稀土沉淀条件及形态控制研究

Research on Precipitating Conditions and Behavior Control of Rare Earths

稀土工业试验中心为生产荧光级氧化稀土产物研究了草酸沉淀中温度、酸度、浓度及草酸用量等对稀土回收率的影响，并试验了控制沉淀产物粒度的各种手段。测定了杂质Ｆｅ、Ｃａ、Ｎｉ、ｃｕ，Ｐｂ等在沉淀时的行为。杂质的含量尤其是Ｃａ的沾污得到了控制。改善了碳酸稀土沉淀的形态以便于过滤操作和产物贮存。热分析表明，如果提供足够的氧可以在较低的的烧温度下把草酸稀土转化为氧化物。

For producing the RE_2O_3 of fluorscent grade products in Industrial Test Centre ofRare Earth,the effects of precipitated conditions such as temperature,acidity,concentration andexpense of oxalic acid on the rate of recovery of rare earth were researched.The conuel methodsof grain-size and behaviors of non-rare earth elements(Fe、Cu、Ca、Ni、Pb)in precipitstion werestudied.The content of impurities,especially Ca,can been controlled.The precipitated forms ofrare-earth carbonates were improved in order to filter and reserve. The thermal analysis of rareearth oxalate indicated that the conversion of oxalate into oxide can been accomplished under lowercalcination temperature if providing O_2 for RE_2(CrO_4)_3。