石煤提钒水浸过程的动力学研究

基于未反应核收缩模型和液膜非稳态扩散模型,探讨了石煤提钒水浸过程的动力学机理。以搅拌强度对浸出速率的影响作为辅助判断,通过尝试法确定了浸出过程的控制步骤。研究表明,可用上述两模型分段描述浸出过程,搅拌强度在250r/min时,浸出过程在0～50min受液膜非稳态扩散控制,其动力学方程为4α+3[(1-α)4/3-1]=kD t1/2,表观活化能为8.51 kJ/mol;适当加强搅拌、升高温度或减小矿样粒度能提高可溶钒通过液膜的扩散速率。

STUDY ON LEACHING KINETICS OF EXTRACTING VANADIUM BY WATER FROM STONE COAL

Based on the shrinking unreacted core modle and the unsteady-state diffusion model of liquid film,the leaching mechanism of extracting vanadium by water from stone coal is discussed in this article.The control step of leaching is confirmed by tentative method after the assistant judgement on the effects of stirring intensity on the leaching velocity.The results reveal that the leaching process can be described in two steps by the modles,the control step is unsteady-state diffusion of liquid film,the model's equationand is 4α+3[(1-α)4/3-1]=kD t1/2 in 50min,and the apparent activation energy is calculated to be 8.51 kJ/mol,while the stirring intensity is 250r/min.Also,prolonging temperature,increasing stirring intensity and reducing average grain size of calcine properly can enhance the diffuse velocity effectively of dissoluble vanadate through the liquid film.