NEPHELINE SYENITE POWDER WITH CONTROLLED PARTICLE SIZE AND NOVEL METHOD OF MAKING SAME
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.