从含银氧化铁矿提取银及其动力学研究  

Silver Extraction from Silver Iron Oxide and Its Kinetic Study

作　　者：陈国兰[1] 朱云[1] 

机构地区：[1]昆明理工大学冶金与能源工程学院,云南昆明650093

出　　处：《昆明理工大学学报（自然科学版）》2014年第2期7-11,33,共6页Journal of Kunming University of Science and Technology(Natural Science)

基　　金：云南省科技计划项目(14051395)

摘　　要：针对含银氧化铁矿中银被磁性铁所包裹而不易被浸出的特性，采用硫酸预浸-酸性硫脲浸出工艺回收其中的银，相对直接硫脲浸出，银的可浸性由40％提高到80％以上．在液固比为10∶1，Fe3＋浓度为0.01 mol/L，硫脲浓度为10 g/L，pH为1.0～2.0，搅拌时间为1 h，银的浸出率为85.23％．采用未反应收缩核模型对硫脲浸银进行动力学研究，试验结果表明：该浸出反应对硫脲的表观反应级数为0.68；动力学方程为：1-23η-（1-η）2/3＝0.0377e-5.725/RT·CTu0.68·t；反应的表观活化能为5.725 kJ/mol，浸取过程为固膜扩散控制过程．Based on the characteristics that silver is wrapped by the magnetic iron and hard to leach in silver ox-ide ore,acid pre -acidic thiourea leaching process is employed to recover Ag.Compared with direct thiourea leaching,the leaching rate of Ag increases from 40% to over 80%.When ratio of liquid to solid is 10∶1 ,the concentration of Fe3＋0.01 mol/L,concentration of thiourea 10 g/L,pH 1.0~2.0,and the mixing time 1h,the leaching rate of Ag is 85.23%. The model of contractibility and unreacted core is used for study on kinetics of thiourea leaching of Ag. The results show that the reaction apparent reaction progression of thiourea is 0.68;the kinetics equation is 1 -23 η-（1 -η）2/3 =0.0377e-5.725/RT·CTu0.68 ·t;the apparent activation energy of the reaction is 5.725 kJ/mol.The leaching reaction is mostly controlled by the solid membrane diffusion process.

关 键 词：含银氧化矿 酸浸 硫脲浸出 浸出动力学 

分 类 号：TQ342.742[化学工程—化纤工业]