Pitt Mill Demonstration

Technical Report · Tue May 01 00:00:00 EDT 1990

DOI:https://doi.org/10.2172/6471498· OSTI ID:6471498

Oder, R R; Borzone, L A

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.

• Research Organization: EXPORTech Co., Inc., New Kensington, PA (USA)
• Sponsoring Organization: DOE/FE
• DOE Contract Number: AC22-88PC88884
• OSTI ID: 6471498
• Report Number(s): DOE/PC/88884-T5; ON: DE91002406
• Country of Publication: United States
• Language: English

Related Subjects

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