Geologic Environment Division, Korea Institute of Geoscience and Mineral Resources, Daejeon, Republic of Korea.
J Hazard Mater. 2011 Dec 15;197:153-60. doi: 10.1016/j.jhazmat.2011.09.069. Epub 2011 Sep 22.
A cover system for mine tailings with a solidified layer (called an engineered hardpan) was developed in this study to reduce water infiltration, acid generation and sulfide oxidation. Hydrated lime and waterglass were used to produce calcium silicate, which can serve as a binder when constructing a hardpan layer. The compressive strength of each solidified/stabilized material was found to be sufficient in the lab, and the amounts of heavy metals were significantly reduced in chemical leaching tests. Various characteristics of tailings may affect the layer's mechanical strength early on, but a long curing period is capable of compensating for these effects. Heavy metals were stabilized as carbonate-bound phases and sulfide minerals were surrounded by calcium silicate matrix, thereby preventing further reaction. To evaluate the field performance of the system, a hardpan layer was installed on top of tailings on a pilot scale. Leachate with high salt content was generated in the tailings layer in the early stages of monitoring, but after approximately 6 months, the objective was achieved as the hardpan layer gradually stabilized. Notably, during the heavy rainfall season of the later monitoring stage, water infiltration was continuously prevented by the system.
本研究开发了一种具有固化层（称为工程硬底）的尾矿覆盖系统，以减少水的渗透、酸的生成和硫化物的氧化。水硬石灰和水玻璃被用来生产硅酸钙，它可以作为建造硬底层的粘合剂。实验室发现，每种固化/稳定材料的抗压强度都足够高，化学浸出试验中重金属的含量显著降低。尾矿的各种特性可能会对早期的层状机械强度产生影响，但较长的养护期可以弥补这些影响。重金属被稳定为碳酸盐结合相，硫化物矿物被硅酸钙基质包围，从而防止进一步反应。为了评估系统的现场性能，在一个试点规模的尾矿上安装了一层硬底。在监测的早期阶段，尾矿层中产生了高盐含量的浸出液，但大约 6 个月后，随着硬底层逐渐稳定，目标得以实现。值得注意的是，在后期监测阶段的强降雨季节，该系统不断阻止水的渗透。
