ASTM classification of coals

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

Table 3.4 ASTM classification of coal by rank (ASTM D-388 [13]), extended by the mean random reflectance R, and bed moisture [3,10],...

Adapted, with permission, from D388-99, Standard Classification of Coals by Rank copyright ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428. 

ASTM 2003a. ASTM D388-99el Standard Classification of Coals by Rank. ASTM International. World Wide Web Address http// www.astm.org. 

Lignite) 854 (Peat) 1067 (Splint) 1084 (Sub-bituminous) 25)0. W. van Krevelen, "Coal Topology, Chemistry, Physics and Constitution Elsevier, Amsterdam (1961) 26)ASTM Stds 1961, Part 8, Method D388-38, ppl227-37 (Classification of coals) 27)H.H. Lowry,... 

Although the validity of the analytical data is uncertain, a generally accepted fouling classification of coal, according to total chlorine content (ASTM D-2361 ISO 352 ISO 587), is as follows ... 

The classification of coal (ASTM D-388) depends on calculation of the volatile matter yield and fixed carbon values on a dmmf basis. Calorific values are calculated on a moist, mineral-matter-free basis. The Parr formula is used in the classification system to calculate the mineral matter from ash and sulfur data. 

Table 4.6 ASTM rank classification of coals (approximate boundary values after Stach et al. 1982 Ward 1984)...

ASTM. 2011. Classification of Coals by Rank (ASTM D388). Annual Book of ASTM Standards, Section 05.05. American Society for Testing and Materials, Philadelphia, PA. 

In the ASTM system for the classification of coals by rank and in the International System for the classification of hard coals (Chapter 2), high-volatile coals are classified according to their calorific value on a moist basis. In this instance, the calorific value is quoted for the coal containing its natural bed moisture. 

Other bases may be required for the expression of analytical data. Moist, ash-free basis (maf) assumes that the sample is free of ash, but with moisture (ASTM D388, Standard Classification of Coal by Rank, requires calorific value to be expressed on a moist, mineral matter-free basis (mmmf)). The various national standards organizations present different formulae for the calculation of mineral matter (which is not a generally determined value) reference to their publications is necessary to determine which calculation is appropriate in given circumstances. 

TaUe 17.5. Classification of coals by rank according to ASTM D388... 

One classification of coal is by rank, i.e., according to the degree of metamorphism, or progressive alteration, in the natural series from lignite to anthracite. In the ASTM classification, the basic criteria are the fixed-carbon content and the calorific valnes (in British thermal units) calcnlated on a mineral-matter-free basis. 

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 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... 

Classilicalion of coals in Europe and other parts of the world differs somewhat from the American system. European classifications include ( ) the International Classification of Hard Coals by Type and (2) the International Classification of Brown Coals. These systems were developed by a Classification Working Party established in 1949 by the Coal Committee of die Economic Commission for Europe. The term "hard coal" is defined as a coal with a clorific value of more than 10.260 Blu per pound (5705 Calories/kg) on the moist, ash-free basis. The term "brown coal" refers to a coal containing less than 10.260 Blu per pound (5705 Calories/kg). In European terminology, ihe term "type" is equivalent to rank in American coal classification terminology and the term class approximates ihe ASTM rank. Space docs not permit a full comparison or the various systems. Reference to various ASTM publications is suggested. 

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

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