Liquid gypsum set accelerator
AssigneeNational Gypsum Properties, LLC
InventorsChris Fewox, Joseph J. Bailey
Life of this patent
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Abstract
A liquid accelerator composition for accelerating the setting reaction of calcium sulfate hemihydrate and water and methods of forming a liquid gypsum accelerator are provided. The liquid accelerator composition includes a liquid media in which calcium sulfate dihydrate is less than fully soluble and a ground product of a mill grinding of a mixture comprising calcium sulfate dihydrate.
Claims33
A gypsum set accelerator composition, comprising:
- a slurry including:
- ground gypsum in an amount of about 95 wt % to about 20 wt % of the slurry, the ground gypsum having a particle size distribution with at least about 15% of the mass of ground gypsum having a particle size of about 5.5 μm or less;
- and
- a non-aqueous liquid medium in which gypsum has a solubility of about 10 g/l or less at 25° C.
(canceled)
A method of making a gypsum set accelerator, comprising the steps of:
- providing gypsum and a non-aqueous liquid medium in which gypsum has a solubility of about 10 g/l or less at 25° C.;
- grinding the gypsum to a particle size distribution with at least about 15% of the mass of ground gypsum having a particle size of about 5.5 μm or less;
- and
- combining the liquid medium and the ground gypsum to form a slurry comprising about 95 wt % to about 20 wt % gypsum.
(canceled)
The method of claim 22, wherein the solubility inhibitor is a phosphate.
(canceled)
(canceled)
A method of making a gypsum board composition, comprising the steps of:
- providing dry ingredients including stucco, and wet ingredients including water;
- mixing the dry and wet ingredients to form a gypsum slurry;
- providing gypsum and a liquid medium in which gypsum has a solubility of about 10 g/l or less at 25° C.;
- grinding the gypsum to a particle size distribution with at least about 15% of the mass of ground gypsum having a particle size of about 5.5 μm or less;
- combining the liquid medium and the gypsum to form a gypsum set accelerator comprising about 95 wt % to about 20 wt % gypsum;
- adding an aqueous foam to the gypsum slurry;
- and
- adding the gypsum set accelerator to the gypsum slurry with the foam.
(canceled)
A method of making a gypsum set accelerator, comprising the steps of:
- combining stucco and an aqueous liquid medium in which gypsum has a solubility of about 10 g/l or less at 25° C., to undergo a hydration reaction and precipitate gypsum from the aqueous liquid medium;
- and
- grinding the gypsum during precipitation to a particle size distribution with at least about 15% of the mass of ground gypsum having a particle size of about 5.5 μm or less;
- wherein the liquid medium and the ground gypsum form a slurry comprising about 95 wt % to about 20 wt % gypsum.
Dependencies are inferred from the claim text.