How is coal mined? Urgently needed ！！！！

Mining of coal has always been one of the most arduous tasks, and a great deal of effort is being expended to improve the working conditions. As coal resources are buried at different depths, they are generally mined accordingly by both shaft mining (deeper burial) and open pit mining (shallower burial). Can open pit mining resources in the total resources in the proportion of the size, is an important indicator of the advantages and disadvantages of mining conditions, China can be open pit mining reserves accounted for only 7.5%, the United States for 32%, Australia for 35%; mine mining conditions are good or bad and the number of coal mines containing gas is inversely proportional to how much coal mines contain gas, China's coal mines containing gas proportion is high, high-gas and gas protruding mines accounted for more than 40%. China's coal mining to mine mining, such as Shanxi, Shandong, Xuzhou and the northeast most of this mining method, but also open-pit mining, such as Inner Mongolia Hollinhe coal mine is China's largest open-pit mining area.

Open-pit mining

Removing the topsoil and rock (overburden) above the coal seam and mining the exposed coal seam. This method of coal mining, customarily called stripping method mining, this is because the coal exposed to the ground has been mined out, it is necessary to strip the topsoil, so that the coal seams are exposed. This method is most appropriate where the seams are not y buried, and many modern open-pit mines use equipment sufficient to strip overburden up to 60 meters thick. In Europe,

lignite mines are widely mined by surface mining, and in the United States, most anthracite and lignite are mined by this method. Surface mining is most economical when the terrain is flat and the seams are horizontally extended, allowing for extensive stripping. When the topography of the deposit is undulating or hilly, the contour stripping method is used to create steps with a hillside on one side and a nearly vertical cliff on the other. Surface is damaged or completely destroyed by open-pit mining, and measures should be taken to regain the surface. Several state and federal laws in the United States provide for measures to restore the ground, and many extractive companies now voluntarily enforce these provisions.

Mine Mining

For coal seams that are too y buried to be mined by surface mining, access to the seams may be obtained by three methods, namely, vertical shafts, inclined shafts, and flat caves.

A vertical shaft is a type of shaft that is dug from the ground to provide access to a particular coal seam or seams. Vertical shafts that are dug down from one coal seam to another are called blind shafts. In the underground, the mined coal is poured into a bunker located below the level of the coal seam on the side of the shaft, and then loaded into a shaft skip to be lifted up from the shaft.

A sloping shaft is an inclined tunnel used to mine a non-horizontal seam or to reach a seam or seams from the surface. Inclined shafts are equipped with belt conveyors used to transport coal, and personnel and materials are transported by rail cars.

A level mine is a horizontal or near-horizontal tunnel that is excavated where a horizontal or inclined seam is exposed at the surface, often along with the seam, and which permits the continuous transportation of coal from the working face to the surface by any conventional method.