Abstract: The invention relates to a particulate powder, said powder having a median circularity of greater than 0.87 wt % and less than 9.0 wt % of particles having a size greater than 100 ?m. The powder and at least 80 wt % of the particles have a chemical composition in wt % on the basis of the oxides and for a total of 100%: Cr2O3+Al2O3+ZrO2+MgO+Fe2O3+SiO2+TiO2?90%; Cr2O3+Al2O3+MgO?60%; Cr2O3?9%; 20%?SiO2?0.5%; and other oxides: ?10%. The invention can be used for a glass furnace.

Abstract: The invention relates to a composition for the production of a refractory ceramic moulded body, a non-fired or fired moulded body formed from the composition and a possibility for use.

Abstract: An artificial ore, characterized in that it is prepared by melting one of silicon, a silicon compound, tourmaline and a ceramic, and adding iron, aluminum and calcium into the resultant melt to melt them, followed by cooling to a mass. The artificial core has good thermal properties such as heat conductivity, heat diffusion coefficient and fire resistance temperature, can dissociate molecules in a liquid, and further can prevent the electrification by static charge and the transmission of an electromagnetic wave.

Abstract: A material for refractory shaped bodies or compounds, the material being a pleonaste and/or a spinel of the pleonaste type. In addition to FeOx and Al2O3, the material also includes MgO. The ratio of the iron in the material is calculated as Fe2O3:Al2O3 and ranges from 30:70 to 60:40. The material contains from 20 to 60% by mass of MgO, as based on Fe2O3+Al2O3.

Abstract: A material for refractory shaped bodies or compounds, the material being a pleonaste and/or a spinel of the pleonaste type. In addition to FeOX and Al2O3, the material also includes MgO. The ratio of the iron in the material is calculated as Fe2O3:Al2O3, and ranges from 30:70 to 50:40. The material contains from 20 to 60% by mass of MgO, as based on Fe2O3+Al2O3.

Abstract: A resistor, which is solidified from a melt, is provided for a refractory shaped body, and includes a refractory mineral metal-oxide main component having elasticizers a general formula A2+B3+2O4 in an amount so that solubility of the main component for the elasticizer is exceeded with the elasticizers providing precipitation areas in the main component. The resistor is produced by a joint melting of the main component and the oxides which form the elasticizers. A process is provided for the production of the resistor.

Abstract: A composite and monolithic refractory structure, particularly adapted for making furnaces for glassmaking or the like, constituted by a block-shaped component made of electro-cast refractory material based on oxides of aluminum, zirconium, silicon, and the like, having shapes and dimensions that are adapted for its uses, inside which at least one protective element is monolithically inserted; the protective element is highly resistant to the attack of molten glass baths or the like and is chosen among metals, noble metals, refractory metals, refractory materials, conventional and non-conventional ceramic materials, such as carbides, nitrides, borides, and the like, or graphite-based materials, alloys and/or compounds and/or composites thereof; the element is provided substantially in the shape of a plate that is shaped and sized so as to have a profile that is similar to the peripheral profile of the refractory block and is arranged, inside the block, so that its surfaces are located at, and proximate to, the

Abstract: A refractory mix made comprising magnesite having an MgO content of at least about 95 wt. % and fused spinel-zirconia grain comprising 1 to 40 wt. % zirconia and refractory shapes, particularly brick, made therefrom.

Abstract: A burned chrome-containing refractory and method which provides a refractory having less than 5 ppm total soluble chromium. Such product is obtained by adding to the starting mix less than 10 wt. % (often less than 3 wt. %) zirconia, silica, zircon, or molybdic oxide either individually or in combination.

Abstract: Chrome oxide refractory materials which are a mixture of coarse fused chrome oxide particles and fine chrome oxide particles are disclosed as resistant to silica attack. The refractory materials have a Cr.sub.2 O.sub.3 content of at least about 98.5% and substantially no MgO.

Abstract: A rebonded, fused brick resulting from burning a mix consisting essentially of a fused magnesite chrome grain, a fused chrome-magnesite grain or mixtures thereof, and a chrome ore having a Cr.sub.2 O.sub.3 /(Al.sub.2 O.sub.3 +Fe.sub.2 O.sub.3) ratio of at least about 1.15, a maximum silica content of about 3.85, and an Fe.sub.2 O.sub.3 content of less than about 25% by weight.

Abstract: A novel method of making a refractory material is disclosed comprising the steps of providing an electrical arc metal furnace, charging that furnace with a charge of refractory oxide, and selecting voltage, amperage and electrode spacings to create novel "hum and scum" melt conditions. This hum and scum condition is maintained until said charge is substantially melted. The described technique is particularly useful for melting magnesia chrome materials to produce fusion cast refractory products which are highly reduced and quite dense. The elaboration of this product requires higher energy input per pound concurrent with an increased consumption of reducing materials compared with standard preparation conditions. The resulting product exhibits higher oxidation weight gains, higher densities, lower porosities, high cold crush strengths, more thermal shock resistance, and better corrosion-erosion resistance than similar magnesia chrome refractory products fused using prior "arc and bark" processes.

Abstract: A raw batch for a ramming cement is shown adapted to be fired in place to protect studded boiler tubes and the like. The fired cement includes a major proportion of a particulate chromia-magnesia spinel that is bonded in-situ with a clay phase including kaolinite and montmorillonite components and a reacted chromia and magnesia compound together with sodium hexametaphosphate.

Abstract: A fused cast ceramic composition having superior corrosion and stoning resistance in the presence of E glass when compared with prior art compositions having comparable chromia content. The composition is a solidified fusion of from about 65 to about 98 weight percent Cr.sub.2 O.sub.3, from about 0.75 to about 4 weight percent MgO and from about 1 to about 34.25 weight percent alumina. The invention also comprises the method for manufacturing the composition by fusing the appropriate materials at the required concentrations.

Abstract: Refractory chrome-magnesia bricks and compositions composed of a granular fused material having a grain size of 12 mm or less, and a content of from 71 to 83 wt. % Cr.sub.2 O.sub.3 and from 17 to 29 wt. % MgO, the minimum content of Cr.sub.2 O.sub.3 and MgO being 94 wt. %.

Abstract: A spinel type dense fused refractory product having excellent corrosion resistance comprises a crystalline structure consisting essentially of more than 50% by weight of composite spinel phase comprising RO component selected from MgO and FeO and R'.sub.2 O.sub.3 component selected from Cr.sub.2 O.sub.3, Al.sub.2 O.sub.3 and Fe.sub.2 O.sub.3 and periclase phase and a small content of glass matrix phase which consists essentially of the following constituents, analytically on a weight basis; a ratio of Cr.sub.2 O.sub.3 to Al.sub.2 O.sub.3 of 3.5 to 5.5; and 20% to 40% of MgO; 1.5% or less of CaO; 15% or less of Fe.sub.2 O.sub.3 (FeO is also calculated for Fe.sub.2 O.sub.3) and 5% or less of SiO.sub.2.

Abstract: The invention refers to an unshaped refractory composition which can be used in the construction of glass furnace hearths and which comprises by weight:(a) 55 to 99% of particles of a fused cast refractory material, the fused cast refractory material including a vitreous phase and containing, as main constituents, ZrO.sub.2, Al.sub.2 O.sub.3, SiO.sub.2, and optionally Cr.sub.2 O.sub.3 ;(b) 0 to 5% of a hydraulic cement;(c) 1 to 15% of a filler consisting of very fine, substantially spherical particles of a metal oxide;(d) 0 to 25% of fine particles of a size less than 40 microns chosen from particles of ZrO.sub.2, Al.sub.2 O.sub.3, Cr.sub.2 O.sub.3, fused cast refractory products comprising by weight 75-85% ZrO.sub.2, 2-8% SiO.sub.2, 9-17% Al.sub.2 O.sub.3, 0.5-0.7% of other oxides, and mixtures thereof; and(e) 0.01 to 1% of a surface-active agent, the amount being with respect to the total weight of the constituents (a), (b), (c) and (d).