Abstract
Sources and management of acid mine drainage.
Acid mine drainage (AMD) from both active and abandoned derelict mine sites is a major environmental issue for the mining industry. The term AMD is used to describe any seepage, leachate or drainage affected by the oxidation products of sulphide minerals in mine sites when exposed to air and water. The AMD is typically characterised by low pH and high levels of dissolved metal salts, as well as high concentrations of acidity, sulphate, iron and other metals. Once the AMD process begins, it is difficult to control, often accelerates and is likely to persist for decades or centuries. In the absence of natural or added neutralising materials (carbonate minerals such as calcite or dolomite), the AMD is likely to contain toxic levels of heavy metals such as Fe, Al, Mn, Cu, Pb, Zn, Cd etc. which can cause serious environmental problems in soil and water systems.
Regulations in many countries have developed ways to address the issue of AMD at the permitting stage rather than as an afterthought. Since AMD generation is a site-specific phenomenon, effective control and treatment measures have been directed towards fulfilling the problem on site rather than to providing universal solutions. This presentation describes the sources, and chemical and biological reactions resulting in acid mine drainage. It also covers the measures to prevent AMD formation and the methods to manage their environmental impacts.
Sources and management of acid mine drainage.
Acid mine drainage (AMD) from both active and abandoned derelict mine sites is a major environmental issue for the mining industry. The term AMD is used to describe any seepage, leachate or drainage affected by the oxidation products of sulphide minerals in mine sites when exposed to air and water. The AMD is typically characterised by low pH and high levels of dissolved metal salts, as well as high concentrations of acidity, sulphate, iron and other metals. Once the AMD process begins, it is difficult to control, often accelerates and is likely to persist for decades or centuries. In the absence of natural or added neutralising materials (carbonate minerals such as calcite or dolomite), the AMD is likely to contain toxic levels of heavy metals such as Fe, Al, Mn, Cu, Pb, Zn, Cd etc. which can cause serious environmental problems in soil and water systems.
Regulations in many countries have developed ways to address the issue of AMD at the permitting stage rather than as an afterthought. Since AMD generation is a site-specific phenomenon, effective control and treatment measures have been directed towards fulfilling the problem on site rather than to providing universal solutions. This presentation describes the sources, and chemical and biological reactions resulting in acid mine drainage. It also covers the measures to prevent AMD formation and the methods to manage their environmental impacts.
Presentation
Sources and management of acid mine drainage.
Presented on 30th March 2017 at the 7th Annual Best Practice Ecological Rehabilitation of Mined Lands Conference (2017)
3.00pm_20_min_nanthi_bolan_sources_and_management_of_acid_mine_drainage_amd-bolan.pdf |