Analysis of coal

The elemental analysis of coal, i.e., its C, H, O, N, S, and ash residue, may be important to a chemist who wishes to use coal as a chemical or source of carbon, but to an engineer who wants to bum the coal in a heat- or power-generating plant or a coking oven, other parameters are more important— most notably its heat of combustion, moisture level, volatile matter, carbon and sulfur content, as well as the ash. This is called the proximate analysis and it is determined as follows  

Moisture content. A sample of coal is ground to pass 20/60 mesh and weighed. It is dried in an oven at 110°C and reweighed. The loss in weight represents the moisture content of the coal. 

Class/group Fixed carbon, C (%) Volatile matter, V (%) Calorific value, AH (MJ/kg) 

High-volatile B bituminous High-volatile C bituminous  

Subbituminous Subbituminous A coal Subbituminous B coal Subbituminous C coal Lignitic Lignitic A Lignite B 

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An AH, Smith BW, Winefordner JD (1989) Direct analysis of coal by electrothermal atomization atomic-absorption spectrometry. Talanta 36 893-896. 

Bettinelli, M., Baroni, U., Pastorelli, N. and Bizzarri, G. (1992). ICP-AES, GFAAS, XRF and NAA coal fly-ash analysis - comparison of different analytical techniques. In Elemental Analysis of Coal and Its By-Products, ed. Vourvopoulos, G., World Scientific, Kentucky, pp. 372-394. 

Analysis of coal extract with the ion-trap detector. Finnigan MAT Application Data Sheet ADS 12. 

Analysis of coal-mineral association in samples of Upper Freeport and Indiana No. 3 coals showed significant differences in the association of minerals with the coal matrix. In terms of bulk properties, the mineral matter was generally more liberated in the Upper Freeport coal than in the Indiana No. 3 coal. Also, based on bulk properties, pyrite was found to be preferentially liberated in the Upper Freeport coal, while no such preferential liberation was observed for minerals in the Indiana No. 3 coal. For both coals, the... 

The hypothesis that coals can be considered to consist of two component phases has its origins in observations of coal behaviour as well as deriving from the analysis of coals and attempts to define their structure. The results of extensive studies of untreated, preheated and hydrogenated coals, using analytical and microscopic techniques, have allowed some insight into the association between the so-called mobile phase and macromolecular network, and have provided information upon differences in their chemical properties. 

Trace element analysis of coal and extract ashes... 

Analysis of Coal Liquids by Size Exclusion Chromatography—Gas Chromatography—Mass Spectrometry... 

Analysis of Coal and Ash Samples Ultimate Analysis - Utah II Bituminous Supplied by EER. Inc. 

Wong, A. S. Robertson, J. D. 1993. Multi-elemental analysis of coal and its by-products by simultaneous proton-induced gamma-ray/X-ray emission analysis. Journal of Coal Quality, 12, 146-150. 

Choice of an Internal Standard. One of the difficulties in the spec-trometric trace analysis of coal ash samples, in addition to choosing a suitable comparison standard matrix, is choosing an internal standard. The first choice in both analytical methods was indium, which was used as a constant internal standard added to the graphite powder diluent-buffer. The results obtained had poor reproducibility, as previously... 

Sheibley, D. W., Trace Element Analysis of Coal by Neutron Activation, ... 

Table I. Analysis of Coal Before and After Crushing...

Table III. Proximate Analysis of Coal Consumed During Test Period ...

Coal, Analytical Procedures. The most frequently made analysis of coal is the proximate analysis. This includes detns of moisture, volatile matter, fixed carbon and ash. Sometimes it is combined with detn of sulfur and phosphorus, which really belongs to the ultimate analysis, and includes also detn of carbon, hydrogen, nitrogen and sulfur. In most cases, the heating value of coal expressed in BTU/lb is also detd,... 

There are many problems associated with the analysis of coal (Lowry, 1963 Karr, 1978) not the least of which is its heterogeneous nature. Other problems include the tendency of coal to gain or lose moisture and to undergo oxidation when exposed to the atmosphere. In addition, the large number of tests and analyses required to characterize coal adequately also raise issues. 

As a result, the formation of various national standards associations has led to the development of methods for coal evaluation. For example, the American Society for Testing and Materials (ASTM) has carried out uninterrupted work in this field for many decades, and investigations on the development of the standardization of methods for coal evaluation has occurred in all the major coal-producing countries (Montgomery, 1978 Patrick and Wilkinson, 1978). There are in addition to the ASTM, organizations for methods development and standardization that operate on a national level examples are the International Organization for Standardization (ISO) and the British Standards Institution (BS), which covers the analysis of coal under one standard number (BS 1016) (Table 1.2). 

Total moisture of coal Ultimate analysis of coal Ultimate analysis of coke Chlorine in coal and coke Phosphorus in coal and coke Arsenic in coal and coke Analysis of coal ash and coke ash Determination of moisture-holding capacity of hard coal General introduction and methods for reporting results Determination of total moisture of coke Proximate analysis, determination of moisture content of the general analysis test sample... 

Ultimate analysis of coal and coke, determination of nitrogen content... 

Ultimate analysis of coal and coke, determination of total sulfur content, Eschka method Ultimate analysis of coal and coke, determination of total sulfur content, high temperature combustion method... 

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