Abstract: A process for making a filter suitable for filtering molten metal comprising (i) forming a slurry comprising (a) particles of a refractory material, (b) a binder and (c) a liquid carrier, (ii) coating a disposable former with a slurry, (iii) drying the coated former, (iv) optionally applying one or more additional coats of a refractory material and/or a binder, optionally with liquid carrier, and drying the one or more additional coats, and (v) firing the coated former to produce the filter, wherein the binder is a carbon rich source selected from one or more of the following classes of materials: pitches, tars and organic polymers that degrade to form carbon on pyrolysis.

Abstract: A process for making a filter suitable for filtering molten metal comprising (i) forming a slurry comprising (a) particles of a refractory material, (b) a binder and (c) a liquid carrier, (ii) coating a disposable former with a slurry, (iii) drying the coated former, (iv) optionally applying one or more additional coats of a refractory material and/or a binder, optionally with liquid carrier, and drying the one or more additional coats, and (v) firing the coated former to produce the filter, wherein the binder is a carbon rich source selected from one or more of the following classes of materials: pitches, tars and organic polymers that degrade to form carbon on pyrolysis.

Abstract: A filter for molten metal is an open-pored porous material comprising particles of refractory material embedded in and bonded together by a carbon matrix bonding material. The filter can be made by forming a porous article from refractory particles, e.g. refractory oxide, carbide or graphite, and a carbon-rich binder, e.g. tar, pitch or an organic (preferably aromatic) polymer that degrades to form carbon on pyrolysis, and then firing the porous article to generate the carbon matrix in which the refractory particles are embedded. The porous article is preferably made by coating a reticulated polyurethane foam with binder and refractory particles, and firing at preferably no higher than 800° C.

Abstract: A filter for molten metal is an open-pored porous material comprising particles of refractory material embedded in and bonded together by a carbon matrix bonding material. The filter can be made by forming a porous article from refractory particles, e.g. refractory oxide, carbide or graphite, and a carbon-rich binder, e.g. tar, pitch or an organic (preferably aromatic) polymer that degrades to form carbon on pyrolysis, and then firing the porous article to generate the carbon matrix in which the refractory particles are embedded. The porous article is preferably made by coating a reticulated polyurethane foam with binder and refractory particles, and firing at preferably no higher than 800° C.

Abstract: A filter for molten metal is an open-pored porous material comprising particles of refractory material embedded in and bonded together by a carbon matrix bonding material. The filter can be made by forming a porous article from refractory particles, e.g. refractory oxide, carbide or graphite, and a carbon-rich binder, e.g. tar, pitch or an organic (preferably aromatic) polymer that degrades to form carbon on pyrolysis, and then firing the porous article to generate the carbon matrix in which the refractory particles are embedded. The porous article is preferably made by coating a reticulated polyurethane foam with binder and refractory particles, and firing at preferably no higher than 800° C.