Fine grinding of coal in a two-stage high-pressure roll mill/ball mill hybrid mode

Book · Sun Oct 01 04:00:00 EDT 1995

OSTI ID:110024

Fuerstenau, D W; De, A; Diao, J; Kapur, P C ^[1]

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1. Univ. of California, Berkeley, CA (United States). Dept. of Materials Science and Mineral Engineering

Because of its pronounced tendency to undergo visco-plastic flow, coal ground in the energy-efficient high-pressure roll mill invariably comes out as a briquetted product which must be disintegrated in a conventional type of grinding device such as the ball mill. The aggregates comprise comminuted coal particles that are apparently extensively cracked and weakened during passage of the coal through the high-pressure rolls. Their desegregation in a ball mill in the second stage is accompanied by further grinding of the coal with a relatively small expenditure of energy. Thus in spite of energy dissipation in briquetting in the roll mill and in disintegrating the briquettes in the ball mill, significant energy savings are possible in the fine grinding of coal in a two-stage serial grinding mode, as compared to ball mill grinding stages must be apportioned in a n optimal manner; the energy consumption in the ball milling step is comparable to, even in excess of, the energy spent in the high-pressure roll mill; and 20 to 50 percent energy savings might be possible grinding coal to minus 200-mesh size by this two-step process, as compared to conventional milling.

• OSTI ID: 110024
• Report Number(s): CONF-950002--; ISBN 0-87335-130-4
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
AGGLOMERATION
BITUMINOUS COAL
BRIQUETS
COAL PREPARATION
ENERGY CONSERVATION
EXPERIMENTAL DATA
GRINDING
NET ENERGY
PARTICLE SIZE
PERFORMANCE
PULVERIZERS