Thermodynamic Calculations of Uranium Accumulation in Saline Lakes of West Mongolia

The saline lakes are a unique geochemical barrier for the migration of uranium which forms oxides, hydroxides, carbonates, phosphates, fluorides and other minerals in lakes sediment. This article presents data of chemical composition of some salt lakes in Western Mongolia. The concentration U-238 in some lake waters up to 3 mg/l. Uranium, in turn, forms complexes with carbonate-ions and migrate to the lakes, and precipitates in lake sediments by influence of evaporation and water-rock interaction time. There is shown that accumulation of uranium in lake water due to two main factors: first, localization of the lakes and their watersheds in potential provinces of U-bearing rocks and, second, uranium complexing with carbonate (bicarbonate) anions.