Abstract: An additive for reducing the calcium aluminate cement content in a refractory mix containing calcium aluminate cement. The additive is comprised of about 80% by weight amorphous, powdered metakaolin, the metakaolin having a mean particle size of less than about 3.0 microns, and about 20% by weight microsilica, the microsilica having a mean particle size of less than 45 microns.

Abstract: This invention relates to cement-free refractories exhibiting high green strength, improved corrosion resistance, and improved magnesium oxide hydration resistance useful as refractory castables for steel ladles, slag contact areas, ladle sidewalls and bottoms, and the like and as precast refractory shapes, such as well blocks, nest blocks, and the like. More particularly, this invention is directed hydraulically-bonded monolithic refractories containing a calcium oxide-free binder comprised of a hydratable alumina source and magnesium oxide and which exhibit high green strength, improved corrosion resistance, improved magnesium oxide hydration resistance, and controllable work and set times.

Abstract: A method of applying a cement-free refractory castable to the surface of a refractory structure, comprising the steps of:a) preparing an intimately mixed refractory castable having alumina aggregate and a cement-free binder comprised of hydratable alumina;b) conveying the refractory castable under pressure through a delivery hose to a dispensing nozzle for applying the refractory castable; and,c) adding a salt solution to the refractory castable prior to application by the nozzle at a rate wherein the salt solution comprises about 0.2% to 0.9% by weight of the refractory castable applied by the dispensing nozzle.

Abstract: A method of calcining kaolin, comprising the steps of:a) producing a clay slurry comprised of water and kaolin clay of a specific particle size;b) mixing a water insoluble potassium containing glass forming compound into the clay slurry in an amount wherein the potassium content of the slurry is equal to about 1% by weight of the kaolin clay in the slurry;c) removing sufficient water from the slurry to form a material having an extrudable consistency;d) extruding the material into elongated shapes;e) heating the shapes by continuously moving them through a furnace having a zone, wherein the material is exposed to temperatures of at least 2700.degree. C. for at least 30 minutes.

Abstract: The present invention is directed to an insulating coating for refractory articles, adapted to be applied by spraying or gunning, which is easy to apply, cost effective, eliminates the potential health hazards associated with ceramic fiber paper, and which imparts sufficient insulating properties to the refractory article in high temperature environments. More particularly, the present invention is directed to an insulating coating and a method of preparing the insulating coating wherein the coating composition is comprised of about 25% to about 75% by weight of lightweight aggregate, up to about 25% to about 75% by weight of binder, up to 0.5% by weight of organic fiber, up to about 15% by weight of an additive to improve green strength, and up to about 5% by weight of a foaming agent.

Abstract: A taphole assembly for a vessel containing a molten solid. The assembly is comprised of a tubular element formed of a refractory material. The tubular element has a continuous passage extending therethrough along a first axis. A socket block formed of a plurality of mating refractory components is provided to hold the tubular element. The socket block has a first convex cylindrical surface on one side thereof and a second convex cylindrical surface on an opposite side thereof. The first and the second cylindrical surfaces are defined about a second axis extending through the socket block. The socket block has an inner cavity dimensioned to receive and to capture the tubular element. A first rectangular saddle block has a first concave recess formed therein that is dimensioned to match and to receive the first convex surface on the socket block.

Abstract: A molten steel pouring nozzle having a bore therethrough, at least a portion of the nozzle forming the bore being comprised of a refractory having calcium zirconate: from 20 to 75 weight %, graphite: from 5 to 30 weight %, and calcium silicide: from 0.5 to 15 weight %.

Abstract: A method of forming powdered metakaolin for use as an additive in cement based materials comprising the steps of calcining kaolin so as to reduce the hydroxyl content thereof to produce a meta-stable material have an identifiable amorphousness, and pulverizing the meta-stable material into a powder having a particle size of 50 microns or less.

Abstract: The present invention is directed to an insulating coating for refractory articles, adapted to be applied by spraying or gunning, which is easy to apply, cost effective, eliminates the potential health hazards associated with ceramic fiber paper, and which imparts sufficient insulating properties to the refractory article in high temperature environments. More particularly, the present invention is directed to an insulating coating and a method of preparing the insulating coating wherein the coating composition is comprised of about 25% to about 75% by weight of lightweight aggregate, up to about 25% to about 75% by weight of binder, up to 0.5% by weight of organic fiber, up to about 15% by weight of an additive to improve green strength, and up to about 5% by weight of a foaming agent.

Abstract: This invention relates a refractory gas purging device for the introduction of gases through a metallurgical vessel to molten metal therein, the device having improved wear indication, safety, and performance. In particular, the refractory gas purging device has a porous refractory inner wear indicator which indicates the end of the useful life of the device. Further, the refractory gas purging device has directional gas passages which do not extend throughout the entire length of the device to prevent molten metal leaks from the metallurgical vessel and such directional gas passages being designed to improve the performance of the device.