This research aimed to study the leaching characteristics of arsenic from the Zn–Pb mine tailings under different conditions. The parameters and factors controlling the arsenic concentration of leachate were also determined. In order to estimate the concentrations of arsenic leached in different environmental conditions, four leaching protocols were used. These protocols included toxicity characteristic leaching procedure (TCLP), synthetic precipitation leaching procedure (SPLP), field leach test (FLT) and leachate extraction procedure (LEP) which was performed on two samples (S₁ and S₂) of the Zn–Pb mine tailings from Zanjan province, Iran. Also, the effects of various factors such as the pH of leaching water, the contact time of tailings with water, liquid to solid ratio and the particle size of tailings on the concentration of arsenic released from the Zn–Pb mine tailings were assessed using batch leaching tests. The results showed that in both samples, the highest concentration of arsenic was in the residual fraction that was relatively stable under natural environmental situations. The highest arsenic concentration occurred in the LEP test performed on the S₁ sample. According to the SPLP protocol, the Zn–Pb tailings had a high potential for contamination of surface and underground water. The mobility of arsenic in the tailings was entirely affected by the pH of leaching water, the contact time of the tailings with water, the particle size of the tailings and solid to liquid ratio. The leaching of arsenic enhanced in acidic and alkaline conditions and the concentrations of arsenic leached in acidic conditions were much higher than the concentrations of arsenic leached in alkaline conditions. The pH-dependent leaching behavior of arsenic from the Zn–Pb mine tailings was amphoteric. In both S₁ and S₂ samples, a larger fraction of arsenic released from the Zn–Pb mine tailings as the liquid to solid ratio and the contact time of the tailings with the water increased. In the S₁ sample, the highest concentration of arsenic released was observed in particles with a size of 500–600 μm, while for the S₂ sample, it was observed in particles with a size of 150–250 μm. According to the results of this experiment, important factors in preventing the release of arsenic from the Zn–Pb mine tailings into the environment are 1) controlling the pH of leaching water, 2) reducing the amount of pore water, and 3) reducing the contact time of the tailings with the water.

这项研究旨在研究不同条件下Zn-Pb矿尾矿中砷的浸出特性。还确定了控制渗滤液中砷浓度的参数和因素。为了估算在不同环境条件下浸出的砷的浓度，使用了四种浸出方案。这些协议包括毒性特征浸出程序（TCLP），合成沉淀浸出程序（SPLP），田间浸出试验（FLT）和浸出液浸出程序（LEP），它们在两个样品（S ₁和S _{2）上进行}）来自伊朗赞詹省的Zn-Pb矿尾矿。此外，还通过分批评估了淋洗水的pH，尾矿与水的接触时间，液固比和尾矿的粒径等各种因素对Zn-Pb矿尾矿中砷浓度的影响。浸出测试。结果表明，在两个样品中，砷的最高浓度都在自然环境下相对稳定的残留部分中。最高的砷浓度发生在对S ₁进行的LEP测试中样本。根据SPLP协议，Zn-Pb尾矿具有很高的潜在污染地表水和地下水的能力。砷在尾矿中的迁移率完全受浸出水的pH值，尾矿与水的接触时间，尾矿的粒径以及固液比的影响。在酸性和碱性条件下砷的浸出增强，在酸性条件下浸出的砷浓度远高于碱性条件下浸出的砷浓度。Zn-Pb矿尾矿中砷的pH依赖性浸出行为是两性的。在S ₁和S _2中样品中，随着液固比和尾矿与水的接触时间的增加，从Zn-Pb矿尾矿中释放出的砷含量也更大。在S ₁样品中，在500-600μm的颗粒中观察到了最高的砷释放浓度，而在S ₂样品中，在150-250μm的颗粒中观察到了最高的砷释放量。根据该实验的结果，防止砷从Zn-Pb矿尾矿释放到环境中的重要因素是：1）控制浸出水的pH值，2）减少孔隙水的量，以及3）减少废水中的砷。尾矿与水的接触时间。