The goal of coal mining is to obtain coal from the ground. Coal is the important energe resource, and play an important role in industrial production. Coal is valued for its energy content, and since the 1880s has been widely used to generate electricity. Steel and cement industries use coal as a fuel for extraction of iron from iron ore and for cement production. Coal mining can have a large environmental impact and needs to be managed. Many mines are required by government to rehabilitate the area that was mined.
Coal mining methods
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 of draglines, trucks, conveyor, jacks and shearers. Coal is mined by two methods: surface mining (or 'opencast' mining) and underground mining (or 'deep' mining). The choice of mining method is largely determined by the geology of the coal deposit. Underground mining currently accounts for a bigger share of world coal production than opencast; although in several important coal producing countries surface mining is more common. For example, surface mining accounts for around 80% of production in Australia; while in the USA it is used for about 67% of production.
Coal mining machines
There are many kinds of machines used in coal mining, such as excavators, draglines, drills, roof bolters, continuous miners, longwall miners, rock dusters, shuttle cars and scoops.
Miners traditionally used shovels and steam shovels to break and remove earth, but today's miners rely on excavators. An excavator is a mobile vehicle that moves on tracks or with standard wheels. It features a rotating platform, off of which comes a hinged arm with a bucket or scoop attached to its end for digging.
Draglines are enormous earth moving machines that miners use to drag away dirt and expose underlying coal or mineral deposits. Draglines are some of the largest machines on the planet, and can remove several hundred tons of material in a single pass, according to Kentucky Coal Education.
Miners who extract natural gas and oil commonly rely on drills to reach underground deposits before piping the resources to the surface. Coal and mineral miners also use drills to create extensive series of holes, which they then fill with explosive charges to blast away chunks of earth.
Roof bolters are large, hydraulically-powered machines used to force bolts into roofs. Miners use roof bolters to support tunnel roofs and prevent underground collapses.
Continuous miners are machines with massive, rotating arrays of teeth, often made from tungsten carbide. Subterranean coal miners use the machines to scrape coal from coal beds. In particularly dangerous situations, workers control robotic continuous miners remotely.
In contrast to continuous miners, longwall miners remove large, rectangular sections of coal instead of scraping coal from a bed bit-by-bit. According to Kentucky Coal Education, continuous miners consist of a series of large cutting shearers and a self-raising hydraulic system that supports the mineshaft ceiling as sections of coal are removed.
Rock dusters are pressurized pieces of equipment that coal miners use to spray inert mineral dust over highly flammable coal dust. The inert dust helps prevent accidental fires and explosions.
Shuttle Cars and Scoops
Coalminers use electric-powered shuttle cars to transport coal from the coal bed to safer points in the mine. From there, miners can use standard scoops, or haulage vehicles, to drive their loads completely out of the mine. Miners of all types use haulage vehicles for various tasks.
Coal Mining Knowledge
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