The present disclosure relates generally to plaster wall panels, for example, suitable for covering interior wall frames. The present disclosure relates more particularly to a plaster wall panel including a first plaster layer, a second plaster layer, and a damping layer disposed between the first and second plaster layers. The first plaster layer has a first thickness and is composed of a first plaster material that has a first material property. The second plaster layer has a second thickness and is composed of a second plaster material that has a second material property. The first thickness is smaller than the second thickness, and the first and second material properties are different.

The cementitious material for a radioactive waste disposal facility includes base cement, and porous and amorphous silica powder. The amount of the silica powder in the entire cementitious material ranges from 35% to 65% on a mass basis.

The cementitious material for a radioactive waste disposal facility includes base cement, and porous and amorphous silica powder. The amount of the silica powder in the entire cementitious material ranges from 35% to 65% on a mass basis.

A method for producing a gypsum plasterboard comprising the steps of providing bundler dust obtained from gypsum plasterboard leftovers of a plasterboard trimming process by a trimming device, in particular by a bundler saw; and adding at least a part of the bundler dust to a gypsum slurry for producing the gypsum plasterboard.

Disclosed are product (e.g., panels), slurry, and methods relating to a pregelatinized starch having a mid-range viscosity (i.e., from about 20 centipoise to about 700 centipoise).

A method of making a gypsum board including: preparing an aqueous slurry including a mixture of: calcium sulfate hemihydrate, water at a weight ratio of water to calcium sulfate hemihydrate of 0.2:1 to 1.2:1, and on a dry basis per 100 parts by weight (pbw) calcium sulfate hemihydrate: 0.2 to 2 pbw siloxane, 0.01 to 2 pbw siloxane polymerization catalyst including magnesium oxide and optionally fly ash, and 0.01 to 0.2 pbw triethanolamine (TEOA); allowing the siloxane to polymerize to polysiloxane; and depositing the slurry on a first cover sheet and covering the slurry with a second cover sheet to shape the slurry, and allowing the shaped slurry to set to form the gypsum board. Also, disclosed is the gypsum board resulting from the method.

A constrictor valve can be associated with a conduit in fluid communication with a mixer to control a flow of cementitious slurry discharged from the mixer through the conduit. The constrictor valve can include a constrictor housing, a webbing constriction assembly, and a drive mechanism. The webbing constriction assembly includes a pair of rotatable members rotatably mounted to the constrictor housing and a plurality of webbing straps connected to the rotatable members and wrapped around the conduit. The drive mechanism includes a drive shaft and a gear assembly configured to rotate the rotatable members in opposing winding directions in response to the drive shaft rotating in a tighten direction to wrap the webbing straps tighter around the conduit to compress it and to rotate in opposing unwinding directions in response to the drive shaft rotating in a loosen direction to loosen the grip of the webbing straps on the conduit.

A constrictor valve can be associated with a conduit in fluid communication with a mixer to control a flow of cementitious slurry discharged from the mixer through the conduit. The constrictor valve can include a constrictor housing, a webbing constriction assembly, and a drive mechanism. The webbing constriction assembly includes a pair of rotatable members rotatably mounted to the constrictor housing and a plurality of webbing straps connected to the rotatable members and wrapped around the conduit. The drive mechanism includes a drive shaft and a gear assembly configured to rotate the rotatable members in opposing winding directions in response to the drive shaft rotating in a tighten direction to wrap the webbing straps tighter around the conduit to compress it and to rotate in opposing unwinding directions in response to the drive shaft rotating in a loosen direction to loosen the grip of the webbing straps on the conduit.

The present application pertains to methods for making metal oxides and/or citric acid. In one embodiment, the application pertains to a process for producing calcium oxide, magnesium oxide, or both from a material comprising calcium and magnesium. The process may include reacting a material comprising calcium carbonate and magnesium carbonate. Separating, concentrating, and calcining may lead to the production of oxides such as calcium oxide or magnesium oxide. In other embodiments the application pertains to methods for producing an alkaline-earth oxide and a carboxylic acid from an alkaline earth cation-carboxylic acid anion salt. Such processes may include, for example, reacting an alkaline-earth cation-carboxylic acid anion salt with aqueous sulfur dioxide to produce aqueous alkaline-earth-bisulfite and aqueous carboxylic acid solution. Other useful steps may include desorbing, separating, and/or calcining.

Gypsum panels, sheathing systems, and methods of making and using the same are provided. A gypsum panel includes a gypsum core associated with a first fiberglass mat having a continuous barrier coating, the coating penetrating a portion of the first fiberglass mat opposite the gypsum core, wherein gypsum penetrates a remaining fibrous portion of the first fiberglass mat such that voids in the first fiberglass mat are substantially eliminated. A building sheathing system includes at least two gypsum panels and a seaming component to provide a seam at an interface between the gypsum panels.