Document 154kED8ZDJVqKVp4BxwbZrdna

WsgigiSimm-Wmmms . fICuA i'NTER-Omce Let t er Cleveland- . Dr J , Huso . Research Center Auxiliaries . suaiccr n*cra*eo RECEIVED APR 221962 deducts April-19, 1963 Lithopone Germany At w conference March 28 you showed as (and then took back with fan) & memo concerning lithopone production in Germany by Saehtleben A*<2 I belie-ve there waa the possibility of the exsteage of information between this company and oars* Tou-suggested, 1 believe, that X should give seas considersties to how Saehtleben sight be asking high strength lithopone* A 161* page book entitled, "Lithopone*, by Dr. Erich A* Becker, ms published in 1957 by the Berliner Onion GAS of Stuttgert, Germssy. It contains what appears to be a detailed description of current practices in Genas lithopone aaaufaetore* It' might be a good idea for us to psreheae this book. I bam in front of as,; now, - a copy which belongs to John Crarar library'and I sea. that the technology used by Saehtleban is quite different from our own* . flie book says, that in the 1890*8, Mr. R. Saehtleben ms the first to achieve commercial success with a lithopaae pasme based m ehlsridisinf roasting. . This proses, which is saM to be in wide use1 is Germny t present, .is based on an ore consisting' of a mixture of iron pyrite and sine sulfide, This . ere is given a'preliminary roasting, which converts sneh of the sulfur to S0g which is than used to sake sulfuric acid. The residue consists of iron aside and sins eoapetsods in which most of the sins is still present as .inS with saell amounts ', ofv:ZaQ and ZaS04. ^ This roasted residue is mixed with about $% of uaroastsd pyrite and 17% of rock salt and in then reroasted in a BMhanieally rabbled multiple hearth furnace at 500 - 550*0. The reaction is 'exothermic end essentially all of the sine is fcrougtt into a water soluble form. Countercurrent leashing with water is carried out on thisjeterial and a solution is obtained, con taining; the ions Zn * Ha , Cl", and S0"". The residue of iron adds is used in a blest furnace for the production of metallic iron* The ratio of tins sulfate to sine chloride in the sine liquor is than adjusted by refrigerating the solution to remove sodium sulfate by crystallisation, using the fact that the solubility of H&gS04 is 21.9% st 25*0 and only b.5% at 0%. The sodium sulfate crystal are used to make bias. fixe and in other chemi cal processes. 0007-SWP-000006571 N11889 Us sine liquor is purified by adjusting the pH with ZnO and osidisiag with chlorine, (which is said to her* replaced the older perwsnganate aethod)* sad by adding sine duet to pre< 'eigLtate. heavy. ratals ' '' Far regular .lithOpom* the purified zinc liquor is uisad with barita liquor sod the following reaction takes place* ZaCl** BS ZaS ''BaS04 * 2&S1 To obtain lithopoae of higher strength* a sine' liquor with a lower sulfate content*/(ssds by refrigeration), is used* The following; equations are gibes for the product! of Hthopane eanteining h$*$$ , 2nd and 62.5# Isl respectively. fSsCl* > Sag^- * 2s SZnS BbS04 B&C1* 2HSC1 kZsClg pj^)4 IjBsS ItSaS . BaS04 3BaCl* * 21aCl ; The berlun chloride solution obtained aa a by-product in the Shove ' equations i* adaped with the previously separated NatS04 to precipi, tat blane flat. If the sis liquor is prepared fire* an aeid^oluble sim-ecffisoorad^ eushae ZnOs, ibis dissolved not in HaS04, but In i adztere^of EgS04 *i SSI so as to preelpitate' 'the lithopone fire* a chlfig*idtiicantini^ aalMtios* | The bosk:di'u9effi the baieiaetisn.of Uthopone and tits way this is affected by, ehlorMssu it ssyr chlorides are good for the calcine* tioas* peittii5g ilt to be carried cut at a lower teegwratwe. Wash* iag th* pi^st te rtasree sdlrtsle efcloridee is done after the cal* '-.elnatlaa/j.> ' , 1 " I bhve presented ths above description in s ms detail because it appears that the Gemea practice- is a long way fire* our own* end is in a direction in which we would probably not want to go, even if we knew every technical secret. X aae-ia doubt* therefore* as t whether Sfichblabsnts/latfw-haw in lithopoae is. worth:.buyiae 1 have ashed,:cop."librarian at Crerar for anre lnfaraatian Shout Gerwan lithopaoe wsthods* and this will be available at a later date. I wanted you to have this inferstie now* however* because it nay be relevant to your future'planning.'or negotiations* TI*vfe 'cet.'SBC' att. . Tnn Urtepatrick Mneral Products Research Laboratory 0007-SWP-000006572