高压旋喷工艺钝化尾矿库中重金属的研究

    Passivation of heavy metals in tailings dam of metal mine byhigh pressure rotary jet process

    • 摘要: 为了固化金属矿山尾矿库中重金属,研究了沸石、凹凸棒土和膨润土三种钝化剂对土壤中Cr、Zn、Cd、Pb的固化效果,并采用高压旋喷技术将钝化剂注入到尾矿库中,对重金属进行钝化处理。测定了尾矿砂中各重金属(Cr、Zn、Cd、Pb)的含量,以及钝化前后尾矿砂中重金属的浸出浓度,评价了钝化剂对尾矿砂的钝化效果;通过改变旋喷的注入压力、提升速率、以及孔径间隔等参数,得出一套最优高压旋喷参数。结果表明,以粒径小于74 μm的凹凸棒土为钝化材料,材料与土壤的添加比为1∶10时,重金属的钝化效果显著,其中Cr的平均浸出浓度降低了30.5%,Zn、Cd、Pb分别降低了87.8%、82.9%、42.4%;旋喷参数模拟试验表明,当样点处于旋喷柱的旋喷辐射范围内(辐射直径60 cm),浆液比为1.12,泵压为23 MPa,浆液流量为90 L/min,提速为14 cm/min,转速为14 r/min,耗材为75 kg/m时,修复材料对重金属的钝化效果更显著。

       

      Abstract: In order to passivate heavy metals in the tailing pond of metal mine, the stabilization of Cr、Zn、Cd、Pb in tailing sand was studied by using three passivating agent, namely, thomsonite, Bentonite and attapulgite, and high pressure rotary jet technique was used to passivate heavy metals in the tailing sand by injecting passivating agent into the tailing dam.Heavy metals contents in the tailing sand and in the leaching solution, before and after the injecting process, have been analyzed to evaluate the ability of the attapulgite clay in immobilizing the active form of heavy metals.Changing the parameters of high pressure rotary jet grouting, such as injection pressure, hoisting speed and aperture interval, the immobilizing effect have been analyzed completely and a set of relatively perfect experimental parameters have been gotten.The results showed that putting and mixing the attapulgite clay filtering less than 74 μm seize into tailing land by the clay-land mixture ratio of 1∶10, the average decrease rates of the active form of Cr, Zn, Cd, Pb in land were 30.5%, 87.8%, 82.9% and 42.4% respectively.And the simulation experiment showed that when the sampling sites were in the area of the spinning jetting of the pile, liquid-solid rate in slurry was 1.12, pumping pressure was 23 MPa, the flow of slurry was 90 L/min, hoisting speed was 14 cm/min, rotate speed was 14 r/min, the rate of consumable material was 75 kg/m, the effectiveness of the passivating agent in immobilizing heavy metals active forms was the best in the experiments.

       

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