Separation of Scandium and Thorium in the Processing of Scandium Rough Concentrate Obtained from Circulating Solutions of In-Situ Leaching of Uranium

Abstract

Studies have been carried out to separate scandium and thorium from nitric acid solutions using two extraction systems 7.5% Cyanex 923 + 7.5% TBP and 40% TBP in kerosene for processing the primary scandium concentrate obtained from the circulating solutions of underground uranium leaching at JSC “Dalur.” Comparison of the values of the separation coefficients showed the fundamental possibility of using both systems for the separation of scandium and thorium. It was recommended to use a 40% solution of TBP in kerosene at the first stage of separation, and a mixture of extractants 7.5% Cyanex 923 + 7.5% TBP in kerosene at the stage of fine purification. For this system, higher scandium losses due to coextraction with thorium were noted. The possibility was demonstrated of increasing the degree of purification from radioactivity by adding 15% trialkylmethylammonium nitrate to the TBP solution.