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Title: Pitt Mill Demonstration

Abstract

Results of a technical and economic evaluation of application of the Pitt Mill to fine coal grinding are presented. The Pitt Mill is a vertically oriented, batch operated, intermediate energy density (0. 025 kW/lb media), stirred ball mill. The mill grinds coal from coarse sizes (typically 3/16 inch or 4 mesh topsize) to the 10 micron to 20 micron mean particle diameter size range in a single step using a shallow grinding bed containing inexpensive, readily available, course grinding media. Size reduction is efficient because of rapid product circulation through the grinding bed caused by action of a novel circulation screw mounted on the agitator shaft. When a dispersant is employed, the grinding can be carried out to 50% to 60% solids concentration. Use of coarse grinding media offers the possibility of enhanced mineral liberation because size reduction is achieved more by impact shattering than by attrition. The batch method offers the possibility of very close control over product particle size distribution without overproduction of fines. A two- phase program was carried out. In the first phase, Grinding Studies, tests were run to determine a suitable configuration of the Pitt Mill. Machine design parameters which were studied included screw configuration,more » media type, agitator RPM, time, media size, and slurry chamber aspect ratio. During the last part of this phase of the program, tests were carried out to compare the results of grinding Pocahontas seam, Pittsburgh {number sign}8, and East Kentucky Mingo County coals by the Pitt Mill and by a two-stage grinding process employing a Netzsch John mill to feed a high energy density (0.05 kW/Lb media) disc mill. 22 refs., 25 tabs.« less

Authors:
;
Publication Date:
Research Org.:
EXPORTech Co., Inc., New Kensington, PA (USA)
Sponsoring Org.:
DOE/FE
OSTI Identifier:
6471498
Report Number(s):
DOE/PC/88884-T5
ON: DE91002406
DOE Contract Number:
AC22-88PC88884
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
01 COAL, LIGNITE, AND PEAT; 32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION; COAL; GRINDING; GRINDING MACHINES; DESIGN; ENERGY CONSUMPTION; PARTICLE SIZE; PERFORMANCE TESTING; PROGRESS REPORT; CARBONACEOUS MATERIALS; COMMINUTION; DOCUMENT TYPES; ENERGY SOURCES; FOSSIL FUELS; FUELS; MACHINE TOOLS; MACHINING; MATERIALS; SIZE; TESTING; TOOLS; 010300* - Coal, Lignite, & Peat- Preparation- (1987-); 320301 - Energy Conservation, Consumption, & Utilization- Industrial & Agricultural Processes- Energy Sources

Citation Formats

Oder, R.R., and Borzone, L.A. Pitt Mill Demonstration. United States: N. p., 1990. Web. doi:10.2172/6471498.
Oder, R.R., & Borzone, L.A. Pitt Mill Demonstration. United States. doi:10.2172/6471498.
Oder, R.R., and Borzone, L.A. Tue . "Pitt Mill Demonstration". United States. doi:10.2172/6471498. https://www.osti.gov/servlets/purl/6471498.
@article{osti_6471498,
title = {Pitt Mill Demonstration},
author = {Oder, R.R. and Borzone, L.A.},
abstractNote = {Results of a technical and economic evaluation of application of the Pitt Mill to fine coal grinding are presented. The Pitt Mill is a vertically oriented, batch operated, intermediate energy density (0. 025 kW/lb media), stirred ball mill. The mill grinds coal from coarse sizes (typically 3/16 inch or 4 mesh topsize) to the 10 micron to 20 micron mean particle diameter size range in a single step using a shallow grinding bed containing inexpensive, readily available, course grinding media. Size reduction is efficient because of rapid product circulation through the grinding bed caused by action of a novel circulation screw mounted on the agitator shaft. When a dispersant is employed, the grinding can be carried out to 50% to 60% solids concentration. Use of coarse grinding media offers the possibility of enhanced mineral liberation because size reduction is achieved more by impact shattering than by attrition. The batch method offers the possibility of very close control over product particle size distribution without overproduction of fines. A two- phase program was carried out. In the first phase, Grinding Studies, tests were run to determine a suitable configuration of the Pitt Mill. Machine design parameters which were studied included screw configuration, media type, agitator RPM, time, media size, and slurry chamber aspect ratio. During the last part of this phase of the program, tests were carried out to compare the results of grinding Pocahontas seam, Pittsburgh {number sign}8, and East Kentucky Mingo County coals by the Pitt Mill and by a two-stage grinding process employing a Netzsch John mill to feed a high energy density (0.05 kW/Lb media) disc mill. 22 refs., 25 tabs.},
doi = {10.2172/6471498},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Tue May 01 00:00:00 EDT 1990},
month = {Tue May 01 00:00:00 EDT 1990}
}

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