Decomposition of an Eudialyte Concentrate with Nitric Acid by Sorption Conversion

Abstract

The nitric acid decomposition of an eudialyte concentrate by sorption conversion is studied. This method is based on the interaction of the concentrate with a low concentrated solution of HNO3 in the presence of sulfonic cation-exchange resin. During sorption conversion, the target metals are predominantly sorbed by a sorbent, which is easily separated from the solution and silica gel-containing residues. When the solution containing 2% HNO3 is used, the extraction of rare elements is comparable and the acid consumption is 6–8 times lower than that in the case of the traditional decomposition of an eudialyte concentrate using concentrated nitric acid. The procedure simultaneously produces a nonradioactive silica gel product appropriate for the production of qualitative building materials. The possibility of the further increase in the degree of extraction of rare elements is discussed. A route for the processing of the sorbent saturated with rare metals is proposed to produces salt concentrates of these elements.