Also called mines to pit, open pit mines are those mining operations that take place on the surface, unlike the underground mines. This is possible when the reservoir slightly appears on the surface or at a very small depth. It began to be realized in the middle of the 16th century and now it is used all over the world. In order for an open pit mine to be carried out, excavation (using machinery or explosives) of the land surrounding the site is necessary. The material that is not usable on the farm is called sterile as well as is deposited in dumps situated outside the mine site, which will be used in the future to restore it once it is worn out.
Advantages & Disadvantages of Open Pit Mining:
The open – pit mining is profitable when the site is not very deep or when the soil is sandy or delicate, so that underground mining is not possible. Labour costs are lower, both in excavation and transportation, and allow the use of large machinery. It does not require artificial lighting as well as allows the use of explosives of any type, without forgetting that the safety and hygiene of workers is much important. Open pit methods are leading the way in the mining sector.
However, it is true that it has environmental implications to be considered, which generates a strong environmental impact such as aesthetic, noise, dust in the area and that the work is carried out in the open. The need to work in large area of land is another issue to consider. Companies should consider working in a large, open area of land to avoid pollution generated by open pit mining.
Types of open mines:
- Quarries: They are usually small and the materials that are oppressed do not need a strong subsequent treatment. Of these, aggregates, industrial as well as ornamental rocks are extracted.
- Discovered: Mines almost horizontal, at an invariable height.
- Short: They are usually excavated with hole as well as blasting in the form of an inverted cone. They are generally made of metals or coal.
- Floods: Exploitation of sand deposits for gold, precious stones as well as other elements extracted during mining.
Consequences of open pit mining:
One of the main disadvantages of this type of mining operation is the environmental impact it causes. Since cyanide, mercury as well as sulfuric acid are used to remove the wastewater, groundwater and air are infected as toxic dust. This is absorbed by animals as well as plants.
The extraction itself generates a sound impact that scares away the animals of the nearby area, which causes a change in the habitat of many species; which is a very common issue these days. In addition, the miners work on a large area of land that is spoiled by mechanical action. This diminishes the aesthetic appeal as well as tourism of the area, and disturbs the nearby communities.