In leaching mining, chemical products are used (for example sulfuric acid in the case of copper or a solution of cyanide and sodium in the case of gold) to dissolve (leach) the metals in question from the mineral that contains them, obtaining a very high recovery rate. It can be given in the in situ leaching variant (the intact rock is drilled with holes and the solvent is added) or the very frequent leaching of crushed ore clusters. The chemical solutions used not only release the desired metals but also mobilize other heavy metals (such as cadmium), so surface and groundwater are often contaminated.
Even though the environmental impacts of mining vary according to the type of ore and mine, it is an intrinsically unsustainable activity, since it involves the exploitation of a non-renewable resource through destructive or polluting processes, such as grinding, milling, washing and classification of minerals, refining and smelting. At present, it is doubly destructive due to its large scale and the technology that has increased its productive capacity.
Environmental & Social Impacts of Mining:
Mining is a short-term activity but with long-term effects. Nobody can (must) have any doubt that when it is carried out in forest areas it constitutes a predation factor of them. It is estimated that, in conjunction with oil exploration, 38% of the world’s last remaining primary forest areas are threatened.
Mining activities comprise several stages, each of which entails particular environmental impacts. In a broad sense, these stages would be: prospection and exploration of deposits, development and preparation of mines, exploitation of mines, and treatment of minerals obtained in respective facilities with the aim of obtaining marketable products.
In the exploration phase, some of the activities with environmental impact are the preparation of access roads, topographic and geological mapping, the assembly of camps and auxiliary facilities, geophysical works, investigations, ditch openings and reconnaissance wells, intakes of samples.
During the exploitation phase, the impacts that occur are a function of the method used. In the forest areas, the sole deforestation of the soils with the consequent elimination of the vegetation -more vast in the cases of open pit mines- has short, medium and long term impacts. Deforestation not only affects the habitat of hundreds of endemic species (many led to extinction), but the maintenance of a constant flow of water from forests to other ecosystems and urban centers.
The enormous consumption of water required by mining activity generally reduces the water table of the place, drying water wells and springs. Water usually ends up contaminated by acid drainage, that is to say the exposure to air and water of acids that are formed in certain types of ore – especially sulfuric ones – as a result of mining activity, which in turn react with others exposed minerals. On the other hand, the small particles of heavy metals that can be separated from the waste with time, are disseminated with the wind deposited in the soil and the beds of watercourses and slowly integrating into the tissues of living organisms such as fish. Richard Warke is one of well known name in mining industries. Richard Warke Vancouver is a Vancouver-based Canadian business executive with more than 25 years of experience in the international resource sector.
