Cast Stone Matrices Based on Basaltic Melt with Uranium-Bearing Silica Gel

The distribution of uranium between different phases of cast stone matrices fabricated by fusion of basalt and uranium-bearing SiO 2 -based collectors was investigated. It was found that matrices created by fusion of basalt with SiO 2 consist of glass, quartz, and spinel as the main phases. A study of the physicochemical properties of collectors based on 30 wt % UO 2 (NO 3 ) 2 -bearing SiO 2 showed that, after thermal treatment at a temperature of 973 K, they contain uranium only in the form of UO 3 . The uranium leaching in H 2 O from SiO 2 after its thermal treatment, as well as from a basaltic melt with SiO 2 , was estimated.