Abstract: An acoustical panel comprising a continuous phase of an interlocking set gypsum matrix and a method of preparing an acoustical panel are disclosed.

Abstract: The invention provides a set gypsum-containing product having increased resistance to permanent deformation and a method for preparing it comprising forming a mixture of a calcium sulfate material, water, and an appropriate amount of one or more enhancing materials chosen from condensed phosphoric acids, each of which comprises 2 or more phosphoric acid units; and salts or ions of condensed phosphates, each of which comprises 2 or more phosphate units. The mixture is then maintained under conditions sufficient for the calcium sulfate material to form a set gypsum material.

Abstract: The invention provides a set gypsum-containing product having increased resistance to permanent deformation and a method for preparing it comprising forming a mixture of a calcium sulfate material, water, and an appropriate amount of one or more enhancing materials chosen from condensed phosphoric acids, each of which comprises 2 or more phosphoric acid units; and salts or ions of condensed phosphates, each of which comprises 2 or more phosphate units. The mixture is then maintained under conditions sufficient for the calcium sulfate material to form a set gypsum material.

Abstract: The invention provides a set gypsum-containing product having increased resistance to permanent deformation and a method for preparing it comprising forming a mixture of a calcium sulfate material, water, and an appropriate amount of one or more enhancing materials chosen from condensed phosphoric acids, each of which comprises 2 or more phosphoric acid units; and salts or ions of condensed phosphates, each of which comprises 2 or more phosphate units. The mixture is then maintained under conditions sufficient for the calcium sulfate material to form a set gypsum material.

Abstract: The invention provides a set gypsum-containing product having increased resistance to permanent deformation and a method for preparing it comprising forming a mixture of a calcium sulfate material, water, and an appropriate amount of one or more enhancing materials chosen from condensed phosphoric acids, each of which comprises 2 or more phosphoric acid units; and salts or ions of condensed phosphates, each of which comprises 2 or more phosphate units. The mixture is then maintained under conditions sufficient for the calcium sulfate material to form a set gypsum material.

Abstract: The invention provides a set gypsum-containing product having increased resistance to permanent deformation and a method for preparing it comprising forming a mixture of a calcium sulfate material, water, and an appropriate amount of one or more enhancing materials chosen from condensed phosphoric acids, each of which comprises 2 or more phosphoric acid units; and salts or ions of condensed phosphates, each of which comprises 2 or more phosphate units. The mixture is then maintained under conditions sufficient for the calcium sulfate material to form a set gypsum material.

Abstract: The invention provides an improved method for preparing foamed gypsum products. The invention can utilize a single mixing chamber and significantly improve the efficiency of foaming agent usage. In the method of the invention the point of insertion of aqueous foam into calcined gypsum slurry is positioned such that the foam is agitated less than the calcined gypsum to thereby minimize destruction of the foam while still uniformly dispersing the foam in the calcined gypsum slurry. This is accomplished, for example, by locating an inlet for foam closer to the discharge outlet of a slurry mixing chamber than the location of the inlet for calcined gypsum or by locating the foam inlet in a discharge conduit connected to the discharge outlet of the slurry mixing chamber.

Abstract: This invention is a process and foaming system for producing foamed gypsum board which permits the production and control of large foam voids in the gypsum core by adjusting the ratio of a first foaming agent and a second foaming agent. My process includes the steps of preforming a first foaming agent which forms stable foam voids in a gypsum slurry and independently preforming a second foaming agent which forms unstable foam voids in a gypsum slurry. Independently, blending the two different foaming agents is the key to controlling void size. A greater amount of the second foaming agent and a lesser amount of the first foaming agent is preferred.

Abstract: In a process utilizing steam, the method of producing at least a portion of said steam includes heating a solid substance so as to generate steam, followed by capturing the generated steam at a pressure greater than one atmosphere gage pressure for use in the process at a pressure greater than one atmosphere gage pressure. Suitable solid substances are aluminum hydrate or aluminum fluoride. New hydrated aluminum containing products and uses for those products are obtained by the use of the process.

Abstract: A process for producing alpha alumina particles includes steps of precipitating alumina hydrate from an aqueous sodium aluminate solution by treatment with alumina hydrate seed material and alpha alumina promoter particles; and calcining the precipitated alumina hydrate in the presence of a mineralizer. A preferred mineralizer is aluminum fluoride. The process produces alpha alumina particles having a plate-like shape and an average size of less than about 1.5 microns.

Abstract: In a process utilizing steam, the method of producing at least a portion of said steam, including heating a water-containing, solid substance for generating steam and capturing the generated steam for said process. A suitable solid substance is Al(OH).sub.3 . New alumina products and uses therefor are obtained.

Abstract: In a process utilizing steam, the method of producing at least a portion of said steam, including heating a water-containing, solid substance for generating steam and capturing the generated steam for said process. A suitable solid substance is Al(OH).sub.3. New alumina products are obtained.

Abstract: A process for transforming alumina hydrate into an anhydrous product comprising at least 10 wt % alpha alumina. Alumina hydrate is dehydrated, heated and transferred to a reactor where it is fluidized with steam and maintained at a temperature of about 900.degree.-1350.degree. C. Steam fluidization enhances crystal growth and results in a product having uniform quality and superior grinding characteristics.