硫酸铵法中低品位锂瓷土矿提锂尾液铷铯提取技术

Extraction of rubidium and cerium salts from lithium tail liquid of medium and low grade lithium clay by ammonium sulfate process

研究了硫酸铵法利用宜丰中低品位[w(氧化锂)<2.0%]锂瓷土矿制备碳酸锂后的提锂母液进一步提取铷铯等贵金属的技术路线。一次碳化提锂后的母液中还含有若干溶解的铷、铯等金属的硫酸盐类,采用分步结晶法,结晶母液降温析出过程中,在温度高的前段步骤析出的是铷铯等溶解度较低的矾盐,而温度低的后段步骤析出的是钾铵等溶解度高的矾盐,从而达到铷铯矾与铵钾矾等初步分离的目的。将成矾除铝阶段硫酸铝钾、硫酸铝铵等矾盐,以焙烧分解的形式继续分出硫酸钾和氧化铝。

The technical route of preparing lithium carbonate by ammonium sulfate process was studied for the medium and low grade lithium clay with w(Li2O)<2.0%in Yifeng.The precious metals such as rubidium and cesium from the lithium extraction mother liquor were further studied.The mother liquor after carbonization and extraction of lithium contains several dissolved sulfates of metals such as rubidium and cesium.Using stepwise crystallization method,the less soluble alum salts such as rubidium and cesium,were precipitated in the previous step of higher temperature,while alum salts such as potassium and ammonium were precipitated in the later step of lower temperature.By this way,the rubidium and cesium alum and ammonium and potassium alum were separated.The alum salts such as aluminum potassium sulfate and aluminum ammonium sulfate were roasted at high temperature to decompose as potassium sulfate and alumina.