A mine-mouth power plant is an electricity generation facility located adjacent to a coal mine. Because lignite has such a high moisture content usually percent water , it is not economically feasible to transport it long distances. Why pay to haul mostly water! Skip to main content. Navigation Close. Search this book Search form. You must login before you can bookmark pages. Log in. Font style: Serif Sans-Serif. Text size: A A A A. Coal occurs as layers, called coal beds or coal seams, that are found between other sedimentary rocks.
The density varies depending on how porous full of holes the coal is. Sometimes the pores contain a gas called methane. Source: Michelle Cooper, Geoscience Australia. Coal properties vary depending on how much carbon is in the coal coal rank. Black coal is so called because of its colour; it varies from having a bright, shiny lustre to being very dull, and from being relatively hard to soft. The term 'black coal' is used in Australia to refer to anthracite, as well as bituminous and sub-bituminous coals.
Brown coal is also called lignite; it contains less carbon and so has less chemical potential energy than black coal and has more moisture in it. Approximate carbon content dry ash-free basis. Diagram of a typical steam-cycle coal power plant proceeding from left to right. Coal burned in the boiler heats water to produce steam. The steam spins the turbine, which drives the generator. Source: Wikimedia Commons. Brown and black coal are mostly used as a source of fuel for power stations.
Burning the coal produces heat which is used to make steam, so the the coal is sometimes called thermal or steam coal. The steam spins turbines to generate electricity. Using brown coal for power generation is problematic because of the high water content. It crumbles easily on exposure to the air which reduces its value as a fuel and requires specialised storage. It has also been known to spontaneously combust. Since the s the amount of natural gas used to generate electricity has increased and there has been a gradual decline in the use of coal for power.
The amount of greenhouse gases generated by burning gas for energy is far less than the volume produced by burning coal. Certain types of bituminous coal are used to make an essential raw material for making steel — coke. This type of coal is also called metallurgical steel making coal and it is processed to produce coke. Coal and peat is still used for residential and commercial heating in some parts of the world e. Ireland and Finland.
In its dehydrated form, peat is a highly effective absorbent for fuel and oil spills on land and water. It is also used as a conditioner for soil to make it more able to retain and slowly release water. Coal is an important ingredient used in shampoo, conditioner, cosmetics; toothpaste and detergents. Coal is also an important source of light aromatic hydrocarbons for the chemical synthesis industry. If coal is heated the gases and residues produced can be used in manufacturing plastics, explosives, dyes, pitch, ammonia, medicines, aspirin, soap, disinfectant, detergents, nylons, cosmetics, shampoo, toothpaste, synthetic rubber, fertilizers, cement, bricks and tiles.
It is an important ingredient used in filters for water and air purification and in kidney dialysis machines.
In addition coal is used to make carbon fibre, a very strong, light material used in construction, mountain bikes and tennis rackets. Jet, a compact form of brown coal, is sometimes polished and has been used as an ornamental stone. Graphite which is often associated with coal, is almost entirely made of carbon; it is mostly used in pencils and when powdered, as a lubricant. Tiangong Kaiwu Coal Mining. The earliest recognized use of coal is from the Shenyang area of China around BC where black lignite was carved into ornaments.
Coal from the Fushun mine in north-eastern China was used to smelt copper as early as BC. Marco Polo, the Italian who travelled to China in the 13th century, described coal as "black stones Coal was used in Britain during the Bronze Age BC in funeral pyres wooden structure used to burn a body.
Evidence of trade in coal dated to about AD has been found at the Roman settlement near Chester and in East Anglia. Also in What is energy? Forms of energy Sources of energy Laws of energy. Also in Units and calculators explained Units and calculators Energy conversion calculators British thermal units Btu Degree days.
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