基于不同粒级硫化铜矿石生物浸出的动力学

Kinetics of Bioleaching for Copper Sulfide Ore with Different Grade

西藏甲玛地区的硫化铜矿石中含铜矿物以次生硫化铜矿物为主,且含量较低.采用氧化亚铁硫杆菌柱浸的方法对该矿石进行了生物浸出并研究了浸出动力学.基于不同粒级矿石,考察了粒级对铜浸出速率和浸出率的影响,并对浸出率与收缩核模型中的控制方程进行了拟合,确定了浸出过程的控速环节.试验结果表明,铜的浸出速率和浸出率随粒级的减小而增加.矿石表面形貌的SEM表明,浸出过程中矿石表面形成了包含黄钾铁矾的产物层,阻碍了浸出反应的进行.浸出动力学表明,该矿石的浸出过程符合收缩核模型,且浸出应主要受固体产物层内扩散控制.

The copper-bearing minerals in the copper sulfide ore in the Jiama area of Tibet are mainly composed of secondary copper sulfide minerals with low content.The ore was bioleached using the column leaching method of Thiobacillus ferrooxidans and the leaching kinetics was studied.For different ore grades,the effects of particle size on copper leaching rate and leaching ratio were investigated.The leaching ratio and the control equation in the shrinkage nucleus model were fitted to determine the speed control link in the leaching process.The test results show that the leaching rate and leaching ratio of copper increase with the decrease of the grain size.The SEM of the surface morphology of the ore indicates that the product layer containing jarosite is formed on the surface of the ore during the leaching process,which hinders the progress of the leaching reaction.The leaching kinetics indicates that the leaching process of the ore is conformed to the shrinkage nucleus model,which is mainly controlled by the diffusion within the solid product layer.