Abstract: A gypsum slurry is described that includes water, a hydraulic component comprising at least 50% calcined gypsum by weight based on the dry weight of the hydraulic component, foam, a defoamer and a polycarboxylate dispersant. In some embodiments of the invention, the defoamer is combined with the dispersant prior to being added to the gypsum slurry. The defoamer and dispersant can be added as a physical mixture, wherein the defoamer is attached onto the dispersant polymer, or a combination thereof. A gypsum building panel is made from the gypsum slurry.

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: A method for preparing a de-aired hydraulic setting hardenable bone cement for filling a boney void or cavity by combining a powder bone substitute material and a aqueous liquid component, the method comprising the steps of: (a) supplying said powder bone substitute material in a first evacuable container; (b) withdrawing air from the first container to form a de-aired powder bone substitute material; and, then (c) mixing the de-aired powder bone substitute material and the aqueous liquid component together.

Abstract: In a process for the continuous conditioning of gypsum plaster, the gypsum plaster is passed from a calcination facility connected upstream to a gypsum plaster cooler in the form of particles. In the gypsum plaster cooler, soluble calcium sulphate anhydrite is initially converted to calcium sulphate hemi-hydrate and calcium sulphate dihydrate to calcium sulphate hemi-hydrate, and crystal defects are eliminated. Subsequently, the gypsum plaster is brought into contact with ambient air and dehumidified by the latter and thereby simultaneously cooled indirectly.

Abstract: A cement additive contains industrial waste and has the effect of inhibiting formation of monosulfate in a hardened cementitious material. The cement additive contains specifically calcium carbonate, gypsum and coal ash and/or blast-furnace slag powder. This enables efficient use of industrial waste, allows inhibiting monosulfate formation in the hardened cementitious material, and allows producing a hardened cementitious material having good durability (sulfate resistance).

Abstract: Polymerization of siloxane is improved using a gypsum-based slurry that includes stucco, Class C fly ash, magnesium oxide and an emulsion of siloxane and water. This slurry is used in a method of making water-resistant gypsum articles that includes making an emulsion of siloxane and water, then combining the slurry with a dry mixture of stucco, magnesium oxide and Class C fly ash. The slurry is then shaped as desired and the stucco is allowed to set and the siloxane polymerizes. The resulting product is useful for making a water-resistant gypsum panel having a core that includes interwoven matrices of calcium sulfate dihydrate crystals and a silicone resin, where the interwoven matrices have dispersed throughout them a catalyst comprising magnesium oxide and components from a Class C fly ash.

Abstract: A gypsum slurry is described that includes water, a hydraulic component comprising at least 50% calcined gypsum by weight based on the dry weight of the hydraulic component, foam, a defoamer and a polycarboxylate dispersant. In some embodiments of the invention, the defoamer is combined with the dispersant prior to being added to the gypsum slurry. The defoamer and dispersant can be added as a physical mixture, wherein the defoamer is attached onto the dispersant polymer, or a combination thereof. In some embodiments, a gypsum building panel is made from the gypsum slurry.

Abstract: Efficient antimicrobial additives are provided comprising a wettable, cake-forming inorganic material having dispersed therein an inorganic or organometallic antimicrobial agent capable of releasing antimicrobial metal ions. These antimicrobial additives are especially effective for use in cements, mortars and cementitious compositions.

Abstract: Emulsions are provided which are useful in imparting water-resistance to gypsum wood fiber products. In one embodiment, the emulsions comprise a wax or a combination of waxes, an alkyl phenol, at least one surfactant, Polynaphthalenesulfonic acid, and an alkali metal hydroxide. In another embodiment, the emulsions comprise a wax or a combination of waxes, an alkyl phenol, at least one surfactant, polynaphthalenesulfonic acid, an alkali metal hydroxide, and a complexed starch.

Abstract: The acoustical product of the present invention comprises an acoustical product including a matrix of calcium sulfate dihydrate crystals and expanded perlite distributed throughout the matrix. The expanded perlite has a particle size distribution with at least 10% of the perlite having a particle diameter of 700 microns or more, and the amount of expanded perlite to calcium sulfate dihydrate is about 35% to about 75% by weight, based upon the dry weight of the calcium sulfate dihydrate. A dispersing agent and glass fibers having a particle length of about ¼ inch to about 1 inch are dispersed throughout the gypsum matrix.

Abstract: The present invention relates in general to implantable compositions, and method for preparing same, containing a calcium salt-containing component, optionally demineralized bone, a plurality of discrete fibers, optionally a flow additive, and optionally continuous reinforcing fibers or an array of organized fibers in the form of mesh. Advantageously, the discrete fibers have a specific aspect ratio (length/diameter) from about 50:1 to about 1000:1. The addition of a small amount of discrete fibers and/or the continuous reinforcing fibers or fiber mesh can cause drastic increases in certain mechanical properties including flexural strength, flexural toughness, and/or screw pullout strength.

Abstract: A process for reducing the set time a plaster slurry. The process comprises the steps of providing a pre-determined amount of water, providing a pre-determined amount of the plaster, mixing the water and the plaster together at a first time to form a slurry, and, re-directing a portion of the slurry formed at the first time to combine with slurry formed at a second time.

Abstract: Provided are methods and systems for introducing a wet gypsum accelerator or other high viscosity production additive to an aqueous dispersion of calcined gypsum in a discharge apparatus downstream of a stucco mixer in which the dispersion was prepared. These methods and systems are useful in the production of various gypsum products such as board including wallboard and ceiling tiles.

Abstract: The invention relates to a method for the production of hard plaster made from calcined beta hemihydrate plaster, comprising adding of plaster material mainly consisting of beta hemihydrate plaster to a post reactor (3), after-treating in the post reactor (3) for forming hard plaster, wherein the beta hemihydrate plaster is directly converted into alpha hemihydrate plaster at a temperature above the calcining temperature of 95 degrees Celsius, removing the hard plaster from the post reactor (3), and cooling down. During the adding of the plaster material to the post reactor (3) the temperature is adjusted to at least the calcining temperature, the conversion is carried out in the post reactor (3) at a dwell time of less than 30 minutes while externally adding water vapor, and the temperature and the pressure in the post reactor (3) are regulated such that the temperature is at least 95 degrees Celsius and an overpressure is present.

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 present invention relates to a system and associated method for the production of gypsum in manufacturing plant. More specifically, the invention relates to the production of alpha-type gypsum in a gypsum board manufacturing plant. The system yields increased efficiencies by capturing heat given off during processing steps and using that heat to reduce the energy needed for calcination. The invention finds particular application in the production alpha-type gypsum. The present invention is described in greater detail hereinafter in conjunction with the following specific embodiments.

Abstract: Disclosed is a method for producing alpha-calcium sulfate hemihydrate from calcium dihydrate. Said method has the following features: a) calcium dihydrate is fed to an agitated autoclave (1); b) the agitated autoclave (1) is indirectly heated; c) water is added and incorporated in a controlled manner; d) the feedstock is prevented from adhering to surfaces of the reaction chamber by means of moved chains (3) that are mounted on the paddles and/or the drive shaft (16) of the agitated autoclave (1); e) the pressure in the reaction chamber is regulated at intervals or in a continuous manner by discharging vapor when a certain pressure has been reached in the interior, the vapor being conducted via a centrifugal separator (17) and a control valve (18); f) cold air is delivered for residual drying purposes; g) the process material is removed. Also disclosed is a corresponding apparatus for carrying out said method.

Abstract: A joint compound or wall repair composition and the method of making the same is disclosed that reduces the amount of airborne dust emitted during traditional sanding processes. Generally, such a reduction can be achieved by combining a first binder that has a high glass transition temperature and a second binder that has a low glass transition temperature with conventional joint compound compositions.

Abstract: A system (100) for calcining natural gypsum, synthetic gypsum (112) or a combination thereof, the system including: a mill (114) for grinding and drying natural gypsum, synthetic gypsum (112) or a combination thereof, to produce dried gypsum (116); a flash calciner (118) for calcining the dried gypsum to produce an exhaust gas (130) and calcined gypsum (128); and a mechanism (134) for transporting at least a portion of the exhaust gas (130) produced by the flash calciner (118) to an air heater (126) that supplies hot gas (126a) to the flash calciner (118).

Abstract: A gypsum slurry is described that includes water, a hydraulic component comprising at least 50% calcined gypsum by weight based on the dry weight of the hydraulic component, foam, a defoamer, a polycarboxylate dispersant having olefinic unsaturated mono-carboxylic acid moieties and (poly)oxyalkylene moieties, a first portion of a retarder and a second portion of a retarder. In some embodiments of the invention, the defoamer is combined with the dispersant prior to being added to the gypsum slurry. The defoamer and dispersant can be added as a physical mixture, wherein the defoamer is attached onto the dispersant polymer, or a combination thereof. In some embodiments, a gypsum building panel is made from the gypsum slurry.

Abstract: A process for treating beta calcium sulfate hemihydrate is disclosed. The process comprises exposing beta calcium sulfate hemihydrate to steam at a pressure above atmospheric pressure.

Abstract: Described herein is a cementitious article and a method of making using a water-based manufacturing system that incorporates a closed-loop or partially closed loop water recycling system and an alkali removal process. The system, as such is environmentally friendly, saves resources, such as water and other raw materials, and reduces waste disposal. The system further provides for a cementitious article having a low alkali content. Articles prepared by one or more processes described herein have characteristics that include a low apparent density, high strength and high freeze-thaw performance as compared with an article of the same general formulation but made from a comparative manufacturing system that does not include an alkali removal process. Articles described herein are suitable for use as building products, such as siding, the underlayment panel, board, trim, fascia, roofing, decking, and fence.

Abstract: A gypsum slurry includes calcium sulfate hemihydrate, a set retarder in amounts of at least 0.15 lb/MSF, a set accelerator, water and aqueous foam. The set accelerator is selected to provide nucleation sites for crystallization of calcium sulfate dihydrate and is present in amounts of at least 5 Ib/MSF. The water to calcium sulfate hemihydrate ratio is at least 0.95. Further, aqueous foam is added in amounts sufficient to create a gypsum board having a dry density of about 29 to about 35 lbs/ft3.

Abstract: A process for treating beta calcium sulfate hemihydrate is disclosed. The process comprises exposing beta calcium sulfate hemihydrate to steam at a pressure above atmospheric pressure.

Abstract: A gypsum slurry includes calcium sulfate hemihydrate, water and calcium sulfate dihydrate, where the calcium sulfate dihydrate is added downstream of the mixer. In an optional embodiment, the a gypsum slurry includes calcium sulfate hemihydrate, a polycarboxylate dispersant, water and coated calcium sulfate dihydrate. In this case, the hydrophilic, dispersible coating is selected to serve as a modifier to enhance the ability of the dispersant to fluidize the gypsum slurry.

Abstract: The method for recycling construction and demolition fines involves using mixed fines from construction and demolition debris that would otherwise be disposed of at landfills as an ingredient in cement or concrete. The mixed fines contain a plurality of materials selected from the group consisting of asphalt, plastics, ceramics, fiberglass and batt insulation, soil, dust, drywall, wood, plaster, paper, cardboard, dirt. The fines may also contain particles of recyclable materials, such as concrete, bricks, mortar, metals, glass, and the like. The fines may range in size from microns up to 6 inches in at least one direction. The recycler may incorporate the fines into a concrete mix for bulk sale to commercial enterprises, or may himself form precast, lightweight concrete products, such as decorative columns, pedestals and table bases, trim moldings and cornices, door surrounds, etc.

Abstract: Polymerization of siloxane is improved using a gypsum-based slurry that includes stucco, Class C fly ash, magnesium oxide and an emulsion of siloxane and water. This slurry is used in a method of making water-resistant gypsum articles that includes making an emulsion of siloxane and water, then combining the slurry with a dry mixture of stucco, magnesium oxide and Class C fly ash. The slurry is then shaped as desired and the stucco is allowed to set and the siloxane polymerizes. The resulting product is useful for making a water-resistant gypsum panel having a core that includes interwoven matrices of calcium sulfate dihydrate crystals and a silicone resin, where the interwoven matrices have dispersed throughout them a catalyst comprising magnesium oxide and components from a Class C fly ash.

Abstract: Polymerization of siloxane is improved using a gypsum-based slurry that includes stucco, Class C fly ash, magnesium oxide and an emulsion of siloxane and water. This slurry is used in a method of making water-resistant gypsum articles that includes making an emulsion of siloxane and water, then combining the slurry with a dry mixture of stucco, magnesium oxide and Class C fly ash. The slurry is then shaped as desired and the stucco is allowed to set and the siloxane polymerizes. The resulting product is useful for making a water-resistant gypsum panel having a core that includes interwoven matrices of calcium sulfate dihydrate crystals and a silicone resin, where the interwoven matrices have dispersed throughout them a catalyst comprising magnesium oxide and components from a Class C fly ash.

Abstract: Methods of preparing improved settable compositions free of Portland cement and methods of using such compositions in subterranean operations are provided. An example of a method of preparing such compositions may comprise providing an unhydrated mixture of raw materials comprising a silica component, an aluminum component, a magnesium component, a sodium component, a calcium component, a ferrous or ferric component, a sulfurous component, and a potassium component, wherein the mixture has been formed without heating any of the components to above about 3000° F.; and adding water to the unhydrated mixture of raw materials to form a settable composition.

Abstract: A structural component on the basis of a mineral, crystalline binder matrix composed of hardened cement and/or construction lime and/or gypsum, wherein the matrix can have aggregates and/or additives and/or admixtures, forms a surface that receives light, in its usability or use, on which surface photocatalytically active particles are situated. The particles are situated and fixed in place only on the surface of the structural component. The remainder of the structural component body does not have the particles. A method for production of the structural components is also provided.

Abstract: Polymerization of siloxane is improved using a gypsum-based slurry that includes stucco, Class C fly ash, magnesium oxide and an emulsion of siloxane and water. This slurry is used in a method of making water-resistant gypsum articles that includes making an emulsion of siloxane and water, then combining the slurry with a dry mixture of stucco, magnesium oxide and Class C fly ash. The slurry is then shaped as desired and the stucco is allowed to set and the siloxane polymerizes. The resulting product is useful for making a water-resistant gypsum panel having a core that includes interwoven matrices of calcium sulfate dihydrate crystals and a silicone resin, where the interwoven matrices have dispersed throughout them a catalyst comprising magnesium oxide and components from a Class C fly ash.

Abstract: Method and apparatus for converting wet synthetic gypsum from a flue desulphurization process (FGD) to easily handled and metered briquettes by mixing a hydraulic additive such as by-pass dust from a cement kiln with synthetic gypsum and allowing the heat from the resulting hydraulic reaction to reduce the water content of the mixture to a formable consistency without adding external heat to the mixture as it is formed into briquettes.

Abstract: The invention provides gypsum wallboard, made from gypsum-containing slurries having outstanding hydration rate characteristics comprising alpha-hemihydrate ground to a particular particle size distribution range and having a Blaine surface area in the range from about 3100 cm2/g to about 9000 cm2/g, alone or in combination with beta-hemihydrate.

Abstract: A laminate board for building element to be used in the construction of buildings includes a core layer made of moisture-impermeable polymers, and one or more external layer, facing and attached to the core layer wherein the external layer includes a fibre net and a mixture of construction materials and flame-retarding materials.

Abstract: A gypsum slurry includes water, a hydraulic component including stucco and a polycarboxylate dispersant. The dispersant has two repeating units wherein the first repeating unit is an olefinic unsaturated mono-carboxylic acid repeating unit or an ester or salt, and the second repeating unit is a vinyl or allyl group bound to a polyether by an ether linkage. The slurry can be made into a gypsum panel.

Abstract: Provided herein are mixtures, emulsions and other additives for use in manufacturing gypsum wallboard. The mixtures and emulsions may be wax-based emulsions or wax-free mixtures or emulsions, with wax-based emulsions including water; at least one wax, a dispersant which may include sulfur or a sulfur-containing group, and a particular wetting agent or surfactant. Mixtures may also be prepared including water, a dispersant, and a particular wetting agent or surfactant. Gypsum slurries may be prepared using such emulsions and mixtures.

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: A process for making calcined gypsum in slurry or powder form. The process includes adding at least two types of crystal modifiers to the slurry. The first crystal modifier is to control crystal morphology of the calcined gypsum (such as succinic and/or malic acid). The second crystal modifier is to prevent or retard setting to control set time (such as tetrasodium pyrophosphate (TSPP)) to form a water stable product. An accelerator is typically added at the site of use for specific applications such as setting type joint compound, media casting, exterior/interior coating, and sprayable fireproofing. A composition made by the process and a kit for using the composition are also disclosed.

Abstract: A cementitious veneer and laminate composition is provided. The cementitious laminate composition includes a substrate, a primer layer applied to the substrate, the primer layer comprising a mixture of polyvinyl alcohol catalyst, Portland cement, and sand; and a cementitious veneer layer applied to the primer layer, the veneer layer comprising a mixture of magnesium sulfate, filler, magnesium oxide, gypsum cement, and polyvinyl alcohol catalyst. The polyvinyl alcohol catalyst comprises a mixture of polyvinyl alcohol fibers dissolved in water and mixed with butylene carbonate. The veneer layer is applied to the substrate and primer layer by means including spraying and manual spreading. The veneer layer can be ornamentally manipulated either before or after curing of the veneer layer. The veneer composition can be formed into laminated tiles or panels for use in building applications.

Abstract: The invention generally provides gypsum-containing slurries including stucco, naphthalenesulfonate dispersant, and pregelatinized starch. The naphthalenesulfonate dispersant is present in an amount of about 0.1%-3.0% by weight based on the weight of dry stucco. The pregelatinized starch is present in an amount of at least about 0.5% by weight up to about 10% by weight of pregelatinized starch by weight based on the weight of dry stucco in the formulation. Other slurry additives can include trimetaphosphate salts, accelerators, binders, paper fiber, glass fiber, and other known ingredients. The invention also comprises the gypsum-containing products made with such slurries, for example, gypsum wallboard, and a method of making gypsum wallboard.

Abstract: A sulphoaluminate clinker includes as a phasic formulation, compared with the total weight of clinker: 5 to 25% of a calcium aluminoferrite phase with a formulation corresponding to the general formula C2AXF(1?X), with X comprised between 0.2 and 0.8; 15 to 35% of a calcium sulphoaluminate phase yee' limit (C4A3$); 40 to 75% belite (C2S); from 0.01 to 10% of one or several minor phases selected from the group consisting of calcium sulphates, alkali sulphates, perovskite, calcium aluminates, gehlenite, free lime and periclase, and/or a vitreous phase, and additives including at least sodium and boron present in the following quantities, by weight as compared to the total weight of the clinker: from 0.1 to 5% of sodium expressed as sodium oxide and from 0.2 to 3% of boron, expressed as boron oxide, the total content of said additives being less than or equal to 15%.

Abstract: A hydraulic composition including: a ground burned product A having a hydraulic modulus (H.M.) of 1.8 to 2.3, a silica modulus (S.M.) of 1.3 to 2.3 and an iron modulus (I.M.) of 1.3 to 2.8; and a gypsum. The hydraulic composition is capable of reducing heat of hydration and producing a mortar or a concrete excellent in flowability and strength development.

Abstract: Methods and systems are provided for preparing a heat resistance accelerator (HRA) slurry. Also provided are methods and systems for introducing a HRA slurry to an aqueous dispersion of calcined gypsum in a discharge apparatus downstream of a stucco mixer in which the dispersion was prepared. These methods and systems are useful in the production of various gypsum products such as board including wallboard and ceiling tiles.

Abstract: Methods and compositions that comprise sub-micron alumina for accelerating setting of a cement composition. An embodiment includes a method of cementing in a subterranean formation. The method may comprise introducing a cement composition into the subterranean formation, wherein the cement composition comprises hydraulic cement, sub-micron alumina, and water. The method further may comprise allowing the cement composition to set in the subterranean formation. Another embodiment includes a cement composition that may comprise hydraulic cement, sub-micron alumina, and water.

Abstract: Disclosed is an improved alpha-type calcium sulfate hemihydrate. Methods of producing an improved powdered calcium sulfate hemihydrate (CaSO4.½H2O) [alpha-type] compound are disclosed, at least one method including forming calcium sulfate dihydrate (CaSO4.2H2O) into a briquette, calcining the briquette to transform the calcium sulfate dihydrate to calcium sulfate hemihydrate [alpha-type], drying the calcium sulfate hemihydrate [alpha-type] briquette, and optionally grinding the briquette. Also disclosed are methods of producing an improved gypsum plaster including producing the disclosed powdered calcium sulfate hemihydrate [alpha-type] and mixing the powdered calcium sulfate hemihydrate [alpha-type] with water.

Abstract: A method for producing a bone filler basically comprising: a bone model producing step (step 1) for producing a bone model; a figure forming material filling step (step 2) for filling a figure forming material into a bone defect site of the bone model obtained in the bone model producing step; and a bone filler producing step (step 3) for producing a bone filler which is to be filled in a bone defect site based on the figure forming material filled in the bone defect site of the bone model in the figure forming material filling step.

Abstract: A method of producing a foamed plaster comprises the following steps: (a) mixing plaster of Paris and calcium carbonate; (b) supplying water, and (c) adding phosphoric acid. The phosphoric acid reacts with the calcium carbonate to release gaseous carbon dioxide. It also reacts with any steel present to form an insoluble iron phosphate coating.

Abstract: An embodiment of the present invention includes a method of cementing in a subterranean formation comprising: providing an extended settable composition comprising hydraulic cement, cement kiln dust, water, and a set retarding additive, wherein the extended settable composition is capable of remaining in a pumpable fluid state for at least about 1 day; adding a cement set accelerator to the extended settable composition; introducing the extended settable composition into a well bore; and allowing the extended settable composition to set. Another embodiment of the present invention includes a method of cementing in a subterranean formation comprising: providing an extended settable composition comprising hydraulic cement, cement kiln dust, water, and a set retarding additive; storing the extended settable composition; adding a cement set accelerator to the extended settable composition; introducing the extended settable composition into a well bore; and allowing the extended settable composition to set.

Abstract: A process and system for manufacturing gypsum wallboard that aerates and cools a portion of the stucco used in the manufacturing process. This conditioning of the stucco reduces the amount of water needed to manufacture the gypsum wallboard which in turn reduces the amount of energy and cost needed to manufacture the wallboard.