离子交换法提取磷矿中稀土元素的初步研究

Preliminary Research on the Extraction of Rare Earth Elements from Phosphate Rock with Ion Exchange Method

采用55%硝酸溶解稀土伴生磷矿,得到硝酸溶解液,然后用离子交换法分离提取硝解液中稀土元素。采用单因素法研究了离子交换时间、淋洗剂pH值、EDTA浓度及硝解液中钙离子等因素对稀土提取的影响。结果表明,最佳工艺条件为:离子交换50min,淋洗剂pH值9.0、EDTA浓度0.020mol/L、淋洗50min;在此条件下树脂对硝解液中稀土一次吸附率最高达到50%,稀土一次洗出率最高达到94%以上。硝解液经浓缩冷冻除钙后,稀土吸附率明显提高。

Rare earth associated phosphate rock was dissolved with 55% nitric acid to obtain the digested solution,where rare earth elements were extracted with ion exchange method.Effects were studied of ion exchange time,eluent pH,EDTA concentration and calcium ion in the digested solution on rare earth extraction.The results show that the optimum technological conditions are as follows：ion exchange time of 50 min,eluent pH of 9.0,EDTA concentration of 0.020 mol/L and elution time of 50 min.Under the above conditions,rare earth adsorption rate of the resin can be up to 50%from the digested solution by one step ion exchange,and rare earth elution rate is beyond 94% by one step elution.Rare earth adsorption rate significantly increases after calcium is removed from the digested solution by concentrating and freezing.