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Attrition mill operating characteristics.
Sadler-LY III; Stanley-DA; Brooks-DR
Powder Technol 1975 Jul; 12(1):19-28
The attrition mill is a device for mechanically reducing solid particle size by intense agitation of a slurry of material being milled and coarse milling media. For example, in 10 hours of milling, specific surfaces of 40 and 25 m2/g were obtained for alumina and barite, corresponding to 38 and 56 nm equivalent spherical diameter, respectively. Size reduction rates for relatively coarse particles were first-order and increased linearly with power input to the mill. Optimum milling medium concentration corresponded to medium particles moving a distance of approximately 0.7 of their diameter before collision with another such particle. Power characteristics of the attrition mill were essentially the same as those of a radial flow turbine mixer. Laminar flow became disrupted at NRe = 200, while turbulent flow was established at NRe > 8000. Slurries of fine powders exhibited the same linear power-average density dependence as single-phase liquids. However, a different dependence was observed with large particles.
Milling-industry; Particulate-dust; Dust-particles; Dust-exposure; Dust-analysis; Respirable-dust
OP; Journal Article
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Page last reviewed: September 2, 2020
Content source: National Institute for Occupational Safety and Health Education and Information Division