Recovery of thorium and rare earths from leachate of ion-absorbed rare earth radioactive residues with N1923 and Cyanex(R) 572

• 作者: Jia Su Xiangguang Guo Yun Gao Shan Wu Ruigao Xu Xiaoqi Sun
• 来源期刊: 稀土学报（英文版）
• 年，卷（期）: 2021,（10）
• 所属期刊栏目: CHEMISTRY AND HYDROMETALLURGY
• 页码范围: 1273-1281
• 页数: 9页
• 语种: 英文

摘要

Ion-absorbed rare earth ores radioactive residues (IREORR) are a class of waste residue from the pro-duction of rare earth elements (REEs).Because of its radioactive dose,IREORR are usually stored in waste warehouses.IREORR are difficult to be disposed of.However,it contains relatively high concentrations of REEs,which can be considered as a valuable secondary resource.In this paper,a novel process is developed for the separation of thorium (Th) and recovery of REEs from IREORR hydrochloric acid leachate with primary amine N1923 and Cyanex(R) 572,respectively.The effects of sulfate concentration,extractant concentration and pH on N1923 extraction in hydrochloric acid solution were investigated in detail.The results show that the extraction capacity of N1923 can be improved by adding sulfate to the solution and increasing the concentration of N1923.Acidity has little effect on the extraction of Th when pH is higher than 1.As for the stripping,REEs are more easily stripped from loaded organic phase than Th,and nitric acid is a better stripping agent than hydrochloric acid.Combined with the extraction of Cyanex(R) 572 for REEs,a fractional extraction experiment for separating Th and enriching of REEs was performed.The yield of Th is higher than 99.9％ and the concentration of REEs is enriched to 183.84 g/L.