MINERAL DISPERSION
Use of an inorganic and an organic dispersant to disperse a particulate mineral in aqueous medium, for example wherein the inorganic dispersant is used to disperse the particulate mineral prior to a dewatering step and the organic dispersant is used to disperse the particulate mineral after the dewatering step, and products and intermediate products of said use.
1 - 20 . (canceled)
21 . A method of dispersing a mineral composition, the method comprising combining the mineral composition and an aqueous medium in the presence of an organic dispersant, wherein the mineral composition comprises a particulate mineral and an effective amount of an inorganic dispersant.
22 . The method of claim 21 , wherein the mineral composition is re-dispersed in the aqueous medium.
23 . The method of claim 21 , wherein the inorganic dispersant is a phosphate salt such as a condensed phosphate salt.
24 . The method of claim 21 , wherein the inorganic dispersant is a hexametaphosphate salt.
25 . The method of claim 21 , wherein the organic dispersant is a homopolymer or copolymer of acrylic acid and/or methacrylic acid or wherein the organic dispersant is an alkanolamine.
26 . The method of claim 21 , wherein the organic dispersant is salt of polyacrylate.
27 . The method of claim 21 , wherein the inorganic dispersant and/or organic dispersant is a sodium salt.
28 . The method of claim 21 , wherein the particulate mineral comprises ground calcium carbonate (GCC), particulate calcium carbonate (PCC), or another inorganic particulate mineral.
29 . The method of claim 21 , wherein the method comprises dispersing (e.g. grinding) the particulate mineral in a first aqueous medium in the presence of an inorganic dispersant to form the mineral composition.
30 . The method of claim 29 , wherein the method comprises dewatering the mineral composition such that it has a solids content ranging from equal to or greater than about 70 wt % to about 100 wt %.
31 . The method of claim 30 , wherein the mineral composition has a solids content ranging from about 20 wt % to about 90 wt %.
32 . The method of claim 21 , wherein the mineral composition comprises the inorganic dispersant in an amount equal to or greater than about 0.2% by weight of the particulate mineral.
33 . The method of claim 21 , wherein the organic dispersant is used in an amount ranging from about 0.2% to about 2% by weight of the particulate mineral.
34 . The method of claim 21 , wherein the dispersed mineral composition has a solids content ranging from about 30 wt % to about 90 wt %.
35 . The method of claim 29 , wherein the dispersion of the particulate mineral in the first aqueous medium has a Brookfield viscosity equal to or less than about 1500 m Pa.s immediately after preparation.
36 . The method of claim 29 , wherein the dispersion of the particulate mineral in the first aqueous medium has a Brookfield viscosity equal to or greater than about 1500 mPa.s one hour after preparation.
37 . The method of claim 21 , wherein the dispersed mineral composition has a Brookfield viscosity equal to or less than about 1500 mPa.s immediately after preparation.
38 . The method of claim 21 , wherein the dispersed mineral composition has a Brookfield viscosity equal to or less than about 1500 mPa.s one hour after preparation.
39 . The method of claim 21 , wherein the particle size distribution of the mineral composition is substantially the same as the particle size distribution of the dispersed mineral composition.
40 . The method of claim 21 , wherein the mineral composition is devoid of organic dispersant.
41 . The method of claim 21 , wherein the mineral composition is devoid of calcium ion-containing and/or carbonate ion-containing compounds.
42 - 59 . (canceled)