Abstract:
A basic refractory ceramic hollow body for use in metallurgy, characterized by the following characteristics: a) the hollow body is monolithically created from a material; b) the material is based on a mixture of 10-40 mass per cent of carbon, 50-89 mass per cent of MgO, 1-35 mass percent of other constituents; c) the hollow body has an open pore volume of between 5 and 20 volume per cent with a substantially constant proportion of pores ranging from 0.1-15 DEG m.
Abstract:
A molten steel pouring nozzle (10) having a bore (22) therethrough, at least a portion (26) of the nozzle (10) forming the bore (22) 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 carbonaceous refractory which generates little decomposition gas having a foreign odor, is excellent in spalling resistance and has kneadability and moldability equivalent or superior to those of a phenolic resin; and a process for the production thereof. The above refractory is characterized in that starch sugar and/or reducing starch sugar is used as the binder instead of the phenolic resin used in the prior art. More specifically, the above refractory is produced by using a binder comprising 40 to 80 % by weight of starch sugar and/or reducing starch sugar and 20 to 60 % by weight of water, or a binder comprising 40 to 80 % by weight of starch sugar and/or reducing starch sugar, 1 to 25 % by weight of water, and 5 to 50 % by weight of an alcohol having a boiling point of 80 DEG C or above.
Abstract:
Carbon-bond forming unshaped refractories excellent in workability and service life by solving the problems of the refractories used for the working or repair of various molten metal containers, such as bursting, lack of volume stability, low adhesion strength and low hot strength. An example of the refractories comprises 100 parts by weight of refractory material and 1-30 parts by weight of pitch having the fixed carbon content of 65-90 wt.% and the softening point of 250-350 DEG C, and another example thereof further contains 0.01-0.5 part by weight of carbon fibers. These refractories are applicable as any of gunning refractories, casting materials of particularly water-base type, baking materials, mortars, and stamping materials. The refractory materials usable herein include all of the basic, neutral and acidic materials. When the gunning refractories also contain high-molecular-weight thermosetting phenol resins, the effects of the refractories are further improved.
Abstract:
The invention concerns a fired magnesia-carbon shape (12) having a combination of properties making it especially suitable for slide gate plates, inserts for such plates and for pouring nozzles (2) useful in casting aggressive steels. The fired refractory shape (12) is formed from a batch consisting essentially of, by weight percent: 2 to 8 finely divided graphite (natural or synthetic); 3 to 8 aluminum metal powder; 1 to 5 of finely divided silica and/or a silicon yielding powder; an effective amount of carbon bond forming resins; and the balance coarse and fine magnesia grains. The magnesia grains should contain less than about 0.02 weight percent boron oxide. After firing, the shape is characterized by a carbon bonding system including a spinel (magnesia-alumina) phase plus aluminum carbide bonding the magnesia-carbon matrix. The refractory shape is preferably carbon impregnated after firing to further enhance its properties.
Abstract:
The present invention relates to a dry refractory particulate composition comprising a zeolithic microstructure, to a green body and to a refractory lining formed therefrom, and to uses thereof.