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US 11,446,620 B2Granted
Flash calcined gypsum wallboard
AssigneeGold Bond Building Products, LLC
InventorJoseph J. Bailey
Life of this patent
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Abstract
Processes are disclosed for producing gypsum-based products from a gypsum slurry. Additives or combinations of additives for improving compressive strength, fluidity and/or set time of the gypsum product are mixed in intimate contact with raw gypsum prior to or during grinding and/or flash calcination to form stucco. The stucco is used to prepare a gypsum slurry which is shaped and sets to form the gypsum product.
Claims10
A method of making a gypsum board, comprising the steps of:
- combining raw gypsum, and an additive selected from the group consisting of:
- ammonium phosphate monobasic, ammonium phosphate dibasic, aluminum phosphate, sodium aluminum sulfate, calcium chloride, potassium chloride, sodium hydroxide, sodium bicarbonate, potassium carbonate, sodium carbonate, ferric chloride, ferric nitrate, aluminum nitrate, boric acid, ammonium sulfate, potassium sulfate, boric oxide, sodium trimetaphosphate, sodium phosphate tribasic dodecahydrate, citric acid, Borax, sodium tripolyphosphate, ammonium polyphosphate, sodium phosphate monobasic, trisodium phosphate, calcium phosphate monobasic, calcium phosphate tribasic, calcium carbonate, sodium phosphate tribasic dodecahydrate, calcium nitrate tetrahydrate, urea, talc, sodium acetate, aluminum sulfate, calcium phosphate dibasic, sodium metaborate, tartaric acid, trisodium phosphate, potassium phosphate tribasic, and a mixture thereof to first form a combined raw gypsum and additive;
- then milling the combined raw gypsum and additive to form a milled raw gypsum and additive;
- next flash calcining the milled raw gypsum and additive to produce stucco;
- mixing the stucco with water to form a gypsum slurry;
- and
- sandwiching the gypsum slurry between two sheets of facing material to form the gypsum board.
4 more elements
Dependencies are inferred from the claim text.