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Coal tar is produced through thermal destruction of coal. Its composition varies with the process and type of coal used – lignite, bituminous or anthracite. [13] Coal tar is a mixture of approximately 10,000 chemicals, of which only about 50% have been identified.
One can produce a tar-like substance from corn stalks by heating them in a microwave oven. This process is known as pyrolysis. Tar is a dark brown or black viscous liquid of hydrocarbons and free carbon, obtained from a wide variety of organic materials through destructive distillation. Tar can be produced from coal, wood, petroleum, or peat. [1]
Pitch is a viscoelastic polymer which can be natural or manufactured, derived from petroleum, coal tar, [1] or plants. Pitch produced from petroleum may be called bitumen or asphalt , while plant-derived pitch, a resin , is known as rosin in its solid form.
Coal ash is hazardous and toxic to human beings and some other living things. [141] Coal ash contains the radioactive elements uranium and thorium. Coal ash and other solid combustion byproducts are stored locally and escape in various ways that expose those living near coal plants to radiation and environmental toxics. [142]
Bituminous coal. Bituminous coal, or black coal, is a type of coal containing a tar-like substance called bitumen or asphalt. Its coloration can be black or sometimes dark brown; often there are well-defined bands of bright and dull material within the seams. It is typically hard but friable.
The term creosote has a broad range of definitions depending on the origin of the coal tar oil and end-use of the material. With respect to wood preservatives, the United States Environmental Protection Agency (EPA) considers the term creosote to mean a pesticide for use as a wood preservative meeting the American Wood Protection Association (AWPA) Standards P1/P13 and P2. [6]
Scientists have taught a piece of material to play the game Pong, they say, in a major breakthrough. A simple hydrogel – a soft, flexible material – was able to play the game and learn so that ...
From the 1960s until the 1990s, significant amounts of naphthalene were produced from heavy petroleum fractions during refining, but present-day production is mainly from coal tar. [citation needed] Approximately 1.3 million tons are produced annually. [citation needed] Naphthalene is the most abundant single component of coal tar.