Abstract: The present invention discloses a method of removal of nitrogen oxides, particularly for the use in a cement raw material burning installation, said method comprising the step of introducing the reduction agent for the removal of nitrogen oxides into the zone, where is heated to about to 800.degree. to 1,100.degree. C of a duct connecting between a furnace such as a rotary kiln and the lowermost cyclone of a suspension type heater system, thereby removing nitrogen oxides produced in the burning furnace.

Abstract: This specification discloses a method of and apparatus for forming concrete reinforcing elements having enlarged ends and also discloses a reinforced composite incorporating such elements. In one embodiment the enlarged ends are formed by folding the edges of a strip of sheet metal onto itself while in another form the enlarged ends are formed by edge rolling a strip. In both cases the reinforcing element is formed by transversly shearing the strip after its edge has been modified. The reinforcing elements as described above are shown to have a greater pull-out resistance than plain elements.

Abstract: A cellular product useful for such purposes as fireproofing, thermal insulation, and acoustical soundproofing, may be produced from a mineral cement, such as portland cement, calcium aluminate cement, and gypsum cement, a water soluble organic film-former, an emulsion of a synthetic resin with a glass transition temperature of 10.degree.-25.degree. C, a mixture of anionic and nonionic surfactants, an aggregate, and air in an amount substantially in excess of that used in air entrainment of cements, admixed in the form of a stabilized foam, whereby the product has a density which is substantially lower than the density of the mineral cement and aggregate per se.

Abstract: A high bulk clay product and method of making the same are provided in which kaolinite is selectively flocculated to produce an ultra fine particle fraction in the presence of fine mica below 150 mesh in size and the resulting flocculant is collected and dried.

Abstract: A method for the production of an expanding cement which includes the steps n which so-called "Portland cement" is dry-mixed with an expanding additive which comprises 6 to 30% of the total weight of the cement. The expanding additive contains 2 to 8% dialuminium pentahydroxychloride, 4% to 15% gypsum, and optionally, a small amount up to about 7% lime. All percentages are by weight.The dialuminium pentahydroxychloride (Al.sub.2 (OH).sub.5 Cl 2.5 H.sub.2 O) is a source of aluminium ions, which are necessary to form an increased (expanded) quantity of ettringite. It has high solubility, forming a solution having a concentration above 50%, and has a high content of active dialuminium trioxide (approximately 46%), a low content of chlorine and is not hygroscopic. The lime component is not critical and its addition depends on the desirability for greater expansion (without lime) or lesser expansion and higher strength (with lime).

Abstract: A fire resistant door, panel or building element is manufactured from unique compositions which are free of asbestos, thereby minimizing the health hazards associated with the manufacture of conventional asbestos-containing fireproof doors, panels or building elements. In essence, the compositions comprise calcium silicates, vermiculite, sisal fibers and fiberglass.

Abstract: A method of producing briquettes comprising cold pressing at relatively low pressures of a homogeneous mixture consisting of at least a fibrous material which acts as both a filler and a binder together with metallic particles such as iron borings or other machine shop waste. The fibrous material is preferably paper in pulp form. The composition may include cement and/or additional material in pulverant form or dust form selected from coke, coal, limestone and fluospar.

Abstract: A coated titanium dioxide pigment and the process for its preparation consisting essentially of a core of pigmentary titanium dioxide (TiO.sub.2), a dense inner coating of dense amorphous silica (SiO.sub.2) in an amount from 1 to 10% by weight, based on the uncoated pigment, and, optionally, up to 15% of alumina (Al.sub.2 O.sub.3) and a porous outer coating of porous silica (SiO.sub.2) and alumina (Al.sub.2 O.sub.3), said porous silica being present in an amount from 0.5 to 15% by weight and said alumina being present in an amount from 0 to 15% by weight, based on the uncoated pigment. As a component of coating compositions, this pigment providesa high degree of hiding power and durability for indoor and outdoor applications.

Abstract: The present invention relates to cement compositions including both mortars and concretes and methods of making such compositions. The invention further concerns the discovery that mortars and concretes can be obtained with improved properties by including in their composition an aggregate filler ingredient which has been pretreated by an acidizing and de-acidizing process.

Abstract: A fired refractory brick composed of magnesia, 2 to 10% alumina, calcium oxide and up to 1.5% silica, the weight ratio of calcium oxide to silica being more than 1.4, and at least 2.2(CaO -1.4 SiO.sub.2)% zirconia, calcium and zirconium forming a calcium zirconate phase in the brick and the content of the calcium zirconate phase being from 0.5 to 8%, all percentages being by weight. This brick is prepared from a mixture of the components by pressing the mixture into the shape of a brick and firing the brick at a temperature of 1600.degree. C to 1800.degree. C until the brick contains the indicated amount of the calcium zirconate phase.

Abstract: A hydraulic cement composition containing a hydrogenation product of an oligosaccharide, such as a hydrolyzate of starch, cellulose or hemicellulose, having an average molecular weight of 300 to 3,500, as an agent for improving the properties of the cement.

Abstract: A glass article having an optical quality surface smoothness can be formed by molding a "silanol" glass material against a die having a molding surface which is a mirror of that required for the glass article, thereby obviating glass grinding and polishing steps. The article is prepared by first forming an anhydrous base glass comprising, in mole percent on the oxide basis, about 72 to 82% SiO.sub.2, 10 to 17% Na.sub.2 O and/or K.sub.2 O, and 5 to 15% of an oxide or oxides selected from ZnO and PbO. The base glass may include up to 5% Al.sub.2 O.sub.3 and up to 3% of B.sub.2 O.sub.3, BaO and/or MgO. The anhydrous base glass is then hydrated to include a water content ranging from 0.5 to 10% by weight to form a "silanol" glass. That glass is then molded against the die surface at a temperature ranging from about 250.degree. C. to 500.degree. C.

Abstract: A method of making improved SIALON ceramics without the need for hot pressing, is disclosed. A homogeneous slip is prepared from Si.sub.3 N.sub.4, Al.sub.2 O.sub.3 and Y.sub.2 O.sub.3 in the presence of a suspension agent; Y.sub.2 O.sub.3 being present in at least 1% by weight (preferably between 1-25%) and Al.sub.2 O.sub.3 being present in the range 16-40% by weight (preferably 16-18%). The slip is cast and dehydrated. The cast shape is reaction sintered at about 1550.degree.-1700.degree. C (preferably 1600.degree. C) for no less than 3 hours (preferably between 3-12 hours).

Abstract: A process for the manufacture of aluminous cement from aluminum smelting residue and the novel resulting cement are provided. According to the process, a mixture of predetermined amounts of aluminum smelting residue, limestone, aluminum siliceous clay, and, if necessary, fluorite and manganese ore for the acceleration of oxidation, is prepared and the mixture is finely crushed and then burned at temperatures between 1,300.degree. C and 1,500.degree. C to form a clinker which is then powdered to produce an aluminous cement of excellent quality. The product contains no harmful chemical compositions that tend to become a source of public hazards such as air or water pollution.

Abstract: Burned, magnesite-chrome refractory shapes having a lime to silica ratio between about 1.7 and 2.1 to 1, and a chromic oxide to aluminum oxide plus iron oxide ratio in excess of about 1.5 to 1.

Abstract: Cured cementitious compositions having a modulus of rupture of greater than 15 MN/m.sup.2 are prepared by curing and drying a homogeneous uncured cementitious composition which comprises in defined proportions hydraulic cement, water and a selected water-dispersible polymer.

Abstract: A process for preparing a catalyst component supported on a carrier which comprises contacting a titanium tetrahalide in the liquid or gaseous phase with a solid in the absence of mechanical pulverization, said solid being obtained by mechanically pulverizing specified combinations of components selected from the group consisting of a magnesium dihalide component selected from magnesium dihalides and adducts thereof with monocyclic aromatic monocarboxylic acid esters; a monocyclic aromatic monocarboxylic ester; and a titanium component selected from titanium compounds of the formula Ti(OR).sub.n X.sub.4-n wherein R is alkyl or optionally substituted phenyl, X is halogen, and n is an integer of 0 to 4 and complexes thereof with monocyclic aromatic monocarboxylic acid esters, the amounts of the magnesium dihalide (a), the monocyclic aromatic monocarboxylic acid ester (b), and the titanium compound (c) being selected such that the molar ratio of (a):(b):(c) is 1: (not less than 0.005):(100 to 0.001).

Abstract: A portland cement product with or without added gypsum is described in which carbon dioxide gas has been homogeneously reacted with the cement slurry during the water-cement mixing. The use of carbon dioxide in an amount from 0.1% to 6.0% by weight of ground cement controls setting and also results in hydraulic cement mixes which are more stable following hydration. The portland cement mixes of this invention may also include the addition of certain acids or acid/salts in amounts sufficient to improve fluidity and accelerate hydration and hardening of the cement products, in amounts from 0.1% to 5.0% by weight of said ground cement. Lignosulfonates and other water reducers may also be added.

Abstract: A porous refractory body is formed by bonding Si.sub.2 ON.sub.2 grain or other suitable refractory grain with fine crystals of Si.sub.2 ON.sub.2 formed in situ by firing a shaped body under nitridation conditions. The body has an open pore structure, is resistant to the constituents of an aluminum chloride electrolysis cell and has good structural strength.

Abstract: An additive for mortar and concrete composed of water-soluble, swellable polymeric substances, said water soluble, swellable polymeric substances being employed in a finely dispersed state in an aqueous solution of salt or organic solvents.