Patent ID: 7942351
Filing Date: 2011-05-17
Classification: B02C,C04B,C08K,C09D,Y10T

Abstract:
1. The method of converting a pre-processed nepheline syenite particulate feedstock with a particle size profile having a maximum particle size greater than 20 microns to an ultra-fine grain finish product for subsequent commercial use, said ultra-fine grain product having a maximum grain size of less than 10 microns, said method comprising: (a) grinding said feedstock in a dry state by passing said feedstock vertically downward through a continuous, high speed stirred ball mill having stirring arms rotated at a selected high speed in a vertically extending chamber filled with a grinding media whereby said feedstock is ground into an intermediate powder by action of said media as said media is moved at high speed by said rotating stirring arms, said intermediate powder having a drastically reduced particle size profile than the grain size profile of said feedstock; (b) passing said intermediate powder through an air classifier using a rapidly moving high speed air stream moving along a given path to convey said ultra-fine grain produced along said path and from said classifier and to allow coarse particulate material including particles larger than said ultra-fine product to be separated from said intermediate powder by centrifugal force and then expelled from said classifier; (c) collecting said ultra-fine product; and, (d) returning said coarse material to said high speed ball mill for regrinding.