ULTRAFINE NEPHELINE SYENITE
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.