Uranium in Saline Lakes of Mongolia and Adjacent Areas

Abstract

Increasing demand for uranium raw materials for the nuclear industry has stimulated interest in non-traditional sources, including hydromineral ones [Qin, 2009]. Those are saline lakes located in the uranium ore districts. Accumulation of uranium in such lakes results from the leaching of uranium from the rocks by surface and ground waters and its deposition in terminal basins. We have studied concentrations of uranium in saline lakes located in the uranium ore provinces of Mongolia and in adjacent areas. The lakes were hydrochemically explored during the 2007-2013 joint Russian-Mongolian field trips. About one hundred salt lakes were investigated. The highest concentrations of uranium (up to 3 mg/l) were found in the lakes of north-western Mongolia. For comparison, concentrations of uranium in the lakes of the Chuya basin (Gorny Altai) do not exceed 0.03 mg/l and maximum concentration of uranium in the lakes of the Steppe Altai is 0.04 mg/l. In addition to uranium, the lakes water has rather high concentrations of such microelements as boron (up to 250 mg/l), bromine (1.1 g/l), lithium (100 mg/l), strontium (10 mg/l), iodine (10 mg/l), rubidium (1.3 mg/l), cesium (0.4 mg/l), and arsenic (0.8 mg/l) [Isupov, 2011, 2013]. Our obtained data on the composition of the lakes water allowed us to calculate reserves of U and other microelements. Lake Hyargas Nuur has the greatest stock of uranium, about 6000 tons, which is priced to ca. 1 billion USD. Regularities of leaching of uranium, its transportation to lakes and accumulation in water and sediments were investigated in the intermountain basin of Lake ShaazgaiNuur locating in the southern part of the Kharkhirin Highland, north-western Mongolia (Fig. 1). The mountains around the lake are Early Carboniferous granitoid complexes: Kharkhirin and Yelinskii. The Kharkhirin Vitaly ISUPOV, Ariunbileg SODOV, Svetlana SHATSKAYA, Marina KOLPAKOVA, Ljudmila RAZVOROTNEVA , Alexander VLADIMIROV, Stepan SHVARTSEV, Leonid KUIBIDA Sergey KRIVONOGOV and Ekaterina MOROZ. 2014. Uranium in Saline Lakes of Mongolia and Adjacent Areas. Acta Geologica Sinica (English Edition), 88(supp. 1): 137-138.