Investigation To Intensified Uranium Extraction From Uranium Tailings Using Oxidants

With the development of nuclear industry and the increasing demand of nuclear fuel, the number of uranium ore especially having high uranium grade had been decreasing. The percentage of uranium in uranium tailing is small, but the amount of uranium tailing is huge. Recovery uranium from the tailing not only can solve the problem of fuel lacking but also can reduce pollution risk of uranium tailing.Using uranium extraction character in the process of uranium extraction and strengthen extraction by oxidant, this paper investigated mineralogical environment of uranium tailing and uranium dissociate character in the uranium extraction process in acid solution by research methods of process mineralogy and materialogy. Based on this, this paper also discussed uranium extraction character in the view of thermodynamics and kinetics and function of oxidants in the extraction process by hydrometallurgy theory. The kinetics expressions in the extraction process was improved and perfacted by fitting uranium extraction and process parameters respectively.The investigation of uranium extraction character in the process of conventional extraction and strengthen extraction by oxidant suggested that uranium extraction increase with the increase of sulfric acid concentration and the decreace of solid-liquid ratio and the particle size. In addition, uranium dissolution rates and efficiency were significantly improved by added oxidants. For oxidative leaching, a maximum uranium dissolution of near 95% was improved to from less than 45%under identical conditions within 1 hour. What's more, this paper investigated micro mineralogical environment of uranium tailing and uranium dissociate character in the uranium extraction process in acid solution by methods of process mineralogy and materialogy. The results suggested that uranium extraction is promoted by dissolving gangue after adding oxidants, meanwhile, the gangue dissolution will make uranium tailings rougher surface, bigger superficial area and stronger adsorbtivity, which have negative effect to the promotion function.Based on shrinking core model and arrhenius formula, the activation in the extraction process was decreased from 13.89 kJ/mol to 13.76 kJ/mol after adding oxidant, which make the process closer to diffusion stage. Addationally, the extraction kinetics expression was changed after the addition of oxidant in the leaching process,which increased the effect of rotation rate and decreased the effect of concentration of H2SO4 to uranium extraction in the kinetic expression.This paper would provide basis for recovery of uranium from tailings contain uranium and ultra low grade uranium ore and controlling the amount of oxidant in intensified uranium extraction using oxidants. Basides, the article will give referance to regulate technological parameters effeciently to improve uranium extraction in the process of uranium extraction and strengthen extraction by oxidant.