Power and operating behavior in stirred media mills

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:271947

Zheng, J; Harris, C C ^[1]

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1. Columbia Univ., New York, NY (United States). Henry Krumb School of Mines

It has been estimated that 1.3% of Us electrical power production is consumed for comminution, particularly by fine grinding. Stirred media mills have especially attracted attention because of the reported high energy efficiency, ability for grinding into the micron and sub-micron range, and reduced contamination. Stirred media mills have been applied for fine particle production in many industries such as mineral, ceramic, metallurgical, electronic, pigments, paint and lacquer, chemical, bio-technology, rubber, agricultural, pharmaceutical, photographic, coal and energy. While applications of stirred media mills for fine particle production have continued to increase, there is a lack of understanding of operating behavior and power requirement. Investigations in laboratory stirred media mills have been carried out with grinding media, limestone and yttria stabilized zirconia. The torque required to rotate impellers immersed in dense particulate media with supernatant versus impeller rotational speed displays four regions marked by sharp transitions: transition from static to dynamic friction; channeling; dispersing; and centrifuging. Equations, including dimensionless group correlations of power and modified Reynolds number, for relating power, speed, impeller and tank dimensions and design, media size and density, solid concentration, and other relevant variables have been established. Scale-up guidelines with respect to power consumption are also proposed.

• OSTI ID: 271947
• Report Number(s): CONF-9510120--; ISBN 0-87335-140-1
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
COAL PREPARATION
COMMINUTION
ENERGY CONSUMPTION
ENERGY EFFICIENCY
LIMESTONE
MIXING
PULVERIZERS
SLURRIES
ZIRCONIUM OXIDES