Coal as one of energy alternative is obtain from the ground. The Coal is valued for its energy content, and since the 1880s has been widely used to generate electricity. In the United States, United Kingdom, and South Africa, a coal mine and its structures are a "colliery". In Australia, "colliery" generally refers to an underground coal mine.
As one of the alternative energy, the coal mining has had a lot of developments over the recent years, from the early days of men tunneling, digging and manually extracting the coal on carts to large open cut and long wall mines. Mining at this scale requires the use ofr, trucks, conveyor, jacks and shearers.
Methods of extraction
The most economical method of coal as energy alternative is extraction from coal seams which depends on the depth, quality of the seams, geology and the environmental factors. The coal mining processes are differentiated from the surface or underground. Many coals extracted from both surface and underground mines require washing in a coal preparation plant.
Surface mining and deep underground mining are the two basic methods of mining. The choice of source alternative energy mining method depends primarily on depth of burial, density of the overburden and thickness of the coal seam. Seams relatively close to the surface, at depths less than approximately 180 ft (50 m), are usually surface mined.
Surface mining and deep underground mining are the two basic methods of mining. The choice of source alternative energy mining method depends primarily on depth of burial, density of the overburden and thickness of the coal seam. Seams relatively close to the surface, at depths less than approximately 180 ft (50 m), are usually surface mined.
Coal that occurs at depths of 180 to 300 ft (50 to 100 m) or below 300 ft (100 m) are usually deep mined.
Surface or opencast mining
Open cut mining methods is economically to extract coal seam which near the surface. It is also recovers a greater propotion of the coal deposit than underground methods. As source of energy alternative, Large Open Cast mines can cover an area of many square kilometers and use very large pieces of equipment.
This equipment can include the following: Draglines which operate by removing the overburden, power shovels, large trucks in which transport overburden and coal, bucket wheel excavators, and conveyors.
In this method, explosives are first used in order to break through the surface, or overburden of the mining area. The overburden is then removed by draglines or by shovel and truck. Once the coal seam is exposed, it is drilled, fractured and thoroughly mined in strips. The coal is then loaded on to large trucks or conveyors for transport to either the coal preparation plant or directly to where it will be used.
Underground or deep mining
Most coal seams are too deep underground for opencast mining and require underground mining.The source of energy alternative in deep mining, the room and pillar or bord and pillar method progresses along the seam, while pillars and timber are left standing to support the mine roof. Once room and pillar mines have been developed to a stopping point, miners remove the coal in the pillars, thereby recovering as much coal from the coal seam as possible. A work area involved in pillar extraction is called a pillar section.
Modern pillar sections use remote-controlled equipment, including large hydraulic mobile roof-supports, which can prevent cave-ins until the miners and their equipment have left a work area. The mobile roof supports are similar to a large dining-room table, but with hydraulic jacks for legs. After the large pillars of coal have been mined away, the mobile roof support's legs shorten and it is withdrawn to a safe area. The mine roof typically collapses once the mobile roof supports leave an area.
In order to make efeciency and increase the coal production, many equipment are need it.
Coal Mining Equipment
In order to make efeciency and increase the coal production, many equipment are need it.
- Road headers are indispensable equipment for infrastructure construction for road tunnels, railroad tunnels, dam headrace tunnels, coal-mine drifts,
- Truck and excavator mining method is the primary method currently utilised.
- Coal excavator
- The Limestone ultrafine grinding mill is the thin powder and super thin powder making machine. The final size of powder is 0.047-0.005mm in limestone powder plant.
- Low Coal Mining Hat
- Coal mining Belt Conveyor
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