LABORATORY STUDIES ON THE GRINDABILITY OF ANTHRACITE AND OTHER COALS
Special Research Report SR-6 Grinding is an important process in such widely differing industries as the coal industry, paint industry, cement industry, and electric power industry, but although there is a wealth of information concerning the practical performance of the many types of grinding machines in use, studies of the fundamental basis of grinding processes have not made much progress until recent years. Not only are such studies important in the field of grinding machine design, but it is likely that investigation of grinding strengths will give valuable information on the chemical and physical properties of the materials studied. In particular, the shape and surface area of ground coal particles is of great importance in the following processes: (a) the combustion of pulverized coal ·in oent'ra.l power stations, (b) the gasification of pulverized coal, (c) the manufacture of electrodes from low volatile coals, (d) the blending of coal fines in the production of metallurgical coke, (e) the briquetting of waste coal fines to produce saleable products, (f) the production of low temperature coke and coal chemicals in fluidized bed processes, (g) the firing of open cycle turbines with pulverized coal, and (h) the hydrogenation and chemical processing of coal suspensions. The handling, combustion, gasification and chemical processing of coals dispersed in gases or liquids are regions in which much work is yet to bedone, and the influences of particle reactive surface area, surface chemical properties, porosity, hydrodynamic behavior and resistance to thermal shock will depend, to a certain extent, on the size of the particles, and on the physical and chemical changes occurring when coal is ground to fine sizes. Other important factors will be the size and distribution of the mineral particles associated with coals. The stress laid on fundamental studies of grinding mechanisms and process can be gauged by the number of papers published in this field in recent years. An examination of B.C.U.R.A. Fuel Abstracts (1) from January, 1957 to August, 1958 reveals that 27 papers have been published detailing theoretical and fundamental studies on coal strength and grinding, of which 14 are by British authors, 5 by Russian or Satellite authors, and 3 by authors from the United States. As the initial work on coal in this field was performed by Hardgrove (2) in the U.S.A. in 1932, it would appear that the initial lead of the United States has not been consolidated. Anthracite is of particular interest in grinding studies because of its hardness and resistance to grinding, and because its disadvantage (for many processes) of low reactivity can be overcome by using it in finely divided form.
|Work Title||LABORATORY STUDIES ON THE GRINDABILITY OF ANTHRACITE AND OTHER COALS|
|License||Attribution-NonCommercial-NoDerivs 3.0 United States|
|Deposited||July 27, 2016|
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