Leaching kinetics of low-grade copper ore containing calcium-magnesium carbonate in ammonia-ammonium sulfate solution with persulfate  

氨-硫酸铵体系过硫酸盐氧化含钙镁碳酸盐低品位铜矿的浸出动力学(英文)

作　　者：刘志雄[1,2] 尹周澜[1] 胡慧萍[1] 陈启元[1] 

机构地区：[1]中南大学化学化工学院,长沙410083 [2]吉首大学化学化工学院,吉首416000

出　　处：《Transactions of Nonferrous Metals Society of China》2012年第11期2822-2830,共9页中国有色金属学报（英文版）

基　　金：Project(2007CB613601)supported by the National Basic Research Program of China;Project(10C1095)supported by the Foundation of Hunan Educational Committee,China

摘　　要：The leaching kinetics of copper from low-grade copper ore was investigated in ammonia-ammonium sulfate solution with sodium persulfate. The effect parameters of stirring speed, temperature, particle size, concentrations of ammonia, ammonium sulfate and sodium persulfate were determined. The results show that the leaching rate is nearly independent of agitation above 300 r/min and increases with the increase of temperature, concentrations of ammonia, ammonium sulfate and sodium persulfate. The EDS analysis and phase quantitative analysis of the residues indicate that bornite can be dissolved by persulfate oxidization. The leaching kinetics with activation energy of 22.91 kJ/mol was analyzed by using a new shrinking core model （SCM） in which both the interfacial transfer and diffusion across the product layer affect the leaching rate. A semi-empirical rate equation was obtained to describe the leaching process and the empirical reaction orders with respect to the concentrations of ammonia, ammonium sulfate and sodium persulfate are 0.5, 1.2 and 0.5, respectively.研究在氨?硫酸铵体系中用过硫酸盐氧化低品位铜矿浸出动力学,确定搅拌速度、浸出温度、矿物粒度及氨、硫酸铵和过硫酸钠的浓度对浸出的影响。结果表明,搅拌速度在300r/min以上时对浸出速度无影响,浸出速度随反应温度及氨、硫酸铵和过硫酸钠浓度的增大而增加。对浸出渣的EDS和物相定量分析表明斑铜矿被过硫酸盐氧化而溶解于氨?硫酸铵溶液。用产物层的界面传质和扩散控制的收缩核模型分析铜矿的溶解动力学,其表观活化能为22.91kJ/mol,同时获得了描述浸出过程的半经验动力学方程,其对氨、硫酸铵和过硫酸钠的浓度的表观反应级数分别为0.5、1.2和0.5。

关 键 词：low-grade copper ore calcium-magnesium carbonate leaching kinetics ammoniacal solution sodium persulfate activation energy shrinking cure model 

分 类 号：TF811[冶金工程—有色金属冶金]