铜渣浮选尾砂中铜在NH_3·H_2O-NH_4Cl体系中浸出动力学研究

Leaching kinetics of copper flotation tailings in ammonia/ammonium chloride solution

研究铜渣浮选尾砂中铜在NH_3·H_2O-NH_4Cl体系中的浸出行为。结果表明,铜的最佳浸出条件为:炉渣粒度为-0.045mm,浸出温度60℃,氨水浓度3.0mol/L,氯化铵浓度2.5mol/L,双氧水添加量0.2mL/g,液固比6∶1,搅拌速度500r/min,浸出时间120min,铜的浸出率为62.22%;浸出过程受内扩散控制,浸出反应的表观活化能Ea=11.56kJ/mol,反应表观级数为0.938 83,温度条件下铜浸出反应动力学方程为lnk=-1.390 42×103/T-2.108 67,氨水浓度条件下铜浸出反应动力学方程为lnk=0.938 83lnc-9.292 29。

Leaching of copper in NH_3·H_2O-NH_4Cl system from flotation tailings was studied.The optimum leaching conditions were found to be as follows：slag particle size,-0.045 mm;leaching temperature,60 ℃;concentration of NH_3·H_2O,3.0mol/L;concentration of NH_4Cl,2.5mol/L;amount of H_2O_2,0.2 mL/g;liquid-to-solid ratio,6∶1;stirring speed,500r/min;and leaching time,120 min.Under such conditions,copper leaching rate reached 62.22%.Kinetic study indicated that copper leaching is controlled by the inner diffusion of reactants,the apparent activation energy of leaching reaction is 11.56kJ/mol,and the apparent reaction order is 0.938 83.The kinetic equation of temperature on copper leaching reaction is lnk=-1.390 42×103/T-2.108 67,and that of NH_3·H_2O concentration on copper leaching reaction is lnk=0.938 83lnc-9.292 29.