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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.
Tar made from coal or petroleum is considered toxic and carcinogenic because of its high benzene content, [citation needed] though coal tar in low concentrations is used as a topical medicine for conditions such as psoriasis. [11] [12] Coal and petroleum tar has a pungent odor. Coal tar is listed at number 1999 in the United Nations list of ...
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.
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.
While uses for coal tar developed by the late-19th century, the market for tar varied and plants that could not sell tar at a given time could store tar for future use, attempt to burn it as boiler fuel, or dump the tar as waste. Commonly, waste tars were disposed of in old gas holders, adits or even mine shafts (if present).
How did the coal tar get there? In 1917, Southern Public Utilities began manufacturing gas to fuel the city of Greenville. At that time, coal was used as a power source. The gasification of coal ...
Coal-tar creosote is the most widely used wood treatment today; both industrially, processed into wood using pressure methods such as "full-cell process" or "empty-cell process", and more commonly applied to wood through brushing. In addition to toxicity to fungi, insects, and marine borers, it serves as a natural water repellent.
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