不同液固比条件下尾矿中重金属浸出的规律研究

尾矿渗滤液中的重金属是尾矿库环境污染的重要来源，而降雨量及尾矿在雨水中浸泡的时间是影响重金属浸出的关键因素。基于此，本文探讨了不同液固比条件下尾矿中重金属的浸出规律，采用静态淋溶和动态淋溶两种试验方式对不同粒度尾矿进行重金属浸出模拟试验，分析尾矿样品中重金属（Cu、Mn、Zn）浸出浓度变化情况。结果表明：pH为5.4的模拟条件下，静态淋溶下重金属浸出浓度均随液固比的增加而减小，且不同粒度尾矿中重金属浸出规律为：细粒度优于中粒度，粗粒度浸出程度最小；不同重金属浸出浓度受液固比影响程度为：锰>铜>锌；动态淋溶下重金属浸出浓度随淋溶量的增加呈明显下降趋势，存在快速下降和缓慢下降两个阶段。重金属释放数学模型的拟合发现，重金属的释放是一个复杂的过程，Cu和Zn的释放动力学特征与双常数速率方程拟合程度较高；锰的释放过程由修正Elovich方程描述效果更优。

Study on the law of heavy metal leaching from tailings under different liquid-solid ratios

Heavy metals in tailings leachate are an important source of environmental pollution in tailings ponds, and rainfall and the time that tailings are soaked in rainwater are the key factors affecting the leaching of heavy metals. Based on this, this paper discusses the leaching law of heavy metals in tailings under different liquid-solid ratios. Two experimental methods, static leaching and dynamic leaching, were used to simulate the tailings with different particle sizes, and the change of leaching concentration of heavy metals (Cu, Mn, Zn) in tailings samples were analyzed. The results show that: under the simulated conditions of pH 5.4, the leaching concentration of heavy metals in static leaching decreases with the increase of liquid-solid ratio, and the leaching degree of heavy metals in tailings with different particle sizes is: fine particle size is better than medium particle size, and coarse particle leaching is minimal; the effects of liquid-solid ratio on leaching concentrations of different heavy metals is as follows: manganese>copper>zinc; under dynamic leaching, the leaching concentration of heavy metals shows an obvious downward trend with the increase of leaching amount, and there are two stages of rapid decline and slow decline. The fitting of the mathematical model of heavy metal release showed that the release of heavy metals was a complex process, and the release kinetics of Cu and Zn fitted well with the double constant rate equation; the release process of manganese was better described by the modified Elovich equation.