Ash Impurities (iron, alumina, silica) contained in coal
Basin A depression in the Earth’s crust filled with sediment
Biomass Living material which can be converted to energy
Bituminous A rank of black coal of medium energy value. It is used mainly for power generation, but is sometimes used for steel making.
Bord and pillar Underground mining method that leaves spaces (bords) and pillars (blocks of coal) supporting the roof
Blast furnace A tall furnace in which coke reacts with iron ore to reduce it to pure iron
Btu British thermal unit. It is the amount of heat required to raise the temperature of 1 pound (453g) of water by 1°F (17°C)
Bulk commodities Low value materials, such as iron ore and coal, which must be handled efficient in large quantities if a profit is to be made from their sale
Carbon dioxide Colourless, odourless, non-toxic, radiative gas formed when carbon combines with oxygen – CO2. A major greenhouse gas
Clean coal technologies Technologies which improve the environmental performance of coal and other energy use through decreased emissions.
Coal An organic sedimentary rock formed from partly decayed plant material which has been metamorphosed by heat and pressure of geologic time
Coalification The process where heat and pressure turn decomposing plant material to coal
Coal preparation The process to convert mined coal to provide a pure product. This is done by washing out ash, either through crushing and sieving, electro-static treatment or via a liquid form.
Coal terminal Stockpile of coal kept at a port
Colliery An underground coal mine
Coke A solid lump of almost pure carbon formed when coal is heated (at heats as high as 2000°F (1093°C) in the absence of air. This de-volatilised coal is used as a reductant in the blast furnace. It is derived from coking coal. Coke is hard, grey and porous, and is used in iron and steelmaking
Coking coal Coal from which coke is produced (also known as metallurgical coal). It is a low-ash, low-sulphur bituminous coal.
CV Calorific value
Dragline A large bucket excavator used in open-cut mines
Energy The capacity to do work, also a term used for fuel sources used to provide power
Energy Mix The combination of available fuel sources used to provide energy. The ‘mix’ includes coal, gas, oil, water (hydro), uranium (nuclear), wind, sunlight (solar) and geothermal.
Generator A machine which, when the magnet around its shaft is turned, generates electricity in the surrounding coils of wire
Glossopteris An extinct seed-fern which made up most Permian coal deposits
Greenhouse gases Gases which restrict the re-radiation of infrared heat in the atmosphere
Kinetic energy Energy possessed by a moving or rotating object
Lignite Lowest rank of coal, known as brown coal. Moisture content c. 45%. Heat content varies from 9 to 17 million Btu per ton (.907 tonne). Used in power generation.
Liquefaction The process of converting coal into a liquid fuel
Longwall mining Mining technique where a mechanical shearer cuts along a coal face beneath a roof supported by hydraulic jacks
Metallurgical Coal This is the coal used in metallurgical (steelmaking) processes. The main metallurgical coals are coking coal and PCI (pulverisation coal injection) coals.
Methane A gas comprising one atom of carbon bound to four hydrogen atoms – CH4. A major greenhouse gas, it is the principal component of natural gas and is also a radiative gas.
Open-cut A surface mining method where coal is exposed by removing the overlying rock
Outcrop Rock or mineral material exposed on the Earth’s surface
Overburden Waste rock material overlying a coal seam, also called spoil. It is removed and either dumped or used in reclaiming mined areas
Peat Partially decomposed vegetation from marshes and swamps, it is dark brown or black in colour. First stage of the coalification process.
Permian A major coal forming geological period, about 250 million years ago
Radiative gases These gases in the atmosphere allow the sun’s heat to pass through to Earth, but do not let the heat radiate from Earth and escape from the atmosphere.
Rank A method of classifying coal based on the amounts of carbon and volatile matter it contains. It signifies the coalification of the organic material
Rehabilitation The process of returning a minded land surface into productive use
Run-of-mine (ROM) Mined ore of a size that can be processed without the need for further crushing
Seam Layer of coal – also called a bed
Sediment Rock particles, such as sand and clay, produced by weathering
Shearer A rotating cutting device used in underground coal mining
Steaming coal All non-metallurgical coal
Sub-bituminous coal This coal ranges from lignite to bituminous coal. It is used primarily for power generation. It contains 20 – 30% moisture. The heat content is 17 – 24 million Btu per ton (.907 tonne).
Thermal coal Coal used in boilers for generating steam. Also known as steaming coal. This coal is used in power generation and as a fuel in cement kilns.
Topsoil Surface layer of soil
Turbine Machine in which blades are turned by gas or steam, usually connected to a generator
Volatile matter Gas or vapour products, exclusive of water, given off by coal when it is heated to 9500°C
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Photo by Robert Billington, courtesy of NSWMC