The invention relates to mold material mixtures containing an oxide of aluminum and an oxide of zirconium as particulate mixed metal oxide, in combination with refractory mold base materials and a water glass-based binder system. The mold material mixtures, also in the form of multicomponent systems, are used for the production of molds and cores for the foundry industry.

The invention relates to mold material mixtures containing at least one aluminum oxide in the alpha phase and/or at least one aluminum/silicon mixed oxide, except for aluminum/silicon mixed oxides having a layered silicate structure, as a particulate metal oxide, in combination with refractory mold base materials and a water glass-based binder system. The mold material mixtures are used for the production of molds and cores for the foundry industry.

To provide a binder composition for molding, by which a mold made of aggregate has an excellent resistance to moisture. The binder composition for molding contains a water-soluble binder and at least one kind of lithium salt that is selected from a group of lithium silicate, lithium oxide, lithium hydroxide, lithium carbonate, lithium bromide, lithium chloride, lithium nitrate, and lithium nitrite.

The invention relates to a mold material mixture for producing casting molds for metal processing, a process for producing casting molds, casting molds which can be obtained by the process and their use. The production of the casting molds is carried out using a refractory base molding material and a binder based on water glass. A proportion of a particulate metal oxide selected from the group consisting of silicon dioxide, aluminium oxide, titanium oxide and zinc oxide is added to the binder, with particular preference being given to using synthetic amorphous silicon dioxide. The mold material mixture contains a surface-active material as further significant constituent. The addition of the surface-active material enables the flowability of the mold material mixture to be improved, which makes it possible to produce casting molds having a very complicated geometry.

Material system suitable for a 3D printing method or 3D printing method material system comprising or consisting of a particulate material, a printing liquid, and an ester activator as well as 3D printing processes that use such a material system and molding parts produced by means of such material systems and 3D printing processes.

A composition for making cores and a process for metal casting, the composition comprising: a particulate refractory material; an inorganic binder comprising at least one alkali metal silicate; a pozzolanic additive; and a lustrous carbon former. The process includes forming a core from the composition and assembling a mould comprising the core and supplying molten metal.

A method of reusing core sand includes: crushing a core used for casting into granules; heating the granules at a temperature of 300 C. to 550 C.; causing the heated granules to collide against each other such that water glass used as a binder detaches from the core sand; and blowing air into a mixture of the water glass and the core sand, which are detached from each other, such that the core sand is separated and collected from the mixture due to a difference in specific gravity between the water glass and the core sand.

In a method for producing moulds and cores with cold box through curing sodium silicate sand for casting by blowing, a sand mixture for producing moulds and cores is filled into a forming tool by a core shooter or manually and then is shaped, and the operations of blowing, curing and stripping are carried out. Gases are sequentially blown in the order of CO.sub.2 and compressed gas; or gases are sequentially blown in the order of compressed gas-CO.sub.2-compressed gas.

The invention relates to a method of producing an article selected from the group consisting of casting mold, core, feeder and molding compound for production of part of a casting mold, core or feeder, comprising the following steps: (S1) producing or providing in the foundry: a first component (A), comprising a first binder component (b1) of a binder system and an amount of a first mold base material and, spatially separated therefrom, a second component (B), comprising a second binder component (b2) of the binder system and an amount of a second mold base material wherein the first binder component (b1) and the second binder component (b2) are suitable for chemical reaction with one another and for curing of a mixture of the first component (A) and the second component (B), (S2) mixing by contacting the first component (A) and the second component (B) in a particular mass ratio, so as to result in a self-curing molding compound.

This invention relates to lost cores for use high pressure die casting, the cores preferably comprising a water-soluble synthetic ceramic aggregate having an appropriate strength and tolerance for various casting pressures and temperatures, an inorganic binder comprising sodium silicate, an additive comprising particulate amorphous silicon dioxide, and a refractory coating, wherein the cores have the capacity to be removed from a casting by dissolution with water.