An expandable aggregate mixture for a mold, which contains an aggregate, a water-soluble binder, a water-soluble foaming agent, water, and spherical metal oxide particles.

An expandable aggregate mixture for a mold, which contains an aggregate, a water-soluble binder, a water-soluble foaming agent, water, and spherical metal oxide particles.

An expandable aggregate mixture for a mold, which contains an aggregate, a water-soluble binder, a water-soluble foaming agent, water, and spherical metal oxide particles.

A sand additive for use in a “no bake” foundry mix composition having a polyurethane-based binder system reduces the amount of smoke emitted when molds and cores formed from the composition are exposed to molten metal, as compared to when the sand additive is not used. The sand additive comprises yellow iron oxide having the chemical formula Fe(OH).sub.3. It can also comprise at least one of red iron oxide, black iron oxide and wüstite. In such cases, the yellow iron oxide accounts for about 10 to about 40 weight percent of the combined weight of the yellow iron oxide, red iron oxide, black iron oxide and wüstite, and preferably, about 20 to about 30 weight percent of the combined weight of the yellow iron oxide, red iron oxide, black iron oxide and wüstite.

A sand additive for use in a “no bake” foundry mix composition having a polyurethane-based binder system reduces the amount of smoke emitted when molds and cores formed from the composition are exposed to molten metal, as compared to when the sand additive is not used. The sand additive comprises yellow iron oxide having the chemical formula Fe(OH).sub.3. It can also comprise at least one of red iron oxide, black iron oxide and wüstite. In such cases, the yellow iron oxide accounts for about 10 to about 40 weight percent of the combined weight of the yellow iron oxide, red iron oxide, black iron oxide and wüstite, and preferably, about 20 to about 30 weight percent of the combined weight of the yellow iron oxide, red iron oxide, black iron oxide and wüstite.

What are described is a process for producing casting molds, cores and mold base materials regenerated therefrom, a mixture for combination with a solution or dispersion comprising waterglass for production of casting molds and/or cores, a molding material mixture, a mold base material mixture, and a casting mold or a core. What is also described is the corresponding use of an amount of particulate sheet silicates having a d.sub.90 of less than 45 μm or a corresponding mixture as additive for production of a molding material mixture comprising waterglass and particulate amorphous silicon dioxide, which is cured by chemical reaction of constituents of the molding material mixture with one another, in the production of a casting mold or a core, to facilitate the breakdown and/or to increase the regeneratability of the casting mold or core.

The invention relates to a method for more quickly producing molds (2) or cores (2′) for foundry purposes by adapting the specific electrical resistance in the selection of the core box to the mixture (9) of a molding material and of a water-containing binder, which binder, when dissolved, forms an electrolyte and has a sufficient electrical conductivity. It is essential to the invention that an electrically conductive material (7) for holding the mixture (9) is introduced into an electrically non-conductive housing (3), wherein the specific electrical conductivity of the material (7) at operating temperature (7) at least approximately corresponds to the specific electrical conductivity of the mixture (9) at temperatures between 100° C. and 130° C., and that electrical energy and thus heat are supplied to the material (7) via electrodes (10) arranged in/on the housing (3) (resistance heating principle), leading to curing of the mixture (9). Depending on the sand core, up to 30% shorter cycle times can be achieved.

The invention relates to a method for more quickly producing molds (2) or cores (2′) for foundry purposes by adapting the specific electrical resistance in the selection of the core box to the mixture (9) of a molding material and of a water-containing binder, which binder, when dissolved, forms an electrolyte and has a sufficient electrical conductivity. It is essential to the invention that an electrically conductive material (7) for holding the mixture (9) is introduced into an electrically non-conductive housing (3), wherein the specific electrical conductivity of the material (7) at operating temperature (7) at least approximately corresponds to the specific electrical conductivity of the mixture (9) at temperatures between 100° C. and 130° C., and that electrical energy and thus heat are supplied to the material (7) via electrodes (10) arranged in/on the housing (3) (resistance heating principle), leading to curing of the mixture (9). Depending on the sand core, up to 30% shorter cycle times can be achieved.

The present invention relates to nanoparticle based sand conditioner composition and a method of synthesizing the same. The composition has the raw material compound RM 1, RM 2, RM 3 and RM 4. The RM1 has carbonaceous material, hydrocarbons, ultrafine metal/metal oxide and ceramic oxide nanoparticles and metallic wires. The RM 2 has natural carbon source. The RM 3 comprises synthetic/non-renewable carbon source. The RM 4 has hydrocarbons. The method of synthesizing nanoparticle based sand conditioner comprises mixing RM 2 and RM 4 in a mixer for 10 minutes for coating RM 2 with RM 4 to obtain an intermediate product. The RM 1 and RM 3 are added to an intermediate product in a mixer and mixed for 10 minutes to get a uniform/homogeneous mixture which is cooled to obtain a sand conditioner composition impregnated with nanoparticles into carbon.

The present invention relates to nanoparticle based sand conditioner composition and a method of synthesizing the same. The composition has the raw material compound RM 1, RM 2, RM 3 and RM 4. The RM1 has carbonaceous material, hydrocarbons, ultrafine metal/metal oxide and ceramic oxide nanoparticles and metallic wires. The RM 2 has natural carbon source. The RM 3 comprises synthetic/non-renewable carbon source. The RM 4 has hydrocarbons. The method of synthesizing nanoparticle based sand conditioner comprises mixing RM 2 and RM 4 in a mixer for 10 minutes for coating RM 2 with RM 4 to obtain an intermediate product. The RM 1 and RM 3 are added to an intermediate product in a mixer and mixed for 10 minutes to get a uniform/homogeneous mixture which is cooled to obtain a sand conditioner composition impregnated with nanoparticles into carbon.