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A composition including, but not limited to, a mixture of a calcium sulfate material, water, and a tetrametaphosphate compound is disclosed. Desirably, the inclusion of the tetrametaphosphate compound (e.g., salt or ion) in a pre-set treatment of a calcium sulfate material enhances the resistance to

A composition including, but not limited to, a mixture of a calcium sulfate material, water, and a tetrametaphosphate compound is disclosed. Desirably, the inclusion of the tetrametaphosphate compound (e.g., salt or ion) in a pre-set treatment of a calcium sulfate material enhances the resistance to permanent deformation (e.g., sag), dimensional stability, and/or compressive strength of the composition while also preferably avoiding any significant retardive effect on the rate of hydration of calcined gypsum to calcium sulfate dihydrate. A set gypsum-containing product and a method for producing a set gypsum-containing product having increased resistance to permanent deformation are also disclosed.

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1. A composition comprising a mixture of a calcium sulfate material, water, and a tetrametaphosphate compound, wherein when said composition is cast in the form of a cube comprising an interlocking matrix of set gypsum according to ASTM C472-93, said cube has a compressive strength as measured by AS

1. A composition comprising a mixture of a calcium sulfate material, water, and a tetrametaphosphate compound, wherein when said composition is cast in the form of a cube comprising an interlocking matrix of set gypsum according to ASTM C472-93, said cube has a compressive strength as measured by ASTM C472-93 greater than or equal to the compressive strength that would result if the tetrametaphosphate was not included in the mixture. 2. The composition of claim 1, wherein the mixture further comprises a pregelatinized starch. 3. The composition of claim 1, wherein the mixture further comprises aqueous foam. 4. The composition of claim 3, wherein the mixture further comprises a pregelatinized starch. 5. The composition of claim 1, further comprising starch, and particles of a water-redispersible polymer. 6. A machinable set gypsum-containing product formed from the composition of claim 5. 7. The composition of claim 1, further comprising binder, a thickener, and a non-leveling agent. 8. A product for finishing joints between edges of gypsum boards formed from the composition of claim 7. 9. The composition of claim 1, further comprising gelatinized starch, and a mineral wool. 10. An acoustical tile formed from the composition of claim 9. 11. The composition of claim 1, further comprising gelatinized starch, expanded perlite particles, and a fiber reinforcing agent. 12. An acoustical tile formed from the composition of claim 11. 13. The composition of claim 1, further comprising an accelerator. 14. The composition of claim 13, wherein the mixture further comprises a pregelatinized starch. 15. The composition of claim 13, wherein the mixture further comprises an aqueous foam. 16. The composition of claim 15, wherein the mixture further comprises a pregelatinized starch. 17. The composition of claim 1, wherein when said composition is cast in the form ½ inch board, the board has a sag resistance, as determined according to ASTM C473-95, of less than about 0.1 inch per two foot length of said board. 18. A gypsum board formed from the composition of claim 13. 19. A composition comprising a mixture of host particles having accessible voids therein; calcium sulfate material, at least a portion of which is in the form of crystals in and about the voids of the host particles; and a tetrametaphosphate compound, wherein when said composition is cast in the form of a cube comprising an interlocking matrix of set gypsum according to ASTM C472-93, said cube has a compressive strength as measured by ASTM C472-93 greater than or equal to the compressive strength that would result if the tetrametaphosphate was not included in the mixture. 20. The composition of claim 19, wherein when said composition is cast in the form a ½ inch board, the board has a sag resistance, as determined according to ASTM C473-95, of less than about 0.1 inch per two foot length of said board. 21. A composition comprising a mixture of a calcium sulfate material, water, and a tetrametaphosphate compound, wherein when said composition is used to prepare a product comprising an interlocking matrix of set gypsum, said product has greater strength than it would have if the tetrametaphosphate compound had not been included in the mixture. 22. The composition of claim 21, wherein the mixture further comprises a pregelatinized starch. 23. The composition of claim 21, wherein the mixture further comprises a pregelatinized starch. 24. The composition of claim 21, wherein the mixture further comprises aqueous foam. 25. Gypsum board comprising an interlocking matrix of set gypsum formed from a mixture comprising calcium sulfate material, water and at least one tetrametaphosphate compound, wherein, when said mixture is cast in the form of a cube comprising an interlocking matrix of set gypsum according to ASTM C472-93, said cube has a compressive strength as measured by ASTM C472-93 greater than or equal to the compressive strength that would result if the tetrametaphosph ate was not included in the mixture. 26. The gypsum board of claim 25, wherein the amount of said tetrametaphosphate compound is from about 0.004 to about 2.0% by weight of said calcined gypsum. 27. The gypsum board of claim 25, wherein said set gypsum is in the form of a core material sandwiched between cover sheets. 28. The gypsum board of claim 27, wherein said cover sheets comprise paper. 29. The gypsum board of claim 25, wherein said tetrametaphosphate compound is selected from the group consisting of sodium tetrametaphosphate, lithium tetrametaphosphate, potassium tetrametaphosphate, ammonium tetrametaphosphate, aluminum tetrametaphosphate, and mixtures thereof. 30. The gypsum board of claim 25, wherein said tetrametaphosphate is sodium tetrametaphosphate. 31. The gypsum board of claim 25, wherein said gypsum board has a drying shrinkage of less than about 0.06 inch per four foot width and less than about 0.30 inch per twelve foot length, as determined according to ASTM C473-95. 32. The gypsum board of claim 25, said gypsum board having a drying shrinkage of less than about 0.13% across its width and less than about 0.26% across its length, as determined according to ASTM C473-95. 33. The gypsum board of claim 25, wherein said gypsum board further comprises a pregelatinized starch. 34. The gypsum board of claim 33, wherein the amount of pregelatinized starch is from about 0.08 to about 0.5 percent by weight of the gypsum. 35. The gypsum board of claim 32, wherein the amount of pregelatinized starch is from about 0.16 to about 0.4 percent by weight of the gypsum. 36. The gypsum board of claim 33, wherein the amount of pregelatinized starch is about 0.3 percent by weight of the gypsum. 37. The gypsum board of claim 25, wherein said set gypsum has voids uniformly distributed therein. 38. The gypsum board of claim 37, wherein said set gypsum is further formed from at least one foaming agent, having the formula: 3 (CH 2 ) x CH 2 (OCH 2 CH 2 ) y OSO 3 θM⊕wherein X is a number from 2 to 20, Y is a number from 0 to 10 and is 0 in at least 50 weight percent of the foaming agent or blend of foaming agents, and M is a cation. 39. The gypsum board of claim 38, wherein Y is 0 in from 86 to 99 weight percent of the foaming agent. 40. The gypsum board of claim 37, wherein the set gypsum is further formed from a pregelatinized starch. 41. The gypsum board of claim 25, wherein the gypsum board has a sag resistance, as determined according to ASTM C473-95, of less than about 0.1 inch per two foot length of said board. 42. The gypsum board of claim 1, wherein the tetrametaphosphate compound has been included in the mixture in an amount such that the gypsum board has a sag resistance, as determined according to ASTM C473-95, of less than about 0.1 inch per two-foot length of said board. 43. A composition comprising a mixture of a calcium sulfate material, water, and a tetrametaphosphate compound, wherein when said composition is cast in the form a ½ inch board comprising an interlocking matrix of set gypsum, said board has a sag resistance, as determined according to ASTM C473-95, of less than about 0.1 inch per two foot length of said board. 44. A gypsum board comprising a core of material sandwiched between cover sheets, wherein the core comprises an interlocking matrix of set gypsum, said board having been prepared by a method comprising:forming or depositing a mixture between the cover sheets, wherein the mixture comprises a calcium sulfate material, water, and one or more tetrametaphosphate compounds, andmaintaining the mixture under conditions sufficient for the calcium sulfate material to form the interlocking matrix of set gypsum,the tetrametaphosphate compound having been included in the mixture in an amount such that, when the mixture is cast in the form of a cube comprising an interlocking matrix of set gypsum according to ASTM C472-93, the cube has a compressive strength as measured by ASTM C472-93 grea ter than or equal to the compressive strength that would result if the tetrametaphosphate was not included in the mixture.