A method of processing plasterboards or plasterboard for recover a calcium sulphate source for producing a hydraulic binder, includes comminuting plasterboards or a gypsum fraction thereof so as to obtain plasterboard particles and, thereafter, subjecting the plasterboard particles to a heat treatment at an elevated temperature so as to volatilize and/or decompose organic components present in the plasterboard particles.

A plasterboard comprises a gypsum matrix having fibres embedded therein. The plasterboard optionally has a backing lamina attached to one of the faces thereof. The gypsum matrix of the plasterboard optionally comprises a polymeric additive.

A plasterboard comprises a gypsum matrix having fibres embedded therein. The plasterboard optionally has a backing lamina attached to one of the faces thereof. The gypsum matrix of the plasterboard optionally comprises a polymeric additive.

The invention pertains to a method for stabilizing stucco wherein a fresh stucco is provided; water is added to the fresh stucco to obtain moistened stucco, and the moistened stucco is maintained at a temperature of at least 30 C. for a time interval of at least 30 minutes to obtain a stabilized stucco.

The process allows inter alia for an easy adjustment of the activity of the stabilized stucco, which is useful to e.g. adjust setting time of a corresponding stucco slurry. The invention further pertains to a method for producing gypsum plasterboards, wherein a stabilized stucco obtained with the above method is used.

A penetration part fireproof covering material used when a penetration part covered for fireproof is formed in a fireproof beam that is a fireproof constructional member that constitutes a wooden building, wherein the penetration part fireproof covering material is formed to have a tubular shape by stacking a plurality of gypsum board pieces (13a) formed from gypsum boards in a thickness direction and unitarily connecting the plurality of gypsum board pieces. The penetration part fireproof covering material is formed to have the tubular shape by stacking the plurality of gypsum board pieces that preferably have an annular shape and are cut out from commercially available gypsum boards having thicknesses of 9.5 mm to 25.5 mm while fixing the plurality of gypsum board pieces to each other preferably using metal fasteners such as staples, and unitarily connecting the plurality of gypsum board pieces.

A penetration part fireproof covering material used when a penetration part covered for fireproof is formed in a fireproof beam that is a fireproof constructional member that constitutes a wooden building, wherein the penetration part fireproof covering material is formed to have a tubular shape by stacking a plurality of gypsum board pieces (13a) formed from gypsum boards in a thickness direction and unitarily connecting the plurality of gypsum board pieces. The penetration part fireproof covering material is formed to have the tubular shape by stacking the plurality of gypsum board pieces that preferably have an annular shape and are cut out from commercially available gypsum boards having thicknesses of 9.5 mm to 25.5 mm while fixing the plurality of gypsum board pieces to each other preferably using metal fasteners such as staples, and unitarily connecting the plurality of gypsum board pieces.

A method for continuously forming gypsum-based panels of high fixing strength comprises the steps of: forming a mixture comprising stucco, non-pregelatinized migratory starch, glass fibre, fluidizer and water; casting the mixture in a continuous band; maintaining the band under conditions sufficient for the stucco to form an interlocking matrix of set gypsum; cutting the band to form one or more wet panel precursors; and drying the wet panel precursor to form one or more gypsum-based panels. The weight ratio of water to stucco in the mixture is less than 0.7; the stucco is present in the mixture in an amount of over 60 wt % relative to the total solids content of the mixture; the starch is present in the mixture in an amount of over 3 wt % relative to the the stucco; the glass fibre is present in the mixture in an amount of over 1 wt % relative to the stucco; the fluidizer is is present in the mixture in an amount of at least 0.1 wt % relative to the stucco; and the density of the gypsum-based panel is greater than 700 kg/m.

From the viewpoint of a decrease in environmental impact in recent years, an object of the present invention is to effectively utilize lignin as a circulative biomass resource having high effect of reducing environmental impact. Specifically, the object is to provide a lignin derivative that can improve the dispersibility of various substances to be dispersed regardless of uses of cements, dyes, oil field drilling mud, and the like. The present invention provides a lignin derivative compound that is a reaction product of a lignin sulfonic acid-based compound with an aromatic water-soluble compound, and a dispersant containing the same. The lignin derivative compound preferably has an anionic functional group and/or a polyalkylene oxide chain.

From the viewpoint of a decrease in environmental impact in recent years, an object of the present invention is to effectively utilize lignin as a circulative biomass resource having high effect of reducing environmental impact. Specifically, the object is to provide a lignin derivative that can improve the dispersibility of various substances to be dispersed regardless of uses of cements, dyes, oil field drilling mud, and the like. The present invention provides a lignin derivative compound that is a reaction product of a lignin sulfonic acid-based compound with an aromatic water-soluble compound, and a dispersant containing the same. The lignin derivative compound preferably has an anionic functional group and/or a polyalkylene oxide chain.

A composite structure for use in tiling surfaces is disclosed. The composite structure can include a fiber matrix impregnated with a water-activated setting material. The composite structure can be wet and then compressed between a tile and an application surface. The composite structure can cure to provide a support surface for the tile.