Treatment of waste water involved in acid uranium ore processing

The uranium ores lixiviation is one of the hydrometallurgical processes which generate waste waters that need to be treated in accordance with the quality requirement of NTPA - 001/2002. The uranium ores acid lixiviation process generates two types of waste waters: (I) an alkaline solution out of which uranium is extracted by an ionic exchange process and (II) a mixture of mother - water and washing waters from DUNa precipitation. In order to treat wastewater (I) a flow sheet is proposed that includes: the uranium removal to the CMA level using the ion exchange process; the effluent's neutralization with sulphuric acid and reverse osmosis, which recovers more then 80% of water; the treatment of the mineral salts concentrate by crystallization - evaporation. Wastewater (II) is processed using its recirculation in the elution industrial process. The excess is treated by neutralization with sulphuric acid, molybdenum adsorption on active carbon, sulphate removal using calcium chloride; the sodium chloride solution is recycled to add up to the elution of uranium recovered from (I). (authors)