Systems and methods for making gypsum board using a liquid gypsum set accelerator. Stucco and water are mixed to form a gypsum slurry, such as in a pin mixer. A gypsum set accelerator is mixed with a liquid medium to form a liquid gypsum set accelerator, such as in an eductor. The liquid gypsum set accelerator is added to the gypsum slurry, which is shaped to form the gypsum board.

A method for manufacturing hydraulically hardening building materials, includes the steps of: providing concrete demolition waste with a maximum particle size of up to 150 mm as a starting material, mixing the starting material with water to form a feedstock slurry, introducing carbon dioxide or a precursor thereof into the feedstock slurry to form carbonated concrete fines in an amount from 1 to 100 wt.-% of the hardened binder contained in the starting material and to detach the concrete fines from the aggregate contained in the starting material to form a product slurry, and mixing the product slurry with a cement forming the building material, and use of the obtainable building material for manufacturing building structures as well as method for manufacturing a supplementary cementitious material slurry.

An apparatus (100) for the production of a plaster slurry is described, the apparatus (100) comprising a mixer (102) for mixing at least plaster and water to form a plaster slurry, the mixer (102) comprising an outlet conduit (122), a foam generator (106) for mixing at least air, a foaming agent and water to produce a foam, the foam generator (106) in fluid communication with the mixer (102) via a fluid pathway (116) comprising a foam conduit (117); and a mass flow meter (124), wherein the mass flow meter (124) is configured to measure the density and mass flow rate of the foam within the foam conduit (117) or the plaster slurry within the outlet conduit (122). Additionally, a method of manufacturing a plaster slurry is described.

A system and method for disposing carbon dioxide is disclosed. The system includes a foam generator that generates a plurality of disposable foam vessels from a polymer based solution mixed with water and captured carbon dioxide from the atmosphere. The plurality of disposable foam vessels contains an amount of carbon dioxide. The plurality of disposable foam vessels is mixed in a cementitious material with a set of mixers. In a preferred embodiment, the set of mixers is a concrete mixing plant. During the curing process of the cementitious material the plurality of disposable foam vessels dissipates allowing for a timely release of CO.sub.2 to chemically react with the surrounding cementitious material. This irreversible chemistry change permanently disposes of the carbon dioxide.

This disclosure describes volumetric mobile powder mixer (VMPM) systems and methods for VMPM operation and use. The VMPM is providing with a number of storage compartments (or bins) for liquid or solid ingredients including at least one powder storage bin, a powder transport system, a dust handling system, a solid/liquid mixing system, a cellular foam generator, a product delivery system, and a controller capable of monitoring the delivery and mixing of each of the ingredients, as well as the discharge of the final product. The controller determines if the proper mixture is being discharged by the VMPM and, if not, alerts the VMPM operator. In an automated embodiment, the VMPM controller is also configured to independently control the delivery and mixing of each of the ingredients, as well as the delivery of the final product.

Provided herein are methods and compositions for carbonation of recycled concrete aggregates (RCA) to produce carbonated RCA. In addition, uses of the carbonated RCA, such as in building materials, and building materials containing RCA, are included. Carbonation of RCA may be used alone or may be used in combination with other carbonation processes associated with concrete manufacture, such as carbonation of wet concrete mixes and/or carbonation of concrete wash water.

Systems and methods of sequestering carbon dioxide in concrete are described herein. The methods include combining water and a foaming agent to form a foaming agent mixture, adding a gas comprising carbon dioxide to the foaming agent mixture in a first mixing chamber, mixing the water, the gas comprising carbon dioxide and the foaming agent to form a foam mixture in the first mixing chamber, the foam mixture comprising a plurality of foam bubbles containing the at least a portion of the carbon dioxide, combining the foam mixture with concrete materials in a second mixing chamber so that the foam mixture contacts the concrete materials, the concrete materials comprising cement, and mixing the foam mixture and the concrete materials in the second mixing chamber to form the concrete having the carbon dioxide sequestered therein.

A system and method for introducing a slurry mixture for making gypsum board is disclosed. The system includes, for example, a mixer, a foam injector, and a canister for mixing and moving a slurry mixture of foam and gypsum slurry. Also included in the system is an apparatus having a funnel body constructed and arranged to further mix the slurry mixture. The funnel body includes a number of baffles projecting from its inner wall towards a center and that are spaced around the inner wall. The baffles induce turbulence into the slurry mixture as the slurry mixture moves towards its outlet, thus further mixing the mixture and reducing the flow rate of the slurry mixture before its exits from the outlet for forming the gypsum board.

A system and method for introducing a slurry mixture for making gypsum board is disclosed. The system includes, for example, a mixer, a foam injector, and a canister for mixing and moving a slurry mixture of foam and gypsum slurry. Also included in the system is an apparatus having a funnel body constructed and arranged to further mix the slurry mixture. The funnel body includes a number of baffles projecting from its inner wall towards a center and that are spaced around the inner wall. The baffles induce turbulence into the slurry mixture as the slurry mixture moves towards its outlet, thus further mixing the mixture and reducing the flow rate of the slurry mixture before its exits from the outlet for depositing onto paper to form the gypsum board.

A gypsum slurry mixer output canister is provided, including a canister housing having an upper end, an opposite lower end and defining a canister interior, a cover secured to the upper end, a slurry inlet in operational relationship to the upper end, a spiral block associated with the upper end, and having a helical flow surface depending into the interior. A flow distributor is secured to the lower end and is in fluid communication with the interior, and a slurry outlet is defined by the lower canister housing end.