Petroleum asphalt

Asphalt (qv) is prepared from petroleum and often resembles bitumen. When asphalt is produced simply by distillation of an asphaltic cmde, the product can be referred to as residual asphalt or straight-mn petroleum asphalt. If the asphalt is prepared by solvent extraction of residua or by light hydrocarbon (propane) precipitation, or if blown or otherwise treated, the term should be modified accordingly to qualify the product, eg, propane asphalt. 

ASTM (1) further classifies asphalts or bituminous materials as soHds, semisoUds, or Hquids. SemisoHd and Hquid asphalts predominate in commercial practice today. Prior to 1907, the principal portion of asphalt used occurred naturally since that time most asphalts have been produced from the refining of petroleum. Air-blown petroleum asphalts (5) of diverse hardness became available in the early 1900s, and as thek use increased, the demand for native products diminished. 

Asphalt (bitumen) also occurs in various oil sand (also called tar sand) deposits which occur widely scattered through the world (17) and the bitumen is available by means of various extraction technologies. A review of the properties and character of the bitumen (18) suggests that, when used as an asphaltic binder, the bitumen compares favorably with specification-grade petroleum asphalts and may have superior aging characteristics and produce more water-resistant paving mixtures than the typical petroleum asphalts. 

Petroleum asphalts, compared to native asphalts, are organic with only trace amounts of inorganic materials. They derive their characteristics from the nature of their cmde origins with some variation possible by choice of manufacturing process. Although there are a number of refineries or refinery units whose prime function is to produce asphalt, petroleum asphalt is primarily a product of integrated refineries (Fig. 1). Cmdes may be selected for these refineries for a variety of other product requirements and the asphalt (or residuum) produced may vary somewhat in characteristics from one refinery-cmde system to another and even by cut-point (Table 2) and asphalt content (Fig. 2) (5,6). The approximate asphalt yields (%) from various cmde oils are as follows ... 

Table 7. Elemental Analyses of Representative Petroleum Asphalts...

Test Procedures. Most tests apphed to petroleum asphalts are empirical in nature (45). The ASTM tests are not the only ones appHed to asphalt testing. Private tests of a propriety nature have been used within companies. Some of these tests are now being made pubHc and occur from time to time in Hterature reports. Such tests may become a part of the ASTM standards. 

Chemical Designations - Synonyms Asphalt Cements Asphaltic Bitumen Bitumen Petroleum Asphalt Chemical Formula Not pertinent. 

Chemical Designations - Synonyms Liquid asphalt Petroleum asphalt Slow-curing asphalt Chemical Formula Not applicable. 

In pipelining, the trend is towards all-welded steel for long lines, and since the wall thickness is less than that of cast iron, protection is the more important. Many types of coating are used, from thick concrete to thin paint films, and each has its own particular suitability, but the majority of pipelines throughout the world today are coated with hot-applied coal tar or petroleum asphalt-base-filled pipeline enamels, into which reinforcing wraps, such as glass fibre are applied. 

The majority of pipelines today are coated with hot-applied plasticised coal tar or petroleum asphalt enamels. Both coal-tar pitch and petroleum asphalt have been used as protectives with and without filling materials. When filled... 

Petroleum asphalt or coal-tar pitch as coatings The question of whether coal-tar pitch or petroleum asphalt is the more suitable for the coating of underground pipelines has raised a good deal of controversy. Asphalt and pitch are both waterproof materials, and they resemble one another in physical type. In the right circumstances both can be very effective in preventing the access of water to buried or submerged steel surfaces. 

Originally bituminous materials such as natural asphalt but now a by-product of petroleum refining - an air-blown petroleum asphalt. In rubber compounding it is a tack-producing softener in larger proportions it is classed as an extender. 

About 75 percent of U.S. production of petroleum asphalt is used for paving while 15 percent is used for roofing. The remaining 10 percent is used for the more than 200 other known uses of asphalt. 

The production of carbon fibres is based on the pyrolysis of organic fibres or precursors. The main starting materials are polyacrylonitrile (PAN) and pitch (coal tar or petroleum asphalt). They can be classified according to their mechanical performances ... 

Synonyms Asphaltic bitumen asphaltum petroleum asphalt bitumen... 

In mice skin-painting studies, skin tumors were produced by steam-refined petroleum bitumens, an air-refined bitumen in toluene, two cracking residue bimmens, and a pooled mixmre of steam- and air-blown petroleum bitumens. In contrast, standard roofing petroleum asphalts produced no tumors. 

ASPHALT Asphaltic Bitumen, Petroleum Asphalt, Bitumen Combustible Liquid, III 0 1 0 ... 

Blown, or oxidized, petroleum asphalts were first produced commercially by Byerley about 1894. But neither blown nor residual asphalts from the early crudes enjoyed very good repute in the United States, partly because of the nature of the crudes and partly because of insufficient care in manufacture. Discovery of sources of asphaltic and semi-asphaltic crudes made possible the production of residual petroleum asphalts suitable for paving, and improvements in the blowing process led to products well suited for the manufacture of prepared roofings. In fact, the early growth of the roofing industry corresponded closely with the production of petroleum asphalts (86). 

By 1911 the tonnage of domestic petroleum asphalts exceeded the importations of Trinidad and Bermudez asphalts. Starting about 1920, and coincident with the rapid expansion in rural road building, the production of petroleum asphalt has rapidly increased, as shown by Figure 1, so that it exceeded 9,000,000 tons in 1949. The ratio of petroleum to native and rock asphalt production in 1949 was approximately 8 to 1 (186). 

Table I. Petroleum Asphalts Sold in the United States in 1949 (126)...

Monsit. An expl mixture consisting of AN 72, Amm picrate 23 petroleum asphalt 5%... 

BITUMEN. Natural flammable substances of a wide range of color, hardness, and volatility, constituted mainly of a mixture of hydrocarbons and essentially free from oxygenated bodies. Petroleums, asphalts, natural mineral waxes, and asphaltites arc considered bitumens. See also Tar Sands. 

Mansit. An expl mixt consisting of AN 72, Amin Picrate 23 and petroleum asphalt 5% Ref Blinov, Vol 2 (1948)... 

Asphalt Institute-an international, non-profit association sponsored by members of the petroleum asphalt industry that serves both users and producers of asphaltic materials through programs of engineering service, research, and education. 

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