Dissolution kinetics of malachite in ammonia/ammonium sulphate solution  

作　　者：刘志雄 尹周澜 胡慧萍 陈启元 

机构地区：[1]School of Chemistry and Chemical Engineering,Central South University [2]College of Chemistry and Chemical Engineering,Jishou University

出　　处：《Journal of Central South University》2012年第4期903-910,共8页中南大学学报（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 dissolution kinetics of malachite was investigated in ammonia/ammonium sulphate solution. The effects of ammonia and ammonium sulphate concentration, pH, leaching time, reaction temperature, and particle size were determined. The results show that the optimum leaching conditions for malachite ore with a copper extraction more than 96.8% are ammonia/ammonium concentration 3.0 mol/L NHaOH ＋ 1.5 mol/L （NH4）2SO4, liquid-to-solid ratio 25：1 mL/g, leaching time 120 min, stirring speed 500 r/rain, reaction temperature 25 ℃ and particle size finer than 0.045 mm. The dissolution process of malachite with an activation energy of 26.75 k J/tool is controlled by the interface transfer and diffusion across the product layer. A semi-empirical rate equation is obtained to describe the leaching process and the reaction orders with respect to concentration of ammonia and ammonium sulphate are 2.983 0 and 0.941 1, respectively.The dissolution kinetics of malachite was investigated in ammonia/ammonium sulphate solution.The effects of ammonia and ammonium sulphate concentration,pH,leaching time,reaction temperature,and particle size were determined.The results show that the optimum leaching conditions for malachite ore with a copper extraction more than 96.8% are ammonia/ammonium concentration 3.0 mol/L NH4OH + 1.5 mol/L(NH4)2SO4,liquid-to-solid ratio 25:1 mL/g,leaching time 120 min,stirring speed 500 r/min,reaction temperature 25 °C and particle size finer than 0.045 mm.The dissolution process of malachite with an activation energy of 26.75 kJ/mol is controlled by the interface transfer and diffusion across the product layer.A semi-empirical rate equation is obtained to describe the leaching process and the reaction orders with respect to concentration of ammonia and ammonium sulphate are 2.983 0 and 0.941 1,respectively.

关 键 词：COPPER MALACHITE KINETICS AMMONIA ammonium sulphate 

分 类 号：O611.3[理学—无机化学]