某低品位复杂稀土精矿中提取稀土的研究

Study on Recycling Rare Earth from A Low-grade and Complex Rare Earth Concentrate

对某低品位复杂稀土精矿采用传统的浓硫酸低温焙烧工艺,可以较好的浸出稀土和铍,浸出率分别达到95%和90%以上,但钽、铌浸出率只能达到40%左右;采用添加活化剂后,可使钽铌的浸出率提高到80%,同时稀土和铍的浸出率也分别达到97%和99%;将水浸液采用添加草酸沉淀稀土,经过煅烧后成稀土氧化物后稀土总量达到86%,将稀土氧化物采用盐酸溶解后,通过调整pH值,除去部分杂质,采用碳铵沉淀稀土,得到碳酸稀土,非稀土杂质小于2%。

The leaching of a low-grade and complex rare earth concentrate was discassed.Rare earth and beryllium（Be） can be easily leached by using traditional concentrated sulfuric acid calcinating at low temperature,the leaching rates of rare earth and beryllium（Be） can reach respectively above 95% and 90%,but the leaching rates of Ta and Nb are only about 40%.It can improve the leaching rate of Ta and Nb by using concentrated sulfuric acid activation calcinating at low temperature,the leaching rates of rare earth and beryllium（Be） can reach respectively above 97% and 99%.The TREO can reach 86% when the rare earth in leaching solution is precipitated by adding oxalic acid and then calcined.Further the rare earth oxide is dissolved by hydrochloric acid,the impurity of solution can removed by adjusting the value of pH.The rare earth carbonate can be gained by adding ammonium bicarbonate,with impurity of non-rare earth below 2%.