Abstract: A monolithic, fired ceramic gas diffuser for injecting gas into a molten metal bath, including a first portion, a second portion integrated with the first portion, and a bore passing through the first portion and communicating with the second portion for supplying gas to the second portion, wherein at least the second portion has a network of interconnected pores that provides preferential gas flow from the bore through the second portion to inject gas into the molten metal bath.

Abstract: A monolithic, fired ceramic gas diffuser for injecting gas into a molten metal bath, including a first portion, a second portion integrated with the first portion, and a bore passing through the first portion and communicating with the second portion for supplying gas to the second portion, wherein at least the second portion has a network of interconnected pores that provides preferential gas flow from the bore through the second portion to inject gas into the molten metal bath.

Abstract: A monolithic, fired ceramic gas diffuser for injecting gas into a molten metal bath, including a first portion, a second portion integrated with the first portion, and a bore passing through the first portion and communicating with the second portion for supplying gas to the second portion, wherein at least the second portion has a network of interconnected pores that provides preferential gas flow from the bore through the second portion to inject gas into the molten metal bath.

Abstract: A riser tube for transfer of molten metal therethrough, including a porous ceramic substrate having a hollow cylindrical structure and ceramic impregnant material penetrating into pores of the substrate and plugging at least a portion of the surface pores thereof, to improve gas impermeability of the substrate. According to the present invention, the porous ceramic substrate is immersed in impregnation media containing ceramic particles, the impregnation media is subjected to an elevated pressure such that the media penetrates the pores of the substrate, and the impregnated substrate is then fired, whereby the ceramic particles form a ceramic impregnant material that plugs at least a portion of the surface pores of the substrate.

Abstract: A refractory brick particularly suited for constructing a diffusor wall for an industrial heat source. The brick includes a substantially tubular body having a first end, a second end opposed to the first end, an inner surface defining a passageway extending in the longitudinal direction of the body from the first end to the second end, and an outer peripheral surface extending from the first end to the second end. The outer peripheral surface has a complementary shape that allows mating of a plurality of the bricks to form cooperatively a diffusor wall. Mating means is formed on or in the outer peripheral surface for engaging corresponding mating means formed on or in outer peripheral surfaces of adjacent bricks when assembled as a diffusor wall.

Abstract: Ceramic filter of various configuration have been used to filter particulates from hot gases exhausted from coal-fired systems. Prior ceramic cross-flow filters have been favored over other types, but those previously horn have been assemblies of parts somehow fastened together and consequently subject often to distortion or delamination on exposure hot gas in normal use. The present new monolithic, seamless, cross-flow ceramic filters, being of one-piece construction, are not prone to such failure. Further, these new products are made by novel casting process which involves the key steps of demolding the ceramic filter green body so that none of the fragile inner walls of the filter is cracked or broken.

Abstract: A ceramic ferrule, an array of ceramic ferrules, and a ceramic ferrule refractory wall, all for shielding a tube sheet/boiler tube assembly of a heat exchanger connected to an industrial heat source. The head portion of each ferrule replaces conventional cast refractory walls, and has an outer-peripheral shape that allows the ferrules to mate at the operating temperature of the industrial heat source. The mated ferrules expand and contract substantially independently of one another, but form a substantially gas-tight barrier for shielding the tube sheet/boiler tube assembly from the waste gas of the industrial heat source.

Abstract: Novel aqueous inorganic particle slurries, wherein some of the particles have had their charge potential altered to a sufficient extent to prevent segregation or settling of the particles, are described, along with a method for their preparation. The method of forming slurries of negatively charged particles comprises treating some of the particles with a cationic agent to reduce their charge and mixing these treated particles with the remainder of the particles to form a thick, cream-like flowable composition of a thixotropic nature. When slurries of positively charged particles are to be formed, an anionic agent is used instead of a cationic agent.

Abstract: Composite inorganic articles are produced by bringing two separate inorganic slurries, each containing different ceramic materials, into contact with each other, simultaneously freezing the slurries while in contact with each other to form a unified frozen structure, thawing and drying the structure, and firing the unified structure.

Abstract: Composite inorganic articles are produced by bringing two separate inorganic slurries, each containing different ceramic materials, into contact with each other, simultaneously freezing the slurries while in contact with each other to form a unified frozen structure, thawing and drying the structure, and firing the unified structure.