How is water used in mining, and what are the effects of mining on water?
Mining operations often use huge quantities of water for mineral processing, slurry transport, dust control, and human consumption. The water may come from nearby surface and groundwaters, but if fresh water is unavailable, it must be transported to the site or purified from existing low-quality sources.
Water extraction for mining can cause water shortages. Water quality is impacted by acid mine drainage resulting from chemical reactions that occur when excavated rock is exposed to water and air, the leaching of heavy metals, erosion, and contamination of water from processing chemicals. This pollution can poison the environment, cause flooding, and clog waterways with sediment, which kills wildlife, destroys natural habitat, and renders water unusable.
Prevention is key in containing these pollutants, along with sustainable management of water resources. Water must be diverted from run-off and properly treated for reuse or safe discharge back into nature.
Slower conventional methods like activated sludge, that requires energy-intensive compressed air, are being replaced by modern, efficient membrane treatment systems. Technologies such as reverse osmosis can rapidly remove contaminants from wastewater, maximize water recovery for reuse, decrease dependency on external water supplies, and help miners meet ever more stringent discharge requirements.
Has your mining operation experienced difficulties with water supply or environmental degradation? How are you managing your water usage?