Bitumen
Encyclopedia : B : BI : BIT : Bitumen
Bitumen is a category of organic liquids that are highly viscous, black, sticky and wholly soluble in carbon disulfide.
Bitumen is obtained by fractional distillation of crude oil. Bitumen being the heaviest and being the fraction with the highest boiling point, it appears as the bottommost fraction.
In British English, 'bitumen' refers to heavy, black viscous material obtained from the distillation of crude oil. The word 'asphalt' in British English refers to a mixture of mineral aggregate and bitumen (tarmac in common parlance). The word 'tar' refers to a black viscous material obtained from the destructive distillation of coal and is a chemically distinct material different to bitumen.( In American English, 'bitumen' is refered to as 'asphalt' or 'asphalt cement'in engineering jargon. In Australian English, 'bitumen' is sometimes used as the generic term for road surfaces
Bitumen is primarily used for paving roads. Its other uses are for the general waterproofing products, including the use of bitumen in the production of roofing felt and for sealing flat roofs. It is also the prime feed stock for petroleum production from tar sands currently under development in Alberta, Canada.
In the past, bitumen was used to waterproof boats, and even as a coating for buildings; it is possible, for example, that the city of Carthage was easily burnt down due to extensive use of bitumen in construction.
Vessels for the heating of bitumen or bituminous compounds are usually excluded by public liability insurance policies.
Most geologists believe that naturally occurring deposits of bitumen are formed from the remains of ancient, microscopic algae and other once-living things. These organisms died and their remains were deposited in the mud on the bottom of the ocean or lake where they lived. Under the heat and pressure of burial deep in the earth, the remains were transformed into materials such as bitumen, kerogen, or petroleum.
A minority of geologists, proponents of the theory of abiogenic petroleum origin, believe that bitumen and other hydrocarbons heavier than methane originally derive from deep inside the mantle of the earth rather than biological detritus.
See also
From Wikipedia, the Free Encyclopedia. Original article here. Support Wikipedia by contributing or donating.
All text is available under the terms of the GNU Free Documentation License See Wikipedia Copyrights for details.