Abstract: The present invention provides a method of producing a shaped object by coating a pattern with a slurry of a refractory powder in a binder. The binder comprises an acidic zirconium salt and also a gellation delaying agent. The slurry is caused to gell by contacting it with ammonia vapor.

Abstract: A method of making a shaped article from particulate solid material, such as a foundry mould or core from sand, comprisesI. forming a mixture of the particles and an anaerobically-curing adhesive containing, as a curing accelerator, either an aliphatic amine having at least two primary aliphatic amino groups or a condensation product of such an amine with a ketone or with an aldehyde,Ii. forming the mixture into the desired shape, andIii. in the presence of water, causing the adhesive to cure and to bond the particles together by displacing air or other oxygen-containing gas in the environment of the shaped article with an inert gas or vapor.

Abstract: Particulate material, hereinafter called sand, is used in a sand article, such as a mold article, for foundry purposes such as a green sand mold and sand core consisting of sand and a binder and is hardened in a molding box by sucking a catalyst gas from a catalyst gas source through the molding box and the sand article. The molding box is continuously exposed to the action of a reduced pressure source and normally evacuated to the atmosphere. When the pressure has been reduced to a predetermined pressure less than atmospheric pressure, the catalyst gas is briefly supplied to the molding box under slight increase of the absolute pressure, whereupon the molding box is evacuated to the catalyst gas source until the pressure therein is reduced to the predetermined pressure to recycle the unused catalyst gas leaving the molding box to the catalyst gas source.

Abstract: There is disclosed a method of burning a ceramic shell mold for use in precision casting for curing the ceramic shell mold. The ceramic shell mold is positioned within a heating compartment while a mass of sand within the heating compartment is fluidized so as to submerge the ceramic shell mold thereinto. Thereafter, particles of the sand are heated to a predetermined curing temperature, which sand particles then heat the ceramic shell mold enveloped by the sand particles.

Abstract: The invention concerns the binding of refractory powders into self-supporting `green` shapes which are fired to provide refractory objects. In accordance with the invention the binders are based on zirconium salts and include a separate gell time delaying agent to ensure satisfactory gelling and to achieve control and to allow complex shapes to be made.