A description is given of a method for producing a molding material mixture or for producing a molding material mixture and a molding therefrom, preferably casting molds or cores, for use in the foundry industry, where the molding material mixture comprises a mold base material and a solution or dispersion comprising lithium-containing waterglass, comprising the following steps: (1) producing or providing a kit at least comprising as separate components: (K1) an aqueous solution or dispersion comprising waterglass and (K2a) a first waterglass-free solution or dispersion comprising lithium ions in solution in water, and also preferably (K2b) a second waterglass-free solution or dispersion, preferably comprising lithium ions in solution in water with a lower concentration than in component (K2a), and thereafter (2) producing a mixture of the mold base material with a fraction of component (K1) and with a fraction of component (K2a), and also optionally with a fraction of component (K2b). Further described is an aforementioned kit, more particularly for application in the method of the invention. An installation is specified as well for producing an intermediate solution or dispersion, comprising lithium-containing waterglass, for use in producing a molding material mixture or for producing a molding material mixture and a molding therefrom.

A sand mold shaping material contains an aggregate comprising inorganic particles, and microcapsules enclosing a binder which causes the aggregate to bind. The binder is a liquid binder that is in a liquid phase at room temperature, and is enclosed in an outer shell comprising a resin that forms the microcapsule. The sand mold shaping material is in a dry state when used to fill a molding die for shaping.

A sand mold shaping material contains an aggregate comprising inorganic particles, and microcapsules enclosing a binder which causes the aggregate to bind. The binder is a liquid binder that is in a liquid phase at room temperature, and is enclosed in an outer shell comprising a resin that forms the microcapsule. The sand mold shaping material is in a dry state when used to fill a molding die for shaping.

A structure for manufacturing a cast article includes an organic component, at least a portion thereof being an organic fiber. The structure has a mass reduction rate of 1 mass % or greater to less than 20 mass % when heated under nitrogen atmosphere at 1000 C. for 30 minutes. The cast-article-manufacturing structure includes an inorganic particle. The cast-article-manufacturing structure includes, as the inorganic particle, a first inorganic particle having a predetermined shape and/or physical property, and a second inorganic particle having a predetermined shape and/or physical property different from the first inorganic particle. In addition thereto or instead thereof, the cast-article-manufacturing structure has a maximum bending stress of 9 MPa or greater measured in conformity with JIS K7017, and a bending strain of 0.6% or greater at the maximum bending stress.

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 a casting core for casting moulds, the casting core comprising an inner core and an outer core arranged around the inner core. The outer core contains or consists of ceramic particles bound with a binder. The inner core contains ceramic particles bound with a binder and additionally one or more placeholder elements. The placeholder element(s) is/are at least partially thermally decomposable. The present invention also relates to a method for producing the casting core according to the invention and to the use of the casting core according to the invention.

Compositions useful for green sandcasting are discussed, as well as methods of preparing and using such compositions. Binder compositions may comprise a carbonaceous material, an inorganic binding agent, and a high aspect ratio silicate, wherein at least one of the carbonaceous material or the inorganic material in the binder composition may be oxidized. For example, the inorganic binding agent may be oxidized with a ratio of ferrous iron (Fe.sup.2+) to ferric iron (Fe.sup.3+) less than 1.2. or less than 1. Green sand prepared from such binder compositions may exhibit a reduction in emissions during sandcasting.

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.

The present invention relates to the selection of materials for methods for producing moulds (2) or cores (2) for foundry purposes. When selecting the core box material, a special ceramic, such as for example silicon carbide or silicon nitride, is used instead of metals such as steel or aluminium. It is essential for the inventionthat a material (7) for receiving the mixture (9) is introduced into a housing (3), the material consisting of silicon carbide or silicon nitride, that electrical energy is supplied to the material (7) by way of electrodes (10) arranged in/on the housing (3) and in this way heat is supplied, leading to curing of the mixture (9). This allows longer service lives to be achieved for the core boxes as a result of low abrasive wear.