Cu-PGMs合金电解阳极泥中EDTA·2Na浸铜动力学

Kinetics analysis on the leaching process of Cu from electrolytic anode mud of Cu-PGMs alloy by using EDTA·2Na solution

以Cu-PGMs合金电解所得铜阳极泥为原料,采用EDTA·2Na浸出阳极泥中的铜和其他贱金属,达到富集阳极泥中贵金属的目的。通过单因素实验,探究了EDTA·2Na浓度、反应温度、浸出时间、搅拌速率、液固比等工艺条件对铜浸出率的影响,得出适宜的浸出条件为EDTA·2Na浓度0.3mol/L、温度55℃、浸出时间3 h、搅拌速率250 r/min、液固比10:1,该条件下铜的浸出率可达91.12%。同时,对EDTA·2Na浸出阳极泥中的铜的动力学进行了分析,结果表明EDTA·2Na的浸出过程符合未反应核的收缩模型,为内扩散控制,其浸出的表观活化能(E_(a))为8.6 k J/mol,浸出动力学方程为1﹣3(1-RCu)^(2/3)+2(1-R_(Cu))=0.13117 t。

EDTA·2Na was used to leach copper-containing anode mud produced in the electrolysis process of Cu-PGMs alloy,with an aim of removing Cu and enriching the precious metals.Through single-factor experiments,the effects of process conditions of EDTA·2Na concentration,reaction temperature,leaching time,stirring speed and liquid-solid ratio on the leaching rate of Cu were investigated.It was concluded that the leaching rate of copper was 91.12%under the appropriate conditions of 0.3 mol/L of EDTA·2Na,a temperature of 55℃,a leaching time for 3 h,a stirring speed at 250 r/min,and a liquid-solid volume-tomass ratio of 10:1.The dynamics on copper leaching by EDTA·2Na solution from anode mud were analyzed,and the process was determined to be an internal diffusion controlling model,with a kinetic equation of 1-3(1-x)^(2/3)+2(1-x)=13.117 t×10^(-2).The apparent activation energy E_(a) is 8.6 kJ/mol.