Open-pit mining, also known as opencast mining, is a surface mining technique that extracts minerals from an open pit in the ground. Open-pit mining is the most common method used throughout the world for mineral mining and does not require extractive methods or tunnels.
How does open pit coal mining work?
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 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).
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 open pit mining safe?
Open-pit mining is much safer than shaft mining. In underground mining, the threat of a cave-in or release of toxic gas is a constant concern. When shaft mining was the most common method of ore extraction, thousands died in cave-ins, gas events and accidents involving equipment.
Why is open pit mining cheaper?
The cost advantage of open pit mining to investors is a matter of scale. … It is cheaper to operate an open pit mine because less manpower and equipment is required. Strip mining, or open pit mining is profitable sooner than a shaft mine because more ore can be extracted from an open pit mine and more quickly.
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.
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.
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.
How deep do coal mines go?
Coal that occurs at depths of 55 to 90 m (180 to 300 ft) are usually deep mined, but in some cases surface mining techniques can be used. For example, some western U.S. coal that occur at depths in excess of 60 m (200 ft) are mined by the open pit methods, due to thickness of the seam 20–25 metres (60–90 feet).
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).
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;
How many mines are in SCCL?
What are the negatives of mining?
Across the world, mining contributes to erosion, sinkholes, deforestation, loss of biodiversity, significant use of water resources, dammed rivers and ponded waters, wastewater disposal issues, acid mine drainage and contamination of soil, ground and surface water, all of which can lead to health issues in local …
What does it mean to reclaim a mine?
Reclamation is the combined process by which adverse environmental effects of surface mining are minimized and mined lands are returned to a beneficial end use. End uses may be open space, wildlife habitat, agriculture, or residential and commercial development.
Why is open pit 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 …