Leaching Kinetics Of Uranium From Waste Residue By Sulfuric Acid With Surfactant MES

Uranium resources are important strategic resources in our country,but with the exploitation and utilization of uranium resources, damage to the environment is becoming more and more serious. Especially in uranium mining and hydrometallurgy, large amounts of uranium waste residue was produced and stacked on surface, leading to seepage containing uranium,promoting the migration and diffusion of the uranium in the residue to, which not only affect the quality of surface water, groundwater and soil, but also threaten the people health and safety aroundsite. Thus, Looking for a technology to reduce the uranium content in waste residue was very urgent.The study of leaching kinetics of uranium from waste residue by sulfuric acid with surfactant MES to improve the leaching rate of uranium has great significance in the full use of uranium resources and reduce impact on the environment.First,This study first through the static experiment, the surfactant caused uranium leaching rate of the highest was screened out from the three kinds of surfactants(MES, MAEPK, DMSS), and the tension of the leachant added different surfactants were analyzed respectively. The surface tension of leachant without surfactant is 84.56 m N/m, with MES?MAEPK?DMSSare42.23 m N/m?62.24 m N/m?49.72 m N/m respectively. The results showed that the leaching rate of uranium is associated with the surface tension of leaching agent, the surface tension of leachant with MES is the minimumand it promote the leaching rate of uranium is the highest in three kinds of surfactants, thus the surfactant MES was choose to Continue study. Second,Leaching Kinetics characteristics of uranium from waste residue by sulfuric acid with surfactant MES was approached through static experiment and the shrinking core model for the reaction between liquid and solid in order to further explore the mechanism of leaching uranium. The results show that whether or not to adding surfactants MES, leaching rate of uranium increased with the increase of leaching time in range from 1h to 6 h, and the leaching rate of uranium increased with the increase of contact temperature in range from 25? to 45 ?. The Dynamics analysis show that the apparent reaction rate constant with MES, which the range is from 1.235×10-6 to 2.726×10-6, is more an order of magnitude than that without MES, which the range is from6.789×10-7 to 9.550×10-7. The apparent activation energy with MES is29.523 k J/mol, that without is 12.493 k J/mol. Leaching uranium by sulfuric acid is controlled by solid film diffusion within the temperature range from 25 to45?.By the experimental results, the conclusion can be concluded that the surfactant MES can effectively improve the leaching rate of uranium inuranium waste residue, which is beneficial to uranium resources recycling and environmental protection, for uranium mining and environmental protection has important significance and value of research.