Nepheline syenite powder with controlled particle size and novel method of making same
View Patent ↗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. An ultra-fine nepheline syenite powder having a D 99 particle size in the range of 15-19 microns, a D 1 particle size in the range of 2-8 microns and a D 50 particle size in the range of 8-11 microns.
2. An ultra-fine nepheline syenite powder as defined in claim 1 where said powder has a narrow particle size distribution between the D 95 particle size and the D 5 particle size of a value less than 12 microns.
3. An ultra-fine nepheline syenite powder as defined in claim 2 wherein the D 99 particle size is targeted at about 15 microns and the D 5 particle size is targeted at about 5 microns.