ED-2\oo%3&. ' I' ' '' \ //" A,R,C.A,E.E,/Rop,-228 J '/'4 v' v< "'•""? ARAB REPUBLIC OF EGYPT >,* 4 ATOMIC ENERGY .ESTABLISHMENT '- - \,f < ?, i ' '. 'NUCLEAR,CUEM1STBY DEPARTMENT " - .//. / / / I ' t ' - X We regret that some of the pages in the microfiche copy of this report may not be up to the proper legibility standards/even though the best possible copy was used for preparing the master fiche. A.R.E.A.S.E./Rep,- 288 A1AB M3PUBT.TC OF MYPT ATOMTC ENERGY ESTABLISHMENT NUCLEAR CHEMISTRY DEPARTMENT IITGH GRACE MAGNESIUM FROM WASTE BITTERN B7 T.S0*SY.-YAMANI, MoYoPAlAK? » and S0L,ISAAC 1979 SCIENTIFIC INFORMATION DIVISION ATOMIC ENERGY POST OFFICE CAIRO?AoRoEo - i - CONTENTS Page Ani* TRACT ...............o......................««....««».«.<>(>..s. * 1 INTRODUCTION. „ „ o 0 u . u. o. ». ....... 1 EXPERIMENTAL. „.. o 1 RESULTS AND MSCUWON. 2 a) qtudy on physical and Chemical propertiea of the Bitterns.... 2 b) precipitation with Ammonia Solution: 2 Effect of Magnesium Concentrations G £jX I c l* U OI n w*™! l**g •ooou9oot>oo«*o0«ooa0«*«««bot»«aoaostiooooeobo w I4 * *lt" * I'tli o o o o u n o o Q o f> o Q Q o o o o • Q o o a o 9 o o 9 c o o o o o <* o e o o o o o o n a v it • o tj a o O c) precipitation with Gaseous Ammonias.........................« 7 Effect of Magnesium Concentrations..........„„......„.„,....„ 7 Rate of Ammonia Injections.,,.......,............. ..o... o... 7 [/ — UuU CI XU^j6CXflOE&Duoooooao»oo«o«ood*««o**o<»««ooooooooouooooo ' rjeosoetry of the Container:Ooooo0»ooop*o»o»o»oo»c*«ooooooo»oou T oOJftvl'<(^?£w'-to(io<>ooOQcooooac'Ooouoooooo9oooocoo*#«oeoo(t(>oo<>i9oooooor>oni ** A L» K. JN U >V Xj Ju JJ VJ iu ml w W loooooooooeooaooooooooooooooooooooooon *U A D I; lit H K N L U fsooooovoooiiooooooftvooooeodoooooddooaooooeoooooo •* *"- - ii - ABSTRACT \ ( The pr«di*cti«n of high grade »agnesiit for nuclear purposes fr«» sea vater by use of both aqueous and gaseoua wni.onia has been descri­ bed. The effect of precipitating conditions on the settling rate and » u^nc-sium recovery, was thoroughly examined, Aauuonia gas approach -was recou'tuended and justified. INTRODUCTION The demand of magnasiunu anefyhl.or alloy Is steadily irAcrf"&K»Bing owing to ffidcnicg the circle •©# their industrial applications In the Older-H&H and MurcpuXe type rettcio,ro y »agne:uujfc and xife r alloys particularly fcagraox AL 80J uv-gnox A lsP fc'f-2.r *»d M?-Jhfe are used extensively aepclad materials,. Most of the processes woed'to obtain the fl,eiaJ. rely upon magnesia preparation ao imteirmediate otep in magnKeiura production^ Due to the shortage in reserves'of magnesium ores in generalp sxirs- ction of magnesium was mostly^ achieved from sea watair „ Most of ire* approaches reported involved the treatment of eea -"rater or bittern by lime^ "*v'j burnt dolomite ' and electrolysis^ " "*', Liquid- liquid extraction was attempted more recently on laboratory scale " \ Pew informations were patented on magnesium extraction by aqueous aromoniaj ' '. It is the aim of the"'present 'investigation to carry out a systematic economic study on magnesia extraction from saline water by both aqueous and gaseous aaaionia whereby an i&proved method was suggested for production of high grade aa&gneaia0 ' EXPERIMENTAL Bittern samples used were obtained by evaporation of aea water (Ajiexandriaj 4®Be) by> solar energy in huge ponds whereby crystalline sodium chloride is deposited} the mother liquor (waste bittern) which is usually rejected (by draining again to the sea)?ia used as the starting material in this study. Viscosity and density measurements of the bittern saasples were conducted by ©Oittv«n« tional method„ C» was detenoined complexowetricaliy using Murezid® indicator whereas Mg w-as determined either ,co3spleyometricaily wzih Eriochrome Bl&c& T(in absence of C**-) or by difference (in prfiS«?Biffie of O) between Mg + Ca as determined complesoaietrically with Hrioisfarcase a - Black T indicator and ca **« determined with Murexirie indicator, Sulphuton vrd al*?o dettrotinet* coiupleyc-nietrical ly by «c»r 7!<«p1 * '*nd liriochrott'' fUck Tj carbonate*f litrfoetricaMr uHinr neihyl re* indicutor;totttl httlid*p by t'ol'iurd'* method1 , The offee* of pre- cipHutiop condition* WUA checked by chewical unulvHCM. Mapupsiun recovery van determined by taking ivliquntfi cf th'- nlurrjof. before rettling* treating with pel, neutral izinp, vith uu.tioniu then Kitkinft' ap to volume and Biagm'si'Sis IP thru determined (ia an uliqout) couplero»»ctrically »s u>enlion<:d above, ^ettlinfl r&tf wap dete­ rmined by flhul»iri{r the slurry in a stoppered iLeusuring cylinder (f(«5 cm) and noting the level occupied by the aeltiliair precipitate utter various periods, while using a slurry of 300 ai. u) Study on physical and Chemical properties of the Bittern: The variation of density tend viscosity of different bittern samples vit.h the chemical composition of their constituent element*] was esu- tkiT»od by evaporation of the initial bittern, then cooling to rooit tenperuture ( '" 33°C)| results are represented in Table(l). it is evident that increasing the bittern density enhances n.arlieclly both the viscosity »nd tho total hnlides content while iuhibit* the sulphates, carbonates> calcium and alkali &eta.l*. Tt is worthy c-etiticninr that higher vi?cof»iticp ( ". « centipoiees) are not beneficially uned due to ("•conondc reasons, eptiaoE' B-agnefiuui recovery i« achieved at about 370Be' whereby the niajority of impurities are discarded. b) precipitation with Am&onia Solution: The influence of various precipitating conditions on both the nettling rate (-vhich is used an a criterion for the effectivenepp of filterability) and odt^neniuio recovery, in piven below; the concentration of ABBonit solution used was 24 voliuse % and data are presented in Table (>>). «" 3 " Table (l) The variation of Tjenuity and viscosity of Bittern Samples vith their Chemical Composition, density Viscosity Mg++ Ca++ SO. Total co P Alkali 4£ a °Pe' (Centipo­ (M) (M) (M) Halides 00 Metals ises) (M) (M) 24.2 1,3 1.23 1.20 0,30 6.7 0.02 5.10 W.l 1.5 1,61 0.60 n034 6.0 0.04 4,50 28,1 2,0 1.73 0o04 0„35 5c2 0.09 3,00 29 <. 2 2.5 2„06 o.oi 0o46 5*3 0„l4 2»53 31,7 2.8 2.55 m 0o44 5.6 0,19 1.80 33.o 3,2 2.08 ~ 0.29 8.2 0.21 1,60 34,3 3.8 3.09 - 0,2ft 8o4 n.nl o.m 35,0 3.2 3.*3 - 0*26 P„5 „ «v0» 36.8 5.8 3.91 - 0.25 8.8 - „ 37,9 3.9 4.73 ~ 0.05 io„i - - 38 A 6.5 •5.U - - 10.1 - „ • 39 Complete Crystal liLaatio n - 4 - Table (2) precipitating Conditions of Magnesium Hydroxide vith AamtOQia. Solutions iig Concn. Temp, nate of Stirring y'inal Settling Mg (g/l) ,c Addit xon f^ate ftate *}ecovory (cai3/»in.) (r„p.m„) pH (cro/oiin.) (#) 11.5 0.25 95.0 23 0.17 95.2 34.5 27 25 1000 10.4 0.10 95.6 56.5 0.02 96.0 69.0 0.01 96.2 90 0,01 96.8 26 0.27 96.0 40 0.30 96.5 11.5 55 20 500 10.0 0.48 97.0 70 0.61 97.5 10.2 0.24 45.0 15 0.26 45.7 45 of\ 20 250 S.9 0.28 45.7 25 o„u 45.9 60 0.0R 46.0 immediately 0.06 46.5 100 0.2 96.5 250 2.4 96.2 11.5 26 20 500 10.0 2.7 96.3 750 2.4 96.5 1000 1.9 96.2 - s -- Con. Table (2) Mg Concn. Temp. Rate of gtirring Final Settling Mg, 1 (g/ ) er, Addition Rate . pH Rate Recorei-y (cm /rain.) , (r.p.aa.) (cnj/min.) -(#) 8.7 0.04 81.1 8.9 0.25 45.1 Ho5 26 20 500 9.1 0.30 60,2 9,7 0.32 87,5 9.9 0,45 93.4 10 „o 0,36 97,0 "ttss^^asataSaaasssBaaassnssai^aaasasastfsssasasasaastSGesstes^ass G Effect of Magnesium Concentration: Settling rate and recovery- of magnesium *»» examined as a function ot magnesium concentration in the bittern (11.5-90 g/l Mg)j aamplea uaed were obtained from concentrated bittern (37'B«') by appropriate dilutions with aea water (4*Be'). T* *• revealed that for higher eon- contrationa ( \.90 g/l Mg)» the precipitate ia ao compact and bed does not settle. Optimal data are developed arouad 11.5 g/l magaeaium whereoy good settling rates are obtained. Temperature: The increase of temperature of precipitation, raises appreciably the settling rate and slightly, magnesium recovery. The ambient tem­ perature ( ^ 25*) is advised to be used. pate of Addition: Insignificant influence of the rate of ammonia addition on magnesium recovery, ia observed. Settling rate -was shown to be improved markedly with riae of addition rate upto about 20 cm /mia. then decreaaea aharply afterwards. Optimum values are hence achieved at about 20 «•> /min. Effect of Stirrings Although recovery remains nearly unaffected with riae of the stirring speed, the aettling rate is considerably improved with agita­ tion upto about 500 r.p.m. then decreaaea gradually afterwards. Moderate stirring ia hence required for attaining beat results. Final pHj Increase in pH leads to a pronounced riae in recovery and gives also a marked improvement in settling rate. Recovery was raised by more than 3-fold while settling rate by 9-fold, wiAh increase of pH from 8.7 to 10.