固固转化法高效制备氯化稀土的工艺研究

采用固固转化法, 使用碳酸氢铵溶液对硫酸稀土焙烧矿进行直接转型, 得到氯化稀土。重点考察了碳酸氢铵用量、焙烧矿粒度、反应固液比、转化时间等因素对稀土收率的影响, 确定了最优工艺条件:硫酸稀土焙烧矿粒度为0.18 mm, 碳酸氢铵加入量为焙烧矿质量的60%, 固液比1∶6, 转化时间7 h, 酸溶时间1 h, 此条件下稀土收率可达到93%以上, 同时工艺用水量减少了50%, 生产效率更高, 为节能减排开辟了新途径。

Technology for Rare Earth Chloride Prepared Directly from Roasted Rare Earth Sulfate Ore

Rare earth chloride solution was obtained from roasted rare earth sulfate through the solid-solid phase transformation method with ammonium bicarbonate. The influences on the rare earth recovery by factors of ammonium bicarbonate dosage, roasted ore particle size, solid/liquid ratio for the reaction, transformation time were investigated. The optimal reaction conditions were finally determined as follows: particle size of roasted ore at 0.18 mm, the dosage of ammonium bicarbonate at 60% of roasted ore mass, solid /liquid ratio at 1∶6, 7 h for transformation and 1 h for acid dissolution, which resulted in the recovery of rare earth over 93% and water consumption reduced by 50%. It can not only improve the production efficiency, but also provide a new approach for energy saving and emission reduction.