de Almeida Rodrigo Pereira, Leite Adilson do Lago, Borghetti Soares Anderson
Universidade Federal de Ouro Preto, Ouro Preto, Brazil
Universidade Federal de Ouro Preto, Ouro Preto, Brazil.
Waste Manag Res. 2015 Apr;33(4):353-62. doi: 10.1177/0734242X15572178. Epub 2015 Mar 6.
The extraction of gold, coal, nickel, uranium, copper and other earth-moving activities almost always leads to environmental damage. In metal and coal extraction, exposure of sulfide minerals to the atmosphere leads to generation of acid rock drainage (ARD) and in underground mining to acid mine drainage (AMD) due to contamination of infiltrating groundwater. This study proposes to develop a reactive cover system that inhibits infiltration of oxygen and also releases alkalinity to increase the pH of generated ARD and attenuate metal contaminants at the same time. The reactive cover system is constructed using steel slag, a waste product generated from steel industries. This study shows that this type of cover system has the potential to reduce some of the adverse effects of sulfide mine waste disposal on land. Geochemical and geotechnical characterization tests were carried out. Different proportions of sulfide mine waste and steel slag were studied in leachate extraction tests. The best proportion was 33% of steel slag in dry weight. Other tests were conducted as follows: soil consolidation, saturated permeability and soil water characteristic curve. The cover system was numerically modeled through unsaturated flux analysis using Vadose/w. The solution proposed is an oxygen transport barrier that allows rain water percolation to treat the ARD in the waste rock pile. The results showed that the waste pile slope is an important factor and the cover system must have 5 m thickness to achieve an acceptable effectiveness.
金、煤、镍、铀、铜的开采以及其他土方工程活动几乎总会导致环境破坏。在金属和煤炭开采中，硫化物矿物暴露于大气会导致酸性岩排水（ARD）的产生，而在地下开采中，由于渗入的地下水受到污染，会导致酸性矿井排水（AMD）。本研究提议开发一种反应性覆盖系统，该系统既能抑制氧气的渗入，又能释放碱度以提高所产生的ARD的pH值，同时衰减金属污染物。反应性覆盖系统是用钢渣构建的，钢渣是钢铁行业产生的一种废弃物。本研究表明，这种类型的覆盖系统有潜力减少硫化物矿山废弃物处置对土地造成的一些不利影响。进行了地球化学和岩土特性测试。在渗滤液提取试验中研究了不同比例的硫化物矿山废弃物和钢渣。最佳比例是干重中钢渣占33%。还进行了如下其他试验：土壤固结、饱和渗透率和土壤水分特征曲线。通过使用Vadose/w进行非饱和通量分析，对覆盖系统进行了数值模拟。所提出的解决方案是一个氧气传输屏障，它允许雨水渗流以处理废石堆中的ARD。结果表明，废石堆坡度是一个重要因素，覆盖系统必须有5米厚才能达到可接受的效果。
