Several different mining techniques are often used to remove mineral deposits after they have been located. The technique used to remove mineral deposits depends on the types of mineral resources and their locations. In many cases, the materials that lie over a natural resource or deposit are removed in order to expose and mine the natural resource before it is processed.
Mining starts with the removal of all types of vegetation, forests, earth (soil), and rock that is the overlying mineral deposits on a site. Mining—specifically, the area strip mining technique—often leaves behind deposits of wastes called spoils or “spoil banks which are banks or heaps of excavated refuse or waste earth produced from surface mining activities. Generally speaking, mining scars and disrupts the land surface, and does long-term harm to the environment in a number of ways.
6 negative impacts of mining on the environment
1. Area strip mining creates spoil banks (which are very susceptible to wind erosion, water erosion, and chemical weathering) and makes it difficult for vegetation to regrow because of the absence of topsoil on sites where the spoil banks have been created.
Due to this reason, spoil banks have a negative impact on the environment and economy and often contribute to national capital degradation and expenditure, especially when a substantial amount of money and long process of primary ecological succession is required to return sites—that have spoil banks—back to their previous natural condition.
2. During mining and mountaintop removal, enormous and powerful machines plow great volumes of dirt and waste rock into the valleys that exist below mountaintops. This activity creates a negative impact on the environment because it produces toxic and wastewater sludge behind dams in the valleys, buries mountain streams, increases floods, and destroys forests.
3. The large quantities of debris deposited in the valleys destroy forests and create huge floods that can cause dams to overflow or collapse, and release toxic substances such as sulphuric acid, mercury, and arsenic.
4. Mining damages the environment of the communities around mining sites and makes it almost impossible for the people who live in the communities to avoid breathing debris or dust and other toxic chemicals released into the atmosphere as a result of large-scale daily blasting which also pollutes wells and rivers, and disrupts groundwater springs.
5. Surface mining in tropical areas or forests degrades or destroys the diversity of important animal and plant life in the habitat that is around such areas or forests, especially when the areas or forests are cleared and rivers are polluted with mining wastes that contaminate freshwater supplies which keep fish and other forms of aquatic life alive.
6. Subsurface mining, which usually produces less waste material, creates a negative impact on the environment because it cracks or breaks sewer lines, damages houses, and causes hazards such as explosions, combustion of flammable materials, and cave-ins (the sudden collapse of land above underground mines).