Leaching Of Uraniferous Alkalescence Dreg And Hydrogen Peroxide Precipitation Of Lixivium

The technique of calcining-leaching-curing-precipitation- extracting was used to recover Uranium in the alkalescence dreg. The operating parameters of recovering Uranium in alkalescence dreg were determined. Nuclear pure UO2 (NO3)2 solution was obtained. The recovery rate of the process was good. Advantages of the method include brief equipments, simple operation, less waste and more benefit.Technics of calcining alkalescence dreg were studied. Factors affecting leaching effect were analyzed including temperature, time and oxidant. Experimental results have finalized the calcining parameters to be 750℃, 8 hours and blasting air. Process of calcining can reduce the Uranium content of first leavings to be more than 50% in the bulk. Colloidbe will be prevented in leaching after calcining. Thus filtration of lixivium is comparatively easy.Based on the factors affecting on leaching: temperature(A), acidity(B), time(C) and granularity(D), orthogonal experiment of L16(44) was used. Experimental result showed A2B3C4D2 was the best condition. In this condition leaching rate could be more than 97.5% and the Uranium content of first leavings be less than 3%.The acid-curing method and second calcining method for leaching Uranium from first leavings were adopted. Factors influencing the leaching result of Uranium were studied. The results have shown that nitric acid curing result in a low Uranium leaching rate, which can not meet the standard of"abandon dregs". The leaching rate of Uranium was well improved by second calcining, which may meet the standard of treatmen. The second calcining is a suitable method to deal with first leavings.The hydrogen peroxide precipitation for purifying Uranium from lixivium was studied. Factors influencing the result of hydrogen peroxide to precipitate Uranium were analyzed. The key factors of this method are the temperature and pH value. By hydrogen peroxide precipitation it can purify lixivium partly. After TBP- sulfoniced kerosene extracting, the impurity of solution can meet the technique requirement. It can be used for production of nuclear-grade UO2 powder.