Uranium recovery from coal ash dumps of Mongolia

The concentration of natural radionuclides and the feasibility of recovery of uranium from browncoal ash of a Mongolian cogeneration plant were investigated. The concentrations of the elements were determined by instrumental gamma-activation (IGAA) and X-ray fluorescence (XRF) analysis. Uranium from brown-coal ash was leached with an 8 M HNO3 + HF (10%) mixture. The extraction of uranium from the solution and its purification for the removal of accompanying elements were carried out on an anion exchanger. An ash sample after leaching contains neither natural radioactive elements (U-238 and Th-232) nor their decay products, thereby allowing for the use of the ash as a building material.