Leaching kinetics of uranium from a quartz-chlorite-biotite rich low-grade Indian ore

This paper describes the results of ore characterization and acid dissolution kinetics of uranium from a low-grade uranium ore in eastern part (Narwapahar, Singhbhum district) of India. The host rock for uranium mineralization is quartz-chlorite-biotite schist. The average U3O8 content is 0.025 % chemically and the main radioactive phase is uraninite. Critical process conditions which influence the leachability of uranium values in sulfuric acid media were studied as a function of reaction time. The results indicate that particle size, acid concentration and temperature of reaction, affect the dissolution behavior of uraninite significantly. The mechanism of leaching of uranium was determined using the shrinking core kinetic model and has been found to follow the product layer diffusion process. A rate equation was formulated using the activation energy and reaction orders of important process parameters.