ASTM classification

The combustion of coal results in the formation of an ash—the noncombustible component of coal— part of which is carried off with the combustion products as very fine particulate powder called fly ash. The heavy ash remaining in the combustion chamber is called bottom ash or boiler slag. The continuous mining process produces a coal containing about 28% ash. Coal used to generate steam usually has about 15% ash. 

The ash is an undesirable component of the coal and is usually reduced during the cleaning process that coal is normally subjected to after being shipped from the mine. This cleaning process removes the rocks, clay, and minerals which invariably mix with the coal. 

Element Symbol Coal Bottom ash Precipitated ash Bag ash Stack ash 

Hy ash is usually precipitated by a Cottrell electrostatic precipitator and/or collected in filter bags. The composition of the fly ash usually differs from the bottom ash due to thermal fractionation of the oxides. This is illustrated in Table 2.4 where the composition of the bottom ash is compared with various fractions of the fly ash which is classified into five groups  

As of 2006, about 125 million tons of coal—combustion by-products, including fly ash— were produced in the USA each year, with about 43% of that amount used in commercial applications, according to the American Coal Ash Association website. As of 2005, US coal-fired power plants reported producing 71.1 million tons of fly ash, of which 29.1 million tons were reused in various applications. 

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The combination of contrast and granularity produces a signal to noise ratio which allows for direct comparison of various films. The classes have minimum values for eontrast and maximum values for graininess. The ASTM classification system employs the same parameters as the European Standard EN584-1 and ISO CD (see Table 1). 

Analysis. Analyses of a number of lignitic coals are given in Table 3. Figure 1, a distribution plot of 300 U.S. coals according to ASTM classification by rank, indicates the broad range of fixed carbon values (18). According to the ASTM classification, fixed carbon for both lignite and subbituminous coals has an upper limit of 69%, but in practice this value rarely exceeds 61%. 

The ASTM Classification of Pig Tin B 339 lists three grades as shown in Tables 4 and 5 (16). 

The ASTM Glassification. The ASTM classification system was adopted in 1938 as a standard means of specification. This system is used in the United States and in many other parts of the world, and is designated D388 in the ASTM Standards (18). The higher rank coals are specified by fixed carbon >69%, or for volatile matter <31%, on a dry, mineral-free basis. Lower rank coals are classified by calorific value on the moist, mineral-matter-free... 

ASTM classification by rank Coke, wt % Tar, gal/ton Light oil, galAon Gas, ftVton Water, wt %... 

ASTM Classification Industry Type ASTM Classification Industry Type... 

ASTM C920 sealant specification, 22 46 ASTM classification, of pig tin, 24 790,... 

Castable refractories, ASTM classifications and specifications for, 27 510 Castables, 27 482 Cast alloys, 73 524 Cast copper-beryllium alloys, 3 653t,... 

High alumina brick, ASTM classifications and specifications for, 21 508 High alumina catalysts, 11 724 High alumina refractories, 21 515, 518 High analysis fertilizers, 11 123, 124 High aspect ratio micromachining... 

Insulated dye developers, 19 285-286 Insulated gate bipolar transistors (IGBTs), silicon carbide in, 22 539—540 Insulating brick, ASTM classifications and specifications for, 21 508, 509t Insulating castables, classification of, 21 510t... 

Silica analysis of water, 26 39 Silica-based glass fibers fabrication of, 77 136-137 transparency of, 77 132 Silica brick, ASTM classifications and specifications for, 27 509 Silica components, production of, 23 56 Silica fibers... 

According to the ASTM classification (ASTM D 1765 and D 2516), rubber blacks are characterized by one letter and three digits. The former shows the influence of... 

TABLE 2. REPRESENTATIVE UNITED STATES COALS ARRANGED IN ORDER OF ASTM CLASSIFICATION... 

In a fully synthetic oil, there is almost certainly some mineral oil present. The chemical components used to manufacture the additive package and the viscosity index improver (VI) contain mineral oil. When all these aspects are considered, it is possible for a "fully synthetic" engine oil to surpass mineral oil (Shubkin, 1993). Synthetic oils fall into general ASTM classification (a) synthetic hydrocarbons (poly-a-olefins, alkylated aromatics, cycloaliphatics) (b) organic esters (dibasic acid esters, polyol esters, polyesters) (c) other fluids (polyalkylene glycols, phosphate esters, silicates, silicones, polyphenyl esters, fluorocarbons). 

While useful as starting points, SPI and ASTM classifications are not sufficient to describe the wide range of polyethylenes available in the industry. Classifications have been further subdivided to convey additional information, such as molecular weight or comonomer employed. Eurther, manufacturers use their own nomenclature and trade names. Clearly, the names used for various polyethylenes are somewhat arbitrary and subjective. The reader should not rigidly construe classifications and may encounter other nomenclatures. An overview of various classifications of polyethylene in common use in industry is provided below ... 

Important standard specifications for seamless and welded austenitic steel tubing are available from the American Society for Testing Materials (ASTM), classifications A-213 and A-249. 

The ASTM classification provides some information about the carbon black type, but the information still can be broadened if one also uses the old classification along with it, and that is why both classifications are frequently used. 

ASTM Classification of Coals by Rank (in Box) and Corresponding Rank Parameters Not Used in the ASTM Classification... 

This AWS-ASTM classification is intended to be identical with the same classification that appears in the Specification for Copper and Copper-Alloy Welding Rods (AWS I)esignation A5.7 ASTM Desi tion B 259).>... 

Group number is std. ASTM classification, indicating normal use limit (XlOO). t See note under Table 9-7A. 

ASTM classification Unit Heat-resistant High-strength High-glass/epoxy Carbon fiber/epoxy... 

FIGURE 2.5 Comparison of class number (International System) with ASTM classification (1) parameters in the International System are on an ash-free basis, ASTM parameters are mineral matter-free basis and (2) no upper limit of calorific value for class 6 and high-volatile bituminous coals. 

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