DOCSLIB.ORG

Phase Relations in the Systems Titania and Titania--Boric Oxide

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Phase Relations in the Systems Titania and Titania--Boric Oxide This dissertation has been 65—9337 microfilmed exactly as received BEARD, William Clarence, 1934- PHASE RELATIONS IN THE SYSTEMS TITANIA AND TITANIA— BORIC OXIDE. The Ohio State University, Ph.D., 1965 M in eralogy University Microfilms, Inc., Ann Arbor, Michigan PHASE RELATIONS IN THE SYSTEMS TITANIA AND TITANIA—BORIC OXIDE DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of the Ohio State University by William Clarence Beard, B. S. The Ohio State University 1965 Approved by n Adviser Department of Mineralogy ACKNOWLEDGMENTS The author wishes to thank the people who have contributed to the preparation of this dissertation. First, to his adviser, Dr. Wilfrid Raymond Foster, for advice and suggestion of the problem; and second to other members of the faculty of the Department of Mineralogy, Drs. Henry Edward Wenden, Ernest George Ehlers, and Rodney Tampa Tettenhorst, for discussions of the problem and the reading of this dissertation, the author extends his thanks. Thanks also go to his colleague, William Charles Butterman, for assistance in the construction and main­ tenance of many pieces of experimental apparatus. Acknowledgment is made for financial support received under contract No. AF 33(616)-6509 (twenty-four months), spon­ sored by Aeronautical Research Division, Wright-Patterson Air Force Base, Ohio, as well as for a Mershon National Graduate Fellowship awarded (1962-63) by the Mershon Committee on Education in National Security; and a William J. McCaughey Fellowship (1963-64). The author is indebted to his wife, Ursula, for her constant help and encouragement. ii VITA. June 9, 1934 Born - G allipolis, Ohio 195 2-1956. United States Air Force 1960 .... B. S. , The Ohio State University, Columbus, Ohio 1960-1961. Teaching Assistant, Department of Geology, The Ohio State University, Columbus, Ohio 1961-1964. Research Assistant, Department of Mineralogy, The Ohio State University, Columbus, Ohio 196 2-1963. Mershon National Graduate Fellow FIELDS OF STUDY Major Fieid: Mineralogy Thermochemical Mineralogy, Advanced Thermochemical Mineralogy. Professor Wilfrid R. Foster Advanced Crystallography, X-ray Crystallography, Crystallochemical Mineralogy, Descriptive Mineralogy. Professor Henry E. Wenden Microscopic Mineralogy, Microscopic Petrography, Advanced Optical Mineralogy, Crystallography. Professor Ernest G. Ehlers Clay Mineralogy. Professor Rodney T. Tettenhorst CONTENTS Page I. INTRODUCTION . .............................................................................1 II. THE SYSTEM TITANIA.......................................................................3 A. Introduction ............................................................... 3 B. Literature Survey ...................................................................4 1. Natural occurrences .................................. 4 2. Rutile s y n th e s e s ..........................................7 3. Anatase syntheses .................. 14 4. Brookite syntheses .....................................15 5. Amorphous Ti0 2 s y n th e s e s ......................18 6. Polymorphic transformations .................. 19 7. Summary ............................................. 27 C. Experimental .........................................................................27 1. Grinding experiments .................................29 2. Heating of Ti02............................................31 3. Heating of titanium sulfate ..................31 4. Titanium-halide experiments ..................32 5. Flux runs .......................................................33 6 . Hydrothermal bomb ru n s ......................... 34 7. Parallel firing runs .................................... 35 8 . Strip furnace experiments ......................... 37 9. Titania-enamel experiments ..................41 10. Plasma-arc flame spraying . 43 experiment D. Discussion of Literature and Experiments .... 43 1. Possible phase diagrams for Ti02 . 43 2. Discussion of pertinent data .................. 50 3. Selection of a probable diagram . 53 E. Suggested Future W ork..................................................58 iv CONTENTS - Continued Page III. THE SYSTEM T i0 2-B20 3 ................................................................. 59 A. Introduction .........................................................................59 B. Literature Survey ......................................................... 60 C. Experimental .....................................................................62 1. Procedure ............................................62 2. Experimental ru n s .............................. 75 D. Discussion of Experimental Results ......................... 88 1. Liquid immiscibility .....................................88 2. Phase relations of Ti0 2-B20 3...................... 95 IV. SUMMARY . 99 REFERENCES........................................................................................................100 v TABLES Table Page 1. Reported Temperatures for the Anatase-Rutile Transition ............................. 23 2. Reported Temperatures for the Brookite-Rutile Transition. ...................................................... 25 3. Data from Grinding Experiments ............................................. 30 4. Heating of TiOz (Anatase) ........................................................ 31 5. Heating of Titanium Sulfate ..................................................... 32 6. Flux Runs with Anatase and R utile ...................................... 34 7. Hydrothermal Bomb Runs ............................................................ 36 8 . Parallel Firings of Anatase and Rutile with B £>3 .... 37 9. Strip Furnace Platinum Tube Heating Experiments . 38 10. Strip Furnace Heating Experiments ....................................... 40 11. Titania-Enamel Firing Experiments ........................................ 42 12. Bursting Pressure Data for Platinum Tubing ......................... 7 0 13. Preliminary Firings: Pressed Disks ..................................... 76 14. Preliminary Firings: Crucible Runs ..................................... 78 15. Preliminary Firings: Platinum Envelopes .......................... 80 16. Sealed Capsule Firing Runs ..................................... 84 17. Prediction of Liquid Immiscibility ......................................... 93 vi ILLUSTRATIONS Figure Page 1. Graphic Summary of Ti0 2 S y n th ese s ................................... 28 2. Possible Phase Diagrams: One Stable, Two Meta stable Phases .................................................................... 45 3. Possible Phase Diagrams: One Stable, Two Metastable Phases . ..................................................... 46 4. Possible Phase Diagrams: Two Stable, One Metastable Phase ......................................................... 47 5. Possible Phase Diagrams: Three Stable Phases . 48 6. Proposed Phase Diagram for Ti02 ........................................ 55 7. Metastable Precipitation of High-Temperature Phases from Solution ................................................................................ 57 8 . Apparatus for Producing Anhydrous B^D 3............................ 64 9. Heat-Sink Blocks for Welding Platinum Capsules . 66 10. P-T Plots for Various Amounts of W ater ......................... 69 11. Electron Micrograph of B20 3 G l a s s .................................... 89 12. Electron Micrograph of T i02-B 20 3 G la ss............................. 90 13. Electron Micrograph of T i02-B 20 3 G la s s............................. 91 14. Prediction of Liquid Immiscibility ........................................ 94 15. Tentative Phase Diagram Ti02-B20 3 ..................................... 96 16. Tentative Phase Diagram Ti02-B20 3 . ...................... 97 vii I. INTRODUCTION The purpose of this investigation is to determine the high temperature phase relations existing between titanium dioxide and boric oxide at one atmosphere. The polymorphism of titanium dioxide is presented in terms of the pressure-temperature relations which best explain the diverse behavior of titanium dioxide modifications reported in the literature. Mineralogically, titanium ranks ninth in atomic abundance in the igneous rocks of the upper lithosphere. It is nearly always present in the analyses of hgneous rocks, although it does not occur in any great concentration. Titanium is present in the minerals rutile, ilmenite, perovskite, sphene, arizonite, geikielite and pyrophanite of which the first four are the most important sources. Besides rutile, the oxide Ti0 2 also occurs as the minerals anatase and brookite. Boron occurs less abundantly than titanium. However, it does appear in many silicates, e. g. , tourmaline, datolite and danburite, as well as the borates themselves: boracite, borax, kernite, ulexite, and colemanite. 1 Technologically, both titanium dioxide and boric oxide are important. Titania is used as a stain for ceramic bodies and glazes; as a constituent in welding rod coatings; as a nucleating agent in glass-ceramics; in glass and porcelain enamels; in self- opacifying enamels; and in glass compositions partly for its high refractive index. Because of its high index, titania is the strongest white pigment known, and therefore is used as a paint pigment as well as in enamels. In the electronics industry, titania is used to make capa­ citors and piezoelectric porcelain bodies. Slightly reduced single crystals of rutile, produced by the
Load more

Recommended publications
  • 19660017397.Pdf
    .. & METEORITIC RUTILE Peter R. Buseck Departments of Geology and Chemistry Arizona State University Tempe, Arizona Klaus Keil Space Sciences Division National Aeronautics and Space Administration Ames Research Center Mof fett Field, California r ABSTRACT Rutile has not been widely recognized as a meteoritic constituent. show, Recent microscopic and electron microprobe studies however, that Ti02 . is a reasonably widespread phase, albeit in minor amounts. X-ray diffraction studies confirm the Ti02 to be rutile. It was observed in the following meteorites - Allegan, Bondoc, Estherville, Farmington, and Vaca Muerta, The rutile is associated primarily with ilmenite and chromite, in some cases as exsolution lamellae. Accepted for publication by American Mineralogist . Rutile, as a meteoritic phase, is not widely known. In their sunanary . of meteorite mineralogy neither Mason (1962) nor Ramdohr (1963) report rutile as a mineral occurring in meteorites, although Ramdohr did describe a similar phase from the Faxmington meteorite in his list of "unidentified minerals," He suggested (correctly) that his "mineral D" dght be rutile. He also ob- served it in several mesosiderites. The mineral was recently mentioned to occur in Vaca Huerta (Fleischer, et al., 1965) and in Odessa (El Goresy, 1965). We have found rutile in the meteorites Allegan, Bondoc, Estherville, Farming- ton, and Vaca Muerta; although nowhere an abundant phase, it appears to be rather widespread. Of the several meteorites in which it was observed, rutile is the most abundant in the Farmington L-group chondrite. There it occurs in fine lamellae in ilmenite. The ilmenite is only sparsely distributed within the . meteorite although wherever it does occur it is in moderately large clusters - up to 0.5 mn in diameter - and it then is usually associated with chromite as well as rutile (Buseck, et al., 1965), Optically, the rutile has a faintly bluish tinge when viewed in reflected, plane-polarized light with immersion objectives.
    [Show full text]
  • Washington State Minerals Checklist
    Division of Geology and Earth Resources MS 47007; Olympia, WA 98504-7007 Washington State 360-902-1450; 360-902-1785 fax E-mail: [email protected] Website: http://www.dnr.wa.gov/geology Minerals Checklist Note: Mineral names in parentheses are the preferred species names. Compiled by Raymond Lasmanis o Acanthite o Arsenopalladinite o Bustamite o Clinohumite o Enstatite o Harmotome o Actinolite o Arsenopyrite o Bytownite o Clinoptilolite o Epidesmine (Stilbite) o Hastingsite o Adularia o Arsenosulvanite (Plagioclase) o Clinozoisite o Epidote o Hausmannite (Orthoclase) o Arsenpolybasite o Cairngorm (Quartz) o Cobaltite o Epistilbite o Hedenbergite o Aegirine o Astrophyllite o Calamine o Cochromite o Epsomite o Hedleyite o Aenigmatite o Atacamite (Hemimorphite) o Coffinite o Erionite o Hematite o Aeschynite o Atokite o Calaverite o Columbite o Erythrite o Hemimorphite o Agardite-Y o Augite o Calciohilairite (Ferrocolumbite) o Euchroite o Hercynite o Agate (Quartz) o Aurostibite o Calcite, see also o Conichalcite o Euxenite o Hessite o Aguilarite o Austinite Manganocalcite o Connellite o Euxenite-Y o Heulandite o Aktashite o Onyx o Copiapite o o Autunite o Fairchildite Hexahydrite o Alabandite o Caledonite o Copper o o Awaruite o Famatinite Hibschite o Albite o Cancrinite o Copper-zinc o o Axinite group o Fayalite Hillebrandite o Algodonite o Carnelian (Quartz) o Coquandite o o Azurite o Feldspar group Hisingerite o Allanite o Cassiterite o Cordierite o o Barite o Ferberite Hongshiite o Allanite-Ce o Catapleiite o Corrensite o o Bastnäsite
    [Show full text]
  • Mineral to Metal: Processing of Titaniferous Ore to Synthetic Rutile (Tio2) and Ti Metal
    Mineral to Metal: Processing of Titaniferous Ore to Synthetic Rutile (TiO2) and Ti metal Dr Jeya Ephraim, Mineral to Metal May 11 – 13, 2015 * Hilton Birmingham Metropole Hotel * Birmingham, United Kingdom Objective To produce ultra pure high grade synthetic rutile (TiO2) from ilmenite ore and Ti metal from anatase or rutile Dr Jeya Ephraim, Mineral to Metal May 11 – 13, 2015 * Hilton Birmingham Metropole Hotel * Birmingham, United Kingdom Outline 1. Introduction 2. Why titaniferous minerals? 3. Processing Methods for synthetic rutile (TiO2) (i) Alkali Roasting (ii) Reduction followed by leaching 5. Results and discussion 6. Commercialisation 7. Conclusion 8. Bradford Metallurgy on Ti metal powder production 9. Future Plans Dr Jeya Ephraim, Mineral to Metal May 11 – 13, 2015 * Hilton Birmingham Metropole Hotel * Birmingham, United Kingdom Introduction • Titanium always exist as bonded to other elements in nature. • It is the ninth-most abundant element in the Earth. • It is widely distributed and occurs primarily in the minerals such as anatase, brookite, ilmenite, perovskite, rutile and titanite (sphene). • Among these minerals, only rutile and ilmenite have economic importance Dr Jeya Ephraim, Mineral to Metal May 11 – 13, 2015 * Hilton Birmingham Metropole Hotel * Birmingham, United Kingdom Ilmenite deposit in Chavara, Kerala, India Dr Jeya Ephraim, Mineral to Metal May 11 – 13, 2015 * Hilton Birmingham Metropole Hotel * Birmingham, United Kingdom Applications of TiO2 • White powder pigment - brightness and very high refractive index - Sunscreens use TiO2 - high refractive index - protect the skin from UV light. • TiO2 – photocatalysts - electrolytic splitting of water into hydrogen and oxygen, - produce electricity in nanoparticle form -light-emitting diodes, etc.
    [Show full text]
  • Occurrence, Alteration Patterns and Compositional Variation of Perovskite in Kimberlites
    975 The Canadian Mineralogist Vol. 38, pp. 975-994 (2000) OCCURRENCE, ALTERATION PATTERNS AND COMPOSITIONAL VARIATION OF PEROVSKITE IN KIMBERLITES ANTON R. CHAKHMOURADIAN§ AND ROGER H. MITCHELL Department of Geology, Lakehead University, 955 Oliver Road, Thunder Bay, Ontario P7B 5E1, Canada ABSTRACT The present work summarizes a detailed investigation of perovskite from a representative collection of kimberlites, including samples from over forty localities worldwide. The most common modes of occurrence of perovskite in archetypal kimberlites are discrete crystals set in a serpentine–calcite mesostasis, and reaction-induced rims on earlier-crystallized oxide minerals (typically ferroan geikielite or magnesian ilmenite). Perovskite precipitates later than macrocrystal spinel (aluminous magnesian chromite), and nearly simultaneously with “reaction” Fe-rich spinel (sensu stricto), and groundmass spinels belonging to the magnesian ulvöspinel – magnetite series. In most cases, perovskite crystallization ceases prior to the resorption of groundmass spinels and formation of the atoll rim. During the final evolutionary stages, perovskite commonly becomes unstable and reacts with a CO2- rich fluid. Alteration of perovskite in kimberlites involves resorption, cation leaching and replacement by late-stage minerals, typically TiO2, ilmenite, titanite and calcite. Replacement reactions are believed to take place at temperatures below 350°C, 2+ P < 2 kbar, and over a wide range of a(Mg ) values. Perovskite from kimberlites approaches the ideal formula CaTiO3, and normally contains less than 7 mol.% of other end-members, primarily lueshite (NaNbO3), loparite (Na0.5Ce0.5TiO3), and CeFeO3. Evolutionary trends exhibited by perovskite from most localities are relatively insignificant and typically involve a decrease in REE and Th contents toward the rim (normal pattern of zonation).
    [Show full text]
  • Petyayan-Vara Rare-Earth Carbonatites (Vuoriyarvi Massif, Russia)
    geosciences Article Ti-Nb Mineralization of Late Carbonatites and Role of Fluids in Its Formation: Petyayan-Vara Rare-Earth Carbonatites (Vuoriyarvi Massif, Russia) Evgeniy Kozlov 1,* ID , Ekaterina Fomina 1, Mikhail Sidorov 1 and Vladimir Shilovskikh 2 ID 1 Geological Institute, Kola Science Centre, Russian Academy of Sciences, 14, Fersmana Street, 184209 Apatity, Russia; [email protected] (E.F.); [email protected] (M.S.) 2 Resource center for Geo-Environmental Research and Modeling (GEOMODEL), St. Petersburg State University, 1, Ulyanovskaya Street, 198504 Saint Petersburg, Russia; [email protected] * Correspondence: [email protected]; Tel.: +7-953-758-7632 Received: 6 July 2018; Accepted: 25 July 2018; Published: 28 July 2018 Abstract: This article is devoted to the geology of titanium-rich varieties of the Petyayan-Vara rare-earth dolomitic carbonatites in Vuoriyarvi, Northwest Russia. Analogues of these varieties are present in many carbonatite complexes. The aim of this study was to investigate the behavior of high field strength elements during the late stages of carbonatite formation. We conducted a multilateral study of titanium- and niobium-bearing minerals, including a petrographic study, Raman spectroscopy, microprobe determination of chemical composition, and electron backscatter diffraction. Three TiO2-polymorphs (anatase, brookite and rutile) and three pyrochlore group members (hydroxycalcio-, fluorcalcio-, and kenoplumbopyrochlore) were found to coexist in the studied rocks. The formation of these minerals occurred in several stages. First, Nb-poor Ti-oxides were formed in the fluid-permeable zones. The overprinting of this assemblage by residual fluids led to the generation of Nb-rich brookite (the main niobium concentrator in the Petyayan-Vara) and minerals of the pyrochlore group.
    [Show full text]
  • Metal Oxide Compact Electron Transport Layer Modification For
    materials Review Metal Oxide Compact Electron Transport Layer Modification for Efficient and Stable Perovskite Solar Cells Md. Shahiduzzaman 1,* , Shoko Fukaya 2, Ersan Y. Muslih 3, Liangle Wang 2 , Masahiro Nakano 3, Md. Akhtaruzzaman 4, Makoto Karakawa 1,2,3, Kohshin Takahashi 3, Jean-Michel Nunzi 1,5 and Tetsuya Taima 1,2,3,* 1 Nanomaterials Research Institute, Kanazawa University, Kakuma, Kanazawa 920-1192, Japan; karakawa@staff.kanazawa-u.ac.jp (M.K.); [email protected] (J.-M.N.) 2 Graduate School of Frontier Science Initiative, Kanazawa University, Kakuma, Kanazawa 920-1192, Japan; [email protected] (S.F.); [email protected] (L.W.) 3 Graduate School of Natural Science and Technology, Kanazawa University, Kakuma, Kanazawa 920-1192, Japan; [email protected] (E.Y.M.); [email protected] (M.N.); [email protected] (K.T.) 4 Solar Energy Research Institute, The National University of Malaysia, Bangi 43600, Malaysia; [email protected] 5 Department of Physics, Engineering Physics and Astronomy, Queens University, Kingston, ON K7L-3N6, Canada * Correspondence: [email protected] (M.S.); [email protected] (T.T.); Tel.: +81-76-234-4937 (M.S.) Received: 14 April 2020; Accepted: 9 May 2020; Published: 11 May 2020 Abstract: Perovskite solar cells (PSCs) have appeared as a promising design for next-generation thin-film photovoltaics because of their cost-efficient fabrication processes and excellent optoelectronic properties. However, PSCs containing a metal oxide compact layer (CL) suffer from poor long-term stability and performance. The quality of the underlying substrate strongly influences the growth of the perovskite layer.
    [Show full text]
  • Band Gaps of Brookite, Rutile and Anatase
    Optical Analysis of Titania: Band Gaps of Brookite, Rutile and Anatase Ryan Lance Advisor: Dr. Janet Tate A thesis presented in the partial fulfillment of the requirements for the degree of Bachelors of Physics Department of Physics Oregon State University May 5, 2018 Contents 1 Introduction 2 2 Optical Phenomena of Thin Films 3 2.1 The Index of Refraction . 3 2.2 Absorption . 4 2.3 The Band Gap . 5 3 Methods 6 3.1 The Grating Spectrometer . 6 3.2 SCOUT for Optical Modeling . 9 4 Results and Discussion 12 4.1 Band Gap Dependence on Thickness . 14 5 Conclusion 15 6 Appendix 16 6.1 Grating spectrometer settings . 16 6.2 Filtering 2nd Order Light . 16 6.3 Band gap of the substrate . 17 7 Using SCOUT 17 7.1 User configurations . 17 7.2 The Layer Stack . 18 7.3 Materials . 18 8 Acknowledgments 18 1 List of Figures 1 Indirect and direct band gaps . 5 2 The grating spectrometer. 7 3 TiO2 Raw Film Spectra . 7 4 Transmission, reflection, and corrected transmission spectra. 8 5 High-energy region of raw spectra . 9 6 Screenshot of the SCOUT interface . 10 7 Refractive index model constructed in SCOUT. 11 8 Density of states in the OJL band gap model. 11 9 High-fraction brookite film on SiO2 ....................... 12 10 High-fraction anatase film on SiO2 ....................... 13 11 High-fraction rutile film on SiO2 ........................ 13 12 Gap energy vs. Thickness for many polyphase TiO2 films. The phase plots (Rutile, Brookite, Anatase) show how much of each phase is present in each film.
    [Show full text]
  • The Propertiesof Anatase Pseudomorphs After
    Canadian Mineralogist Vol. 27, pp. 495-498 (1989) THE PROPERTIES OF ANATASE PSEUDOMORPHS AFTER TITANITE ERIC R. VANCE* AND DIANE C. DOERN Atomic Energy of Canada Limited, Whiteshell Nuclear Establishment, Pinawa, Manitoba ROE lLO ABSTRACT The object of the present work was to investigate whether a Ti-rich surface layer tends to protect the Two polycrystalline natural anatase pseudomorphs after titanite against further alteration. This information titanite were studied by scanning electron microscopy, X- is of interest in connection with both the rates of for- ray diffraction and differential thermal and thermogravi- mation of an anatase pseudomorph after titanite, and metric analyses. Millimeter-sized natural crystals of titanite, the long-term leaching of titanite glass-ceramics leached for 30 days in 0.3 or I mol/L HCI in water at (Hayward & Cecchetto 1982, Hayward 1986) 100°C, produced relatively porous pseudomorphs, many of which contain siliceous material and rutile in addition designed for the immobilization of radioactive waste. to anatase. The Ti-rich layer produced in titanite leached in near- neutral ~edia at -90°C is only a few micrometers Keywords: anatase, titanite, pseudomorphs, leaching. thick, even after several months of leaching in the laboratory (Vance 1987). A thicker layer would facili- SOMMAIRE tate the study of protection against leaching, so that anatase pseudomorphs after both natural titanite and Deux echantillons polycristallins d'anatase naturel pro- titanite crystals leached in HCI solutions were exa- duit par Ie remplacement de titanite ont ete etudies en uti- mined. lisant la microscopie electronique a balayage, la diffrac- tion X et des analyses differentielles thermique et thermogravimetrique.
    [Show full text]
  • C:\Documents and Settings\Alan Smithee\My Documents\MOTM
    L`x1//6Lhmdq`knesgdLnmsg9Aqnnjhsd This month marks several firsts: our first mineral from an Alpine-cleft deposit, our first from Pakistan, and the first time we’ve seen so many excellent crystals of this rare mineral! OGXRHB@K OQNODQSHDR Chemistry: TiO2 Titanium Dioxide, often containing iron Class: Oxides Subclass: Simple Oxides Group: Brookite Crystal System: Orthorhombic Crystal Habits: Tabular to platy, thin in one direction; sometimes sheet-like, with pseudo-hexagonal cross- sections, parallel striations, and small, brilliant termination faces. Less commonly as black, opaque, six-sided bipyramids (variety arkansite). Twinning rare. Crystals usually less than one-quarter inch in size. Color: Brown, yellow-brown, amber, orange, and reddish-brown. Luster: Submetallic to adamantine Transparency: Transparent to translucent and opaque Streak: Yellowish-white Cleavage: Poor in one direction Fracture: Subconchoidal, brittle Hardness: 5.5-6.0 Specific Gravity: 4.10-4.14 Luminescence: None Refractive Index: 2.583-2.705 Figure 1. Brookite crystal Distinctive Features and Tests: Submetallic luster, relatively high density, reddish-brown color, frequent association with rutile, anatase [both polymorphs of titanium dioxide, TiO2], and quartz [silicon dioxide, SiO2] in alpine-cleft-type deposits. Dana Classification Number: 4.4.5.1 M @L D The name of this month’s mineral is pronounced just as it is spelled—BROOK-ite, and is named after the English crystallographer and mineralogist Henry James Brook (1771-1857). Brookite is also known as “arkansite,” “eumanite,” “jurinite,” “pyromelane,” “acid titanium,” “ortho-rutile,” and “ortho-titanium.” European mineralogists refer to brookite as “brookita” and “brookit.” BNL ONRHSHNM Titanium and oxygen combine to form three distinct minerals, and possible a fourth, as we will see.
    [Show full text]
  • Minerals Found in Michigan Listed by County
    Michigan Minerals Listed by Mineral Name Based on MI DEQ GSD Bulletin 6 “Mineralogy of Michigan” Actinolite, Dickinson, Gogebic, Gratiot, and Anthonyite, Houghton County Marquette counties Anthophyllite, Dickinson, and Marquette counties Aegirinaugite, Marquette County Antigorite, Dickinson, and Marquette counties Aegirine, Marquette County Apatite, Baraga, Dickinson, Houghton, Iron, Albite, Dickinson, Gratiot, Houghton, Keweenaw, Kalkaska, Keweenaw, Marquette, and Monroe and Marquette counties counties Algodonite, Baraga, Houghton, Keweenaw, and Aphrosiderite, Gogebic, Iron, and Marquette Ontonagon counties counties Allanite, Gogebic, Iron, and Marquette counties Apophyllite, Houghton, and Keweenaw counties Almandite, Dickinson, Keweenaw, and Marquette Aragonite, Gogebic, Iron, Jackson, Marquette, and counties Monroe counties Alunite, Iron County Arsenopyrite, Marquette, and Menominee counties Analcite, Houghton, Keweenaw, and Ontonagon counties Atacamite, Houghton, Keweenaw, and Ontonagon counties Anatase, Gratiot, Houghton, Keweenaw, Marquette, and Ontonagon counties Augite, Dickinson, Genesee, Gratiot, Houghton, Iron, Keweenaw, Marquette, and Ontonagon counties Andalusite, Iron, and Marquette counties Awarurite, Marquette County Andesine, Keweenaw County Axinite, Gogebic, and Marquette counties Andradite, Dickinson County Azurite, Dickinson, Keweenaw, Marquette, and Anglesite, Marquette County Ontonagon counties Anhydrite, Bay, Berrien, Gratiot, Houghton, Babingtonite, Keweenaw County Isabella, Kalamazoo, Kent, Keweenaw, Macomb, Manistee,
    [Show full text]
  • Tunable Composition Aqueous-Synthesized Mixed-Phase
    catalysts Article Tunable Composition Aqueous-Synthesized Mixed-Phase TiO2 Nanocrystals for Photo-Assisted Water Decontamination: Comparison of Anatase, Brookite and Rutile Photocatalysts Konstantina Chalastara 1 , Fuqiang Guo 1, Samir Elouatik 2 and George P. Demopoulos 1,* 1 Materials Engineering, McGill University, Montreal, QC H3A 0C5, Canada; [email protected] (K.C.); [email protected] (F.G.) 2 Département de chimie, Université de Montréal, Montreal, QC H3T 2B1, Canada; [email protected] * Correspondence: [email protected]; Tel.: +514-398-2046 Received: 31 December 2019; Accepted: 7 April 2020; Published: 8 April 2020 Abstract: Mixed-phase nanoTiO2 materials attract a lot of attention as advanced photocatalysts for + water decontamination due to their intrinsic structure that allows better photo-excited e−cb-h vb charge separation, hence improved photocatalytic efficiency. Currently, the best-known mixed-phase TiO2 photocatalyst is P25 with approximate composition 80% Anatase/20% Rutile (A/r). Apart from Anatase (A) and Rutile (R) phases, there is Brookite (B) which has been evaluated less as photocatalyst in mixed-phase nanoTiO2 systems. In this work we present a sustainable solution process to synthesize tunable composition mixed-phase nanotitania photocatalysts in a continuously stirred tank reactor (CSTR) by modulating conditions like pH, CTiCl4 and time. In particular three mixed-phase TiO2 nanomaterials were produced, namely one predominantly anatase with brookite as minor component (A/b), one predominantly brookite with minor component rutile (B/r), and one predominantly rutile with minor component brookite (R/b) and evaluated as photocatalysts in the degradation of methyl orange. The three semiconducting nanomaterials were characterized by XRD and Raman spectroscopy to quantify the phase ratios and subjected to nano-morphological characterization by FE-SEM and TEM/HR-TEM.
    [Show full text]
  • 1 the Effect of Crystalline Phase (Anatase, Brookite and Rutile) And
    The effect of crystalline phase (anatase, brookite and rutile) and size on the photocatalytic activity of calcined polymorphic titanium dioxide (TiO2) Norman S. Allena*, Noredine Mahdjoubd, Vladimir Vishnyakovb, Peter J. Kellyb and Roelof J. Kriekc aChemistry and Environmental Sciences Department bSurface Engineering Group Faculty of Science and Engineering, The Manchester Metropolitan University Chester Street, Manchester M1 5GD, UK c Electrochemistry for Energy & Environment Group, Research Focus Area: Chemical Resource Beneficiation (CRB), North-West University, Private Bag X6001, Potchefstroom 2520, South Africa dCRECHE, Center for Research in Environmental Coastal Hydrological Engineering School of Engineering, University of KwazuluNatal, Durban, South-Africa *Corresponding Author: Norman S. Allen: [email protected] *Contact Authors; E-mail: [email protected]; [email protected] __________________________________________________________________________________ Abstract The effect of thermal treatment on the morphology (crystalline phase and size) and photocatalytic activity of freshly prepared TiO2 nano-powder is communicated. TiO2 nano-powders, prepared by hydrolyzing titanium tetraisopropoxide at room temperature, were all dried at 382 K and subsequently calcined at different temperatures, for one hour, up to 1172 K. Raman analysis of each thermally treated sample exhibited different titania phase structures. Up to 772 K a mixture of brookite and anatase phases was observed, while a mixture of all three phases, i.e.
    [Show full text]