The invention relates to a construction unit made from various recyclable materials, for example, from recycled waste plasterboard from the construction industry or flue-gas gypsum which is a by-product from fossil-fueled power plants. The construction units are made from a raw mix comprising gypsum, clay and aggregate and methods of making construction units. The invention also relates to a raw mix for making a construction unit; a kit including a construction unit and mortar; and uses of the construction unit to form a structure.

The present invention provides a method of preparing a recycled cementitious material by a phosphogypsum-assisted carbon sequestration pretreatment process. The method includes: (1) placing 100 mass parts of phosphogypsum, 1 to 2 mass parts of grinding aid, 10 to 20 mass parts of sodium-containing alkali component, 150 to 300 mass parts of zirconia balls, and 150 to 300 mass parts of water into a wet grinding tank for wet grinding. After 10 min to 30 min of wet grinding, introducing CO.sub.2 at a flow rate of 1.5 to 2.2 mass parts/min to keep a temperature of a wet grinding slurry below 40 C. When the wet grinding slurry reaches pH=10, ending the wet grinding and sieving out a wet grinding slurry; (2) mixing the wet grinding slurry with 700 to 1000 mass parts of slag and 100 to 350 mass parts of water to obtain a recycled cementitious material.

Disclosed are a barium slag-modified aluminate quick-hardening special cementing material and a preparation method thereof, wherein the raw materials for the preparation of the barium slag-modified aluminate quick-hardening special cementing material includes, in parts by weight: 10-12 parts of aluminate cement clinker, 2-3 parts of barium slag powder, 1.5-2 parts of sulfate material, and 0-1.5 parts of early-setting agent. The present invention, on the basis of ensuring the original advantages of aluminate cement, can increase the long-term strength, durability, and economy, and solve the possible environmental problems caused by the barium slag, making it more suitable for use in various engineering projects.

The present invention provides dry mix compositions for use in making gypsum plasters or mortars comprising gypsum, preferably, phosphorous gypsum one or more retarder, and one or more crosslinked cellulose ethers containing polyether groups. The compositions enable the provision of gypsum dry mixes, such as those from phosphorus gypsum, that make gypsum mortars with less stickiness while reducing the amount of cellulose ether in the dry mix.

The present invention provides dry mix compositions for use in making gypsum plasters or mortars comprising gypsum, preferably, phosphorous gypsum one or more retarder, and one or more crosslinked cellulose ethers containing polyether groups. The compositions enable the provision of gypsum dry mixes, such as those from phosphorus gypsum, that make gypsum mortars with less stickiness while reducing the amount of cellulose ether in the dry mix.

The invention relates to a construction unit made from various recyclable materials, for example, from recycled waste plasterboard from the construction industry or flue-gas gypsum which is a by-product from fossil-fueled power plants. The construction units are made from a raw mix comprising gypsum, clay and aggregate and methods of making construction units. The invention also relates to a raw mix for making a construction unit; a kit including a construction unit and mortar; and uses of the construction unit to form a structure.

The invention relates to a construction unit made from various recyclable materials, for example, from recycled waste plasterboard from the construction industry or flue-gas gypsum which is a by-product from fossil-fueled power plants. The construction units are made from a raw mix comprising gypsum, clay and aggregate and methods of making construction units. The invention also relates to a raw mix for making a construction unit; a kit including a construction unit and mortar; and uses of the construction unit to form a structure.

Provided is a composite material including a blend of components. The blend includes phosphogypsum, bitumen and particulate matter. The phosphogypsum may be present in an amount of at least 10% w/w out of the total weight of said composite material. Also provided herein is a method of producing the composite material, by, at least, mixing phosphogypsum and particulate matter at a temperature above 150 C. for a time sufficient to receive an essentially dry particulate mixture in which the amount of the phosphogypsum is such to obtain a composite material having at least 10% w/w out of the total dry weight of said composite material. While mixing molten bitumen may be introduced into the essentially dry particulate mixture to obtain the composite material. Articles of manufacture including the composite material are also disclosed.

Provided is a composite material including a blend of components. The blend includes phosphogypsum, bitumen and particulate matter. The phosphogypsum may be present in an amount of at least 10% w/w out of the total weight of said composite material. Also provided herein is a method of producing the composite material, by, at least, mixing phosphogypsum and particulate matter at a temperature above 150 C. for a time sufficient to receive an essentially dry particulate mixture in which the amount of the phosphogypsum is such to obtain a composite material having at least 10% w/w out of the total dry weight of said composite material. While mixing molten bitumen may be introduced into the essentially dry particulate mixture to obtain the composite material. Articles of manufacture including the composite material are also disclosed.

Disclosed is a phosphogypsum-based backfill material, including the following components in parts by weight: 0.2-0.8 parts of water, 0.01-0.3 parts of a cement, 0.01-0.6 parts of a fly ash, 0-0.6 parts of a stone powder, 0-3 parts of a sand, and 0-5 parts of a stone; and further including the following components in parts by weight: 1 part of any one or a combination of two or more selected from the group consisting of phosphogypsum, a modified phosphogypsum, and a modified phosphogypsum powder, and 0-0.5 parts of any one selected from the group consisting of a basalt fiber, graphite, and a steel fiber.