Manufacture of asphalt

Hot asphalt applications had been used for many years in concrete tanks, inner lined with brick for similar service, and also, of course, unlined wood tanks made from timber, and small pickling tanks made by hollowing out cavities in granite blocks. But the use of hot asphalt as a liner for steel tanks had been unsatisfactory due to the erratic cold flow of the asphalt which demonstrated selective adhesion to steel and so would tear and open cracks in the membrane system in the areas of cold flow below the points where it adhered. To overcome this difficulty, a number of inventive persons experimented with the manufacture of asphalt sheet lining materials, similar in form to the sheets of natural rubber, in which the asphalt was compounded with various admixtures, including rubber. These asphaltic compound sheets were then warmed sufficiently to make... 

Distillation of coal tar provides four volatile fractions as well as the pitch that is used for surfacing roads and in the manufacture of asphalt roofing (Figure 27-12). Eight aromatic hydrocarbons obtained in significant amounts by efficient fractional distillation of the light oil fraction are those in Table 27-6. 

The first step in the manufacture of asphalt-based coatings consists of the distillation of crude petroleum, which results in distillate fractions (gasoline, naptha, kerosene, diesel fuel, and gas oil). The fraction of crude oil that boils above approximately 300 C is not distilled, but is withdrawn from the bottom of the distillation... 

Asphaltic cement can be bitumen, or a mixture of asphalt with bitumen, or flux oils, or pitch, which has cementing qualities suitable for the manufacture of asphalt pavements. 

For the construction of a concrete layer, the highest energy demand is required for the manufacture of cement, while for the construction of an asphalt layer, most of the energy is required for the manufacture of asphalt cement and heating during the hot mix production process (Chappat and Bilal 2003). 

Thermoplastic rubbers (TPR) are a type of rubber produced by polymerization of a mixture of substances, such as butadiene and styrene. They have some advantages over conventional rubbers. The advantages are (a) the material can be melted and easily molded and (b) the chemical composition can be varied to improve or to produce a material with new properties with a wider range of use. Styrene-butadiene-styrene (SBS) polymer is conunonly used as a modifier in the manufacturing of asphalt-based roofing materials. 

Cationic surfactants are widely used in the manufacture of asphalt emulsions. Today, over 8 million tonnes of asphalt emulsions are produced worldwide and over 3 million tonnes in the USA. A recent overview of asphalt emulsion technology by James clearly describes the state of the technology and the varied uses of asphalt emulsion in road construction and maintenance [75]. 

Residues to be used in the manufacture of asphalt can also be made but may not always be suitable. The long heat... 

Manufacture of asphalt, lubricant, and miscellaneous products of petroleum and coal... 

In the manufacture of asphalt most refiners limit the temperature to 770 F. Nevertheless, the temperature that may be used without ruining the ductility of the product is greatly dependent upon the characteristics of the stock and upon the manner of heating. One refiner has successfully used a temperature of 835 F at the pipestill outlet, but others have... 

Simple conventional refining is based essentially on atmospheric distillation. The residue from the distillation constitutes heavy fuel, the quantity and qualities of which are mainly determined by the crude feedstock available without many ways to improve it. Manufacture of products like asphalt and lubricant bases requires supplementary operations, in particular separation operations and is possible only with a relatively narrow selection of crudes (crudes for lube oils, crudes for asphalts). The distillates are not normally directly usable processing must be done to improve them, either mild treatment such as hydrodesulfurization of middle distillates at low pressure, or deep treatment usually with partial conversion such as catalytic reforming. The conventional refinery thereby has rather limited flexibility and makes products the quality of which is closely linked to the nature of the crude oil used. 

Tetrahydronaphthalene [119-64-2] (Tetralin) is a water-white Hquid that is insoluble in water, slightly soluble in methyl alcohol, and completely soluble in other monohydric alcohols, ethyl ether, and most other organic solvents. It is a powerhil solvent for oils, resins, waxes, mbber, asphalt, and aromatic hydrocarbons, eg, naphthalene and anthracene. Its high flash point and low vapor pressure make it usehil in the manufacture of paints, lacquers, and varnishes for cleaning printing ink from rollers and type in the manufacture of shoe creams and floor waxes as a solvent in the textile industry and for the removal of naphthalene deposits in gas-distribution systems (25). The commercial product typically has a tetrahydronaphthalene content of >97 wt%, with some decahydronaphthalene and naphthalene as the principal impurities. 

Preparation is accompHshed by simple blending of the diluent into the hot base asphalt. This is generally accompHshed in tanks equipped with coils for air agitation or with a mechanical stirrer or a vortex mixer. Line blending in a batch circulation system or in a continuous fashion (40) is used where the volume produced justifies the extra faciUties. A continuous, line-blending system is appHcable to the manufacture of cutback asphalts and asphalt cements (Fig. 8). 

Sampling (ASTM DUO). This standard provides guidance for the sampling of asphalts, hquid and semisohd, at point of manufacture, storage, or dehvery. 

Asphalt emulsions are dispersioas of asphalt ia water that are stabilized iato micelles with either an anionic or cationic surfactant. To manufacture an emulsion, hot asphalt is mixed with water and surfactant ia a coUoid mill that produces very small particles of asphalt oa the order of 3 p.m. These small particles of asphalt are preveated from agglomerating iato larger particles by a coatiag of water that is held ia place by the surfactant. If the asphalt particles agglomerate, they could settle out of the emulsion. The decision on whether a cationic or anionic surfactant is used depends on the appHcation. Cationic stabilized emulsions are broken, ie, have the asphalt settle out, by contact with metal or siHcate materials as weU as by evaporation of the water. Siace most rocks are siHcate-based materials, cationic emulsions are commonly used for subbase stabilization and other similar appHcations. In contrast, anionic emulsions only set or break by water evaporation thus an anionic emulsion would be used to make a cold patch compound. 

Typical apphcation of a BUR would be to mop or apply asphalt to a substrate to approximately 1.1 kg/m (23 lbs/100 ft ), or the thickness of a dime. A ply sheet would then be unroUed into the hot asphalt. Additional ply are then mopped in, with each layer offset so that the roof has three or four phes of felt over the entire roof. The amount of offset is calculated by the formula, offset = 34 in. (86.4 cm) /number of pHes. Manufacturers of pHes print laying lines on the felts at the correct locations to assist in laying up the roof with the correct offset. 

Petroleum refining and related industries Manufacture of paving and roofing materials Asphalt and tars, felts, paper, cloth, fiber... 

There is a wide range of conversion levels. The term maximum conversion type has no precise definition but is often used to describe a level of conversion, where there is no net fuel oil manufactured. A fuel products refinery with specialities may manufacture lubricating oils, asphalts, greases, solvents, waxes and chemical feed stocks in addition to the primary fuel products. The number and diversity of products will naturally vary from one refinery to another. Refineries produce chemical feed stocks for sale to the chemical affiliates and do not have responsibility for the manufacture of chemical products directly. Both operations may be carried out at the same physical location but the corporate product responsibilities are usually separate. 

Asphalt Manufacture Saleable asphalts are produced from the residua of selected crudes. The residuum itself may be sold as straight reduced cuts to make it easier to handle, producing the so called cut-back asphalts. Another variation is air blown or oxidized asphalts for improved tenacity, greater resistance to weathering, and decreased brittleness. Emulsified asphalts are made for application at relatively low temperatures. 

Since the propane deasphalting operation is primarily directed toward the manufacture of lubes with asphalt as a by-product, the grades of asphalt produced from a deasphalter are usually limited. In some cases considerable blending must be done (frequently with extract oils) to provide the variety of grades required by the consumer. 

The heaviest products obtained directly from oil arc lubricants, waxes, asphalt, and coke. These products have both domestic and industrial uses. Lubricants, for example, are applied in the operation and maintenance of industrial equipment and machinery. Asphalt, because it is not reactive to chemicals in the environment, is a superb material of construction in the building of roads and in roofing. It is also used in the waterproofing of concrete, the manufacture of black paints, and as a material lor tire threads, battery housing, electrical insulation, and other applications. The heaviest of all the petroleum products, coke, is used extensively as a major component of industrial electrodes and as a commercial fuel. 

Salts of a-sulfo fatty acid esters can work as emulsifying agents for the preparation of asphalt emulsions and asphalt-latex emulsions. The ester sulfonates improve the storage stability of the emulsions [101,102]. In the manufacture of lightweight gypsum products air bubbles have to be mixed into the slurries. The use of salts of sulfonated C10 l8 fatty acid alkyl esters as foaming agents produces uniformly distributed fine bubbles [103]. Salts of C10 16 fatty acid alkyl ester sulfonates can also be added to cement mixtures to prevent slump loss of the mixtures [104]. 

For example, treating petroleum distillates with sulfuric acid is generally applied to dissolve unstable or colored substances and sulfur compounds as well as to precipitate asphaltic materials. When drastic conditions are employed, as in the treatment of lubricating fractions with large amounts of concentrated acid or when fuming acid is used in the manufacture of white oils, considerable quantities of petroleum sulfonic acids are formed ... 

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