Sinha, N.C. and Nair, C.P.P. and Bagchi, S. (1969) Studies on the Hardgrove Grindability of Coals. Journal of Mines, Metals & Fuels, 17 (8). pp. 265-274. ISSN 0022-2755

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Abstract

The article reviews the work done on various aspects of Hardgove grindability of coals conducted in different countries of the world during the period 1932-66. The published papers could be grouped into two broad categories, namely, routine assessment of HGI and correlations of HGI with proximate and ultimate compositions of coal ; and relation of HGI with actual pulverizers performance. There is also a small group of papers on mathematical distribution of ground product obtained during Hardgrove tests. From the trend of relationship between HGI (of Brithish coals) and mill power reported by a British Study Team in respect of a Babcock Wilcox ‘E’ type ball mill, the equation, P (KW) = 153.9 – 64.2 log10 HGI has been derived. Thish gives the KW of power required in producing 3.25 tons of coal through 200 mesh per hour in terms of HGI. An analysis of the massive data on HGI of Indian coals, collected at the Central Laboratories and at the Coal Survey Laboratories of the Central Fuel Research Institute during the past on and a half decades has been done and seam-wise variation of HGI figures for major coalfields has been shown in a chart. It is observed that for coking coals of Jharia coalfields (seams I-XVIII) HGI is always in the range of 60-85 and no figure was below 60 ; for caking and non-coking coals the range of HGI is as a rule between 40 and 65 (more precisely 45-60). Majority of the Indian coals to be used for combustion purposes are difficult to grind in the HGI scale. But coking coals as a rule, offer comparatively less resistance to pulverization. The effects of initial size and specific gravity on HGI have also been indicated.

Item Type:	Article
Subjects:	Coal Preparation
Divisions:	UNSPECIFIED
Depositing User:	Dr. Satyendra Kumar Singh
Date Deposited:	22 Jul 2012 05:34
Last Modified:	22 Jul 2012 05:34
URI:	http://cimfr.csircentral.net/id/eprint/1270

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