Aluminosilicate Sorbents Based on Clay-Salt Slimes from JSC “Belaruskali” for Sorption of Cesium and Strontium Radionuclides

Abstract

Mineral composition, physicochemical properties and sorption characteristics of clay-salt slimes (CSS), wastes formed in processing of the sylvinite ore at JSC “Belaruskali” (Soligorsk, Belarus) and aluminosilicate and illite sorbents produced on their basis were studied. It was shown that dressing of CSS samples results in that their chemical and mineralogical compositions change. It was found that the washing of CSS with water, followed by treatment with hydrochloric acid and Trilon B, leads to a 1.2–1.3 times increase in the content of the main component of CSS, illite, due to the dissolution of carbonates (dolomite and calcite) and gypsum. It was found that presence of illite plays a key role in the sorption activity of the sorbents toward the radionuclides 137Cs and 90Sr. With enriched samples of illite sorbents (IS-3o and IS-3m),the distribution coefficients of 137Cs become twice larger, and those of 90Sr, 20 times larger in comparison with the undressed samples of aluminosilicate sorbents (AS-3o and AS-3m). It is shown that the production of aluminosilicate and illite sorbents from CSS and the use of these sorbents for purification of liquid radioactive wastes to remove the radionuclides 137Cs and 90Sr and for creating barriers providing the safe storage and burial of low- and medium-activity of radioactive wastes are promising.