CALCINED DIATOMITE PRODUCTS WITH LOW CRISTOBALITE CONTENT
Described herein is a flux-calcined diatomite composition having a cristobalite content of less than about 5% by weight relative to the total weight of the flux-calcined composition and a whiteness of greater than about 90. Also described herein is a process for producing flux-calcined diatomite compositions including calcining a feed composition including diatomite having an iron content of at least about 0.5% by weight relative to the total weight of the feed composition in the presence of at least one flux including at least one alkali metal.
1 - 82 . (canceled)
83 . A filled polymer composition comprising a polymer and a calcined diatomite composition having a cristobalite content of less than about 5% by weight relative to the total weight of the composition and a whiteness of at least about 90.
84 . The composition of claim 83 , wherein the calcined diatomite has a cristobalite content of less than about 2% by weight.
85 . The composition of claim 83 , wherein the calcined diatomite has a cristobalite content of less than about 1% by weight.
86 . The composition of claim 83 , wherein the calcined diatomite has a cristobalite content of less than about 0.5% by weight.
87 . The composition of claim 83 , wherein the calcined diatomite has a whiteness of greater than about 91.
88 . The composition of claim 83 , wherein the calcined diatomite has a whiteness of greater than about 93.
89 . The composition of claim 83 , wherein the calcined diatomite has been flux calcined in the presence of at least one flux comprising at least one alkali metal chosen from potassium, rubidium, and cesium.
90 . The composition of claim 83 , wherein the calcined diatomite has a mean diameter of less than about 40 μm.
91 . The composition of claim 83 , wherein the calcined diatomite has a mean diameter of less than about 20 μm.
92 . The composition of claim 83 , wherein the calcined diatomite has a mean diameter of less than about 10 μm.
93 . The composition of claim 83 , wherein the calcined diatomite has a d 90 of less than about 50 μm.
94 . The composition of claim 83 , wherein the calcined diatomite has a d 90 of less than about 20 μm.
95 . The composition of claim 83 , wherein the calcined diatomite has an iron content of less than about 0.5% by weight relative to the total weight of the composition.
96 . The composition of claim 83 , wherein the calcined diatomite has a Hunter a value of less than about 1.
97 . The composition of claim 83 , wherein the calcined diatomite has a Hunter b value of less than about 8.
98 . The composition of claim 83 , wherein the calcined diatomite has a Hunter b value of less than about 4.
99 . The composition of claim 83 , wherein the polymer comprises polyethylene.
100 . The composition of claim 99 , wherein the polyethylene comprises a low density polyethylene (LDPE).
101 . The composition of claim 83 , wherein the filled polymer composition is a coating.
102 . The composition of claim 83 , wherein the filled polymer composition is a paint.