模拟酸雨对大宝山尾矿淋滤实验研究

在模拟酸雨作用下,研究了大宝山尾矿中重金属Cd、Pb及Mn的释放规律及动力学。结果表明,在淋滤液不同酸度(pH为5.6、4.8、3.0)条件下,不同重金属呈现出不同的释放规律。随着淋滤量的增加,淋出液pH逐渐上升;Cd和Mn的释放可分为快速释放和慢速释放2个阶段,Pb的释放速度一直相对稳定。随着淋滤液pH的降低,淋出液pH降低,重金属的释放量及释放速度增加;淋滤液pH对3种重金属释放的影响程度为Pb>Mn>Cd。Cd和Mn的释放可用准二级动力学方程及Elovich方程很好拟合,准二级动力学方程更优;Pb的释放可用双常数方程和零级动力学方程很好拟合。

Experimental study on the leaching effect of simulated acid rain on tailings of Dabaoshan mine

Series of experiments were conducted to study the releasing characteristics of heavy metals from tailings under the leached of acid rain.The results revealed that different heavy metals presented the different releasing rules under 3 acidity of acid rain(pH was 5.6,4.8 and 3.0 respectively).The pH of leachate was increased with increasing the leaching quantity.The releasing process of Cd and Mn could be divided into two stage of rapid releasing stage and slow releasing stage,while the releasing speed of Pb was relative stable.With the pH decrement of the acid rain,the pH of the leachate decreased while the heavy metals releasing quantity and releasing speed was gradually increased.The influence intensity of pH of simulated acid rain on the release of heavy metals followed the order of Pb>Mn>Cd.The release kinetics of Cd and Mn could be quantitatively described by Pseudo-second-order kinetic equation and Elovich equation,and the former was better.The kinetics of Pb could be properly described both by two-constant equation and pseudo-zero-order kinetic equation.