发明名称 |
Method for producing alkali-ammonium chromate double salt |
摘要 |
<p>Producing chromium(III) oxide, comprises: (a) decomposing an alkali-metal-ammonium chromate double salt at 200-650[deg] C, preferably 250-55O[deg] C; (b) washing the decomposition product obtained in the step (a); and (c) calcining the product obtained in the step (b) at 700-1400[deg] C, preferably 800-1300[deg] C. The alkali metal ammonium chromate double salt comprises sodium-ammonium chromate double salt, which exhibits a molar ratio of ammonia to sodium of greater than 2. An independent claim is also included for producing the alkali-metal-ammonium chromate double salt of formula (M x(NH 4) yCrO 4) (I) or its hydrate, comprising adding ammonia at 55-95[deg] C to an aqueous solution of alkali dichromate of formula (M 2Cr 2O 7) (II). x : 0.1-0.9, preferably 0.4-0.7; and y : 1.1-1.9, preferably 1.3-1.6; or x+y : 2; and M : Na or K.</p> |
申请公布号 |
EP2530054(A1) |
申请公布日期 |
2012.12.05 |
申请号 |
EP20120182421 |
申请日期 |
2010.12.08 |
申请人 |
LANXESS DEUTSCHLAND GMBH |
发明人 |
FRIEDRICH, HOLGER;ORTMANN, RAINER;STENGER, MATTHIAS;VAN ROOYEN, DANIEL;KALIDEEN, NAVEEN;BOLL, MATTHIAS |
分类号 |
C01G37/00;C01G37/02;C01G37/14 |
主分类号 |
C01G37/00 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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