The Technological Study and Leaching Kinetics of Scandium from Red Mud

Scandium-rich red mud what produced by aluminum production of a Bayer alumina was carried out the technological conditions and acid leaching kinetics of scandium.Red mud particle size,leaching temperature and liquid-solid ratio on the impact of leaching scandium were investigated,kinetic model about leaching scandium from red mud was founded.The results show that when the particle diameter is 65~ 80 μm,the reaction temperature is 90℃,and ratio of liquid to solid is 3∶1,the leaching rate of scandium from the red mud can reach over 80%;The leaching process of scandium-rich red mud by acid corresponds with the model of contractibility and unreacted core,the kinetics equation is the 1-(1-XB)2/3-2/3XB=Kt,the activation energy is 19.55 kJ/mol,the leaching reaction is mostly controlled by the solid-membrane diffusion process.