赤泥中浸出钪的工艺条件及动力学研究

对某厂拜耳法生产氧化铝的副产物富钪赤泥进行了钪的酸浸工艺条件和动力学研究。考察了赤泥粒度、浸出温度、液固比对钪浸出率的影响,建立了钪的酸浸动力学模型。结果表明:颗粒直径65~80μm、反应温度90℃、液固比3∶1,钪的浸出率可达80%以上;钪的酸浸过程符合收缩未反应芯模型,动力学方程为1-(1-XB)2/3-2/3XB=Kt,活化能为19.55 kJ/mol,该反应主要受固膜扩散过程控制。

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.