Vesuvius Crucible Company

Mark K Fishler

Gilbert Rancoule

Dale B Hoggard

Quentin K Robinson

Han K Park

Gilbert I Rancoule

Martin Morris

John B Cahoon

An erosion resistant refractory mortar composition is described which is suitable for bonding a zirconia insert in an alumina graphite plate of a sliding gate valve. The refractory mortar is made from a mix consisting of, in weight percent, about 50%-85% zirconia; about 15%-50% alumina; up to 5% chromium oxide; up to 6% phosphoric acid plus an effective amount of a binder. Sufficient water is added to provide proper plasticity to the mix.

Refractory zirconia mortar

The invention concerns a material for covering the metal contacting surfaces of casting elements such as slide gate valves and casting nozzles and shrouds to resist steel erosion and alumina deposition during the continuous casting of aluminum killed steel. It is comprised of a fused mixture of calcium oxide and zirconia, with a calcium oxide content of between about 20% and about 60% by weight and preferably between about 20% and about 50% by weight, the composition may include a binder producing carbon/carbon bonds by sintering. The material may also include a ceramic bond or may be applied as a fused layer by plasma spraying.

Prevention of erosion and alumina build-up in casting elements

Material for covering a casting shroud

The invention is directed to improved carbon containing refractory compositions and sintered bodies made therefrom which are particularly resistant to slag and metal erosion and to thermal shock. This is achieved by combining grains or powders of SiAlON and/or silicon nitride with elemental carbon in the form of graphite, carbon black or charcoal. The particulate materials are mixed with a carbonaceous binder such as resin or pitch, pressed to shape and fired in a reducing atmosphere. Small amounts of antioxidants are also added to protect the carbon bond phase against slag attack. Additional amounts of a less expensive refractory grain or powder are also optionally added to the mix to dilute the more expensive SiAlON and/or silicon nitride.

Carbon bonded refractory bodies

The present invention provides a refractory tube through which a stream of molten metal is passed during continuous casting which includes an inner refractory member of relatively low thermal expansion and thermal conductivity characteristics and an outer refractory member of high erosion resistance. The cooperation of the inner and outer refractory members results in an end product with a prolonged useful casting life and which does not require preheating prior to use. In a preferred embodiment, the inner refractory member is formed of fused silica and the outer refractory member is formed of alumina graphite and/or zirconia graphite.

Refractory shroud for continuous casting

An elemental carbon-containing refractory composition having superior erosion and oxidation resistance due to the addition of prescribed amounts of boron carbide.

Carbon-containing refractories with superior erosion and oxidation

A nozzle is provided having an elongated conduit extending therethrough for delivering molten metal below the surface of a pool of molten material. The nozzle includes facilities for passing a fluid medium, e.g., argon, through its wall members transverse to the direction of molten metal flow into the elongated conduit to retard the accumulation of undesirable formations, e.g., metal oxides, on the inner wall surfaces of the conduit during molten metal flow. In a first embodiment, gas permeable wall members define portions of the conduit through which the fluid medium percolates. In a second embodiment, a plurality of small ports are provided in the wall members defining the conduit through which the fluid medium is emitted in the conduit. Preferably, the nozzle also includes a base portion that directs the molten metal flow in an upwardly direction and which has facilities for retarding the accumulation of undesirable formations thereon.

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Pittsburgh, PA, United States of America

Mark K Fishler