Permeable reactive barriers to treat mine effluents

酸性矿山排水(AMD)是当今加拿大矿业面临的最严重的环境问题。酸性矿山废水是矿山废渣或尾矿中的硫化物矿物(如黄铁矿或磁黄铁矿)氧化的结果。它的特点是排放到环境中的富含重金属的酸性废水。据估计，未来加拿大各地恢复产酸矿场的总成本约为60亿美元。每年，加拿大各地的矿业公司都要花费数千万美元来中和酸性矿山废水。然而，另一方面，加拿大有一个广泛的铝冶炼提炼工业，每年生产数百万吨高碱性残留物(赤泥)，这些残留物也对环境造成有害影响。2007年，加拿大生产了600万吨高碱性赤泥。申请人将试验一种新的修复技术，利用铝提取行业的碱渣构建可渗透反应屏障(PRB)来处理酸性矿山废水。这一研究项目的成果一方面将有助于解决酸性矿山废水问题，另一方面将有助于解决碱性铝渣问题，从而使这两个行业在可持续发展的背景下受益。据估计，加拿大的经济节省将是可观的。加拿大矿业和冶金公司最终应用这项技术，可以大大节省环境保护成本，从而提高它们的竞争力。此外，这项技术将有助于这两个行业的可持续发展，减少各自的生态足迹。

Acid Mine Drainage (AMD) is the most serious environmental problem facing the Canadian Mineral Industry today. Acid Mine Drainage results from oxidation of sulphide minerals (e.g. pyrite or pyrrhotite) contained in mine waste or mine tailings. It is characterized by acid effluents rich in heavy metals that are released into the environment. It has been estimated that the total cost of restoration of acid producing mine sites across Canada in the future will be about $6 billion. Every year tens of millions of dollars are spent by mining companies across Canada to neutralize acid mine effluents. On the other hand however, Canada has an extensive metallurgical extractive industry of aluminum that produces every year several million tonnes of highly alkaline residues (red mud) that also represent harmful effects to the environment. In 2007, Canada produced 6 million of tons highly alkaline red mud. A new remediation technology will be tested by the applicant by which the alkaline residues from the aluminum extraction industry will be used to construct permeable reactive barriers (PRB) to treat acid mine effluents. The results of this research project will contribute to the solution of the Acid Mine Drainage problem in one hand and the alkaline aluminum residues on the other, thus benefiting both industries in the context of sustainable development. It is estimated that the economic savings for Canada will be substantial. The eventual application of this technology by Canadian Mining and Metallurgical Companies could result in significant savings on environmental protection costs therefore it will increase their competitiveness. Moreover, this technology will contribute to sustainable development for both industries reducing their respective ecological footprints.