An object of the present invention is to provide a mold-making gypsum composition that can contribute, in a case of, for example, making a model of dentures, to improvements in workability in a step of making a gypsum mold (mold) which is necessary for making a model of artificial gingiva (gum) part made of a resin and which is different individually and is required to have an elaborate shape. In detail, the present invention provides a mold-making gypsum composition such that a slurry-like malaxated product obtained by adding water to the mold-making gypsum composition exhibits favorable fluidity and therefore the mold-making gypsum composition is used for tertiary investing for filling a void in a polymerization flask in making a mold, and thereby workability can be improved and a favorable mold in which occurrence of cracks of gypsum is suppressed when the mold-making gypsum composition is set can be formed. The present invention is a cast-making gypsum composition containing gypsum hemihydrate, wherein the gypsum hemihydrate contains ? gypsum hemihydrate and ? gypsum hemihydrate in a ratio of 25:75 to 65:35.

A composition for forming molded mantels, columns and other decorative enhancement to fireplace openings is formed of a mixture of alpha hemihydrate gypsum plaster, cement, filler and milled fiber. By using this composition with water and acrylic binder a mixture is formed which sets and gains strength quickly and is an ideal material for manufacturing architectural and decorative structures. Advantageously, a casted piece can be removed from a mold within two to three hours after casting. The finished product has a desired finish that is similar to a casted gypsum cement, referred to sometimes as a honed finish which can withstand high heat, discoloration and cracking while maintaining suitable strength when exposed to typical temperatures of a fireplace surround in indoor applications.

A composition for forming molded mantels, columns and other decorative enhancement to fireplace openings is formed of a mixture of alpha hemihydrate gypsum plaster, cement, filler and milled fiber. By using this composition with water and acrylic binder a mixture is formed which sets and gains strength quickly and is an ideal material for manufacturing architectural and decorative structures. Advantageously, a casted piece can be removed from a mold within two to three hours after casting. The finished product has a desired finish that is similar to a casted gypsum cement, referred to sometimes as a honed finish which can withstand high heat, discoloration and cracking while maintaining suitable strength when exposed to typical temperatures of a fireplace surround in indoor applications.

The invention relates to a composition for inorganic binders, comprising at least one ketone-formaldehyde condensation product on the basis of a cyclic ketone and at least one anionic or nonionic surfactant and/or a thickener, and also to building material mixtures which comprise this composition, and to the use of the composition. The compositions improve the applications properties of the binder formulations.

The present invention relates to polycondensates containing at least a structural unit, which is an aromatic moiety bearing a polyether side chain, at least a structural unit, which is an aromatic moiety bearing at least one phosphoric acid monoester group, at least a structural unit, which is an aromatic moiety, bearing at least one hydroxy group and at least a methylene unit (CH.sub.2), which is attached to two aromatic structural units. The invention also concerns a process for the production of the polycondensates, their use for the dispersion of inorganic binders, for increasing the strength development of concrete and for improving the slump-retention of concrete. The invention relates also to building material mixtures comprising the polycondensates and inorganic binders.

The present invention relates to a method for producing a gypsum-containing foamed prefabricated building material and to a gypsum-containing foamed prefabricated building material.

The invention relates to a composition comprising at least one binder based on calcium sulfate and at least one polymer obtainable by polymerization of monomers based on alkoxylates of S-vinylthioalkanols. Furthermore a molding, in particular a gypsum plasterboard, a gypsum wallboard, a screed or a knifing filler, obtained by setting of the composition of the invention is disclosed.

The invention relates to a composition comprising at least one binder based on calcium sulfate and at least one polymer obtainable by polymerization of monomers based on alkoxylates of S-vinylthioalkanols. Furthermore a molding, in particular a gypsum plasterboard, a gypsum wallboard, a screed or a knifing filler, obtained by setting of the composition of the invention is disclosed.

The invention relates to a method of producing a binder comprising the steps of preparing (20) a residual material comprising amorphous alumina-rich and/or aluminium hydroxide-rich constituents, heating (30) the residual material to produce a fired material, the heating (30) of the residual material being at a temperature of >800 C.

The invention relates to a method of producing a binder comprising the steps of preparing (20) a residual material comprising amorphous alumina-rich and/or aluminium hydroxide-rich constituents, heating (30) the residual material to produce a fired material, the heating (30) of the residual material being at a temperature of >800 C.