Department of Energy & Mineral Resources Engineering, Sejong University, Seoul, Korea.
Environ Geochem Health. 2011 Jan;33 Suppl 1:151-8. doi: 10.1007/s10653-010-9354-2. Epub 2010 Nov 10.
The objective of this study is to examine the solidification of toxic elements in tailings by the use of cement and blast furnace slag. Tailings samples were taken at an Au-Ag mine in Korea. To examine the best mixing ratio of tailings and the mixture of ordinary Portland cement (OPC) and blast furnace slag (SG) of 5:5, 6:6, 7:3, and 8:2, the 7:3 ratio of tailings and OPC+SG was adapted. In addition, the mixing ratios of water and OPC + SG were applied to 10, 20, and 30 wt%. After 7, 14, and 28 days' curing, the UCS test was undertaken. A relatively high strength of solidified material (137.2 kg cm⁻² in average of 3 samples) at 28 days' curing was found in 20 wt% of water content (WC). This study also examined the leachability of arsenic and heavy metals (Cd, Cu, Pb, and Zn) under the Korean Standard Leaching Test, and it showed that the reductions in leachabilities of As and heavy metals of solidified samples were ranged from 76 to 99%. Thus, all the solidified samples were within the guidelines for special and hazardous waste materials by the Waste Management Act in Korea. In addition, the result of freeze-thaw cycle test of the materials indicated that the durability of the materials was sufficient. In conclusion, solidification using a 7:3 mixing ratio of tailings and a 1:1 mixture of OPC + SG with 20% of WC is one of the best methods for the remediation of arsenic and heavy metals in tailings and other contaminated materials.
本研究旨在利用水泥和高炉矿渣固化尾矿中的有毒元素。尾矿样品取自韩国一座金-银矿。为了研究尾矿和普通波特兰水泥（OPC）与高炉矿渣（SG）的最佳混合比（5:5、6:6、7:3 和 8:2），采用了尾矿和 OPC+SG 的 7:3 比例。此外，还研究了水和 OPC+SG 的混合比为 10、20 和 30wt%的情况。在 7、14 和 28 天的养护后，进行了 UCS 测试。在 20wt%水含量（WC）下，固化材料在 28 天养护时具有相对较高的强度（3 个样品的平均值为 137.2kgcm⁻²）。本研究还根据韩国标准浸出试验检验了砷和重金属（Cd、Cu、Pb 和 Zn）的浸出性，结果表明，固化样品中砷和重金属的浸出率降低了 76%至 99%。因此，所有固化样品均符合韩国《废物管理法》对特殊和危险废物材料的规定。此外，材料的冻融循环试验结果表明，材料的耐久性足够。总之，采用尾矿和 OPC+SG 的 7:3 混合比，以及 20%WC 的方法对砷和重金属污染的尾矿和其他污染材料进行固化是一种最佳的修复方法。
