Lignite, hard coal and coke

Coal is not a single stone but a series of rocks formed over millions of years as plant remains that piled up in swamps were buried and transformed by heat and pressure. The further the transformation has gone, the harder, blacker and richer in carbon the coal is, and the more heat it gives off when burned. The youngest and lowest-quality coal most people know is lignite: brownish, moist and crumbly. Hard coal (bituminous coal) is harder, jet black and shiny, and anthracite is the shiniest and most highly transformed coal. Coke, however, is not a natural coal but a grey, porous fuel made by heating hard coal without air at about 1,000 °C. Almost all the coal mined in Türkiye is lignite; hard coal is mined only at Zonguldak, and most of the hard coal Türkiye uses is imported.

Electricity: According to EURACOAL, coal supplied about 31 percent of Türkiye’s electricity in 2021. Lignite is mostly burned in power stations next to the mines. Heating: In many homes, especially where there is no natural gas, coal is still the fuel for stoves. Steel: Coke is used in blast furnaces to smelt and reduce iron ore. Industry: It is burned as fuel in cement works and other industrial kilns.

Its best-known localities: Soma, Manisa, Türkiye.

Known localities in Türkiye: Soma, Manisa, Türkiye.

Lignite is brown or brownish black and looks dull; it cracks and crumbles as it dries, and a woody texture can sometimes be seen in it. Rubbed on unglazed porcelain, it leaves a brown streak. Hard coal is black with shiny and dull bands, harder than lignite, and blackens your hands; it leaves a black streak on porcelain. Anthracite is the hardest and shiniest coal; it gleams almost like metal and hardly dirties the hands. The charcoal sold for barbecues is not coal in the geological sense; it is made by burning wood without air.

On the “street to diamond” value ladder it sits on step 2 of nine: Raw material by the tonne. The value of coal depends on its calorific value, its moisture, ash and sulfur content, and its lump size. Hard coal and anthracite give far more heat than the same weight of lignite. Hard coal suitable for making coke for steel is the most sought-after kind. Lignite, being moist and low in heat, is not worth transporting far; most of it is burned in power stations next to the mine. Heating coal is also graded and sold by lump size.

Coal stoves, barbecues and coal-fired heaters burning in closed, unventilated spaces can cause carbon monoxide poisoning. This gas is colourless and odourless; it causes headache, dizziness, nausea, weakness and drowsiness, and can kill sleeping people before they notice anything. Have stove chimneys cleaned regularly, never use a barbecue indoors, and if symptoms appear, get into fresh air at once and call the emergency services. Smoke from low-quality coal also pollutes the air with fine dust and sulfur dioxide.