Open-pit mining, also known as open-cast or open cut mining, is a surface mining technique of extracting rock or minerals from the earth by their removal from an open-air pit, sometimes known as a borrow. … Open-pit mines are used when deposits of commercially useful ore or rocks are found near the surface.
What is open cast coal mining?
Open cast mining involves the removal of ore from seams relatively near the surface by means of an open pit (see figure below). These mines often occupy a large area of land for excavation of the ore and disposal of the overburden (the waste rock lying over the ore).
How is coal extracted from an open cast mine?
Once the coal seam is exposed, it is drilled, fractured and thoroughly mined in strips. The coal is then loaded onto large trucks or conveyors for transport to either the coal preparation plant or directly to where it will be used. Most open cast mines in the United States extract bituminous coal.
In which condition is open cast mining used?
Open-pit mines are used when deposits of commercially useful minerals or rocks are found near the surface; that is, where the overburden (surface material covering the valuable deposit) is relatively thin or the material of interest is structurally unsuitable for tunneling (as would be the case for sand, cinder, and …
Why is open pit mining bad?
This type of mining is particularly damaging to the environment because strategic minerals are often only available in small concentrations, which increases the amount of ore needed to be mined. Environmental hazards are present during every step of the open-pit mining process.
Is coal mining still dangerous?
Coal mining is still dangerous. In 2010, West Virginia had the worst coal mining disaster in the US in 40 years, when an explosion killed 29 people. … That year, 3,242 people died in coal mining accidents. Coal mines have continued to have fires and explosions, killing hundreds of miners over the years.
Why is coal mining bad?
Along with adding to greenhouse gas pollution, burning coal emits toxic and carcinogenic substances into our air, water and land, severely affecting the health of miners, workers and surrounding communities.
How do you start an open pit mine?
To create an open-pit mine, the miners must determine the information of the ore that is underground. This is done through drilling of probe holes in the ground, then plotting each hole location on a map. The information gained through the holes with provide an idea of the vertical extent of the ore’s body.
Who is the largest coal producer in world?
What are the steps of open pit mining?
The open-pit mining cycle includes drilling ore and waste rock, loading drill holes with explosives, blasting, ore loading and hauling to stockpiles for processing, waste rock loading and hauling to the waste rock storage pile.
What is the difference between open cast mining and quarrying?
A quarry is the same thing as an open-pit mine from which minerals are extracted. The only trivial difference between the two is that open-pit mines that produce building materials and dimension stone are commonly referred to as quarries.”
Is open cut mining safe?
After the mineral deposits have been exposed, the area is drilled, fractured and the mineral extracted. This method has a high recovery rate when compared to the underground, as 90 percent of mineral deposits are recovered. Overall when compared to other methods, open-cut is much safer.
Where are open pit mines located?
Bingham Canyon mine located south-west of Salt Lake City, Utah, US, is the deepest open pit mine in the world. The Bingham Canyon pit is more than 1.2km deep and approximately four kilometres wide. The mine, which is owned and operated by Rio Tinto Kennecott, has been in production since 1906.
What are the disadvantages of open cast mining?
4. Disadvantages of open pit mining
- Very large amounts of waste rock are mined. …
- Major disruption of surface: pit footprint, waste dumps. …
- Very large volumes of overburden may need to be moved before reaching the orebody (e.g. coal) thus delaying return on capital expenditure;
What are the pros and cons of open pit mining?
Open Pit Mining Pros & Cons
- Efficient Operations. One of the major benefits to open pit mining is the increase in efficiency over deep-shaft mining techniques. …
- Greater Safety. Open-pit mining is much safer than shaft mining. …
- Loss of Ecosystem. …
- Pollution and Drainage.
What are the effects of open pit mining?
The effects of open-pit mining and mineral processing plants on the environment include land degradation, noise, dust, poisonous gases, pollution of water, etc. (Dudka and Adriano 1997).