715, 1990. [21] Franson M. A. H., Standard Methods for Examina- [5] Fan T. Y., Huang C. E., Hu B. Q., Eckhardt R. C., Fan tion of Water and Waste Water. American Publication Y. X., Bayer R. L., Feigelson R. S., Second harmonic Health Associations, the USA, 1995. generation and accurate index of refraction meas- [22] Capelle R., Microdosage colorimétrique du bore en urements in flux-grown KTiOPO4, Appl. Optics, 26, 2391‒2394, 1987. milieu aqueux, au moyen de réactifs a groupement azol̂que ou imine dérivés des acides h et k, Anal. [6] Harrison W. T. A., Gier T. E., Stucky G. D., The synthe- Chim. Acta, 24, 555‒572, 1961. sis and Ab initio structure determination of Zn4O(BO3)2, a microporous, zinc borate constructed of “sused” sub- [23] Zaijun L., Yuling Y., Jiaomai P., Jan T., 1-(2-hydroxy- units, of three- and five-membered rings, Ange. Chem. 3-methoxybenzylideneamino)-8-hydroxynaphthalene- Inter. Ed., 32, 724‒761, 1993. 3,6-disulfonic acid as a reagent for the spectrophotometric determination of boron in ceramic materials, [7] Wells A. F., Structural Inorganic Chemistry, 4th ed. Ox- Analyst, 126, 1160‒1163, 2001. ford University Press, Oxford, 1975. [24] Wu E., POWD, an interactive program for powder dif-

[8] Bell R. J., Carnevale A., A structural model for B2O3 fraction data interpretation and indexing, J Appl. Crys., glass, Philos. Mag. B, 43, 389‒413, 1981. 22, 506‒510, 1989. [9] Rulmont A., Almou M., Vibrational spectra of metabo- [25] Baykal A., Kızılyallı M., X-ray powder diffrac- rates with infinite chain structure: LiBO , CaB O , Sr- 2 2 4 tion and IR study of NaMg(H2O)2[BP2O8]·H2O and B O , Spectrochim. Acta Part A, 45, 603‒610, 1989. 2 4 NH4Mg(H2O)2[BP2O8]·H2O, Mater. Sci., 35, 4621‒4626, [10] Kniep R., Engelhardt H., Hauf C., A first approach to 2000. borophosphate structural chemistry, Chem. Mater., 10, [26] Gozel G., Kızılyallı M., Kniep R., Characterization of a 2930‒2934, 1998. new calcium ultraphosphate, Ca3(P5O14)2, J Solid State Chem., 129, 196‒199, 1997. [11] Levesseur A., Olazcuaga R., Kbala M., Zahir M., Hagenmuller P., Couzi M., Etudes electrique et Raman [27] Gozel G., Baykal A., Kızılyallı M., Kniep R., Solid-state

des verres des systemes B2O3·M2O·M3PO4 (M=Li, Na), synthesis, X-ray powder investigation and IR study of Solid State Ion., 2, 205‒213, 1981. α-Mg3[BPO7], J Europ. Ceram. Soc., 18, 2241‒2246, 1998.

74 BORON 2 (2), 75 - 81, 2017

ULUSAL BOR ARAŞTIRMA ENSTİTÜSÜ ISSN: 2149-9020 NATIONAL BORON RESEARCH INSTITUTE

BOR DE RGİSİ JOURNAL OF BORON

CİLT/VOL SAYI/ISSUE YIL/YEAR 02 02 20 BOR DERGİSİ 17 JOURNAL OF BORON http://dergipark.gov.tr/boron

Mikrodalga enerjisinin kolemanit cevherinin ufalanmasına ve flotasyonuna etkisi İsmail Demir1, Can Güngören2, Şafak Gökhan Özkan3*

1İstanbul Üniversitesi, Maden Mühendisliği Bölümü, 34320 İstanbul, Türkiye, ORCID ID orcd.org/0000-0003-0949-7706 2İstanbul Üniversitesi, Maden Mühendisliği Bölümü, 34320 İstanbul, Türkiye, ORCID ID orcd.org/0000-0002-6664-1551 3İstanbul Üniversitesi, Maden Mühendisliği Bölümü, 34320 İstanbul, Türkiye, ORCID ID orcd.org/0000-0002-7770-7480

MAKALE BİLGİSİ ÖZET

Makale geçmişi: Mikrodalga ısıtma sistemlerinde mikrodalgalar malzeme bünyesinde iç İlk gönderi 24 Şubat 2017 sürtünme meydana getirerek, bir termal gerilim ve iç basınç oluşturmaktadır. Bu Revize gönderi 18 Ağustos 2017 durum malzeme özelliklerine bağlı olarak tane bünyesinde çatlaklar meydana Kabul 18 Ağustos 2017 getirebilmektedir. Bu etkisi sayesinde mikrodalgalardan çeşitli cevher hazırlama Online yayınlanması 25 Eylül 2017 işlemlerinde faydalanılmaktadır. Bu çalışmada önemli bor minerallerinden biri olan kolemanitin ufalanması ve flotasyonuna mikrodalga enerjisinin etkisi araştırılmıştır. Araştırma Makalesi Çalışma sonucunda mikrodalga enerjisinin iri tane boyutunda ufalanma üzerinde olumlu etkisi olurken, ince tane boyutlarında önemli bir etki gözlenmemiştir. Çalışma Anahtar kelimeler: Mikrodalga, kapsamında kullanılan kolemanit cevheri ham hali ile %32,21 B2O3 tenörüne sahiptir. Ufalama, Yapılan boyut küçültme işlemleri sonucunda numuneler flotasyon deneylerinde Fotasyon, kullanmak üzere +0,250, -0,250+0,038 mm ve -0,038 mm tane boyutlarına Kolemanit, ayrılmıştır. Bu numunelerin tenörleri sırası ile %44, %40 ve %21 B2O3’tür. +0,250 Bor mineralleri mm tane boyutundaki numunelerin B2O3 tenörü yüksek olduğu için flotasyon işlemine tabi tutulmamıştır. -0,250+0,38 mm tane boyutundaki numunelere yapılan flotasyon

deneylerinde konvansiyonel flotasyonla %44,76 B2O3 tenörlü konsantre %55,05 verimle, mikrodalga enerji uygulanan numunelerin flotasyonunda ise %42,99 2B O3 tenörlü konsantre %59,69 verimle kazanılmıştır. -0,038 mm tane boyutundaki numunelere yapılan flotasyon deneylerinde ise konvansiyonel flotasyonda %37,91

B2O3 tenörlü konsantre %24,79 verimle, mikrodalga enerji uygulanmış numunelerin flotasyonu sonucunda ise %37,212 B O3 tenörlü konsantre %31,17 verimle elde edilmiştir.

Effect of microwave energy on the comminution and flotation of colemanite ore

ARTICLE INFO ABSTRACT

Article history: Microwaves create internal friction in the material body and hence thermal stress Received 24 February 2017 and internal pressure. This situation can generate fractures according to the Received in revised form 18 August 2017 material features. Therefore, microwaves can be used in various mineral processing Accepted 18 August 2017 processes owing to this effect. In this study, the effect of microwave energy on Available online 25 September 2017 the comminution, and flotation of a colemanite ore, which is an important boron mineral, was investigated. As a result, a positive effect of microwave energy on the Research Article comminution of coarser particles was determined while no significant effect was Keywords: observed on the comminution of finer particles. The colemanite ore as supplied has Microwave, 32.21% B2O3 grade. The samples were sieved to +0.250, -0.250+0.038 mm, and Comminution, -0.038 mm particle size fractions separately before the flotation experiments. The Flotation, grades of these samples were 44%, 40%, and 21% B2O3, respectively. The samples Colemanite, coarser than 0.25 mm particle size were not subjected to flotation because of their Boron minerals high grades. In the flotation experiments of the particles at -0,250+0,38 mm particle

size, a concentrate with 44.76% B2O3 grade was recovered with 55.05% recovery by conventional flotation. On the other hand, a concentrate with 42.99% B2O3 grade was recovered with 59.69% recovery in the flotation of microwave treated samples. In addition, in the flotation of the particles at -0,038 mm particle size, a concentrate with

37.91% B2O3 grade was recovered with 24.79% recovery by conventional flotation. On the other hand, a concentrate with 37.21% B2O3 grade was recovered with 31.17% recovery in the flotation of microwave treated samples.

*Sorumlu yazar: [email protected] 75 Demir İ. ve ark. / BORON 2 (2), 75 - 81, 2017

1. Giriş (Introduction) Bu çalışmada, mikrodalga enerjisinin ülkemizin stra- tejik yeraltı kaynaklarından olan bor elementinin [30] Elektromanyetik dalga türü olan mikrodalgalar 300 en önemli ticari minerallerinden biri olan kolemanitin MHz ile 300 GHz frekans aralığında yayılırlar. Evler- (Ca B O ·5H O) öğütülmesi ve flotasyonuna etkisi de kullanılan mikrodalga fırınlar 2450 MHz frekansa 2 6 11 2 araştırılmıştır. sahiptir. Bir malzemenin mikrodalga ile ısıtılabilmesi için mikrodalga enerjisini adsorbe edebilecek bir ya- 2. Malzemeler ve yöntemler (Materials and methods) pıya sahip olması gerekir. Bu tür malzemeler içerisin- de bulunan çift kutuplu (dipolar) moleküller bir elektrik Çalışma kapsamında Eti Maden İşletmeleri Genel alan içerisine girdiklerinde elektrik alan doğrultusunda Müdürlüğü Emet Bor İşletme Müdürlüğü’nden temsi- dizilirler. Elektrik alan ortadan kalktığında ise bu dizi- li olarak temin edilen Hisarcık ocağına ait kolemanit lim bozulur. Bu yolla ortaya çıkan iç sürtünmenin bir cevheri numuneleri kullanılmıştır. Numunelerin kimya- kısmı ısı enerjisine dönüşerek malzemenin ısınması sal analiz sonuçları Çizelge 1’de, mineralojik sonuçları ile sonuçlanır [1, 2]. Isınma karakteristiği sebebiyle ise Şekil 1’de verilmiştir. konvansiyonel ısıtma sistemlerinde ısıtma dıştan içe doğru gerçekleşirken, mikrodalga ısıtma sistemlerinde Temsili cevher numunesinin ve deneyler sonucu elde ise içten dışa doğru gerçekleşir. edilen ürünlerin mineralojik ve kimyasal analizleri İs- tanbul Üniversitesi İleri Analizler Laboratuvarında Mikrodalga enerjisi madencilik alanında başta kurutma ve liç olmak üzere birçok alanda kullanılabilmektedir uluslararası standartlar göz önünde bulundurularak [3-15]. Mikrodalga ile ısıtılan bir malzemenin içi dışın- yapılmıştır. dan daha sıcak olduğu için bünyesinde bulunan su Ocaktan alındığı haliyle tane boyutu -200 mm olan nu- buharlaşırken malzemenin mukavemetine bağlı ola- muneler primer kırıcı olarak seçilen tek istinat kollu larak bünyesinde çatlaklar oluşturur. Mikrodalga enerjisi bu etkisi sayesinde madencilikte öğütme öncesinde boratuvar tipi çeneli bir kırıcı vasıtası ile iki kademede malzeme bünyesinde süreksizlikler oluşturarak ve var kırılmıştır. Böylelikle malzemenin tamamı -16 mm bo- olan süreksizlikleri arttırarak cevherlerin öğünebilirliği- yutuna getirilmiştir. Mikrodalga enerjisinin çeşitli tane ni arttırmak amacıyla da kullanılmaktadır [16-23]. boyutlarının ufalanması üzerindeki etkisini gözlemle- mek amacıyla, numuneler dar tane boyut aralıklarına Örneğin Kingman ve ark. [24] mikrodalga destekli (-16+10, -10+8, -8+5, -5+2 ve -2 mm) ayrılmıştır. Mik- öğütmede cevher mineralojisinin etkisini araştırmış- rodalga enerji uygulamalı ve uygulamasız deneylerde lar ve öğütme verimliliğinde büyük önemi olduğunda kullanmak üzere her fraksiyon iki kısma ayrılmıştır. değinmişlerdir. Guo ve ark. [25] mikrodalga enerjisi- Yarılanan numunelerin birinci kısmı doğrudan, ikinci ni ilmenit cevherinin öğütülmesinde uygulamışlar ve kısmı ise mikrodalga enerjiye tabii tutulduktan sonra mikrodalgaların mineral ile matris arasında çatlaklara bir merdaneli kırıcı yardımıyla kırılmıştır. sebep olduğunu bildirmişlerdir. Zhu ve ark. [26] linyit öğütmesinde mikrodalga enerjisinin etkisini araştırdık- Mikrodalga enerjisi uygulamaları 2450 MHz sabit fre- ları çalışmalarında mikrodalga uygulanan linyitin öğü- kansta çalışan Arçelik MD595 model ev tipi bir mik- nebilirliğinin ciddi oranda iyileştiğini açıklamışlardır. rodalga fırın kullanılarak, 720 W güçte, 10 dk süre ile Mikrodalganın flotasyonda kullanıldığı bir çalışmada gerçekleştirilmiştir. Xia ve ark. [27] okside olmuş kömürlerin flotasyonu Merdaneli kırıcı ürünleri 1 ve 0,5 mm elek açıklıklı öncesinde kömürün yüzebilirliğini arttırmak amacıyla elekler ile kuru, 0,250 ve 0,038 mm elek açıklıklı elek- mikrodalga uygulamışlardır. Çalışma sonucunda mikrodalga uygulama süresine bağlı olarak yanabilir veri- lerle ise yaş olarak elenerek, tane boyut dağılımı ana- min arttığını bulmuşlardır. lizi gerçekleştirilmiştir. Yaş olarak elenen fraksiyonlar, laboratuvar tipi bir etüvde 60-65 °C sıcaklıkta kurutul- Mikrodalgalar bor mineralleri üzerinde de çeşitli amaç- muştur. Bu sıcaklıkların üzerinde kolemanit mineralinin larla uygulanmıştır. Can ve ark. [28] kolemanitin mikro- kimyasal ve fiziksel yapısının bozulduğu daha önceki dalga destekli kalsinasyonunu çalışmışlar, mikrodalga çalışmalardan bilindiğinden [5], numuneler kurutulur- destekli kalsinasyonun konvansiyonel kalsinasyona ken sıcaklık değerinin bu seviyeleri geçmemesine dik- göre daha iyi sonuçlar verdiğini bulmuşlardır. Kocaku- kat edilmiştir. şak ve ark. [29] susuz boraks üretiminde mikrodalga ısıtma kullanmışlar ve mikrodalga ısıtma ile daha te- Mikrodalga enerjisi uygulanmış ve uygulanmamış nu- miz ve daha hızlı üretim gerçekleştirmişlerdir. muneler, boyu 26,5 cm, çapı ise 20,5 cm olan labora-

Çizelge 1. Numunenin kimyasal analiz sonuçları (The chemical analysis results of the sample).

B2O3 SiO2 MgO CaO TiO2 Al2O3 SrO K2O Fe2O3 As K.K.* (%) (%) (%) (%) (%) (%) (%) (%) (%) (ppm) (%) 32,21 11,52 5,56 21,43 0,09 1,28 0,52 0,68 0,61 6560 23,49 *: Kızdırma Kaybı (900 ºC, 15 dk)

76 Demir İ. ve ark. / BORON 2 (2), 75 - 81, 2017

Şekil 1. Numunenin XRD analizi grafiği (The XRD analysis graph of the sample).

Şekil 2. Deney akım şeması (Experimental flowsheet).

77 Demir İ. ve ark. / BORON 2 (2), 75 - 81, 2017 tuvar tipi çelik çubuklu bir değirmen kullanılarak ayrı Bütün deneysel çalışmalara ait karakterizayon ve zen- ayrı öğütülmüştür. Değirmene, çapı 1 cm olan 79 adet ginleştirme akım şeması Şekil 2’de verilmiştir. çubuk şarj edilmiş ve değirmen dönüş hızı 60 dev/ dk olarak ayarlanmıştır. Aşırı öğünmeyi engellemek 3. Sonuçlar ve tartışma (Results and discussion) için -1+0,500 mm tane boyutundaki numuneler 5 dk, -0,500+0,250 mm tane boyutundaki numuneler ise 3 Çeneli kırıcı çıkışından elde edilen ürün 16, 10, 8, 5 ve dk süre ile öğütülmüştür. Değirmen çıkışı ürünlerin 2 mm’lik laboratuvar tipi elekler kullanılarak elek anali- tane boyut dağılımı 1, 0,500, 0,250 ve 0,038 mm’lik zine tabii tutulmuştur. Tane boyut dağılım grafiği Şekil elekler kullanılarak tespit edilmiştir. 3’te verilmiştir.

Mikrodalga enerjisinin flotasyona etkisini belirlemek amacıyla numunelerin flotasyonu iki farklı tane boyut fraksiyonunda gerçekleştirilmiştir. İlk olarak -0,250 mm tane boyutundaki numunelere 0,038 mm tane boyutunda dekantasyon yoluyla şlam uzaklaştırması uygulanarak flotasyon yapılmıştır. Ayrıca şlam olarak ayrılan kısım içerisindeki borun kazanılması amacıy- la -0,038 mm tane boyutuna da ayrıca flotasyon uy- gulanmıştır. Flotasyon deneylerinde Denver Sub 2A Flotasyon makinesi 1200 dev/dk karıştırma hızında kullanılmıştır. Deneyler 1 L hacimli selüllerde, %10 pülpte katı oranında gerçekleştirilmiştir. Toplayıcı re- aktif olarak, 1500 g/t Cytec R825 (anyonik tip, sodyum alkil sülfonat), köpürtücü olarak ise 100 g/t çam yağı kullanılmıştır. Şekil 3. Numunenin çeneli kırıcı çıkışı tane boyut dağılımı (The particle size distribution of the sample from jaw crusher output).

Şekil 4. Merdaneli kırıcı çıkışı tane boyut dağılımları (Besleme tane boyutu: (a) -16+10 mm (b) -10+8 mm (c) -8+5 mm (d)

-5+2 mm (e) -2 mm). (The particle size distributions of the sample from roll crusher output (Feed particle size: (a) -16+10 mm (b) -10+8 mm (c) -8+5 mm (d) -5+2 mm (e) -2 mm)).

78 Demir İ. ve ark. / BORON 2 (2), 75 - 81, 2017

Şekil 3’ten görüldüğü üzere çeneli kırıcıdan çıkan ve 1,62 mm iken mikrodalga enerji uygulanan numu- numunenin d50 ve d80 tane boyutları sırasıyla 5,600 ve nenin ise sırasıyla 0,72 ve 1,45 mm olduğu görülmüş- 10,440 mm’dir. Çeneli kırıcıdan sonra boyut küçültme tür. işlemlerine devam edilen numune Şekil 2’de görüldü- Şekil 5’te mikrodalga enerji uygulanmamış ve mikro- ğü üzere bir merdaneli kırıcı yardımıyla ufalanmıştır. dalga enerji uygulanmamış numunelerin değirmen çı- Merdaneli kırıcıdan çıkan numunelerin elek analizi 1, kışı tane boyut analizleri verilmiştir. 0,500, 0,250 ve 0,038 mm açıklıklı elekler kullanılarak gerçekleştirilmiştir. Şekil 4’te farklı besleme tane bo- Çizelge 3’te verilen öğütme sonucu elde edilen yutlarının tane boyut dağılımı grafikleri verilmiştir. numunelerin d50 ve d80 tane boyutları incelendiğinde mikrodalga enerjisi uygulanmış numunelerin az da Sınıflandırılmış numunelerin merdaneli kırıcı çıkışın- olsa daha iyi ufalandığı görülmektedir. daki d50 ve d80 tane boyutları Çizelge 2’de verilmiştir. Öğütme sonucunda çıkan +0,250 mm tane boyutunda- Çizelge 2’deki merdaneli kırıcıdan çıkan numunele- ki numune yüksek oranda (%44) B2O3 tenörüne sahip rin d50 ve d80 tane boyutları incelendiğinde mikrodalga olduğu için flotasyon uygulanmamıştır. -0,250 +0,038 enerjisi uygulanmış numunelerin daha çok ufalandığı, mm ve -0,038 mm tane boyutuna sınıflanmış numu- en büyük etkinin ise -5+2 mm tane boyut aralığında nelerle ise mikrodalga enerjisinin etkisinin belirlenmesi olduğu görülmektedir. Burada mikrodalga enerji uygu- amacıyla flotasyon deneyleri yapılmıştır. Flotasyon so- lanmamış numunenin d50 ve d80 boyutları sırasıyla 1,04 nuçları Şekil 6’da detaylı olarak verilmiştir.

Çizelge 2. Merdaneli kırıcı çıkışı numunelerin d50 ve d80 tane boyutları. (The d50 and d80 sizes of the samples from roll crusher output).

Merdaneli Kırıcı Besleme Konvansiyonel Mikrodalga Enerjili

Boyutu (mm) d50 d80 d50 d80 (-) (+) (mm) (mm) (mm) (mm) 16 10 1,14 1,66 1,08 1,64 10 8 0,90 1,57 0,87 1,56 8 5 0,95 1,59 0,87 1,56 5 2 1,04 1,62 0,72 1,45 2 0 0,87 1,54 0,81 1,52

Şekil 5. (a) -1,0+0,500 mm ve (b) -0,500+0,250 mm tane boyutu aralığındaki numunelerin de- ğirmen çıkışı tane boyut dağılımı (The particle size distribution of the samples from rod mill output (a) -1.0+0.500 mm, and (b) -0.500+0.250 mm).

Çizelge 3. Numunelerin öğütme sonrası d50 ve d80 tane boyutları. (The d50 and d80 sizes of the samples after grinding).

Öğütme Besleme Konvansiyonel Mikrodalga Enerjili

Boyutu (mm) d50 d80 d50 d80 (-) (+) (mm) (mm) (mm) (mm) 1,00 0,50 0,24 0,41 0,21 0,38 0,50 0,250 0,17 0,31 0,15 0,29

79 Demir İ. ve ark. / BORON 2 (2), 75 - 81, 2017

Şekil 6. Flotasyon sonuçları: (a) verim (b) tenör (Flotation results: (a) recovery and (b) grade).

Çalışma kapsamında kullanılan kolemanit cevheri çatlak oluşmamasından kaynaklandığı düşünülmekte-

%32,21 B2O3 tenörüne sahiptir. -0,250+0,38 mm tane dir. boyutundaki numunelere yapılan flotasyon deneyle- Mikrodalga enerji uygulamasının kolemanit flotasyonu rinde konvansiyonel flotasyonla %44,76 B2O3 tenörlü konsantre %55,05 verimle, mikrodalga enerji uygula- üzerindeki etkisi incelendiğinde flotasyon veriminde meydana gelen artışın mineral yüzeyine kollektör ad- nan numunelerin flotasyonunda ise %42,99 B2O3 te- nörlü konsantre %59,69 verimle kazanılmıştır. sorpsiyonunu etkilemesinden kaynaklandığı düşünül- mektedir. Böylece daha düşük tenörlü malzeme de yü- -0,038 mm tane boyutundaki numunelere yapılan flo- zerek flotasyon verimini arttırırken konsantre tenörünü tasyon deneylerinde ise konvansiyonel flotasyonda düşürmüştür. %37,91 B O tenörlü konsantre %24,79 verimle, mik- 2 3 Kaynaklar (References) rodalga enerji uygulanmış numunelerin flotasyonu sonucunda ise %37,21 B2O3 tenörlü konsantre %31,17 [1] Vorster W., The effect of microwawe radiation on mi- verimle elde edilmiştir. neral proceessing, Doktora Tezi, The University of Bir- mingham Birmingham, 2001. 4. Sonuçlar (Conclusions) [2] Al-Harahsheh M., Kingman, S. W., Microwave-assisted leaching—a review, Hydrometallurgy, 73 (3-4), Bu çalışmada, ülkemizin en önemli bor minerallerin- 189-203, 2004. den biri olan kolemanitin ufalanması ve flotasyonuna mikrodalga enerjisinin etkisi araştırılmıştır. [3] Marland S., Han B., Merchant A., Rowson N., The effect of microwave radiation on coal grindability, Fuel, Merdaneli kırıcıda boyut küçültme işlemleri sonucunda 79, 1283-1288, 2000. her boyut fraksiyonunda mikrodalga enerji uygulanmış [4] Uslu T., Atalay Ü., Arol A. İ., Effect of microwave hea- numunelerin işlem uygulanmamış numunelere göre az ting on magnetic separation of pyrite, Colloids Surf. A, da olsa daha iyi ufalandığı görülmüştür. Ufalanmadaki 225 (1-3), 161-167, 2003. bu iyileşmenin nedeninin mikrodalga enerjinin uygu- [5] Eskibalcı M. F., Cevher hazırlama ve zenginleştirmede lanması sırasında malzeme içerisindeki suyun içten mikrodalga enerjisinin kullanılabilirliğinin araştırılması, dışa doğru buharlaşırken malzeme bünyesinde mey- Doktora Tezi, İstanbul Üniversitesi, Maden Mühendisli- dana getirdiği çatlakların malzemenin ufalanma diren- ği Bölümü, İstanbul, 2007. cini azaltması olduğu düşünülmektedir. Ufalanmadaki [6] Özbayoğlu G., Depci T., Ataman N., Effect of microwa- en büyük farkın ise -5+2 mm boyut aralığındaki numu- ver radiation on coal flotation, Energy Source Part A, nelerde olduğu saptanmıştır. Bu durumun mikrodalga 31 (6) 492-499, 2009. enerjisinin malzeme içerisine penetrasyon derinliği ile [7] Sayın Z. E., Altın konsantresinden doğrudan liç eldesi, ilişkili olduğu düşünülmektedir. Doktora Tezi, Dokuz Eylül Üniversitesi Maden Mühen- disliği, İzmir, 2010. Merdaneli kırıcı çıkışında elde edilen ürünler üzerin- [8] Tosun Y. İ., Microwave activated crushing and grinding de yapılan öğütme deneylerinde ise mikrodalga enerji of turkish coals and shale for cleaning and desulfuriza- uygulanmış numuneler ile işlem uygulanmamış numu- tion, XVI Balkan Mineral Processing Congress, Belg- nelerin öğünebilirliklerinde ciddi bir fark görülmemiştir. rad, 2015. Bu durumun mikrodalga enerjisinin kırma öncesinde iri [9] Güngören C., Ultrasonik ve mikrodalga enerjilerinin boyutta uygulanması nedeniyle malzeme bünyesinde kolemanit flotasyonunda ön işlem olarak kullanılma oluşan çatlakların kırma esnasında etkili olduğu ancak olanaklarının araştırılması, Yüksek Lisans Tezi, İstan- öğütme öncesinde tekrar mikrodalga enerji uygulama- bul Üniversitesi, Maden Mühendisliği, 2009. sı yapılmadığı için öğünmeyi etkileyecek özelliklerde

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81 BORON 2 (2), 82 - 86, 2017

ULUSAL BOR ARAŞTIRMA ENSTİTÜSÜ ISSN: 2149-9020 NATIONAL BORON RESEARCH INSTITUTE

BOR DE RGİSİ JOURNAL OF BORON

CİLT/VOL SAYI/ISSUE YIL/YEAR 02 02 20 17 BOR DERGİSİ JOURNAL OF BORON http://dergipark.gov.tr/boron

Borojipsin diamonyum hidrojen fosfat çözeltilerinde çözünürlüğünün incelenmesi

Havva Mumcu Şimşek1*, Rövşen Guliyev2, Ayşe Vildan Beşe3, Hacer İçen4

1Osmaniye Korkut Ata Üniversitesi, Kimya Mühendisliği Bölümü, 80000 Osmaniye, Türkiye, ORCID ID orcid.org/0000-0002-8396-3771 2Ardahan Üniversitesi, Çevre Mühendisliği Bölümü, 75000 Ardahan, Türkiye, ORCID ID orcid.org/0000-0003-2396-8201 3Atatürk Üniversitesi, Kimya Mühendisliği Bölümü, 25240 Erzurum, Türkiye, ORCID ID orcid.org/0000-0001-5871-1559 4Osmaniye Korkut Ata Üniversitesi, Kimya Mühendisliği Bölümü, 80000 Osmaniye, Türkiye, ORCID ID orcid.org/0000-0002-2270-3642

MAKALE BİLGİSİ ÖZET

Makale geçmişi: Bu çalışmada, borojipsin (CaSO4.2H2O) diamonyum hidrojen fosfat ((NH4)2HPO4) İlk gönderi 10 Ocak 2017 çözeltilerinde çözünürlüğü incelenmiştir. Deneyde kullanılan parametreler ve Revize gönderi 20 Nisan 2017 aralıkları; katı/sıvı oranı: 0,04-0,20, reaksiyon sıcaklığı: 15-53 oC, karıştırma hızı: Kabul 27 Ağustos 2017 50-1000 devir.dakika-1, çözelti konsantrasyonu: 1-4 M şeklindedir. Borojipsin Online yayınlanması 25 Eylül 2017 çözünme hızı, katı-sıvı oranının azalması, çözelti konsantrasyonu ve sıcaklığının Araştırma Makalesi artması ile artmıştır. Çözünme hızının ürün (veya kül) filminden difüzyon ile kontrol edildiği belirlenmiştir. Aktivasyon enerjisi 14,38 kJ. mol-1 olarak hesaplanmıştır. Anahtar kelimeler: Borojips, Diamonyum hidrojen fosfat, Kinetik

Investigation of solubility of borogypsum in diammonium hydrogen phosphate solvents

ARTICLE INFO ABSTRACT

Article history: In this study, the dissolution of borogypsum was investigated in the diammonium Received 10 January 2017 hydrogen phosphate solutions. Parameters and their ranges used in the experiment Received in revised form 20 April 2017 were as solid-liquid ratio: 0.04-0.20, reaction temperature: 15-53 oC, stirring speed: Accepted 27 April 2017 50-1000 rpm, concentration of solution: 1-4 M. The dissolution rate of borogypsum Available online 25 September 2017 increased with decreasing solid-liquid ratio and increasing solution concentration Research Article and temperature. It was found that the dissolution rate was controlled by product (or ash) layer diffusion process. Activation energy was calculated as 14.38 kJ.mol-1. Keywords: Borogypsum, Diammonium hydrogen phosphate, Kinetics

1. Giriş (Introduction) bileşiklerinden biridir. Ülkemizde borik asit, kolemanit

cevherinin (Ca2B6O11.5H2O) sülfürik asit ile aşağıdaki Bor, yeryüzünde toprak, kayalar ve suda yaygın olarak reaksiyonuna göre üretilmektedir: bulunan bir elementtir. Dünyadaki önemli bor yatakla- rı Türkiye, Rusya ve ABD’de bulunmaktadır. Türkiye, Ca2B6O11.5H2O+2H2SO4+ 6H2O→6H3BO3+2CaSO42H2O (1) %72’lik payı ile dünyanın bilinen en büyük bor rezervi- ne sahip ülkesidir. Türkiye’de rezerv açısından en çok Reaksiyon süresince yan ürün olarak % 3-7 B2O3 ve bulunan bor cevherleri tinkal (Na2O.2B2O3.10H2O) ve diğer kirlilikleri içeren borojips oluşur. Türkiye’de yılda kolemanit (Ca2B6O11.5H2O)’ tir [1]. Borik asit (H3BO3), 385 bin ton borik asit üretilirken, 855-1155 bin ton bo- endüstride B2O3 kaynağı olarak en çok kullanılan bor rojips açığa çıkmaktadır [2]. Borojipsin içerdiği B2O3

*Sorumlu yazar: [email protected] 82 Mumcu Şimşek H. ve ark. / BORON 2 (2), 82 - 86, 2017 yağmur suyu ile çözündüğünden dolayı toprak ve suya miktarda katı ilave edilmiştir. Çözünme işlemi sonunda karışır. Yüksek miktarlarda bor toksik etki gösterdiğin- reaktör içeriği oda sıcaklığına soğutulup süzülmüş ve den dolayı çevresel kirliliğe neden olur [3]. çözeltide sülfat miktarı gravimetrik olarak belirlenmiştir [11]. Çalışmada kullanılan parametreler ve parametre- Borojipsin depolanması için büyük alanlara ihtiyaç du- lerin değerleri Çizelge 2’de verilmiştir. yulması ve çevreye zararlı etkilerinden dolayı pek çok araştırmacı, borojipsin değişik alanlarda değerlendi- Çizelge 2. Çözünme işleminde kullanılan parametreler ve rilmesine yönelik çalışmalar yapmaktadır. Bunlardan değerleri (Parameters and values used in the dissolving process). bazıları; tuğla üretiminde [3], seramik üretiminde [4,5], çimento katkı maddesi olarak [6-8] ve gübre hammad- Parametreler Parametrelerin değerleri desi olarak [9,10] kullanımıdır. Katı/sıvı oranı (g.ml-1) 1/5, 1/10, 1/15, 1/20*, 1/25

Bu çalışmanın amacı borojipsin diamonyum hidrojen Karıştırma hızı (devir.dakika-1) 50, 200, 400, 600*, 800, 1000 fosfat çözeltilerinde çözünmesi üzerine katı-sıvı oranı, karıştırma hızı, çözelti konsantrasyonu ve sıcaklığın (NH4)2HPO4 konsantrasyonu (M) 1, 2*, 3, 4 etkisini incelemek ve çözünmeyi temsil eden reaksi- Reaksiyon sıcaklığı (°C) 15, 23, 33*, 42, 53 yon modelini belirlemektir. * Bir parametrenin etkisi araştırılırken sabit tutulan değerler 2. Malzemeler ve yöntemler (Materials and methods)

Deneysel çalışmalarda kullanılan borojips, Bandırma 3. Sonuçlar ve tartışma (Results and discussion) Borik Asit Fabrikası’ndan temin edilmiştir. Nemli borojips laboratuvar ortamında kurutulmuş, öğütülmüş Borojips ile diamonyum hidrojen fosfat arasında mey- ve ASTM standart 150 μm elekten geçirilmiş ve ça- dana gelen reaksiyonların aşağıdaki gibi olduğu tah- lışmada 150 μm altı tanecikler kullanılmıştır. Deney- min edilmektedir: lerde kullanılacak numuneler etüvde (Gemo DT104) 100 oC sıcaklıkta sabit tartıma ulaşıncaya kadar +2 -2 CaSO4.2H2O(k) ↔ Ca (çöz) + SO4 (çöz) + 2H2O(sıvı) (2) kurutulmuştur. Deneylerde kullanılan borojipsin kimyasal bileşimi Çizelge 1’de gösterilmiştir. + -2 (NH4)2HPO4 (çöz) ↔ 2NH4 + HPO4 (3)

Çizelge 1. Borojipsin kimyasal analizi (Chemical analysis of +2 -2 CaHPO4.2H2O(k) → Ca (çöz) + HPO4 (çöz) + 2H2O(sıvı) (4) borogypsum).

Bileşen B2O3 SiO2 SO3 CaO MgO Fe2O3 Al2O3 Na2O SrO As2O3 H2O (NH4)2.SO4(çöz) + 2H2O (sıvı) ↔ 2NH4OH + H2SO4 ( 5 )

Bileşim ve genel reaksiyon: 4,00 7,50 35,40 22,90 1,30 0,82 0,93 0,12 0,30 0,10 26,63 (%)*

*Bileşim %’si ağırlıkçadır. CaSO4.2H2O(k )+ (NH4)2HPO4(çöz) → CaHPO4.2H2O(k) + (NH4)2.SO4(çöz) (6)

Şekil 1’de borojipsin, Şekil 2’de ise reaksiyon sonucu Çözündürme işlemi 500 ml’lik cam reaktörde ve at- mosferik basınçta yapılmıştır. Karıştırma işlemi dijital oluşan katı ürünün SEM fotoğrafları görülmektedir. göstergeli mekanik karıştırıcı ile yapılmıştır. Reaktör içeriğini sabit tutmak için sabit sıcaklık sirkülatörü kul- Şekillerden görüldüğü gibi reaksiyon sonucu oluşan lanılmıştır. Denemelerde belirlenen hacim ve konsant- katı ürünün yapısı borojipsten farklıdır ve tahmin edi- rasyonda diamonyum hidrojen fosfat çözeltisi ilave len reaksiyonların gerçekleşmiş olabileceği söylenebi- edilmiş ve istenilen sıcaklığa eriştikten sonra belirlenen lir.

Şekil 1. Borojipsin SEM görüntüleri (a. 2μ, b. 10μ) (SEM images of borogypsum).

83 Mumcu Şimşek H. ve ark. / BORON 2 (2), 82 - 86, 2017

Şekil 2. Reaksiyon sonucu oluşan katı ürünün SEM görüntüleri (a. 2μ, b. 10μ) (SEM images of solid product formed after reaction).

Borojipsin çözündürülmesi üzerine bir parametrelerin etkisi incelenirken diğer parametreler sabit tutulmuş- tur. Sabit tutulan değerler Çizelge 2’de (*) ile gösteril- miştir. Borojipsin çözünmesi üzerine karıştırma hızının etkisi 50-1000 devir.dakika-1 aralığında incelenmiş ve sonuç- lar Şekil 3’te gösterilmiştir.

Şekil 4. Borojipsin çözünme hızı üzerine katı/sıvı oranının etkisi (The effect of solid to liquid ratio on the dissolution rate of borogypsum).

Şekil 3. Borojipsin çözünme hızı üzerine karıştırma hızının etkisi (The effect of stirring speed on the dissolution rate of borogypsum).

Şekil 3’ten görüldüğü gibi, 600 devir.dakika-1’ya kadar olan karıştırma hızlarında dönüşüm değerinin artmış, 600 devir.dakika-1’dan daha büyük karıştırma hızların- Şekil 5. Borojipsin çözünme hızı üzerine çözelti konsantras- da ise dönüşüm değeri azalmıştır. Katı/sıvı oranının yonunun etkisi (The effect of solution concentration on the dissolution rate of borogypsum). borojipsin çözünmesi üzerine etkisi 1/5, 1/10, 1/15, 1/20 ve 1/25 g.ml-1 değerleri için çalışılmış ve sonuçlar Şekil 4’te gösterilmiştir.

Şekil 4, borojipsin çözünme miktarının katı/sıvı oranı arttıkça azaldığını göstermektedir. Borojipsin çözünme hızı üzerine konsantrasyonun etkisi 1, 2, 3 ve 4 M çözelti konsantrasyon değerleri kullanılarak incelen- miş ve sonuçlar Şekil 5’te gösterilmiştir. Çözelti kon- santrasyonundaki artış ile çözünme hızının arttığı be- lirlenmiştir. Benzer sonuçlar üleksitin amonyum asetat çözeltisinde çözünmesinde gözlenmiştir [12].

Sıcaklığının etkisi 15, 25, 33 42 ve 53 °C’lik değerler Şekil 6. Borojipsin çözünme hızı üzerine reaksiyon kullanılarak incelenmiştir ve sonuçlar Şekil 6’da gös- sıcaklığının etkisi (The effect of reaction temperature on the dis- terilmiştir. solution rate of borogypsum).

84 Mumcu Şimşek H. ve ark. / BORON 2 (2), 82 - 86, 2017

Grafikten görüldüğü gibi sıcaklık artışı çözünme mik- Elde edilen verilerden yararlanılarak her sıcaklık için tarını arttırmıştır. Sıcaklık değerlerindeki bu davranış hesaplanan hız sabitlerinin (k) 1/T’ye karşı çizilen gra- artan sıcaklığın moleküllerin kinetik enerjisinde artma- fiği Şekil 8’de gösterilmiştir. ya neden olması ve birim zamanda etkin çarpışma sa- yısını artırması ile açıklanabilir [13-15].

Borojipsin di-amonyum hidrojen fosfat çözeltilerinde çözündürülmesi sonucu ile elde edilen değerler, aşa- ğıdaki katı-sıvı heterojen reaksiyon modellerine uygu- lanmıştır.

Film difüzyon kontrol modeli;

t ρ.R = x t* = (7) t* 3bkC Yüzey kimyasal kontrol modeli; Şekil 8. lnk ile 1/T arasındaki ilişki (Relationship between lnk * 1/3 * ρ.R and 1/T). tt=1 −− (1 x ) t = (8) , bkC.. Şekil 8’de görülen doğrunun eğiminden aktivasyon Ürün veya kül tabakasından difüzyon kontrol modeli; enerjisinin değeri 14,38 kJ.mol-1 olarak hesaplanmıştır. 40 kJ.mol-1 değerinden daha düşük aktivasyon enerji 2 değerlerinin reaksiyonu kontrol eden basamağın yü- * 2/3 * ρR tt=1 −− 3(1 x ) +− 2(1 x ) t = (9) zey kimyasal reaksiyonu ifade etmektedir [16]. Benzer , 6.bC .k . d sonuçlar kolemanitin, potasyum hidrojen sülfat, oksa- En yüksek regresyon katsayısı (R2) ile ürün veya lik asit ve fosforik asit çözeltilerinde çözündürülmesin- kül tabakasından difüzyon kontrol modeli en uyumlu de elde edilmiştir [17-19]. denklem olarak bulunmuştur. Çalışılan sıcaklıklarda [1-3(1-x)2/3+2(1-x)] denklemi ile zaman arasındaki ilişki 4. Sonuçlar (Conclusions) Şekil 7’de gösterilmiştir. Yapılan çalışmada borik asit fabrika atığı borojipsin diamonyum hidrojen fosfat çözeltilerinde çözündürülme- si üzerine katı/sıvı oranı, karıştırma hızı, sıcaklık ve çözelti konsantrasyonunun etkisi incelenmiştir. Katı/ sıvı oranındaki artış çözünmeyi azaltmıştır. Bu durum, birim çözelti miktarı başına düşen borojips miktarının artması ile açıklanabilir. Benzer sonuçlar kolamanit cevherinin metanol ve potasyum hidrojen sülfat çözel- tilerinde çözünmesinde de gözlenmiştir [15,17]. Çalı- şılan karıştırma hızlarında dönüşüm değerinin belirli bir değere kadar artması ve bu değerden sonra azalış göstermesinin nedeni, belirli bir hızdan sonra meydana gelen vortekslerin hacim daralmasına neden olma-

(2/3) sı ve taneciklerin akışkanla beraber hareket etmesi Şekil 7. Reaksiyon sıcaklığı için t ile [1-3(1-x) +2(1-x)] ara- sonucu, etkin bir temasın gerçekleşmemesidir. Benzer sındaki ilişki (The relationship between t and [1-3 (1-x)(2/3) +2 (1-x)] for the reaction temperature). sonuçlar kolamanit cevherinin amonyum sülfat ve fosforik asit çözeltilerinde çözünme reaksiyonlarında da Kimyasal reaksiyonun ile sıcaklık arasındaki ilişki Arr- gözlenmiştir [13,14]. henius denklemi ile tanımlanır: Sıcaklık ve çözelti konsantrasyonunun artışı çözünmeyi −E/ RT arttırdığı gözlenmiştir. Arrhenius denklemindeki hız sa- k= ke. (10) o bitinin üstel bağımlılığından beklendiği gibi sıcaklığın veya artması dönüşüm hızını da arttırmaktadır. Kolemanitin oksalik asit çözeltilerinde çözünme kinetiğinin incelen- E diği çalışmada reaksiyon sıcaklığı ve konsantrasyon lnkk= ln o − (11) RT parametrelerinin etkileri incelenmiş ve benzer sonuç bulunmuştur [18]. Çözelti konsantrasyonunun artması lnk’ nın 1/T ye karşı çizilen grafiğinin eğiminden akti- ile birim hacimdeki mevcut hidronyum iyonu artmış bu vasyon enerjisi hesaplanır. ise, reaksiyonun hızlanmasını sağlamıştır [20].

85 Mumcu Şimşek H. ve ark. / BORON 2 (2), 82 - 86, 2017

Çözünme hızı için en uygun modelin ürün (veya kül) properties of Portland cement, Cem. Concr. Res., 33 filminden difüzyon kontrol modeli olduğu belirlenmiş- (11), 1729–1735, 2003. -1 tir. Reaksiyon aktivasyon enerjisi 14,38 kJ.mol olarak [9] Guliyev R., An investigation of borogypsum utilization hesaplanmıştır. Bulunan aktivasyon enerjisi değeri 40 for the production of triple superphosphate containing kJ.mol-1 değerin altında olduğu için reaksiyonun ürün boron fertilizers, Fresenius Environmental Bulletin, 24 veya kül filminden difüzyon kontrollü olduğu söylene- (3), 748-754, 2015 bilir [21]. [10] Chou M., Rostam-Abadi M., Lytle M., Manufacture of ammonium sulfate fertilizer from gypsum-rich byprod- Ekonomik ve çevresel faktörler düşünüldüğünde, uct of flue gas desulfurization: A prefeasibility cost borojipsin değerlendirilmesi için çalışmaların arta- estimate, Prepr. Pap. - Am. Chem. Soc., Div. Fuel rak devam etmesinin gerekli olduğu görülmektedir. Chem., 41, 1996. Borojipsin diamonyum hidrojen fosfat çözeltilerinde [11] Furman N. H., Standarts Methods of Chemical Analy- çözünmesi sürecinde oluşan reaksiyon ürünlerinin sis, 6th edition, D. Van. Nostrand Company, New Jer- (CaHPO4.2H2O - (NH4)2.SO4) gübre olarak değerlen- sey, 1963. dirilmesi üzerine araştırılmaların yapılmasının önemli olduğu düşünülmektedir. [12] Demirkıran N., A study on dissolution of ulexite in ammonium acetate solutions, Chem. Eng. J., 141 (1-3), Kaynaklar (References) 180–186, 2008. [13] Tunç M., Kocakerim M. M., Küçük Ö., Aluz M., Dissolu- [1] “Bor Sektör Raporu”,Eti Maden İşletmeleri Genel Mü- tion of colemanite in (NH ) SO solutions, Korean J. dürlüğü, 2014. 4 2 4 Chem. Eng., 24 (1), 55-59, 2007. [2] “Bor Sektör Raporu”,Eti Maden İşletmeleri Genel Mü- [14] Temur H., Yartaşı A., Çopur M., Kocakerim M. M., The dürlüğü, 5/2016. kinetics of dissolution of colemanite in H3PO4 solu- [3] Emrullahoglu Abi C. B., Effect of borogypsum on brick tions, Ind. Eng. Chem. Res., 39 (11), 4114-4119, 2000. properties, Constr. Build. Mater., 59, 195–203, 2014. [15] Kızılca M., Copur M., Kinetic investigation of reaction [4] Christogerou A., Kavas T., Pontikes Y., Koyas S., Ta- between colemanite ore and methanol, Chem. Eng. bak Y., Angelopoulos G. N., Use of boron wastes in Commun., 202, 1528–1534, 2015. the production of heavy clay ceramics, Ceram. Int., 35 [16] Jackson E., Hydrometallurgical Extraction and Recla- (1), 447-452, 2009. mation, Ellis Harwood Ltd., Chichester, 1986. [5] Genç S., Sevinç V., Özseker A., Çaki M., Etibank Kırka [17] Guliyev R., Kuşlu S., Çalban T., Çolak S. Leaching ki- Boraks İşletmesi konsantratör atığının sır hammaddesi netics of colemanite in ammonium hydrogen sulphate olarak değerlendirilmesi, 4. Seramik Kongresi, 119- solutions, J. Ind. Eng. Chem., 18 (4), 1202-120, 2012. 124, 22-25 Eylül, 1998. [18] Alkan M., Doğan M., Dissolution kinetics of colemanite [6] Kavas T., Olgun A., Erdogan Y., Setting and harden- in oxalic acid solutions, Chem. Eng. Process. Process ing of borogypsum–Portland cement clinker–fly ash Intensif., 43 (7), 867–872, 2004. blends, Studies on effects of molasses on properties of mortar containing borogypsum, Cem. Concr. Res., 35 [19] Yartası A., Özmetin C., Kocakerim M. M., Demirhan M. (4), 711-718, 2005. H., Kinetics and mecanism of leaching colemanite in boric acid solution, Chim. Acta Turc., 26, 7-13, 1998. [7] Boncukcuoğlu R., Kocakeri̇ m M., Tosunoğlu V., Yılmaz M. T., Utilization of trammel sieve waste as an additive [20] Mumcu H., Yeşilyurt M., Kolemanitin Sodyum bisül- in Portland cement production, Cem. Concr. Res., 32 fat Çözeltilerinde Çözünme Kinetiğinin İncelenmesi, (1), 35-39, 2002. Yüksek Lisans Tezi, Atatürk Üniversitesi, Fen Bilimleri Enstitüsü, Erzurum, 2010. [8] Elbeyli I. Y., Derun E. M., Gülen J., Pişkin S., Thermal nd analysis of borogypsum and its effects on the physical [21] Levenspiel O. K., Chemical Reaction Engineering. 2 Edition, John Wiley and Sons, New York, p: 357-377, 1972.

86 BORON 2 (2), 87 - 96, 2017

ULUSAL BOR ARAŞTIRMA ENSTİTÜSÜ ISSN: 2149-9020 NATIONAL BORON RESEARCH INSTITUTE

BOR DE RGİSİ JOURNAL OF BORON

CİLT/VOL SAYI/ISSUE YIL/YEAR 02 02 20 BOR DERGİSİ 17 JOURNAL OF BORON

http://dergipark.gov.tr/boron

Review on magnesium diboride (MgB2) as excellent superconductor: Effects of the production techniques on the superconducting properties Mehran Rafieazad1*, Özge Balcı2,3*, Selçuk Acar4, Mehmet Somer3,5

1Koç University, Department of Chemistry, 34450 Sarıyer, İstanbul, Turkey, ORCID ID orcd.org/0000-0002-2629-5850 2Koç University, Department of Chemistry, 34450 Sarıyer, İstanbul, Turkey, ORCID ID orcd.org/0000-0001-6756-3180 3Koç University Akkim Boron-Based Materials and High Technology Chemicals Research and Application Center, 34450 Sarıyer, İstanbul, Turkey 4Pavezyum Chemicals Inc., Tuzla, İstanbul, Turkey, ORCID ID orcd.org/0000-0002-1987-5275 5Koç University, Department of Chemistry, 34450 Sarıyer, İstanbul, Turkey, ORCID ID orcd.org/0000-0001-5606-9101 ARTICLE INFO ABSTRACT Article history: Although there is a wide variety of superconducting materials, only a few of them Received 17 February 2017 are suitable for practical applications. Nowadays, low temperature superconductors Received in revised form 25 August 2017 such as NbTi and Nb3Sn are widely used. However, after discovery of MgB2 with Accepted 6 September 2017 its considerably high critical temperature which has a simple crystal structure and Available online 25 September 2017 cheap raw materials used in its production, renewed interests have emerged for employing MgB in commercial application as well. Review Article 2 This study reports on the effects of production techniques on the superconducting Keywords: properties of magnesium diboride and includes an introduction to MgB2, its crystal Magnesium diboride, and electronic structure and basics of superconducting properties. The production Superconductor, techniques would be explained as well as the probable problems during process Production techniques, and the way for optimizing superconducting property of MgB . Furthermore, the Properties, 2 MgO reduction, improvement of superconducting properties by oxygen reduction, doping elements MgB doping as well as introducing of defects are covered. Finally, effects of starting materials 2 and studies done by our research team in this regard are mentioned.

1. Introduction applications [3]. The Tc is almost close to the theoreti-

cal value that BCS theory predicted such that MgB2 Magnesium diboride (MgB2) is a simple binary boride can be considered as a non-conventional supercon- crystallizing in the well-known AlB2 type [1] of struc- ductor [5]. ture. Although the compound and its crystal structure are known since 1953 [2], the superconducting prop- As seen in Table 1, Tc of MgB2 is almost twice as much erties of magnesium diboride have been discovered as Nb3Ge [6] which was known to have the highest quite recently by Akimitsu and his group in 2001. The Tc among all binary superconductors, so far. Figure 1 most striking novelty about this discovery was the as- shows the structural comparison of the most important tounding high critical transition temperature (Tc) of 39 superconductors, among which MgB2 is occupying an K [3] conferring the new superconductor an intermedi- outstanding position with its second highest critical ate position between the low temperature supercon- temperature and the very simple crystal structure. ductors (LTS) such as NbTi etc. and the high tempera- Together with the relatively small raw material costs it ture superconductors (HTS)- e.g. YBCO - with Tc > 77 K, which is the boiling point of liquid nitrogen. MgB is is attractive for several applications, such as in MRI- 2 coils, wind generators or superconducting permanent not the first boron based superconductor. Already in magnets [6]. Compared with Nb-based superconduc- 1994, a new class of quaternary transition metal boron tor, MgB superconductor has shorter radioactivity de- carbides with complex structures were reported attain- 2 cay time and higher running temperature. Therefore, ing a Tc of 23 K [4]. Until now, there are more than 50 MgB2 has a great application prospect in international superconductor boride compounds defined in current thermonuclear experimental reactor, to avoid the dis- literature. The critical transition temperature (Tc) val- advantages of Nb-based and ensure the smooth run- ues of some metal borides are given in Table 1. Due ning of the superconducting system [7]. to the outstanding Tc of MgB2, many research studies have been done to improve the properties for potential MgB2 based superconducting materials allow the use

*Corresponding author: [email protected], [email protected] 87 Rafieazad M., et al. / BORON 2 (2), 87 - 96, 2017

* Table 1. The critical transition temperatures (Tc) values of some binary metal borides in comparison with Nb3Ge [3,5,8].

Chemical Composition Critical Temperature (Tc)

MgB2 39

TaB2 9.5

Nb0.76B2 9.2

MoB2.5 8.1

NbB2.5 6.4 ZrB2 5.5

BeB2 0.79

NbB2 0.62

Nb3Ge 23.2 *: Explained in text

Figure 1. Comparison between the crystal structures of different classes of superconductors [8]. of helium-free cryogenic systems to cool-down the terials which is a big asset in applications like magnets below their critical temperatures. This is a big wind-turbines. advantage against traditional low-temperatures NbTi/ • MgB2 systems are more favorable for high-tech fu- Nb3Sn superconductors that need liquid helium for cooling. This is an important issue, hence since 2010 sion applications. The superconducting magnets there are lively discussions on global shortage of he- are exposed to heavy radiation during the fusion lium and its increasing price with every year [8]. From process and after their service time is finished LT economical and technical point of view, replacement of superconducting materials have to be kept in spe- low temperature (LT) superconducting materials with cial containers for thousands of years due to their MgB has the following advantages [5,7,8]: very long half-time radioactive decay. For MgB2, 2 half-time is reported to be several years only. • Lower maintenance cost due to the price of lique- fied hydrogen use instead of liquid Helium. 2. General properties of MgB2

• MgB2 has superior properties such as the thermody- Raw materials of MgB2 are more abundant than LT systems. namic and transport properties[9], the isotope effect [10], band structures [10, 11], promising critical current • MgB2 systems are way lighter than heavy LT ma- density [12, 13], ability of doping effect [15] and pres-

88 Rafieazad M. et al. / BORON 2 (2),87 - 96, 2017

sure effect [16]. However, after discovery of its super- irreversibility field (Hirr)) and TC are parameters which conducting properties in 2001, it has been a promising determine the basic superconducting characteristics compound in superconductivity applications [3]. MgB2 of any superconductive material [23]. With a Tc of ap- is competitive among high temperature superconduc- proximately 39 K [3], MgB2 is a promising material for tors (HTS) because it has fascinating advantages technical applications that require both a high upper such as simple crystal structure, low material cost and critical field, HC2, and ability of carrying a large super- small anisotropy [8, 10]. current under presence of high magnetic fields. High critical current density and an upper critical field values Structure refinement obtained from a single-crystal X- for MgB as semiconductor material have been report- ray diffraction analysis indicated that MgB crystallizes 2 2 ed to be 105 –106 A cm−2 and 40 T, respectively [24]. hexagonal in an AlB2 type of structure with a = 3.0849 Å and c = 3.5187 Å [3,5]. As seen from Figures 1 and 3. Production techniques of MgB2 2, the structure is characterized by hexagonal close- packed Mg atoms which are separated by graphite-like As a fabrication process of MgB2, ‘’in situ’’ and ‘’ex situ’’ boron planes [17]. Like graphite, MgB2 shows a strong methods have been employed. In ‘’in situ’’ technique, anisotropy in the B-B bond lengths. The distances be- precursor materials are mixed with stoichiometric tween B-B planes are considerably longer (d(B- -B) = compositions and heat-treated under inert atmosphere 3.086 Å) than those in the B-B plane (d(B-B) = 1.782 to form the demanded shapes. On the other hand, in

Å) [8]. Overall, there are three different types of chem- “ex situ” method, already synthesized MgB2, MgB2- ical bonding governing in MgB2 ,i.e. (Mg-B), (Mg-Mg), reacted powders, used to form into desired shapes (B-B), whereby the two band nature comes from the [25]. “Ex situ” is promising for obtaining homogeneous (B-B) bonding [11]. The final superconducting property materials as well as dense cores. Since already re- of MgB2 is a result of the metallic nature of 2D boron acted powders of MgB2 are used in this method, the ef- sheets with a phonon mediated BCS type mechanism ficiency of sintering is poor and doping during process [17]. is not effective as compared with that observed in “in

situ” methods. “Ex situ” production of MgB2 usually suf- fers from poor grain conductivity which has a negative effect on critical current density. It has been reported

that this can be overcome by decreasing MgB2 grain size, carbon doping and presence of small amount of nano-sized MgO [23,24]. It has been reported that finer grains which were usually produced by high energy planetary ball milling resulted in extended grain boundaries. These are acting as pinning centers and lead to

higher Jc [25,26], there are wide variety of specific production methods such as in situ preparation [26–28], powder in sealed tube method (PIST), hot isostatic pressing (HIP) [29], mechanical alloying [30,31], thin film[32,33], single crystal [34], and the most common one which is powder-in-tube (PIT) [35–41].

Canfield et al. has demonstrated a simple technique Figure 2. Crystal structure of MgB adapted from Nagamatsu et. 2, for the fabrication of MgB wires from boron filaments al. [3]. 2 and wires produced with this method had a high density and considerably low resistivity [42]. Figure 3 shows It has been demonstrated that Tc of MgB2 varies about 10 11 the temperature-dependent resistivity of MgB2 wires 1 K depending on which boron isotope ( B or B)[10] fabricated with this technique. is used. However, the isotope effect for Mg is negli- gible, such that the B atom vibrations are more im- It should be mentioned that most of the MgB2 wires/ portant for the superconducting property of MgB2. The tapes have been currently fabricated by powder- BCS mechanism can be confirmed by photoemission in-tube (PIT) technique either with or without heat spectroscopy [18], scanning tunneling microscopy [19] treatment after deformation[43]. As demonstrated by and neutron scattering measurements [20]. HongLi Suo et al. [44], annealing improves the core density and increases sharpness of superconducting There are two terms related to superconductive prop- transition, and hence enhancement of Jc by a factor of erties of MgB2 which are of ‘intrinsic’ and ‘extrinsic’ na- 10 has been achieved. Y. Takano et al. [45] showed ture [21]. Intrinsic properties are Hc2 and flux pinning the improvement of intergranular critical current den- while extrinsic properties includes connectivity and sities as well as magnetic flux pinning polycrystalline porosity. By improvement any of this intrinsic and/or MgB2 by using heat-treatment under high pressure o extrinsic features an enhancement of MgB2 supercon- [34,46]. As shown in Figure 4, sintering at 1000 C has ductor can be achieved [22]. Critical current density a sharper transition temperature onset at 39 K than o (Jc), critical magnetic field H( c) (upper critical field (Hc2), that of the sample sintered at 775 C.

89 Rafieazad M., et al. / BORON 2 (2), 87 - 96, 2017

Figure 6 shows susceptibility of MgB2 before and after annealing for different tapes and cold working conditions. As can be seen, due to the induced deformation as-rolled tapes have lower critical temperature than others which is decreased about 1 degree. On the other hand, those which were annealed show higher

Tc, because of the stress relieving due to thermal treatment [44].

Figure 3. Temperature-dependent electrical resistivity of MgB2 wire.

Lower inset: expanded view for temperatures near Tc., adapted from Canfield et al. [42].

Figure 6. A.C. susceptibility and D.C. SQUID susceptibility - temper-

ature for (1): MgB2/Fe annealed; (2): MgB2/Ni annealed; (3) MgB2/Fe

as-rolled; (4): MgB2/Ni as-rolled; (5) starting powder, adapted from Suo et al. [44].

PIT includes two methods for fabrication of wires and tapes – that is – using stoichiometric composition of unreacted Mg and B powders (in situ PIT) [47], and

MgB2-reacted powder (ex situ PIT) [48]. However, all Figure 4. Temperature dependent magnetization curves for MgB 2 the fabrication methods have their own limitation, im- starting powder and the bulk samples sintered at 775oC and 1000oC under high pressure, adapted from Takano et al. [45]. provement techniques, and challenges which should be considered during processing. Some approaches Moreover, Giovanni Grasso et al. [35] fabricated “ex have been developed for improving the superconducting properties such as the reduction of MgO phase, situ” PIT MgB2 using Ag, Cu and Ni tubes and then cold worked the tubes by drawing and rolling. The pressure doping in MgB2 and utilization of different boron sourc- applied during cold working created additional strain es. These considerations in MgB2 production techniques are mentioned in the following subsections. in MgB2 grains indicating the enhancement of intrinsic superconductivity. However, as presented in Figure 5, 3.1. Effects of the MgO reduction on the supercon- there is no change in texture of MgB2 grains after cold working. ductivity MgO can limit the intergranular connection between

grains by formation on surface of MgB2 grains and as a result of which depression of the superconducting properties [49]. It has been demonstrated that MgO formation has two main sources [50]:

1- MgO forms when the Mg precursor powder sintered under oxygen atmosphere based on the following reaction:

2- MgO also can form when B2O3 reacts with Mg based on the following reaction:

Figure 5. XRD patterns of the MgB2 powders before and after the 2 cold working process, adapted from Grasso et al. [35].

90 Rafieazad M. et al. / BORON 2 (2),87 - 96, 2017

It has been also reported that MgO formation occurs Many efforts have been made toward reducing the before the reaction of Mg and B such that MgO formed amount of MgO in both ‘’in situ’’ and ‘’ex situ’’ process- acts as a nucleation sites for the growth of MgB2 [51]. es. The effect of minor addition of Cu (<3 at%) on MgO Qingzhi Shi et al. have shown that MgO forms under reduction during ‘’in situ’’ sintering process has been inert gases as well, as can be seen from the XRD pat- investigated [1,58]. As seen from Figure 8, the amount terns of Figure 7 [52]. of MgO decreases sharply from 16.5% to 12.5% as the amount of Cu addition increases from 0.0 to 0.03

Figure 7. XRD patterns of the samples sintered at different temperatures. Each pattern is labeled with the sintering temperature, adapted from Shi et al.[52] Figure 8. The weight fraction of MgO versus the amount of Cu addition in the Cu-doped samples sintered at 850◦C for 30min, adapted from Ma et al. [1]. The presence of MgO impurity can limit intergranular connection between the grains and results the depres- Likewise, Hiroki Fujii et al. have studied the effect of sion of superconductivity[1]. It has been shown that Ca-based compounds such as CaC and CaH in ‘’ex MgB grains which are covered by MgO layer have a 2 2 2 situ’’ process [59]. Figure 9 shows the effect of addition significant depression of critical current density (J ) c of Ca compounds on MgO formation, together with [53] due to the non-superconducting surface layer of (102) reflection of pure MgB as comparison. MgO [54]. On the other hand, MgO may have some 2 positive effect as well, as Jiang et al. found that light doping of MgO can improve the grain connectivity. As a result, the critical current density of MgB2 should increase [55].

If MgO impurity sizes are comparable with the length of MgB2 grains – 6-7nm –, they can be considered as a flux pinning centers. However, excess amount of MgO with large sizes can block grain boundaries and depress superconducting properties of MgB2 [29,30]. Sigh, D.K., et al. have shown MgO amount also affects the transport and magnetic properties such that samples with larger volume fraction of MgO, 40%, have broader superconducting transition with critical temperature around 37.1K with paramagnetic Meiss- ner effect. However, those have smaller volume fraction of MgO, 8%, exhibit sharper diamagnetic transition at around 38.8 K and also magnetization remains almost constant in temperature range of 35-20K [56]. It has been also mentioned that higher amount of MgO causes lower critical transition temperature as well as inhomogeneous of flux distribution [57]. Thus, the Figure 9. The profiles of XRD peak of MgB and MgO for (a) sin- amount of MgO should be optimized between intro- 2 tered hand mixed powders with the additions of (i) CaC2 and (ii) ducing pinning centers and the inter-grain connectivity CaH and (iii) without addition, adapted from Fujii et al. [59]. [25]. 2

91 Rafieazad M., et al. / BORON 2 (2), 87 - 96, 2017

As afore mentioned, one of the main difficulties in MgB2 far, the application of MgB2 are restricted since it has production is the existence of MgO phases which de- deficient mechanical properties as well as degraded Jc presses the superconducting properties. With this in under high magnetic field [65]. Moreover, many experi- mind, research studies by Inorganic Research Group ments have been conducted on the substituting of Mg in Koç University were focused on oxygen reduction by different elements namely Al [66], Li [67] and most of MgB2 by different methods. Among them, the pu- of the substitutions cause decrease in critical tempera- rification of boron by addition of elemental copper, ture. However, some of the element such as Zn do not treatment with reducing gas mixtures and reduction in show any improvement even the addition of 30% [68]. copper tube are worth mentioning. It is important to note that the employment of all three purification tech- Although the various compound morphologies play niques turned out to be successful and led to a signifi- a decisive role to control its properties, the synthesis cant reduction of oxygen impurities in MgB *. method and doping process define additional, crucial 2 parameters that markedly impact the nature and con- 3.2. Effects of doping elements on the supercon- centration of intrinsic or extrinsic defects and the ma- ductivity terials’ electronic properties [69]. As mentioned before, considerable number of efforts have been done to en- It has been reported that defects in MgB2 structure hance both critical current field and current-carried ca- decrease the mean free path of the normal electrons pacity of magnesium diboride, carbon doping has the then decreasing the coherence length ξ and accord- most significant effect among them [70]. Researches ingly increasing the Hc2 values which is a limiting factor have demonstrated that HC2 (0)>50T for carbon doped in MgB2. Moreover, defects would introduce pinning MgB films which makes MgB a promising alternative centres in order to make the irreversibility line steeper 2 2 for Nb3Sn as a high-field magnet conductor [71]. More- [60]. On the other hand, it has been shown that doping over, silicon carbide, SiC, by means of increasing of in MgB2 would decrease Tc. For instance, supercon- intergranular connection and pinning centers, is one ductivity of Al doped sample would disappear when the most sufficient dopant which has been used for around half of Mg are replaced by Al. It was mentioned improvement of JC and HC2 [49][72]. Figure 10 shows that two different effects led to ac T reduction as Al sub- the dependency of current density to different dop- stitution increased: ants. The Jc value of the all doped tapes have been improved with respect to the un-doped tape. This 1- A positive pressure effect—due to the smaller Al improvement is due to the effective pinning centers ionic which have introduced by dopants [72]. 2- The increased number of electrons contributed by Al [61]

On the other hand, replacing Mg2+ by Al3+ will increase the population of the electrons in the two- dimensional (2D) σ-band. Therefore, substitution of Mg by Al would fill the σ-band completely even before a 100% substitution level. In this situation, only the π-band would take part in various physical processes so the system will no longer be a two- band (σ-band and π-band) system [62]. Amount of doping is related to changing in

Tc value. It has been reported that light doping of C as well as Al (up to 2.5%) would keep Tc unchanged while increasing Jc by the factor of 2 [63]. In carbon doping, the carbon which stays at the grain boundary or at interstitial site can act Figure 10. JC–B properties of Fe-sheathed undoped and nano-SiC, as a pinning center (extrinsic pinning) and hence helps SiC whisker and Si/N/C doped tapes heated at 650 °C for 1h. The in enhancing the Hc2, H irr, and Jc values. Additionally, the measurements were performed in magnetic fields parallel to the carbon into the structure creates disorder in the sigma tape surfaces at 4.2 K., adapted from Zhang et al. [73]. band and causes intrinsic pinning to enhance the critical parameters. Therefore, doping carbon causes ex- 3.3. Effects of the starting materials on the super- trinsic/intrinsic pinning through additions/substitution- conductivity and enhances the superconductivity performance of The finding that the quality of the starting powder (pu- MgB2 in both ways [64] Hc2 are obtained from this data based upon the criterion of 90% of normal resistivity rity, oxygen content and grain size distribution) influences strongly the final properties of the samples, runs i.e. Hc2=H at which Rho=90%Rho; where RhoN is the normal resistivity i.e., resistivity at about 40 K in our like a threat through many papers [74]. The influence case. The Werthamer-Helfand-Hohenberg (WHH. So of the initial grain size of the powder was investigated

*: Unpublished results done by Inorganic Research Group in Koç University 92 Rafieazad M. et al. / BORON 2 (2),87 - 96, 2017 to understand the sintering mechanisms leading to bulk materials were fabricated using many different higher intergranular connectivity in polycrystalline ex- production techniques. The most crucial issue in the situ MgB2 as precondition for improved superconduct- synthesis of high quality magnesium diboride powders ing properties [75]. are, however, amorphousness, purity and the particle size of the precursor boron material. From this point It is known that the quality of the starting materials, es- of view, nano-sized boron powder meets these re- pecially that of the boron powder, has great influence quirements best, yielding high-performance MgB2 with on the superconducting properties of MgB2 wires and superior features. The superconducting properties of bulk materials. Inorganic Research Group in Koç Uni- MgB2 can be further optimized by doping, utilization versity has been working on the development of amor- of different boron sources and reduction of the main phous boron and MgB2 superconductor powders since impurity phase MgO. 2010 with international/national collaborations. Dur- ing these studies, MgB2 samples were synthesized by Among them, the reduction of MgO contributes to bet- using various elemental boron powders with different ter grain connection, increase of critical temperature purity grades and particle sizes. Especially the collab- and hence to a general improvement of superconduct- oration with the national industrial partner Pavezyum ing property of MgB2. In addition, doping elements Chemicals (Turkey) was quite fruitful resulting in a sig- such as carbon by creation of defects have positive nificant improvement of superconducting properties of influence on superconducting performance of MgB2, a

MgB2 powders by using amorphous elemental nano method which is widely used. boron powders as starting material. From the applicative point of view, it seems possible to

Elemental amorphous boron powders have been anticipate that the arrival of MgB2 bulk superconduc- available and produced by Pavezyum in industrial tors will move superconductivity towards the design scale in Turkey since 2010. The product development and realization of practical and cheap cryogenic sys- R&D phase was achieved with the support of National tems at intermediate temperatures. For this target, the Boron Research Institute (Project No: 2010 – S244). production techniques, performance and the low-price

Today, Pavezyum is globally the only producer of in- of MgB2 will be the key issue. dustrial scale fully amorphous elemental nano boron powder and this commercial product was developed References with the support of BOREN granted projects (2008 – [1] Ma Z., Liu Y., Shi Q., Zhao Q., Gao, Z., Effect of Cu ad- Ç388 and 2014 – Ç422). So called “PVZ Nano-Boron” dition in reduction of MgO content for the synthesis of is mainly used by MgB based superconducting mate- 2 MgB2 through Sintering, J. Alloys Compd., 471 (1–2), rial producers and exported by Pavezyum to Colum- 105–108, 2009. bus Superconductors SpA which is a world leader in [2] Russell V., Hirst R., Kanda F. A., King, A. J., An X-Ray cutting-edge MgB2 technology. Among other elemental study of the magnesium borides, Acta Crystallogr., 6 boron powders, MgB2 made of nano size amorphous (11–12), 870, 1953. boron (d <350 nm - DLS) show excellent magnetic 99 [3] Nagamatsu J., Nakagawa N., Muranaka T., Zenitani Y., characteristics like 10-fold higher than the nearest Akimitsu J., Superconductivity at 39K in magnesium pure elemental boron powder (95-97 % pure) does diboride, Nature, 410 (6824), 63–64, 2001. [40]. The difference is based on the following two rea- [4] Flükiger R., MgB Superconducting Wires Basics and sons [30,38,71]: 2 Applications, Word Scientific nd,2 edition, Geneva, • Amorphous nano boron powder has small particle Switzerland, 2016. size, spherical and has larger specific surface [5] McMillan W. L., Transition temperature of strong-cou- area (>40 m2/g - BET) that leads to higher reactiv- pled superconductors, Phys. Rev., 167 (2), 331–344, ity. 1968.

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In-situ formation of borides and enhancement of powder metallurgy properties

Arun K. Chattopadhyay1*, Mustafa Barış2, Tuncay Şimşek3, Murat Bilen4

1Etimine USA Inc.; 1 Penn Center West, Suite-400, PA15276, Pittsburgh, ORCID ID orcd.org/0000-0001-5095-6463 2Eti Maden Works General Management, Ankara, Turkey, ORCID ID orcd.org/0000-0002-2119-0697 3Hacettepe University, Department of Physics Engineering, Ankara, Turkey, ORCID ID orcd.org/0000-0002-4683-0152 4Eti Maden Works General Management, Ankara, Turkey, ORCID ID orcd.org/ 0000-0002-1164-2039

ARTICLE INFO ABSTRACT Article history: Considering the demands for the high strength and corrosion resistant powder Received 7 April 2017 metallurgy parts, the most direct yet cost effective method of production of borides Received in revised form 23 August 2017 can be possibly be routed through the in-situ solid-state reaction in powder Accepted 6 September 2017 metallurgy. Going by the known reaction paths, a composition of boron carbide Available online 25 September 2017 and silicon carbide in combination with aluminum was investigated at three Research Article different sintering temperatures in order to see the effect of boron carbide on mechanical properties of aluminum under conventional high temperature sintering

Keywords: conditions. The limited study on high temperature sintering using SiC and B4C Aluminum, showed gradual improvements in strength sintering above 750 ⁰C, which can be Boron carbide, attributed to the in-situ formation of Si as well as SiB , where n= 2, 4, 6 …. Metal boride, n Powder metallurgy

1. Introduction terial properties of Al and Mg matrices during sintering. The use of metal silicides, carbides, and borides to in- Low density materials have attracted much interest as duce major microstructural rearrangement for improv- structural materials, particularly for use in the medi- ing strength is the general trend. cal, marine, automotive and aerospace industries. In that respect of Beryllium (Be-alloys), Magnesium (Mg- In this communication, mostly the compositions with alloys), Aluminum (Al-alloys) and Titanium (Ti-alloys) Al is reviewed where various complex borides form in- are of only interest in the lightweight alloy category be- situ in the presence of reactive compositions like B4C cause of their high strength-to-weight ratio. Excepting and Silicon Carbide (SiC). A yet another important ob- Be alloys, these alloys are mostly of low toxic nature jective of the present study was to see their effects compared to heavy metals. on the mechanical properties of Al under conventional high temperature sintering conditions. Several past studies on Mg alloys have shown that adding hard metal boride particles improved mechani- 2. Materials and methods cal properties of Mg alloys with high workability. These B4C of 99% purity was obtained from American Ele- studies typically used the alloys, AlB2 and MgB2 and results showed progressive improvement in strength ments and aluminum alloy powder 601 was obtained with the increase in boride content. However, the pro- from Reade Metal Powders. Micro-fine SiC powder cess requires that the reaction system be carefully was obtained from Washington Mill. In all formulations screened. Favorable thermodynamics of the antici- studied, a small quantity of graphite was intentionally pated reaction is the pre-requisite for the process to added for its function as a lubricant and also as a re- be applicable. Reasonably faster reaction kinetics is duction aid. SiC was used as a reactive additive for also required to make the process viable in all practi- both Al and B4C. The formulations studied are given cal purposes. The process of in-situ formation of few below in Table 1. metal borides was discussed recently elsewhere with Transverse rupture (TR) strength bars were compact- reference to strengthening boron carbide B C [1,2]. 4 ed using pressures of 250 MPa to determine the static However, it is still very challenging to improve the ma- mechanical properties of each formulation. Cylindrical

*Corresponding author: [email protected] 97 Chattopadhyay A. K. et al. / BORON 2 (2), 97 - 101, 2017

Table 1. The formulations studied in the experiments

Formulation Al% B4C% SiC% Graphite% 1 92 7.8 0 0.2 2 91 7.8 1 0.2 3 87 11.3 1.5 0.2 4 83 14.8 2.0 0.2 5 80 17.3 2.5 0.2 test slugs of a diameter of 0.5 (~13 mm) inches were various binary and ternary phases such as aluminum compressed to a height of approximately 1 inch (25 boride, aluminum carbide and aluminum borocarbide mm) as per the MPIF standard test procedures. Test (AlB10, Al4C3, Al3B4C etc.), of which, the ternary phase samples were compacted to ~ 2.1 g/cc green density. aluminum borocarbide is most commonly formed. All test samples were then subjected to hot vacuum degassing (HVD) at around 500ºC prior to being sin- There have been several powder metallurgy studies tered at temperatures ranging between 650-850ºC carried out in the past on Al in the presence of B4C. for an average of 140 minutes. HVD was employed These studies revealed the temperature dependen- for the purpose of minimizing voids and to minimize cies for improved mechanical properties of Al where dimensional changes during sintering. Total sintering B4C interacted with Al, forming various borides and time of 140 min included the time in pre-heating zone, boro-carbides, complex forms of boron and carbon, heating zone and cooling zone. To achieve best condi- [3-5,6]. tion of the sintered parts, the residence time in each zone was selected between 60-65 min, 15-20 min and 3. Results and discussion 60-65 min respectively. B4C is a very hard (9.5+ in Mohs scale), low specific The sintered densities were measured using a volume gravity (2.52), covalent ceramic which offers distinct displacement technique. The sintered samples were advantages when used for applications requiring low tested for bending strength and compressive strength. density, high strength metal composites involving Al The method of preparation of the powder matrices and Mg. The experiments demonstrated that the me- comprised cold-pressing of uniformly mixed Al pow- chanical properties of Al can be significantly improved ders and the in-situ boride formers. Then by heating through its association with B4C. The main advantage the cold-pressed compacts under vacuum or in an in- of the compositions studied is, the low-melting-point ert atmosphere, to a temperature above the melting metal phase of Al, which can probably wet the surfac- point of Al and then cooling the heated compact to so- es of B4C and SiC effectively starting from its liquidus lidify Al. The in-situ boride formers can be any suitable state during sintering at near or above the melting point metal oxide, carbide or metal powders like Si, Co, Ni of Al. As shown in Figure 1, the densities of all formula- etc. tions studied indicates that densification significantly By using metal oxides, individual metal borides can be improved as the temperature increased above the melting point of Al. In addition, the resulting compos- produced in-situ through B4C reduction. B4C with its inherent carbon impurity further accelerates the in-situ ites also showed improved mechanical properties. For reductions as the reduction process requires the pres- the composites assessed through the present study, ence of some carbon (Eq. 1.). processing temperatures were kept below 1000°C. The primary interest of this study was to investigate

2MOn (n=1 or 2) + B4C + 3C → 2MBm (m= 2, 3, 4, 6) + 4CO (1) the behavior of B4C and its reactivity with Al in the presence of SiC. Al being the low melting component,

However, for Al powder metallurgy the in-situ boride Al wetted B4C and SiC particulates were brought into formers can be very effectively carried out using SiC close proximity for controlled reactions within the sys- instead of other metal oxides or carbides. The use of tem. Wetting was necessary to achieve strong interfa- fine metal powders like Si, Co and Ni, preferably Si and cial bonding and to allow liquid rearrangement during

Co, in combination with B4C form complex borides and sintering. In order to allow consistent wetting to hap- carbides in-situ providing excellent mechanical prop- pen, the green parts were subjected to hot vacuum de- erty [1,2]. Those reactive metal powders show very gassing at approximately 450-500°C. The hot vacuum good chemical affinity for boron and carbon. For ex- degassing process minimizes the formation of pores. ample, Si with B4C forms SiC and complex silicon bo- The nature of the interfacial reaction between Al par- rides like SiB4, SiB6 and also B6SiC2. The advantage of using silicon over other reactive metals is, the reaction ticulates and SiC below the melting point of Al is well and migration across the Al grain boundary occurs at known [1]. The reaction begins in-situ around 600°C. a relatively lower sintering temperature. Moreover, Al Aluminum reduces SiC to form Al carbide and Si (Eq. even in its liquidus state interacts well with B4C to form 2.):

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Figure 1. Density of the sintered compositions studied at three different sintering temperatures.

2 4Al + 3SiC = Al4C3 + 3Si (2) σT = 3FBL / 2Wτ (3)

Si thus formed in-situ can act two ways; (1) it can get Where σT is transfer rupture strength, FB is bending fail- dissolved into Al quickly, and (2) trans-migration of ure load, L is distance between the lower support rods,

Si occurs towards B4C bringing about changes in the W is the width of the specimen and τ is the thickness structural property of B4C during sintering [1,2]. of the specimen. A compression pressure of 480 MPa was used. For compressive strength, the area of the Variation in density of the sintered parts is shown in specimen varies upon compression. The stress (the Figure 1. At a lower sintering temperature (650°C) the force divided by the area) and compressive strength rise in density was very modest. However, at sintering can be expressed as Eq. 4, temperatures above 750°C there was a sharp rise in density approaching near true density of the compos- F ite indicating the flow of liquid and space filling during σe = (4) the sintering process. The density trend also suggests A0 that the maximum density achieved by the formulations with 1-1.5% SiC at 850°C is probably due to the A0=Original specimen area, and F=load applied just formation of adequate Si to act as glue between Al and before crushing. Correspondingly, the strain is expressed as Eq. 5, B4C. A three-point bending test was employed to assess the Ɩ Ɩ0 mechanical properties of sintered compacts using the εe = (5) Ɩ INSTRON 5869 machine having a 1000 kN maximum 0 load. Transverse rupture strength (TRS) was calculated using the Eq. 3 [7,8] as follows: where l = specimen length before crushing. The hard-

Figure 2. Transverse Rupture Strength of the compositions studied at three different sintering temperatures.

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Figure 3. Compressive strength of the compositions studied at three different sintering temperatures.

Figure 4. Vickers Microhardness of the compositions studied at three different sintering temperatures. ening of the compacted sintered matrix of the formula- 4. Conclusions tions studied are shown Figure 2-4. The results obtained in the experimental studies can It is interesting to note from both the transverse rupture be summarized as follows; strength and compressive strength graphs that there • The primary interest of this study was to investi- exists some sort of optimized synergy between B4C and SiC in compositions 3 and 4, where SiC varied gate the behavior of B4C and its reactivity with Al between 1.5-2%. However, vickers hardness revealed in the presence of SiC following the primary reac- a sharper rise in hardness at sintering temperatures tion paths: above 750°C. Al2O3 + 3B4C + C = 2AlB2--12 + 3CO (i); Further studies are in progress to carry out detailed 4Al + 3SiC = Al C + 3Si (ii); and spectral analysis of the microstructures of the com- 4 3 posites to confirm interfacial compositions at the grain 4Si + nB C = 4SiB + C (iii) boundaries. Nevertheless, previous studies on the in- 4 n teraction of B4C with other metal oxides and carbides • The limited study on high temperature sintering [1,2] and various other existing literatures suggest that using SiC and B4C showed gradual improvements the observed increase in hardening is most probably in strength, which can be attributed to the in-situ due to the chemical reaction. In-situ formation of com- formation of Si as well as SiBn, where n = 2, 4, 6, plex borides along with the formation of Si further ac- …. centuates the effect. Si helps to bind 4B C with Al as it is interactive with both Al and B4C at their interfaces, • Si being highly soluble in Al, the strengthening of thereby improving the mechanical properties of the Al also suggest the transmigration of Si as well as composites. SiBn across the Al grain boundaries.

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Acknowledgements [3] Viala J.C., Bouix J., Gonzalez G, Esnouf C, Chemi- cal reactivity of aluminium with boron carbide, J. Mater The author is thankful to Etimine USA Inc. for the sup- Sci., 32, 4559-4573, 1997. port. The author is also thankful to Ms. Bidyunmala [4] Oh S.Y., Cornie J.A., Russel K.C., Wetting of ceramic Roy and Mr. Aditya B. Chattopadhyay (The Boeing Co, particulates with liquid aluminum alloys: Part II. Study USA) for their ungrudging assistance to help with the of wettability, Metall. Trans. A, 20, 533-541, 1989. manuscript. [5] Nobel B., Trousdale A.J., Haris S.J., J. Mater Sci., 32, References 5969, 1997. [6] Gokmese H., Bostan, B., Baris, M., Fabrication and [1] Chattopadhyay A. K., Selective migration of metals characterization of nanoceramic particle al o /b c com- and metal borides to strengthen boron carbide, Met. 2 3 4 posite by mechanochemical approach, Inorganic and Powder Rep., 71(2), 106, 2016. Nano-Metal Chemistry, 47 (3), 416-422, 2017. [2] Chattopadhyay A. K., Yilmaz O., Bilen M., Baris M., [7] German R. M., Powder metallurgy and particulate ma- Strengthening boron carbide and prevention of high terials processing, MPIF, 377-78, 2005. pressure amorphization by inducing metals or metal borides across the grain boundary during hot press- [8] MPIF Standard: Method for determination of trans- ing or sintering, Adv. Powder. Metall. Part. Mater., 7, verse rupture strength of powder metallurgy materials, 1–12, 2015. MPIF Standard Test Methods, 2006.

101 BORON 2 (2), 102 - 109, 2017

ULUSAL BOR ARAŞTIRMA ENSTİTÜSÜ ISSN: 2149-9020 NATIONAL BORON RESEARCH INSTITUTE

BOR DE RGİSİ JOURNAL OF BORON

CİLT/VOL SAYI/ISSUE YIL/YEAR 02 02 20 BOR DERGİSİ 17 JOURNAL OF BORON

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Alternating current electrophoretic deposition of HA and hBN nanoparticles on Ti substrate

Merve Geçgin1*, Yapıncak Göncü2, Nuran Ay3

1Department of Material Science and Engineering, Anadolu University, Eskişehir, Turkey, ORCID ID orcd.org/0000-0002-9674-9168 2BORTEK Boron Technologies and Mechatronics Inc., Eskişehir, Turkey, ORCID ID orcd.org/0000-0002-8602-9765 1Department of Material Science and Engineering, Anadolu University, Eskişehir, Turkey, ORCID ID orcd.org/0000-0002-2228-9904

ARTICLE INFO ABSTRACT

Article history: Hydroxyapatite (HA) and hexagonal boron nitride (hBN) are biocompatible Received 1 March 2017 materials. In this study, nano HA and nano hBN particles were used for coatings Received in revised form 13 September 2017 on titanium (Ti) substrate. The nanoparticles were deposited on Ti substrates Accepted 14 September 2017 by alternating current electrophoretic deposition (AC-EPD). Suspensions were Available online 25 September 2017 consist of nano HA and also comprised of the various amount of nano hBN (0.0- Research Article 2.0-5.0-10.0 and 25.0 wt% by the percentage of hydroxyapatite). The coated samples were heat treated at 800 oC in Ar atmosphere for 2 hours. Sintered Keywords: samples were characterized by XRD and SEM-EDS. Coating thickness was Alternating current electrophoretic deposition, measured and adhesion tests (ASTM D3359–09-B) were performed. The Hexagonal boron nitride, results showed that nano HA and nano hBN composite coating with the AC-EPD Hydroxyapatite, method is homogeneous and crack free. It is determined that the amount of hBN Composite coating in composite affects the adhesion behavior and the thickness of the coating.

1. Introduction tions [11-14]. In our previous work, hBN and HA were successfully deposited on Ti surface with uniform, Hydroxyapatite is widely used as a biomaterial be- crack-free coating by DC-EPD [15]. hBN improves the cause of its good biocompatible, bioactive and chemi- mechanical properties of HA [16,17] and recent stud- cally similar to inorganic compound of human skeleton ies, indicate that hBN-HA composites were used in the system [1]. Its usage is restricted in the bone and medical application and it was determined that it is the teeth implants because of its poor mechanical proper- important contribution on bone tissue healing[18-21]. ties under load bearing applications [2]. Metal based Ferah (2015) indicated that hBN containing coating composites are developed to improve the mechani- decreases healing period, prevents infection and it can cal properties of HA and several coating techniques be utilized in the patient who has the risk of osteomy- such as dip coating [3], plasma spray [4], biomimetic elitis[22]. [5] and electrophoretic deposition [6] are used. Among these coating techniques, electrophoretic deposition Atilla et.al. demonstrated that the use of hBN in HA (EPD) has some advantages compared with other ceramic composite did not change the stability of the techniques, such as simplicity in set up, low equip- implant and increasing concentration of hBN in the ment cost, the ability to coat complex shape, control of composition did not cause a difference in serum boron deposition thickness. Charged colloidal particles in a level [23]. In this study, nano HA-nano hBN composite suspension are deposited onto an oppositely charged coatings on Ti substrate by AC-EPD were investigated. substrate via AC and/or DC field. While particles flow in one direction in DC, particles flow is constantly chang- 2. Materials and methods ing direction in AC from negative to positive vice versa Nano HA powder was provided by NANOTECH Ltd., [7-10]. Kolath et.al indicated that obtaining denser and Eskişehir-Turkey, while nano hBN powder was sup- uniform coating possible via AC-EPD(10). plied by BORTEK Inc., Eskişehir-Turkey. It was report- Hexagonal boron nitride (hBN) is an artificial material ed our previous study that HA powder included in ~10% with the layered crystal structure that has biocompat- TCP phase and highly crystalline hBN is 98% pure and ible and non-cytotoxic material for orthopedic applica- the average particle size is 120 nm [24]. Commercial

*Corresponding author: [email protected] 102 Geçgin M. et al. / BORON 2 (2), 102 - 109, 2017 pure titanium sheet 30x10x1.5 mm dimensions were 3. Results and discussion utilized as a substrate. Each substrate was polished using SiC papers, washed and ultrasonically cleaned. Figure 2 shows the thickness of AC-HB 0.0 coated samples which was obtained under constant voltage Composite suspensions were made of 1 wt. % nano 15 Vpp and various time by the AC-EPD method. In HA and also comprised of various amount of nano order to obtain a good quality coating under 15 Vpp, hBN (0.0-2.0-5.0-10.0 and 25.0 wt.% nano hBN by the the minimum necessary deposition time is 5 min (Fig- percentage of hydroxyapatite). Samples were coded ure 2). The thickness of AC-HB 0.0 coated samples is as AC-HB 0.0, AC-HB 2.0, AC-HB 5.0, AC-HB 10.0 increasing with extended time, linearly. The thickness and AC-HB 25.0 respectively. Before deposition, N, N– value reached up to ~45 µm when the deposition time dimethylformamide (10%v DMF-Merck) were added to was 20 min under 15 Vpp. The tendency of deposited provide strength and crack-proof improvement. The thickness vs. time in AC-EPD for HA coatings was re- pH values of suspensions were adjusted to 4. ported [10, 26]. Kollath et al. declared that the thick- The experimental set up was shown in Figure 1. Ti ness of the HA coatings by AC-EPD was increased plates were used as working and counter electrodes. with extended time duration (100V-30 sec=5 micron Experimental studies were conducted by forming the and 100 V-60 sec=22 micron) [10]. Also, Chávez-Val- asymmetric wave pattern. 50 Hz using under AC (Key- dez et al. indicated that the deposition yields were in- sight, DSO1072B 70 MHz Digital oscilloscope, Agilent creased linearly with increasing deposition time (1, 3 33500B series Waveform generator, Agilent 33502A and 5 min) at each applied voltage (5V, 10V and 20V) Amplifier) were utilized. The distance between the [26]. This study showed that the linear growth was car- electrodes were 5 mm. AC-HB 0.0 samples were coat- ried out deposition time. ed at 15 Vpp ( 5, 10 and 20 min), 20 Vpp (1,2,3,4 and 5 min) and 25 Vpp (1,2,3,4 and 5 min) and the other Figure 3 shows the thickness of AC-HB 0.0 coated samples were coated at 25 Vpp and 2 minutes. All the samples which was obtained under 20 Vpp and 25 samples were heat treated in laboratory tube furnace Vpp by AC-EPD. The thickness of AC-HB 0.0 coated at 800 oC for 2 h in argon atmosphere. samples, at 20 Vpp increased linearly and at 25 Vpp increased parabolic up to 4 min and then the thickness of the samples reached up to the constant val-

ue. Gardeshzadeh et. al. indicated that coated SnO2 nanoparticles by AC-EPD and deposition yield was gained linearly in the beginning of deposition (to 20 min) at constant applied voltage but the rate of deposit yield were decreased with prolonged time [27]. The reason for this trend is formation of insulating layer of ceramic particles on the electrode surface [6,9,28,29]. The thickness of AC HB 0.0 for various voltages as seen Fig. 3 and Fig. 4 reaches up to the higher value with rising applied voltage for less deposition time.

Figure 1. Experimental setup.

The coating thickness of the samples was measured by EBAN 4000 coating thickness meter. The adhesion was classified according to ASTM D3359-09 cross-cut tape-test (B) [25]. X-Ray powder diffraction patterns were obtained with a Rigaku Rint 2000 X-ray diffractometer with Cu Kα radiation (λ=1.5418 Å), in the 2θ range of 20-80o with the scan speed of 2o/min.

The amounts of the phases of all coated samples were analyzed by using JADE software and Maud program. Figure 2. Coating thickness and adhesion classification of AC-HB The microstructure of deposit layers and adhesion 0.0 samples versus deposition time at 15 Vpp. test samples were investigated by means of scanning electron microscopy (SEM, ZEISS SUPRA 50VP) and There are several test methods to determine coat- the chemical analysis of microstructures was done ing quality. The available standards are: ASTM C633 with an Energy Dispersive Spectrometer (EDS-Oxford and F1147 for tensile strength testing [30,31], ASTM Instrument). D4501 and F1044 for shear strength testing [32,33]

103 Geçgin M. et al. / BORON 2 (2), 102 - 109, 2017 and tape test (ASTM D3359 [34-36]. All samples were all coatings, particle mobility can be considered con- classified according to tape test standard (5B for 0% stant. Moreover, the electric field is constant between removal of coating, 4B for ˂5% removal, 3B for 5-10%, the electrodes, so the relation between m and E is 2B for 15-35%, 1B for 35-65% and 0B for˃65%). This linear. When the distance between the electrodes is observation leads to the conclusion that the adhesion constant, the electric field intensity only varies with the classification of coatings for each AC-HB 0.0 samples voltage of electric field. Therefore, the voltage can be (Fig. 2 and Fig. 3) decreases with the extended of time used instead of the electric field intensity. Considered duration correspondingly with an increase coating Eq. 4 and voltage effect on the thickness, the relation thickness. As a result of this study, it is clear that there between them can be defined linearly. was an adhesion classification depending on the thick- It can be estimated that desired adhesion classifica- ness such as 5B˂~40 µm, 40 µm ˂4B˂45 µm, 45 µm tion is controlled by the coating thickness in complying ˂3B˂50 µm, 50 µm ˂2B˂66 µm, 1B˃66 µm. with various voltage-time combinations. The effect of applied voltage on the thickness for AC- HB 0.0 coated samples was examined at constant deposition time (5 min) (Figure 4). Increasing of applied voltage escalated the thickness linearly. It can be explained with Hamaker equation (Eq.1) [28].

Figure 4. Coating thickness of AC-HB 0.0 samples versus applied voltage (deposition time: 5 minutes).

AC-HB 0.0 coated samples were done at 25 Vpp for 2 min and classified as 3B. Using this data, various Figure 3. Coating thickness and adhesion classification of AC-HB amount of hBN in samples were investigated to obtain

0.0 samples versus deposition time at 20 Vpp and 25 Vpp. how the effect on coating thickness and adhesion. All composite coatings were performed at 25 Vpp for 2 min by AC-EPD and compared with AC-HB 0.0 coated According to the equation, relation between the de- by the same conditions. posit weight, m (g) and electric field intensity/strength, -1 E (V cm ) is: It is observed that all samples are uniform and crack free at 25 Vpp and 2min. The XRD pattern of sin- m= C µ SE t (1) s tered composite coating samples is shown in Figure Where µ (cm2 s-1 V-1) is electrophoretic mobility, S 5. Phase analysis revealed that all major peaks of 2 -3 HA (JCPDS PDF No: 009-0432) were present for all (cm ) is the surface area of the electrode, Cs (g cm ) is the concentration of the suspension and t (s) is time. the samples. hBN (JCPDS PDF No: 034-421), β-TCP

(JCPDS PDF No: 009-0169), TiO2 (Rutile, JCPDS The Eq. 2 can be used instead of deposited mass [28], PDF No: 021-1276) and Ti (JCPDS PDF No: 044- 1294) phases are detected. Beta TCP phase comes m= SC (2) d from raw nano HA powder. Rutile phase is formed as Combining Eq. 1 and 2 gives: an interface phase between the substrate and coating during sintering. Kollath et. al. also observed the rutile

δ = (Cs/Cd ) µE t (3) phase as an interphase between HA and Ti substrate in the XRD spectrum of HA coatings by AC-EPD and When (C /C ) considered constant value therefore Eq. s d DC-EPD after sintering at 900oC for 2 hours in high 3 is expressed by purity argon atmosphere [10]. Moreover, forming metal δ = µE t (4) oxide phase between HA and Ti substrate for producing HA coatings by DC-EPD during sintering was ob- According to Eq. 4, thickness depends on particle served other investigators [37,38]. mobility, time and the applied electric field. In our experiments, AC-EPD were performed at 5 min and var- The phase analysis results of nano HA and nano hBN ies voltages. Due to using the same suspension for phases in AC-HB 5.0, AC-HB 10.0 and AC-HB 25.0

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Figure 5. X-ray diffraction patterns of HA-hBN composite samples (+: hBN, ●: Rutile (TiO2), ▼: β-TCP, *: Ti). samples at 25 Vpp for 2 min are given Table 1. The lently to the Ti substrate. The peeling of the coating calculations are in accordance with the amount of hBN from the surface (less than 5%) was observed in the in prepared suspensions but the amount of hBN in de- sample AC-HB 5.0 and AC-HB 10.0 and classified to position is slightly higher. The error in this calculation category 4B. Figure 7 shows the microstructure of is expected from mathematical calculations during Ri- composite coatings after tape tests. The crosshatch etveld Analysis. patterns on samples are seen Figure 7 a, c, e, g and I. The microstructures between crosshatch lines are Table 1. Rietveld analysis results for calculated percentage of the shown Figure 7 b, d, f, h and j. These results are com- phases present in samples. ply with our assumption. (%) AC-HB 5.0 AC-HB 10.0 AC-HB 25.0 It was determined boron and nitrogen peaks beside HA 94.61 87.63 73.00 Ca, P and O peaks on AC-HB 10.0 (Figure 8) and AC- HB 25.0 (Figure 9) after tape tests. In order to deter- hBN 5.38 12.36 27.00 mine where boron and nitrogen is located in the microstructure, AC-HB 10.0 (Figure 10) and AC-HB 25.0 coated samples (Figure 11) were analyzed by elemen- The coating thickness and the adhesion classification tal mapping. The elemental mapping analysis of each of samples are shown in Figure 6. The coating thick- sample showed that boron and nitrogen distributed on ness decreases with increasing hBN content. It might the coating surfaces are uniform. be that there are two reasons for thickness decreasing. The first reason might be related to decreasing particle mobility in the suspensions. The second reason might be about two different particle size distribution in suspension, and this cause different oscillating-migration behavior under AC-EPD. Therefore, the deposition is the more closed packed structure [10]. After the application of tape-test, coating damage of the samples are classified as 3B for AC-HB 0.0 and AC-HB 2.0, 4B for AC-HB 5.0 and AC-HB 10.0 and 5B for AC-HB 25.0 at 25 Vpp for 2 min (Figure 6). Tape test samples give more objective results about the adhesion of the coating formed by EPD. These results are comply with our assumption. AC-HB25.0 coded Figure 6. The coating thickness and classification adhesion vs HA- samples were good and classified to category 5B ac- hBN composite samples. cording to ASTM standards. The 5B ranking suggests that the HA-hBN nanoparticles coating adhere excel-

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Figure 7. SEM images of HA-hBN composite samples, a, b) AC-HB 0.0; c, d) AC-HB 2.0; e, f) AC-HB 5.0; g, h) AC-HB 10.0; i, j) AC-HB 25.0.

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Figure 8. SEM-EDX analysis of AC-HB 10.0 sample.

Figure 9. SEM-EDX analysis of AC-HB 25.0 sample.

107 Geçgin M. et al. / BORON 2 (2), 102 - 109, 2017

Figure 10. a) Elemental mapping on coating surface of AC-HB 10.0 sample, images (b) – (e) exhibit the element sensitive maps of calcium, phosphorus, boron and nitrogen.

Figure 11. a) Elemental mapping on coating surface of AC-HB 25.0 sample, images (b) – (e) exhibit the element sensitive maps of calcium, phosphorus, boron and nitrogen.

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YAZAR KILAVUZU 2. Bilimsel yazıların kategorileri

1. Genel bilgi Bilimsel yazılar üç kategoride yayına kabul edilmektedir: BOR Dergisi (Journal of BORON), sadece bor ile ilgili bilimsel çalışmaların, özgün nitelik taşıyan temel a.) Özgün araştırma makalesi: Tamamlanmış çalış- araştırmaların, teknik uygulamaların yer aldığı Bilim maları açıklayan, en çok 30000 karakterden (boşluklar Dünyasında ilk ve tek dergidir. Bor Dergisi, bor bilimi, dâhil) oluşan ve yeni sonuçlar içeren deneysel ve teo- bor teknolojisi, bor kullanımı, bor kimyasal maddeleri rik çalışmalardan oluşmaktadır. Araştırma makalesin- ile bor kullanılan alanların tüm çerçevesini kapsamak- de ayrıca en çok 8 şekil ve en çok 6 çizelge yer alabilir. ta olup; fen, tıp, enerji, mühendislik, eczacılık, tarım, savunma sanayi, madencilik, kimya ve uzay sanayi b.) Kısa araştırma makalesi: Hızlı bir şekilde yayım- dallarında geniş bir alanda disiplinler arası araştırma lanması istenen kısa ve önemli sonuçları açıklayan ya- olanağı sağlayan yenilikçi bir element olan bor ele- zıdır. Bu yazı 18000 karakter (boşluklar dâhil ) ve 6’ya mentine odaklanmaktadır. kadar şekil içerebilir.

Dergi, bor ile ilgili ulusal ve uluslararası alanlarda ya- c.) Derleme makalesi: Belirli bir konu hakkında ya- yımlanmış bilgileri özetleyen ve araştırmacıların kendi pılan bilimsel çalışmaları, güncel teknolojileri, özgün sonuçlarıyla sınırlı olmayan yazıdır. Sadece literatür teknikleri ve yaklaşımları yayımlar. Fen, tıp, enerji, mü- taramalarıyla oluşan bilgi topluluğundan ziyade maka- hendislik, eczacılık, tarım, savunma sanayi, madenci- lelerin kapsamlı bir eleştirel açıklanması ve seçimi ön- lik, kimya ve uzay sanayi gibi alanlarında bor ile ilgili celiklidir. Bu yazı genellikle 45000 karakteri (boşluklar makaleleri bekliyoruz. dâhil) geçmemeli ve en fazla 15 şekil içermelidir. Bor Dergisi’ne gönderilen tüm bilimsel makaleler önce 3. Yazıların dergiye gönderilmesi Baş Editör tarafından değerlendirilir. Gerekli öncelik derecesini sağlamayan, Yazar Kılavuzuna uyma- 3.1. Genel yan ya da dergi kapsamında olmayan makaleler daha ileri değerlendirmeye alınmaz ve ayrıntılı yo- Bu dergideki makaleler hem basılmış halde hem de rum yapılmadan yazarlara geri gönderilir. Öncelik elektronik ortamda (on-line) görünecektir. Yazarlar ve/veya kapsam yönünden yapılan bir değerlendirme kabul edilen makaleleri için hiçbir ücret ödemeyecek- göreceli olduğundan, sadece bu yönden değerlendir- lerdir. Yayımlanması kabul edilen yayın haline dönüş- meye bağlı ret kararlarının hatalı olduğunu kanıtlama türülen yazıların telif hakkı BOREN’ e aittir. BOREN, çabalarının nadiren de olsa başarılı olabileceğine dik- makalenin yayımlanmasının ardından, makalenin ya- kat edilmelidir. zar/yazarlarına, “Kamu Kurum ve Kuruluşlarınca Öde- necek Telif ve İşlenme Ücretleri Hakkındaki Yönetme- Gerekli şartları karşılayan yazılar özgünlük ve kalite lik” kapsamında telif ücreti ödeyecektir. ölçütleri yönünden hakem incelemesine tabi tutulur. Yazarlar Sunuş Mektubunda çalıştıkları kurum 3.2. Makale nasıl gönderilir? ve e-posta adresleri ile birlikte konu ile ilgili beş ha- Yazılar, web tabanlı Makale Sunum Sistemi kullanı- kem önerebilir. İnceleme sonrasında karar, ‘‘Büyük larak elektronik ortamda BOR Dergisine (journal of Düzeltme” şeklinde ise makalenin düzeltilmiş yeni hali BORON) gönderilmelidir. Bu hizmet yazıların hızlı, tekrar gönderilebilir, ancak hakemler düzeltilmiş ma- güvenli gönderimini ve hızlı değerlenmesini sağlar. Ya- kalede hâlâ önemli sorunlar belirlerse makale kesin zıların gönderilmesi aşağıdaki basamaklardan oluşur: olarak reddedilir. Kabul edilen makaleler yazımla ilgili değişikliklere tabi tutulabilir. Bir makalenin gerçeklere a.) Yazılar ve şekiller aşağıda verilen talimatlara göre dayanan doğruluğunun sorumluluğu tamamen yazarı- (Bölüm 4.1’ den 4.9’ a kadar) uygun biçimde hazırlan- na aittir. malıdır. Yazılar, Bor Dergisinin (Journal of BORON ) burada verilen bilimsel ve biçimsel talimatlarına uy- Bilgi hırsızlığı (intihal), verilerin uydurulması, so- mak zorundadır. Bu talimatlara derginin ana sayfa- nuçları tahrif etmek/iyileştirmek için görüntüyü/ve- sında http://dergipark.gov.tr/boron “Yazar Kılavuzu” rileri değiştirmek, hakem değerlendirme sürecini kısmından ulaşabilirsiniz. etkilemek vb. dâhil, ancak bunlarla sınırlı olmayan tüm durumlar makalenin reddine/geri çekilmesine b.) Yazarlar ilk gönderisi için http://dergipark.gov.tr/re- neden olacaktır. gister adresinden “Kayıt Sayfasına Gidiniz” sekmesini kullanarak dergiye kayıt olmalıdır. Bu dergi, YÖK Bilimsel Araştırma ve Yayın Etiği Yö- nergesi kurallarını kabul eder ve şüpheli araştırma c.) Derginin web sitesinde verilen ‘‘Açıklamalar’’ durumlarını ve yayın suistimallerini takip eder. YÖK dikkatlice okunmalıdır. Bu sistem makale gönder- Bilimsel Araştırma ve Yayın Etiği Yönergesi hakkında me sürecinde rehberlik eder. Online yardım, süreç daha fazla bilgi için YÖK’ün websitesi http://www.yok. boyunca her zaman kullanılabilir. Yazarlar makale gov.tr/web/guest/icerik/-/journal_content/56_INSTAN- göndermeyi sonlandırmadan önce, herhangi bir aşa- CE_rEHF8BIsfYRx/10279/18187 adresini ziyaret ede- mada çıkış/tekrar giriş işlemlerini yapabilirler. Tüm bilirsiniz. başvurular kesinlikle gizli tutulur. Online başvuru prog- ramı ile ilgili tüm sorunlarınız için [email protected] ii.) “1 Giriş”: Araştırma konusunu, sorunun açıklan- ve [email protected] editörel destek adres- masını ve bu konu ile ilgili var olan literatürün kısa bir leri ile temas kurabilirsiniz. araştırmasını içermelidir.

Yazar, yazının başka bir yerde ya da dergide kısmen, iii.) “2 Malzemeler ve yöntemler”: Araştırmada kulla- tamamen ya da başka bir formatta yayımlanmamış nılan özel malzeme, donanım ve cihazlar bu bölümde olduğunu doğrulamalıdır. Makaleyi gönderen yazar üreticisinin adı ve mümkünse yeri (şehir adı) ile birlikte (‘‘Sorumlu yazar”) diğer tüm yazarların sorumluluğunu verilmelidir. kabul eder. Makaleyi gönderen yazar, tüm ortak yazar- ların makaleyi gördüklerini ve bu dergiye göndermeyi iv.) “3 Sonuçlar ve tartışma” kabul ettiklerini onaylar. v.) “4 Sonuçlar” Tüm bilimsel yazılar, hakem değerlendirmesi- vi.) “Kaynaklar” ne tabi tutulacak ve özgünlük, yenilik ve kalite açısından değerlendirilecektir. Yazarlar, Sunuş Bölümlerin alt başlıkları numaralandırılarak verilmeli- Mektubunda kurumsal e-posta adresleri ve website dir. linkleri ile birlikte değerlendirme sürecinin dışında tutmak istedikleri 5 hakem de önerebilirler. 4.3. Kaynaklar

Düzeltme istenen makaleler yalnızca iki ay içinde dü- Kaynaklar metin içerisinde geçiş sırasına göre ar- zeltilip tekrar gönderildikleri takdirde ilk sunuş tarihle- dışık bir şekilde numaralandırılmalıdır. Metin içe- rini korurlar. risinde kaynaklar [2, 13] gibi parantez içerisinde verilmelidir. Metin içerisinde verilen kaynak numaraları Eğer Bor Dergisine başka bir yerde yayımlanan bilgile- yazının sonunda “Kaynaklar” başlığı altında sırasıyla ri (örneğin şekiller) gönderiyorsanız, bu bilgilerin BOR verilmelidir. Dergi başlıkları aşağıdaki WEB sayfasın- Dergisinde tekrar basılması için izin almanız gerektiği- da verildiği gibi kısaltılarak verilmelidir. ne dikkat ediniz. http://woodward.library.ubc.ca/research-help/journal- 4. Yazıların organizasyonu abbreviations/ .

4.1. Birinci sayfa içeriği Kaynaklar için örnekler aşağıda verilmiştir:

1.) Yazının başlığı: Ana bulguları kapsayan gerekti- Dergi ğinde standart kısaltmalarla birlikte kısa ve açık şekil- [1] Şimşek T., Barış M., Synthesis of Co B nanostruc- de en çok 15 kelimeden oluşmalıdır. 2 tures and their catalytic properties for hydrogen gene- 2.) Yazarların tam adları (ilk adları dâhil) ve kurum- ration, BORON, 2 (1), 28-36, 2017. ları: Eğer yayın farklı kurumlarda çalışan yazarların Kitap ortak çalışması ise, çalıştıkları kurumlar her yazarın adı 1, 2 gibi üst rakam ile numaralandırılarak açık bir [2] Grimes R. N., Metal Interactions with Boron Clus- şekilde belirtilmelidir. ters, 1st edition, Springer Science+Business Media, New York ,1982. 3.) Sorumlu yazarın adı (ve unvanı), posta adresi ve e-posta adresi vb. gerekli iletişim bilgileri gön- Kitaptan bir bölüm ise: derilmelidir. [3] Gürü M., Çakanyıldırım Ç., “Boron Hydrides, 4.) Makalede geçen standart olmayan kısaltmaların High Potential Hydrogen Storage Materials”, Chap.4: bir listesi. Hydrogen Cycle with Sodium Borohydride, Nova Sci- ence Publisher Inc., New York, 2010. 5.)Konu ile ilgili en çok 5 anahtar kelime alfabetik olarak yazılmalıdır. Tez 4.2. Bölümler [4] Yalçınkaya Ö., Bazı eser elementlerin alumi- yum oksit/tek duvarlı karbon nanotüp ve zirkon- Yazılar aşağıdaki gibi bölümlere ayrılmalıdır: yum oksit/bor oksit nano malzemeleri kullanılarak katı faz özütleme tekniği ile zenginleştirilmesi ve ta- i.) “Özet”: Ana metne atıf yapmadan konuyu anla- yini, Doktora Tezi, Gazi Üniversitesi, Fen Bilimleri şılır bir şekilde özetlemelidir. Özet, araştırma ve der- Enstitüsü, Ankara, 2010. leme makaleleri için 220 kelimeyi geçmemelidir. Kısa araştırma makaleleri için 80 kelimeyi geçmemelidir. Kongre veya sempozyum Standart olmayan kısaltmalar ilk kullanıldığında tam olarak yazılmalıdır. Alıntı yapılan her kaynak tam ola- [5] Yılmaz O., Bilen M., Gürü M., Absorption of CO2 rak verilmelidir. Türkçe yazılar için özetin İngilizcesi de in boron solutions and recovery as industrial chemical yazılmalıdır. products, IV. International Conference on Nuclear and 4.9. Birimler ve simgeler Renewable Energy Resources, Antalya-Türkiye, 27- 29 Ekim, 2014. SI birimlerinin kullanılması zorunludur. ASTM veya IU- PAC tarafından tavsiye edilen ve genel kabul görmüş • Birden fazla yazarlı makalelerde ilk yedi yazar ile isimlendirme ve simgeler tercih edilir. Anlaşılırlık için sınırlıdır, daha fazla varsa vd. şeklinde devam et- simgeler metin içerisinde tanımlanmalıdır. Eğer memelidir. tin çok sayıda simge içeriyorsa bunlar metin sonunda • Baskıdaki makalelerin DOI numarası belirtilmeli- (“Kaynaklar” kısmından önce) liste halinde açıklanma- dir. lıdır.

• Tüm seri yayınlara dergilerle aynı şekilde atıf ya- 4.10. Kısaltmalar pılmalıdır. Kısaltmalar en az olacak şekilde sınırlandırılmalıdır ve • Web sitesi adresleri (URL) kaynak olarak verilme- yalnızca metinde sık olarak geçecekse kullanılmalıdır. melidir. Ancak metin içerisinde verinin geçtiği yer- Yalnız çizelge veya şekillerde kullanılan kısaltmalar de veriden sonra belirtilmelidir. şekil ve çizelge başlığında tanımlanmalıdır. Başlık ve 4.4. Teşekkür anahtar kelimelerde standart kısaltmalar kullanılabi- lir. Eğer Özet kısmında standart olmayan kısaltmalar Maddi destek kaynaklarına ilişkin teşekkür yazısı met- kullanıldıysa, bunlar makale metninde ilk geçtiği yerde nin sonunda kaynaklardan önce ayrı bir sayfada veril- olduğu gibi makalenin kısaltmalar listesi kısmında da melidir. tanımlanmalıdır. 4.5. Çıkar çatışması NOT: Türkçe bir makalede; başlığın, özetin, tüm Tüm yazarlar mali ve ticari çıkar çatışmalarını bildir- bölüm, şekil ve çizelge başlıklarının İngilizcesi ol- melidir. Çıkar çatışması yoksa bile bu husus teşekkür malıdır. Grafiklerin x ve y eksenlerinin İngilizcesi bölümünü takiben ayrı bir paragraf olarak şu şekilde olmalıdır. ifade edilmelidir: “Yazarlar çıkar çatışması olmadığı- nı beyan ettiler”. Bu husus tüm makaleler için zorunlu 5. Elektronik makale tasarısı bir gerektir. Gönderilen tüm makale taslakları yükleme işlemi sı- 4.6. Çizelgeler rasında PDF formatına dönüştürülür. Sistem otomatik olarak yazının tüm bölümlerini içeren tek bir PDF dos- Çizelgeler, uygun başlıklar ve normal rakamlarla nu- maralandırılmış bir şekilde metnin sonunda her şekil yası oluşturur. Dosya Yönetimi için aşağıdakiler gere- ayrı bir sayfada olacak şekilde verilmelidir. Sütun baş- kir. lıkları mümkün olduğunca kısa tutulmalı ve birimleri • (Ön Belgeleri içerir) ve içerisindeki şe- içermelidir. Çizelge dipnotları çizelge ile aynı sayfada; Ana metin a), b), c) gibi gösterilmelidir. kil, gösterge ve çizelgeler tercihen doc, docx veya rtf formatında kaydedilmiş dosya verilmelidir. 4.7. Şekiller, şemalar ve başlıklar • Şekiller tercihen JPG, EPS, TIFF veya orijinal for- Şekiller 80 mm genişliğine küçültüldüğünde basılabile- matında olmalıdır. Pdf veya ppt(x) olmamalıdır. cek kalitede olmalıdır. Sayılar, yazılar ve simgeler ye- terli büyüklükte okunaklı olmalıdır. Tüm şekiller metin- Düzeltme yapılmış makalelerde yapılan önemli de- de atıfta bulunularak numaralandırılmalıdır. Her şeklin ğişiklikleri içeren alanlar işaretlenmiş olmalı ve metin içeriğini açıklayan bir başlığı olmalıdır. rengi değiştirilmelidir. Değişiklikleri içeren dosya(lar) tekrar on-line olarak gönderilmelidir. Makalenin kabul 4.8. Yapısal diyagramlar ve matematiksel denklemler edilmesinden sonra en son yüklenen sürüm baskı için esas alınacak ve çoğaltma sürecine geçilecektir. Molekül yapılarının yanı sıra matematiksel denklemler metin içinde ait oldukları yerde çizilmiş veya yazılmış 6. Makale taslak metni ve baskı olmalıdır. Bunlar daima ayrı bir satırda gösterilmelidir. Bu molekül yapıları veya matematiksel denklemler Baskıdan önce yazarlar makalenin taslak metnini defalarca kullanılmışsa sağ yanda parantez içinde nu- e-posta yoluyla alacaklardır. Taslak metin talimatlar maralandırılır ve diğer kısımlarda bu numaralara atıf çerçevesinde dikkatlice düzeltilmelidir. Yazarlar özel- yapılır. likle yazım hataları ile ilgili uyarılara yanıt vermelidir. BOR Dergisi (Journal of BORON)’ da yayımlanmış Eşitlikler ve Denklemler için mevcut MS Word Equati- olan makalelerin yazarlarına, derginin ilgili sayısından on Editor fonksiyonu kullanılır. Simgeler için Word’de Insert/Symbol fonksiyonunu kullanınız. 2’şer adet gönderilir.

AUTHOR GUIDELINES 2. Categories of scientific contributions

1. Instructions to authors Three categories of scientific contributions are accepted for publication: Journal of BORON is the first and only journal in the Science World, in which original and basic scientific a.) Original research article: It consists of experi- research and application studies related to boron are mental and theoretical work with new results describ- published. Journal of BORON covers all aspects of ing completed studies and should comprise about boron science, boron technology, boron usage, boron 30,000 characters (including spaces). In addition, up chemicals and fields which used boron. The journal to 8 figures or schemes, and 6 tables may be included. focuses on innovative element boron giving interdis- ciplinary insights on a broad range of fields including b.) Short communication: It describes results that are brief, timely and/or of such importance that rapid science, medicine, energy, engineering, agriculture, release is warranted. This manuscript should be in the pharmacy, defense industry, mine industry, chemical range of 18,000 characters (including spaces) and 6 industry and aerospace industry. figures. The journal publishes current technologies, original c.) Review article: It summarizes information pub- methods, applications and all approaches about bo- lished on a certain topic and is not limited to own re- ron. Papers dealing with boron issues from such fields sults. Rather than an assemblage of information with as science, medicine, energy, engineering, agriculture, a complete literature survey, a comprehensive critical pharmacy, defense industry, mine industry, chemical description and selection of the material is indispens- industry and aerospace industry, etc., are welcome. able. This contribution should typically not exceed All scientific contributions are assessed initially by the 45,000 characters (including spaces); up to 15 figures Editor-in-Chief. Those manuscripts failing to reach may be included. the required priority rating, failing to comply with 3. Submission of manuscripts the Instructions to Authors or not fitting within the scope of the journal are not considered further 3.1. General and are returned to authors without detailed com- This journal will be published in an online-only format ments. It should be noted that rebuttals that challenge and printed edition will be published. There will no cost rejections based on priority and/or scope alone will to authors for the publication of manuscripts. All copy- rarely be successful, since such a decision is neces- right of the accepted manuscripts belong to BOREN. sarily a matter of opinion. 3.2. How to submit? Manuscripts meeting the requirements will be peer- reviewed on the criteria of originality and quality. Au- Manuscripts to Journal of BORON have to be submit- thors may suggest up to five potential referees in ted via a web-based manuscript submission and peer- the Cover Letter. Please provide their institutional review system. This service guarantees fast and safe e- mail addresses and a link to the website as well submission of manuscripts and rapid assessment. as individuals whom they wish to exclude from the Submission of manuscripts consists of the following review process. If the decision following review is “re- steps: ject subject to major revision”, a revised version may be submitted, but if major issues with the revised ver- a.) Preparation of the manuscript and illustrations in sion are still identified by the reviewers, it will then be the appropriate format, according to the instructions rejected outright. On acceptance, papers may be sub- given below (see Sections 4.1 to 4.9). The paper has jected to editorial changes. Responsibility for the fac- to conform to the scientific and style instructions of the tual accuracy of a paper rests entirely with the author. Journal of BORON as given herein. A link to these instructions can be found at the submission site at the All instances of publishing misconduct, including, homepage of the journal at http://dergipark.gov.tr/bo- but not limited to, plagiarism, data fabrication, im- ron under the link “For Authors”. age/data manipulation to falsify/enhance results, manipulation of the reviewing process, etc., will b.) For the first submission an author’s account in the result in rejection/retraction of the manuscript. system at the submission site, http://dergipark.gov.tr/ register/ has to be created by clicking on the “Registra- This journal endorses the Higher Education Scientif- tion” button. ic Research and Publication Ethics Guidelines rules and will pursue cases of suspected research and c.) The “Author Guidelines” given on the Journal web- publication misconduct. For more information about site have to be read carefully. The system guides Higher Education Scientific Research and Publica- through the submission process. Online help is avail- tion Ethics visit the Higher Education website at http:// able at all times during the process. Authors are also www.yok.gov.tr/web/guest/icerik//journal_content/56_ able to exit/re-enter at any stage before finally “sub- INSTANCE_rEHF8BIsfYRx/10279/18187 mitting” the work. All submissions are kept strictly confidential. For any questions concerning the on- 80 words. Abbreviations, but not standard abbrevia- line submission program, Editorial Support at fkuru@ tions, must be written in full when first used. Any refer- boren.gov.tr and [email protected] can be ences cited must be given in full. contacted. ii.) “1 Introduction” containing a description of the The author vouches that the work has not been pub- problem under investigation and a brief survey of the lished elsewhere, completely, in part, or in any other existing literature on the subject. form, and that the manuscript has not been submitted to another journal. The submitting author (listed under iii.) “2 Materials and methods” for special materials and equipment, the manufacturer’s name and, if pos- “Correspondence”) accepts the responsibility of hav- sible, the location should be provided. ing included as coauthors all appropriate persons. The submitting author certifies that all coauthors have seen iv.) “3 Results and discussion” the manuscript and agreed with its submission. v.) “4 Conclusions” All scientific contributions will be peer-reviewed and judged on the criteria of originality, quality, vi.) “References” and novelty. Authors may suggest up to five potential referees in the Cover Letter, including their institutional Subdivisions of sections should be indicated by num- e- mail addresses and a link to the website as well as bered subheadings. individuals whom they wish to exclude from the review 4.3. References process. References should be numbered sequentially in A revised paper will retain its original date of receipt the order of citation. The reference numbers within only if it is resubmitted within two months after revi- the text should be set in brackets, thus [3, 14]. They sion. are to be collected in numerical order at the end of the manuscript under the heading “References”. Titles of Please note that if you are submitting material (e.g., journals should be abbreviated according to e.g. http:// figures) which has already been published elsewhere, woodward.library.ubc.ca/research-help/journal-abbre- you must also provide permission in writing that this viations/. material may be reprinted in the Journal of BORON. Please note the following examples: 4. Organization of manuscripts Journals 4.1. Contents of first page of manuscript [1] Şimşek T., Barış M., Synthesis of Co2B nanostruc- 1.) Title of the paper, concise (15 words maximum), tures and their catalytic properties for hydrogen gene- providing the main finding of the paper and, only if ration, BORON, 2 (1), 28-36, 2017. necessary, with standard abbreviations. Books 2.) Full names (including first name) of the authors and their affiliation(s). If the publication originates [2] Grimes R. N., Metal Interactions with Boron Clus- from several institutes, the affiliation of each author ters, 1st edition, Springer Science+Business Media, should be clearly stated by using superscript Arabic New York ,1982. numbers after the name and before the institute. Chapter in a book: 3.) Name (and title) and full postal address, e-mail [3] Gürü M., Çakanyıldırım Ç., “Boron Hydrides, address of the author to whom all correspondence High Potential Hydrogen Storage Materials”, Chap.4: (including galley proofs) is to be sent. Hydrogen Cycle with Sodium Borohydride, Nova Sci- 4.) A list of the nonstandard abbreviations used in ence Publisher Inc., New York, 2010. the paper. Thesis 5.) Up to 5 keywords in alphabetical order which will be used for compiling the subject index. [4] Yalçınkaya Ö., Determination of some trace elements after preconcentration by solid phase extraction 4.2. Sections technique using aluminum oxide/single walled carbon nanotube and zirconium oxide/boron oxide nano ma- Manuscripts should be divided into the following sec- terials, Ph.D. Thesis, Gazi University, Institute of Sci- tions: ence and Technology, Ankara, 2010. i.) “Abstract” It must be self-explanatory and intelligi- Conference and symposium ble without reference to the text. It should not exceed 220 words for research and review articles. Ab- [5] Yılmaz O., Bilen M., Gürü M., Absorption of CO2 stracts for Short Communications should not exceed in boron solutions and recovery as ındustrial chemical products, IV. International Conference on Nuclear and may be marked with Arabic numerals in parentheses Renewable Energy Resources, Antalya, Turkey, 27-29 in the right-hand margin. October, 2014. Use the equation editor of the current MS Word for Please note that: equations. Do not import special symbols and characters as graphics/formula in the running text. Please • Papers with multiple authors should be limited to listing the first seven authors, followed by et al. use in Word Insert/Symbol.

• Papers which accepted for publication should be 4.9. Units and symbols cited with their DOI. The use of SI units is mandatory. Generally accept- • Other serial publications should be cited in the ed nomenclature and symbols as recommended by same manner as journals. ASTM or IUPAC are preferred. In the interest of clar- ity, symbols should be defined in the text. If numer- • Website addresses (URL) must not be included ous symbols are involved, they should be listed and as a reference, but should be inserted in the text defined at the end of the text (before “References”). directly after the data to which they refer 4.10. Abbreviations 4.4. Acknowledgements Acknowledgements as well as information regarding Abbreviations should be restricted to a minimum and funding sources should be provided on a separate be introduced only when repeated use is forthcoming. page and will appear at the end of the text (before Abbreviations used only in a table or a figure may be References). defined in the legend. Standard abbreviations may be used in the title and keywords. If nonstandard abbrevi- 4.5. Conflict of interest ations are used in the Abstract they should be defined All authors must declare financial/commercial con- there, in the list of abbreviations of the manuscript, as flicts of interest. Even if there are none, this should be well as when first used in the body of the paper. stated in a separate paragraph following on from the acknowledgements section as follows: The authors 5. Electronic manuscripts have declared no conflict of interest.This is a man- All submissions will be converted to PDF format during datory requirement for all articles. the upload process. The system automatically gener- 4.6. Tables ates a single PDF file which contains all parts of the manuscript.File management requires the following: Tables with suitable captions at the top and numbered with Arabic numerals should be collected at the end Main text (incl. front material) as well as figure leg- of the text, each table on a separate sheet. Column ends and tables (in this order) should be given in one headings should be kept as brief as possible and in- file, preferably saved in doc, docx or rtf format. dicate units. Footnotes to tables should be indicated with a), b), c), etc. and typed on the same page as the Figures should preferably be in JPG, EPS, TIFF or in table. the original format; no ppt(x) or pdf.

4.7. Figures, diagrams, and legends In revised manuscripts the areas containing the major required changes should be marked and the color of The quality of the figures must be such that they can be reproduced directly after reduction to 80 mm width the text changed. The file(s) with the changes visible and the numbers, letters, and symbols must be large on screen should be re-submitted online. Upon accep- enough to still be legible. All figures must be referred to tance of the manuscript the final uploaded version will in the text and numbered with Arabic numerals in the be taken as the basis for copy editing and the subse- sequence in which they are cited. Each figure must quent production process. be accompanied by a legend explaining the contents of the figure. 6. Proofs and reprints

4.8. Structural diagrams and mathematical equa- Before publication authors will receive page proofs via tions e-mail in PDF low resolution file format, together with a sheet including instructions and a reprint order form, Structures of molecules as well as mathematical equa- also as PDF files. The proofs should be carefully cor- tions should be drawn or written in the manuscript in rected following the instructions. In particular, authors the position where they belong. They should always should answer any editing queries. The author(s) will stand alone, i.e., occupy extra lines. If reference to them is made repeatedly, structures and equations receive two hard copies of the related issues.

ULUSAL BOR ARAŞTIRMA ENSTİTÜSÜ ISSN: 2149-9020 NATIONAL BORON RESEARCH INSTITUTE

BOR DE RGİSİ JOURNAL OF BORON

CİLT/VOL SAYI/ISSUE YIL/YEAR 02 02 20 17 BOR DERGİSİ JOURNAL OF BORON http://dergipark.gov.tr/boron

İÇİNDEKİLER/CONTENTS

Borate deposits: An overview and future forecast with regard to mineral deposits ...... Cahit Helvacı 59

Borojipsin diamonyum hidrojen fosfat çözeltilerinde çözünürlüğünün incelenmesi ...... Havva Mumcu Şimşek, Rövşen Guliyev, Ayşe Vildan Beşe, Hacer İçen 82

In-situ formation of borides and enhancement of powder metallurgy properties ...... Arun K. Chattopadhyay, Mustafa Barış, Tuncay Şimşek, Murat Bilen 97

Alternating current electrophoretic deposition of HA and hBN nanoparticles on Ti substrate ...... Merve Geçgin, Yapıncak Göncü, Nuran Ay 102

Ulusal Bor Araştırma Enstitüsü (BOREN)

Dumlupınar Bulvarı (Eskişehir Yolu 7. km), No:166 Kat:10, 06520, Ankara Tel: (0312) 219 81 50, Faks: (0312) 219 80 55 e-mail: [email protected], web: http://dergipark.gov.tr/boron