A method of forming a dry molding sand additive may include recovering a non-sand fraction from a foundry waste material and adding the non-sand fraction to a dry molding sand additive formulation to form a dry molding sand additive. Adding the non-sand fraction to the dry molding sand additive formulation may reduce the amount of fresh clay and carbon to produce the dry molding sand additive. A method of forming a molding sand additive may include recovering a waste molding sand additive composition having a clay or carbon content differing from a desired clay and carbon content, recycling the waste molding sand additive as a raw material in production of a fresh molding sand additive, and adjusting the amount of fresh clay or carbon added during production of the fresh molding sand additive to achieve the desired clay and carbon content.

A method of forming a dry molding sand additive may include recovering a non-sand fraction from a foundry waste material and adding the non-sand fraction to a dry molding sand additive formulation to form a dry molding sand additive. Adding the non-sand fraction to the dry molding sand additive formulation may reduce the amount of fresh clay and carbon to produce the dry molding sand additive. A method of forming a molding sand additive may include recovering a waste molding sand additive composition having a clay or carbon content differing from a desired clay and carbon content, recycling the waste molding sand additive as a raw material in production of a fresh molding sand additive, and adjusting the amount of fresh clay or carbon added during production of the fresh molding sand additive to achieve the desired clay and carbon content.

The present invention relates to the use of closed-pore microspheres of expanded perlite as a filler for producing moldings for the foundry industry, to a composition for producing moldings for the foundry industry, comprising closed-pore microspheres of expanded perlite as a filler, and a binder, the binder being selected from the group consisting of water glass, phenol-formaldehyde resins, two-component systems comprising as reactants a polyisocyanate and a polyol component containing free hydroxyl groups (OH groups), and starch, and also to moldings for the foundry industry and to a process for producing a molding for the foundry industry.

An aggregate mixture for a mold, the aggregate mixture including an aggregate, a water-soluble binder, a water-soluble foaming agent, an aqueous mold release agent, and water.

An aggregate mixture for a mold, the aggregate mixture including an aggregate, a water-soluble binder, a water-soluble foaming agent, an aqueous mold release agent, and water.

The present disclosure includes binder systems for making foundry articles. The binder systems may comprise a humic substance-containing component that comprise lignite, an isocyanate component, and a catalyst component. The binder systems may be mixed with an aggregate (e.g., sand) for making foundry articles such as molds and cores. Also disclosed herein are methods of making foundry articles using the binder systems.

Provided is a catalyst suitable for curing a composite resin composition that includes comprising a blend of at least two tertiary amines selected from dimethylethylamine (DMEA), diethylmethylamine (DEMA), dimethylisopropylamine (DMIPA), and dimethyl-n-propylamine (DMPA), where each of the at least two tertiary amines is present in the blend in an amount of not less than 10% by weight and not more than 90% by weight.

The object of the invention is a component system for producing a binder for metal casting on the basis of phenolic resins of the benzyl ether type and isocyanates containing non-polar solvents.

Provided are: a coated sand having improved fluidity and being capable of improving a filling rate of a casting mold to be obtained; and a coated sand for advantageously manufacturing a casting mold having excellent strength, which coated sand provides a casting mold with good mold-releasability and collapsibility, gives cast products a favorable casting surface, and effectively improves sand adhesion on cast products. The coated sand is formed as a dry granular material having fluidity at room temperature, in which the surface of a refractory aggregate is coated with a solid layer of a water-soluble inorganic binder, and spherical particles of silicone resin having binder-repellency exist on the surface of the binder layer, or form a layer on the surface of the binder layer, a part of the spherical particles being not covered with the water-soluble inorganic binder and being exposed.

A moulding material mixture with at least one refractory material and water glass as an inorganic binding agent is used for producing casting moulds. The binding agent is cured with the aid of a carbonyl compound that has a molecular weight greater than 88 g/mol and less than 200 g/mol and a boiling point at 1013 hPa greater than 20 C. and less than 200 C. The at least one carbonyl compound is introduced into the gas phase, or carried with the gas phase. The at least one carbonyl compound has the formula R.sup.1R.sup.2CO, where R.sup.1 is H or a C1 or C2 alkyl and R.sup.2 is a carboxyl group RC(O)O bonded via the oxygen atom, where R is a C1 to C3 hydrocarbon.