Management of acidic effluents from tailing dams in metalliferous mines

Abstract

Mining activity is one of the many causes of pollution of water resources and creates a condition of imbalance between the land and water regime, in both quantitative and qualitative manners. Among the various causes of qualitative pollution, acid mine drainage (AMD) is more predominant and is produced in mines when pyrite and other sulphide minerals become exposed to the atmosphere. The very nature of mineral processing practices such as milling and grinding which are designed to maximize metal recovery also maximize the exposure of the surface area mine tailings and waste materials to subsequent oxidative processes. Though 3.6×108 Sq. km area out of total 5.6×108 Sq. km area of the earth surface is covered by water, yet it is surprising that only 0.3 percent of total available water is fit for human consumption and there is scarcity of potable water. The rapid industrialization and consequent rapid urbanization is exacerbating this potable water scarcity. By keeping this in mind the current paper discusses merits and demerits of various existing methods to manage or control acid generation due to sulphide minerals in tailing dams in order to utilize dam water for further uses.