Abstract: A method for producing boracites is disclosed in which a solution of divalent metal acetate, boric acid, and halogen acid is evaporated to dryness and the resulting solid is heated in an inert atmosphere under pressure.

Abstract: An improved molten metal pump and gas injection apparatus comprising a submersible pump housing 10 enclosing a rotatable impeller 30, an impeller drive 12 supported above the housing and an elongate drive shaft 16 operatively connected to the impeller. Rotation of the drive shaft effects fluid flow between a pump inlet 35 and a pump outlet 44 both being at least partially defined by the impeller housing. A gas injection conduit 54 extends downwardly from a drive motor support platform 20 and includes an output end 54a that terminates near the pump inlet and which is received by a gas inlet collar 58 that defines a venturi 60, coaxial with the axis of the pump inlet. A passage 62 formed in the collar communicates the end of the gas injection conduit with the throat of the venturi so that the gas is injected into the incoming molten metal in an area of low pressure, thereby reducing the gas pressure needed to effect injection.

Abstract: A process for controlling nitrogen oxides in combustion exhaust gases which comprises adding an oxygen-containing hydrocarbon and/or its precursor to exhaust gases and thereby oxidizing nitric oxide in the exhaust to nitrogen dioxide in the presence of oxygen.

Abstract: Molten slag fresh from a smelting or refining furnace is ladled into a pan on a wheeled carriage and is thereby transported to a first heat recovery station, where water is heated by radiation from the slag while the latter is being agitated and granulated. On granulation the slag is conveyed as by a skip hoist to a second heat recovery station, where the residual heat of the slag is utilized to heat air by convection. The heated air is directed into a utility device such as a boiler, from which the cooled air is fed back to the second heat recovery station for reheating. Several embodiments are disclosed.

Abstract: This invention provides a novel glass composition having numerous uses. More particularly, the invention provides a single phase, radiopaque glass composition.

Abstract: Disclosed is a method of producing cubic boron nitride, which comprises the steps of subjecting to a pressure of from 40 to 70 kilobars and to a temperature of from 1100.degree. to 2000.degree. C. a charge including hexagonal boron nitride and a conversion initiator selected from the group consisting of alkali and alkaline earth metals and borides of the foregoing metals, doping the charge with crystallohydrate in the form of a compound selected from the group consisting of sulfur-, halogen- or nitrogen-containing salts and their mixtures incorporating at least 5 molecules of crystallization water. According to another embodiment, the aforesaid charge is doped with a member selected from the group consisting of alkali metal hydroxide or alkaline earth metal hydroxide.

Abstract: A process for the recovery of selected metal values from silica containing sludges including incineration of the sludge to degrade organic components, followed by acid leaching of the ash, followed by hydrometallurgical recovery of metal values from the remaining solid and liquid residues, wherein prior to incineration of the sludge a quantity of soluble sodium and/or potassium salts are mixed with the sludge, the quantity being in excess by weight of the silica content of the sludge, and then the incineration step is carried out on this mixture so that silicates which form during such incineration are predominantly soluble in water and in the leaching acid, whereby to avoid the occluding of metal values in insoluble glass matrices which would not be attacked by subsequent acid leaching and hydrometallurgical steps.

Abstract: A gas stream containing SO.sub.x and NO.sub.x compounds is first treated for SO.sub.x removal by absorbing the SO.sub.x components in an aqueous liquid absorbent comprising formic or oxalic acid and an alkanolamine containing a tertiary amine functional group. When spent, this absorbent is regenerated by subjection to an elevated temperature sufficient to produce sulfur and/or hydrogen sulfide. The SO.sub.x -purified gas recovered from the first absorption step is then treated for NO.sub.x removal by contact with a second liquid absorbent solution containing a ferrous chelate in an aqueous, acidic medium. This absorbent is regenerated by contact, under conditions of elevated temperature and pressure, and in the presence of added formate ion, with a catalyst comprising a water-insoluble substance containing one or more tertiary amine functional groups such that absorbed NO.sub.x components are converted to elemental nitrogen.

Abstract: A metallurgical vessel supported on a trunnion ring includes a plurality of bracket assemblies, each having a bracket plate which slidably engages a shoe for movement during vessel expansion and contraction. A replaceable wear shim is interposed between the sliding shoe and the upper surface of the vessel trunnion ring. A gib assembly is mounted adjacent the lateral ends of each sliding shoe. Each gib assembly includes a gib block secured to the trunnion ring for clamping engagement with the wear shim, the sliding shoe, and the bracket plate. Tapered spacers are interposed between each gib block, bracket plate and sliding shoe to accommodate relative movement of the block and the bracket plate during vessel expansion and contraction. The vessel may also include a second plurality of bracket assemblies disposed adjacent the lower surface of the trunnion ring and engaging a lower sliding shoe.

Abstract: A non-polluting chemical process for recovery of metals from metal containing ores or other solid materials by:(1) Treating the ore with a large volume of an aqueous solution containing chloride and hypochlorite ions (lixiviant solution);(2) Recovering the solubilized metal values from the lixiviant solution by cementation;(3) Regenerating the hypochlorite ion by electrochemical means; and(4) Recycling the lixiviant solution.In certain instances, steps (3) and (4) may be omitted with hypochlorite ion being provided as makeup to the circuit from external sources. The process of this invention has been shown to be effective for use with ores containing carbonate and cyanicidic minerals, including calcite.

Abstract: A plasma-spray technique using rapid temperature quenching transforms commercially available .beta.-rhombohedral boron in powder form into thick, dense wafers of crystalline .gamma.-tetragonal boron.

Abstract: There is provided a method for converting sulfur dioxide in an exhaust gas to sulfur, which comprises the reduction step of reducing sulfur dioxide in an exhaust gas containing water vapor to hydrogen sulfide in the presence of carbon, a part of the exhaust gas is caused to bypass the reduction step and the remainder of the exhaust gas is fed to the reduction step to convert sulfur dioxide in the exhaust gas to hydrogen sulfide; the gas from the reduction step is mixed with the exhaust gas bypassing the reduction step while controlling the amount of the bypassing exhaust gas so that the ratio of hydrogen sulfide to sulfur dioxide in the mixed gas is maintained at 2; the mixed gas is fed to the Claus reaction step; and the Claus reaction step of reacting hydrogen sulfide formed at the reduction step with sulfur dioxide to convert hydrogen sulfide to sulfur.

Abstract: Nitrogen oxides are removed from gaseous mixtures by treatment with an aqueous solution of nitric acid having a concentration by weight from about 35% to about 58% and containing by weight at least 0.001% but less than 25% of hydrogen peroxide whereby the nitrogen oxides are converted to nitric acid.

Abstract: An improved method for the pyrolysis of silane in a free-space reactor. The improved method involves non-uniform heat input along the axial length of a free-space silane pyrolysis reactor so that the axial temperature profile along the length of the surrounding reactor wall is essentially constant.

Abstract: Disclosed is a method for the preparation of decaborane-14(B.sub.10 H.sub) in high yields from B.sub.5 H.sub.9 which involve three basic procedure steps as follows:(1) conversion of B.sub.5 H.sub.9 to a solid, [N(CH.sub.3).sub.4 ][B.sub.9 H.sub.14 ], by reacting NaH in a tetrahydrofuran (THF) solution in the presence of [N(CH.sub.3).sub.4 ][Cl];(2) performing a hydride abstraction on the solid after removal of THF by reacting, while stirring, a boron trihalide selected from BBr.sub.3 and BCl.sub.3 to form B.sub.10 H.sub.14 ; and,(3) separating the B.sub.10 H.sub.14 from the solid reaction mixture by a sublimation procedure.

Abstract: The lining for a metallurgical container comprises a series of removable plates of heat insulating material designed to be applied to the inside of the metallurgical container against the lateral walls and the bottom of the latter, at least a part of these plates being quadrangular and identical. The quadrangular and identical plates include on their two opposite edges a rib extending over a major fraction of the length of the corresponding edge, this rib defining a support surface designed to receive an identical rib formed along the adjacent edge of another plate. Each plate includes also, on the remaining fraction of the length of said edge, a protuberance defining a support surface oriented in the opposite direction with respect to that of the rib, the support surface of this protuberance being designed to receive an identical protuberance formed on the adjacent edge of another plate. The invention is particularly useful for the internal coating of casting distributors or tundishes.

Abstract: Strontium nitrate is prepared by reacting celestite (strontium sulfate) with excess calcium nitrate in limited amounts of water, quickly extracting strontium nitrate from the reaction mixture by vigorous agitation with additional water, and recovering strontium nitrate by evaporation of the extract solution.

Abstract: The device permits the fixing of a stave plate to the armour shell of the blast furnace by means of a washer and a cup-shaped ring which are welded externally both to the shell and to protecting sleeves for inner water circulating tubes which are extended to outside the shell.The sealing is achieved by the interposition under compression of a preformed flexible apertured rectangular joint element and a preformed circular joint element of silicone elastomer or like plastics material, between the shell and the stave plate with adhesion on the bearing faces. It is completed by an injected mass and an annular joint element between the water circulating tubes and the corresponding protecting sleeves.The device is completed by the provision of packing products respectively between the inner wall of the shell and the stave plates and in gaps between two adjacent stave plates.

Abstract: A SiC-Si.sub.3 N.sub.4 composite system for special heat-resisting ceramic materials which is fabricated by firing in a nitriding gas atmosphere a green compact prepared from and composed of, as starting materials, silicon powder and an organic silicon polymer containing carbon and silicon atoms as the major skeletal components, whereby said composite system, as a final fired compact has an interwoven texture of SiC and Si.sub.3 N.sub.4 with sufficient micro gaps to absorb thermal stresses, wherein the quantitative ratio by weight of SiC to Si.sub.3 N.sub.4 in said composite system being in the range of 5%-20%:95%-80%.

Abstract: The present invention relates to a method for the noncatalytic reduction of NO.sub.x in combustion gases which method includes maintaining an excess of fuel to air during combustion, cooling the combustion gases to between 2400.degree. F. and 3000.degree. F., and injecting into the cooled gases ammonia in a ratio 1:1 to 1:4 NO.sub.x to NH.sub.3. After the ammonia has been injected to reduce the NO.sub.x, the gas is further cooled to between 1900.degree. F. and 2300.degree. F. and secondary air injected into the gases to complete combustion of the fuel.