Nepheline syenite powder with controlled particle size and novel method of making same

Abstract

An ultra-fine nepheline syenite powder produced from a pre-processed nepheline syenite powder feedstock. The powder having a “controlled” maximum grain size D95 or D99 of less than about 20 microns and a “controlled” minimum grain size D5 in the range of 2-8 microns with a particle size spread D5-D95 of less than about 12 microns.

1 - 45 . (canceled) 
     
     
         46 . An ultra-fine powder formed from a naturally occurring rock, said powder having a controlled maximum particle size of less than 20 microns, a controlled minimum particle size in the range of 2-8 microns and narrow particle size distribution with the difference between the D95 particle size and the D5 particle size being less than 12 microns. 
     
     
         47 . The ultra-fine powder as defined in  claim 46  wherein said powder has a D50 particle size that is about 35-55 percent of said controlled maximum particle size. 
     
     
         48 . The ultra-fine powder as defined in  claim 46  wherein said controlled maximum particle size is a D95 particle size is in the range of about 6-15 microns. 
     
     
         49 . The ultra-fine powder as defined in  claim 46  wherein said controlled minimum particle size is a D5 particle size in the range of 2-8 microns. 
     
     
         50 . The ultra-fine powder as defined in  claim 46  wherein said controlled minimum particle size is a D5 particle size in the range of 4-6 microns. 
     
     
         51 . The ultra-fine powder as defined in  claim 46  wherein the D50 particle size of said powder is less than 10 microns. 
     
     
         52 . The ultra-fine powder as defined in  claim 46  wherein the D50 particle size of said powder is in the range of 8-11 microns. 
     
     
         53 . The ultra-fine powder as defined in  claim 46  has a controlled maximum particle size D99 in the range of 10-15 microns. 
     
     
         54 . The ultra-fine powder as defined in  claim 46  having a D99 particle size in the range of 15-19 microns, a D1 particle size in the range of 2-8 microns and a D50 particle size in the range of 8-11 microns. 
     
     
         55 . The ultra-fine powder as defined in  claim 46  having a D99 particle size in the range of 10-20 microns, a D1 particle size in the range of 2-8 microns and a D50 particle size that is 35-55 percent of said D99 particle size. 
     
     
         56 . An ultra-fine powder as defined in  claim 46  wherein said powder is ultra-fine nepheline syenite powder. 
     
     
         57 . An ultra-fine powder as defined in  claim 46  wherein said powder has virtually no free silica.