湿法提纯石英过程的动力学研究

为了提高湿法提纯石英的浸出效率并提供理论依据,从动力学角度研究了酸浸提纯石英工艺中除Al的浸出过程并建立动力学模型.在ω(HF)=2％、ω(H2C2O4)=3％、ω(HNO3)=30％,液固比4:1,搅拌转速150 r/min,粒径100～120目的实验条件下,通过常用的液固相化学反应动力学模型的比较并结合宏观现象,得到描述浸出过程的经验方程,湿法提纯石英过程浸出Al的动力学模型为基于界面反应模型的微粒模型.杂质Al的去除率X(Al)对反应时间t的关系式为1-[1-X(Al)]1/3=k2"t,浸出过程频率因子A=58 204.04 s-1,反应表观活化能为E=44.588 1 kJ/mol,属于化学反应控制.提高温度和酸液浓度、降低石英颗粒的半径,均可提高Al的浸出速率和浸出率.

Study on Kinetics of Hydrometallurgical Purification Unit for Quartz

In order to improve the leaching efficiency of Aluminum(Al) from the quartz and provide its theoretical base,the leaching process was analyzed.On the basis of previous experiments,the dissolved rate of Al from quartz with hydrometallurgical purification unit was studied on the condition of w(HF)=2%,w(H2C2O4)=3%,w(HNO3)=30%,the liquid-solid ratio 4∶1,stirring speed 150 r/min and quartz powder 100~120 mesh.By means of comparison between several common liquid-solid phase chemical reaction kinetics models,an empirical equation for leaching process was established.The leaching process of Al could be simulated with a corpuscular model which is based on the interface reaction model [1-(1-X(Al)]1/3=k2″t with the frequency factor of 58 204.04 s-1 and the apparent activation energy of 44.588 1 kJ/mol.The overall leaching rate appears to be controlled by the chemical-reaction.The leaching rate and speed can be increased by enhancing the temperature and acid concentration and reducing the particle size.