Ultrafine nepheline syenite

Abstract

A useable particulate nepheline syenite having a grain size to provide an Einlehner Abrasive Value of less than about 100 is described. The particulate nepheline syenite is generally free from agglomeration and moisture free. At least 99% of the nepheline syenite particles have a size less than 10 microns

1 - 38 . (canceled) 
     
     
         39 . An ultra-fine inorganic powder formed from a quartz free igneous rock, said powder having a controlled maximum particle size in a range where the upper value of the controlled maximum particle size is less than 10 microns and the lower value of the controlled maximum particle size is about 5 microns. 
     
     
         40 . An ultra-fine inorganic powder as defined in  claim 39  wherein said powder is formed by a dry final grinding process. 
     
     
         41 . An ultra-fine inorganic powder as defined in  claim 40  wherein said igneous rock is a quartz free silicate rock. 
     
     
         42 . An ultra-fine inorganic powder as defined in  claim 39  wherein said igneous rock is a quartz free silicate rock. 
     
     
         43 . An inorganic powder as defined in  claim 42  wherein said igneous rock is nepheline syenite. 
     
     
         44 . An inorganic powder as defined in  claim 41  wherein said igneous rock is nepheline syenite. 
     
     
         45 . An inorganic powder as defined in  claim 40  wherein said igneous rock is nepheline syenite. 
     
     
         46 . An inorganic powder as defined in  claim 39  wherein said igneous rock is nepheline syenite. 
     
     
         47 . An ultra-fine inorganic powder as defined in  claim 46  wherein the fines have been removed from said powder. 
     
     
         48 . An ultra-fine inorganic powder as defined in  claim 45  wherein the fines have been removed from said powder. 
     
     
         49 . An ultra-fine inorganic powder as defined in  claim 44  wherein the fines have been removed from said powder. 
     
     
         50 . An ultra-fine inorganic powder as defined in  claim 43  wherein the fines have been removed from said powder. 
     
     
         51 . An ultra-fine inorganic powder as defined in  claim 42  wherein the fines have been removed from said powder. 
     
     
         52 . An ultra-fine inorganic powder as defined in  claim 41  wherein the fines have been removed from said powder. 
     
     
         53 . An ultra-fine inorganic powder as defined in  claim 40  wherein the fines have been removed from said powder. 
     
     
         54 . An ultra-fine inorganic powder as defined in  claim 39  wherein the fines have been removed from said powder. 
     
     
         55 . An ultra-fine inorganic powder as defined in  claim 39  wherein the maximum particle size is the D99 particle size.