Ion-absorbed rare earth ores radioactive residues(IREORR)are a class of waste residue from the production of rare earth elements(REEs).Because of its radioactive dose,IREORR are usually stored in waste warehouses.IREO...Ion-absorbed rare earth ores radioactive residues(IREORR)are a class of waste residue from the production 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?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■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.展开更多
基金supported by the National Key R&D Program of China(2017YFE0106900)Science and Technology Major Project of Ganzhou(2018)Fujian Program for High-Level Entrepreneurial and Innovative Talents Introduction and Science and Technology Service Network Initiative from Chinese Academy of Sciences。
文摘Ion-absorbed rare earth ores radioactive residues(IREORR)are a class of waste residue from the production 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?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■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.
