Acidification of lead/zinc mine tailings and its effect on heavy metal mobility.
Acidification of lead/zinc mine tailings and its effect on heavy metal mobility.
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DOI：
10.1016/s0160-4120(01)00017-4
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发表时间：
2001-05
影响因子：
11.8
通讯作者：
W. Shu;Z. Ye;C. Lan;Z. Zhang;M. Wong
中科院分区：
文献类型：
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作者：
W. Shu;Z. Ye;C. Lan;Z. Zhang;M. Wong
采用净产酸（NAG）和酸碱核算（ABA）方法研究了广东省乐昌市铅锌（Pb/Zn）尾矿的产酸潜力。尾矿中黄铁矿和全硫含量分别为12.6%和18.7%。平均酸中和能力 (ANC) 为 63.5 kg H2SO4/t，而三个氧化尾矿样品的 ANC 小于零。 NAG和净产酸潜力（NAPP）值为220和326 kg H2SO4/t，NAG和NAPP结果均表明尾矿具有较高的产酸潜力。 NAG 在预测尾矿由于黄铁矿硫未完全氧化而形成酸的潜力方面比 NAPP 更准确。两次剖面测试样品分析表明，酸化主要发生在尾矿表层（0~20 cm），对尾矿深层影响较小。酸化尾矿剖面中Pb、Zn、Cu、Cd的总浓度随着深度的增加而显着增加，而非酸化尾矿剖面不同深度的重金属浓度相似。结果表明，酸化表面重金属的消耗是由于酸化造成的。酸化尾矿表面（0~20 cm）的二乙烯四胺五乙酸（DTPA）可萃取Pb、Zn、Cu和Cd浓度显着高于未酸化尾矿，进一步揭示酸化增强了尾矿中重金属的迁移率。
The acid-forming potential of lead/zinc (Pb/Zn) mine tailings at Lechang City of Guangdong Province was studied using both net acid generation (NAG) and acid–base accounting (ABA) methods. The pyritic and total sulfur contents of the tailings were 12.6% and 18.7%, respectively. The mean acid neutralization capacity (ANC) was 63.5 kg H2SO4/t while three oxidized tailings samples had an ANC less than zero. The NAG and net acid production potential (NAPP) values were 220 and 326 kg H2SO4/t, and both the NAG and NAPP results indicated that the tailings had a high acid-forming potential. NAG was more accurate than NAPP in predicting acid-forming potential of the tailings due to uncompleted oxidization of pyritic sulfur. Analysis of samples from two profile tests indicated that acidification mainly occurred at the surface (0–20 cm) and had little effects at deep layer of the tailings. Total concentrations of Pb, Zn, Cu, and Cd were increased greatly with depth at the acidified tailings profile, while heavy metal concentrations at different depths of nonacidified tailings profile were similar. The results indicated that depletion of heavy metals at the acidified surface was due to acidification. The diethylenetetramine pentaacetic acid (DTPA)-extractable Pb, Zn, Cu, and Cd concentrations of acidified tailings surface (0–20 cm) were significantly higher than those of nonacidified tailings, which further revealed that acidification enhanced the mobility of heavy metals in the tailings.