Abstract: A process for the assembly of at least one adjacent pair of component structural elements to form an upright vault structure, each of the elements having a recess, wherein the elements are arranged flat on the ground in the desired relative configuration and are temporarily joined together into an assembled unit by an assembly device, whereafter the device and the assembled unit are lifted and placed in a final position of the structure, and the joining device is removed from the elements. The joining device includes a post and a pair of opposed spaced jaw members mounted on the post for relative movement toward and away from one another, a pair of wing members being afixed to one of the jaw members, the wing members extending from opposite sides of this jaw member and toward the other of the jaw members and respectively engaging the recess of the structural elements. The jaw members are clamped together about the joined structural element.

Abstract: The invention relates to a granular propping for use in petroleum extraction which has a high mechanical resistance and a density of between 3150 and 3250 kg/m.sup.3, the propping agent consisting of balls formed by melting, granulating and solidifying an initial composition comprising by weight, on the basis of the oxides, 47.1 to 48.7 parts of ZrO.sub.2, 52.9 to 51.3 parts of SiO.sub.2, the total of ZrO.sub.2 +SiO.sub.2 amounting to 100 parts, 8.2 to 16.9 parts of Al.sub.2 O.sub.3 and 4.1 to 8.5 parts of at least one oxide selected from the group formed by MgO, CaO, FeO and TiO.sub.2.

Abstract: A refractory composition for use in the manufacture of pipes for casting steel, the composition consisting essentially of: (a) from 96 to 98% by weight of zirconia which is partially stabilized by CaO, MgO or Y.sub.2 O.sub.3, at least 90% of which has a particle size of between 0.1 and 10 .mu.m, and (b) from 2 to 4% by weight of an aluminous hydraulic binder, this composition having the following overall chemical analysis: 1.4 to 3.2% by weight of Al.sub.2 O.sub.3, 3.7 to 4.6% by weight of CaO, or 0.36 to 1.15% by weight of CaO plus 2.7 to 3.5% by weight of MgO, or 0.36 to 1.15% by weight of CaO plus 5.36 to 8.80% of Y.sub.2 O.sub.3, less than 1% by weight of SiO.sub.2 +Na.sub.2 O+Fe.sub.2 O.sub.3 +TiO.sub.2 taken together, and ZrO.sub.2 to make up to 100%.

Abstract: A transverse-burner recuperative furnace for glass making, which comprises burner blocks of which the inner aperture, of generally elongate rectangular shape, exhibits a first portion of constant cross-section extending from the rear face of the burner block, and a second portion progressively flaring upwards and downwards to the front face of the burner block, such second portion exhibiting an angle of flare .alpha. of not more than 15.degree., and the cumulated total length of these apertures representing at least 0.65 times the distance between the extreme burner blocks.

Abstract: The present invention is directed to a regenerator furnace which is useful in making glass, the regenerator furnace including burner pipes, each burner pipe having a generally square or rectangular cross section, the upper part or cover of each pipe being built with monolithic elements made of refractory material and of sufficient extent for each upper element to rest at its ends on the refractory elements forming port side walls, these lateral elements themselves resting on refractory elements forming the base of the pipes.

Abstract: The invention relates to a fused cast block useful in the construction of steel making furnaces, the block comprising a refractory oxide-based material having embedded therein a steel member which extends over the greater part of the length of the block and emerges from the block on the outer face of the latter, the steel member being embedded in the block in the course of molding the latter and having a cross-section of suitable shape and surface area to impart to the composite block an apparent thermal conductivity at between 500.degree. and 1000.degree. C. of at least 8 Kcal. m./m.sup.2..degree.C. hr.

Abstract: The invention relates to walking beam furnaces. It concerns a skid pad or lug for walking beam furnaces, which comprises a body made of an oxide-based refractory substance and a shell made of refractory metal alloy surrounding the periphery of the body, means being provided to prevent detachment towards the top of the body in relation to its shell.

Abstract: The invention relates to a method of preparing a product containing, as a single crystalline phase, a solid solution or .beta.'-sialon type having the general formula Si.sub.6-Z Al.sub.Z O.sub.Z N.sub.8-Z where Z=1 to 4, which comprises heating in a nitrogen atmosphere, at 1400.degree.-1600.degree. C., agglomerated elements obtained by drying a paste comprising a silico-aluminous material, such as kaolinitic clay, carbon, and a pore-generating agent comprised of fine particles of a ligneous material, such as sawdust or a powder of olive stones.

Abstract: A fused cast refractory composition which is suitable for use as the lining of a glass melting furnace comprises, by weight and on an oxide basis:1 to 74% of CrO.sub.3,15 to 40% of ZrO.sub.2,3 to 76% of Al.sub.2 O.sub.37.5 to 20% of SiO.sub.2,0.4 to 2.5% of Na.sub.2 O, and0.3 to 4.0% of iron oxide and/or manganese oxide,the SiO.sub.2 /Na.sub.2 O ratio being from 5 to 15, and the Na.sub.2 O being optionally partially or wholly replaceable by a technically equivalent amount of one or more other alkali metal oxides, and the sum of the specified ingredients being at least 97% of the total composition.

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).

Abstract: Machine for grinding hard workpieces, with an arm equipped at one end with a grinding tool, a machine base supporting a table on which the workpiece is mounted, and an arrangement for supplying cutting liquid, which comprises in combination:an arm pivoted to swing up and down in a vertical plane which is fixed in position relative to the support,means for raising and lowering the arm,a table supported on hydraulic floatation feet to which a stream of cutting liquid is supplied,a machine base on which the table is mounted to be mobile thereon,means for moving the table in two directions on the machine base.

Abstract: The invention relates to thermally insulating materials. It refers to a thermally insulating slab consisting of entangled refractory fibres, the major portion of the fibres being substantially parallel with the main faces of the slab, characterized in that the back of the slab bears a plurality of furrows or grooves distributed over the back. The slab is used for the insulation of furnaces and the like.

Abstract: The invention relates to gas-permeable parts comprised, by weight, of (A) 60 to 90% of granules of a grain size from 5 mm to 0.2 mm formed from a material selected among the group consisting of a chamotte containing at least 42% of Al.sub.2 O.sub.3, mullite, fired gibbsite containing more than 90% Al.sub.2 O hd 3, sintered or fused cast corundum containing more than 95% Al.sub.2 O.sub.3, natural chromite, sintered MgO, zircon sand and stabilized zirconia, and (B) 10 to 40% of a bonding cement comprised a calcium aluminate, a material selected among SiO.sub.2, Al.sub.2 O.sub.3 and Cr.sub.2 O.sub.3 having a particle size between 100 A and 0.1 micron, and alumina having a particle size between 1 and 100 microns. These parts retain a high mechanical strength when heated between hydraulic setting and ceramization, and are useful for blowing a gas therethrough in order to stir molten steel and cast iron.

Abstract: The invention relates to produced refractory compositions comprising the four following particulate fractions:(1) 30-60% by weight of a coarse fraction at least 50% of which are greater than 0.5 mm;(2) 10-30% by weight of a fine fraction at least 50% of which are smaller than 75 microns;(3) 10-30% by weight of a very fine fraction at least 50% of which are smaller than 5 microns; and(4) 10-30% by weight of an ultra fine fraction at least 80% of which are smaller than 0.1 micron;the fractions being comprised of materials which are inert to water. The refractory compositions, when mixed with less than 10% by weight of water, give injectable pastes suitable for repairing refractory furnace linings.

Abstract: The invention relates to refractory material and in particular to lining parts of the pusher ovens used in steelworks, the lining parts being made of a cast refractory material having a chemical composition ZrO.sub.2, SiO.sub.2, Al.sub.2 O.sub.3 and Na.sub.2 O (or other metal oxide) in defined proportions, but containing substantially no mullite, and furthermore has a crystallographic composition Corundum, Zirconia, Vitreous phase of defined proportions to inhibit cracking and preserve abrasion resistance.

Abstract: The invention is directed to a cement composition comprising (1) 10-30% of an alkaline-earth mineral substance such as a slag or cement having a base of calcium aluminate or a calcined alkaline-earth oxide, (b) 14-56% of a constituent of a grain size of 100 A to 0.1 micron selected from silica, chromium oxide, TiO.sub.2, ZrO.sub.2 and Al.sub.2 O.sub.3, and (c) 14-56% of an inert filler of a grain size from 1 to 100 microns, the sum of (b) + (c) representing from 70 to 90% of the cement. Concrete mixtures which employ the inventive cements display superior properties.

Abstract: The invention relates to beads used for crushing or dispersion which are formed by fusion, conversion into beads and solidification of an appropriate batch consisting essentially, on the oxide basis, of up to 85% by weight of ZrO.sub.2, a proportion of SiO.sub.2 such that the weight ratio ZrO.sub.2 /SiO.sub.2 is greater than or equal to 1.5, an optional proportion of Al.sub.2 O.sub.3 such that the weight ratio Al.sub.2 O.sub.3 /SiO.sub.2 is 0 to 1.5 and an optional proportion of Na.sub.2 O such that the weight ratio Na.sub.2 O/SiO.sub.2 is from 0 to 0.04, the batch also containing at least one of the additional oxides of MgO and CaO in proportions such that the weight ratio MgO/SiO.sub.2 is from 0.03 to 1 and the ratio CaO/SiO.sub.2 is from 0.03 to 1.45.

Abstract: A novel vault for industrial furnaces, such as glass-making and metallurgical furnaces, comprised of a plurality of arches arranged side-by-side and each composed of a plurality of archstones made of fused cast refractory material. The archstones include a relatively thin slab-like lower portion and at least one upper rib integral therewith extending along the longitudinal direction of the individual arches. The corresponding ribs of the archstones of a given arch are aligned and define recessed portions filled with a refractory concrete having preferably good thermally insulating properties. A highly efficient thermally insulating structure covers the filled archstones.