Coal, analyses classification

Moore, E.S. 1940. Coal Its Properties, Analysis, Classification, Geology, Extraction, Uses, and Distribution. John Wiley Sons Inc., New York. 

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%. 

Hard and soft acid and base (HSAB) principle, 16 780 Hard blacks, 21 775 Hard-burned quicklime, 15 28 Hard coals, 6 703 classification, 6 712 Hard copper alloys, 7 723t relief annealed, 7 723t Hard copy systems, 9 513-514 Hard core repulsion, 23 93 Hard-elastic olefin fibers, 11 242 Hardenability, of steel, 23 283—284 Hardened MF resins, analysis of,... 

Using polished pellets 1 inch in diameter, a microscopic particle classification analysis for lithotypes, developed for this research by the authors (I), was made of the various coals. Only vitrain, durain, and fusain were counted. Results are presented in Table IV. Standard visual parameters were used for particle identification. An analysis of this type, although not necessarily conclusive, is important for a relative comparison. Results of a check between... 

Classification by grade covers the quality of the coal as detd by size,proximate analysis, ultimate analysis, ash-softening temp, ability to carbonize, calorific value, etc (See Ref 26, D339-37, p 1232)... 

The final results of the proximate analysis of coal (ASTM D-3172 ASTM D-3173 ASTM D-3174 ASTM D-3175 ASTM D-5142 ISO 562) are usually reported to the first decimal place any subsequent figures have little or no significance. The final report of the analysis should always contain the results on a basis of air-dried coal (i.e., coal in its most stable condition and in which it was analyzed), but for purposes of classification or comparison it is often necessary to convert to another basis, such as dry coal, dry, ash-free coal, or as-received coal. 

Various separation methods have been used to isolate, fractionate, and characterize humic materials. Originally it was fractionation, based on solubility differences of humic components in diluted alkalis and acids, which laid the ground work for the first classifications of humic substances (HS) in the 19th century (Mulder, 1861 Sprengel, 1837) and provided for operational definition of HS (Kononova, 1966). And now, alkali extraction is the method of choice for isolating HS from solid humus-containing substrates like soil, peat, coal, and so on (Swift, 1996), while hydrophobic resins (e.g., Amberlite XAD resins) are typically used to extract HS dissolved in natural waters (Aiken, 1985). Initial research on HS began with the used simple separation methods to prove, examine, and define characteristics of components of humic matter (Oden, 1919).Today, however, advances in HS research require ever more sophisticated techniques of separation combined with structural analysis (Orlov, 1990 Stevenson, 1994). 

It was suggested that computer-based data analysis techniques (often involving multivariate statistical methods) can aid in this classification or simplification, as has been so profitable in other thermochemical conversion endeavours, for example, as applied to coal and petroleum. Again, it was emphasized that there is a need for a critical synthesis of the wealth of experimental data into regimes of behaviour, and simpler predictive equations or simulations, that are useful to the technologists in industry who are designing industrial scale reactors. 

Classification of Coals.—Coals obtained west of Pittsburgh are generally of inferior quality. Coal may be classified according to either the proximate or the ultimate analysis. Thus Frazer s classification ... 

Preliminary analysis and information classification according to the coal mine accidents in China, summarize and classify the historical information, establish reasonable headers in the table, do matting for next step ... 

Liang Y P Wen G C 2000. Comprehensive Analysis Method of Three Zone Classification on Mine Roof Strata. [J]. Coal Science and Technology, 28(5) 39—42. 

This classification is not perfect, unlike the other classifications for example the calcareous fly ash is not distinguished regarding the differences of anhydrite content (SO3). As it results from the analysis presented in Table 7.3, the fly ash from Belchatow could be even used in the production of CEM n/B-V cement, after CaO transformation into the calcium hydroxide, while the fly ash from Konin only in a limited range, because of the SO3 content. The transition of CaO to Ca(OH)2 is necessary, because in the PN-EN 197-1 standard the reactive CaO content in fly ash is restricted to 10%. The aforementioned classification rates Polish fly ash from the hard coal combustion to the siliceous ash and that from the brown coal combustion in Turoszow coal-field— to the aluminous ones respectively. 

European and American researchers in the nineteenth and early twentieth centuries proposed several coal classification systems. The earliest, published in Paris in 1837 by Henri-Victor Regnault (1810-1878), classified coal types according to their proximate analysis (determination of component substances, by percentage), that is, by their percentages of moisture, combustible matter, fixed carbon, and ash. This system is still favored, in modified form, by many American coal scientists (Speight, 2005). 

This system of classification, in fact, indicates the degree of coalification as determined by these methods of proximate analysis with lignite being classed as low-rank coal the converse applies to anthracite. Thns, coal rank increases with the amount of fixed carbon but decreases with the amount of moistnre and volatile matter. It is, perhaps, easy to understand why coal rank is often (and incorrectly) eqnated to changes in the proportion of elemental carbon in coal (ultimate analysis Chapter 8). 

The classification systems for coal variously involve either proximate analysis or ultimate analysis or a combination of both (Chapter 2). Whereas proximate analysis is essentially an examination of the suitability of coal for combustion or for coking purposes, ultimate analysis is, in fact, an absolute measure of the elemental composition of coal. 

The analyses of the air-dried equilibrated sample for moisture, ash, and volatile matter are collectively termed the proximate analysis. Fixed carbon is, by definition, the difference between 100 and the sum of the analytes (moisture, ash, volatile matter). The proximate analysis gives information on the classification of coal by measuring the relative percentage of volatile and nonvolatile organic matter as those of moisture and noncombustible mineral matter. 

Schmidt, C.E., Sherkey, A.G., and Friedel, R.A., in Mass Spectrometric Analysis of Product Water from Coal Classification, U.S. Bureau of Mines, Pittsburgh Energy Research Center Technical Progress Report No. 86, 1974. 

International Organization for Standardization, Central Secretariat, 1 rue de Varembe, BP 56, CH- 1211 Geneve 20 Cellular materials definitions of terms and classification Hard coal Size analysis... 

Laser-microprobc mass spectrometry has an unusually high sensitivity (down to 10 g), is applicable to both inorganic and organic (including biological) samples, has a spatial resolution of about I pm, and produces data at a rapid rate. Some typical applications of laser-microprobe mass spectrometry include determination of Na/K concentration ratios in frog nerve fiber, determination of the calcium distribution in retinas, classification of asbestos and coal mine dusts, determination of fluorine distributions in dental hard tissue, analysis of amino acids, and study of polymer surfaces. ... 

If coal is intended to serve as fuel for industrial gasification processes, it is smart to borrow know-how for coal characterization from combustion research because of its long and comprehensive history. Hence, well-known analysis methods and classification schemes will appear, which must be always reviewed in the light of gasification conditions that differ from combustion in terms of oxidant (oxygen and steam instead of air), operation pressure (20-100 bar), and overall reducing atmospheres (products are CO and H2 instead of CO2, H2O). 

The most commonly used system of classification refers to the American standard (ASTM D-388 [13]) using fixed carbon combined with volatile matter on a dmmf basis for higher-rank coals and higher heating value (HHV) on moist mineral matter-free (mmmf) basis for lower-rank coals. The moisture used should be as close as possible to the natural bed moisture content and is obtained by exposing the sample to 30 °C and a relative humidity of 97%. To convert the analysis data to the mentioned reference state, the Parr formulas must be used assuming that a part of the ash sulfur leaves with the volatile matter ... 

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