Abstract: Improved method for manufacturing spherical cryogenic liquid holding tanks as well as the tanks produced thereby, wherein at least the major hemispherical portions of such tanks are formed from curvilinear elongated quadralateral plate members which in the case of a given tank each have substantially the same arcuate minor axis dimensional width when measured at the midpoint of the arcuate major axis but varying lengths. These plate members of varying lengths are initially selectively arranged and secured to each other to form a series of substantially symmetrical and uniformly dimensioned, individual, triangular spherical tank sectors or modules.

Abstract: Improved self-grinding valve is provided with corrosion-protecting features and an improved floating coupling between the valve stem and valve disc whereby, when the valve disc is brought into contact with its seat, a selected rotation of the valve disc will produce a grinding of the seat, followed by a disengagement of the valve stem from the valve disc. When this disengagement takes place, the full torque load of the stem can be imposed upon the valve disc to obtain the desired seating of the same. The valve stem is advantageously comprised of improved telescoping and theadedly engaged sections that operate to relieve the forces used to hold the valve disc against the seat upon the initial opening of the valve whereby the amount of torque required to ultimately rotate and free the valve disc from its seat is materially reduced and seizing of the valve disc relative to its seat avoided.

Abstract: A plastic chrome ore is made from an admixture of sized chrome ore, sodium silicate, hectorite, and sufficient water to form a plastic mass. It may contain a plasticizer such as plastic kaolin clay in addition to the hectorite.

Abstract: Fluoridic spent and waste materials, such as are generated in electrolytic aluminum reduction systems, are pyrohydrolyzed in a fluidized bed reactor. For fluidization of these materials, as well as for the combustion of carbon present in the materials, an O.sub.2 -containing gas stream, containing at least about 90% by volume O.sub.2, is employed. This results in the generation of an HF-containing offgas of significantly increased HF level, which can be employed for the manufacture of an AlF.sub.3 product of at least about 85% by weight AlF.sub.3 content from hydrated alumina. The offgas having the increased HF content can also be employed for the production of highly concentrated HF acid with significantly lower energy requirement needed for concentration than in conventional systems.

Abstract: A pyrohydrolysis system is provided for the recovery of valuable components from waste and spent materials generated in electrolytic aluminum reduction facilities. The pyrohydrolysis system employs a dense phase fluidized bed reaction zone for the pyrohydrolysis of coarse feed, a dilute phase fluidized reaction zone for pyrohydrolyzing fine feed, this zone being superimposed and interconnected with the dense phase zone. The offgases, after removal of the solids, are contacted in a dilute phase fluidized zone, with a source of Al.sub.2 O.sub.3 to remove residual Na values and to produce Na-free HF. The solids from the first dilute zone, having a desired high Na:Al atom ratio, can be combined with the product clinker from the dense bed zone. The offgas, containing the source of Al.sub.2 O.sub.3, is subjected to solids separation, the solids-free and Na-free HF is utilized, while the solids of low Na:Al mole ratio are recycled to the residual Na conversion step.

Abstract: A foamed insulating refractory shape is made by: (1) preparing a slip of water, deflocculating agent, refractory aggregate, at least 7.5% by weight cement, and, optionally, clay; (2) forming a foam of water, foaming agent, and air having a density not over about 5 lbs per cubic foot (80 g/l); (3) admixing the slip and the foam to form a foamed slurry with a viscosity between 1000 and 30,000 centipoises, the amount of water in the slip being adjusted to yield the desired viscosity in the foamed slurry; (4) pouring the foamed slurry into molds; (5) curing the pieces so formed at a temperature not over about 72.degree. F. (about 22.degree. C.) for about 16 to 24 hours; (6) drying the pieces at a temperature not over about 200.degree. F. (about 93.degree. C.); and (7) firing the pieces. The method of this invention produces insulating refractory shapes with higher strength-to-weight ratios than those produced by prior art methods.

Abstract: Ammonium polyphosphate fertilizer solutions contaminated with carbon and carbonaceous residues are decarbonized by a sequential treatment to produce a light-colored solution/slurry of fertilizer solution containing essentially no visible carbon. In the first step, a mixture of an organic amine with a quaternary ammonium salt is dispersed in the contaminated fertilizer solution. In the second step a water immiscible hydrocarbon of low polarity is incorporated into the fertilizer solution by low shear agitation. In the third step a very slow agitation of the mixed system provides for the rising and coalescence of the low density hydrocarbon droplets containing the carbonaceous particles into a layer above the fertilizer solution.

Abstract: A refractory composition, suitable for ramming, casting, or gunning, which can be heated rapidly without exploding is made from sized refractory aggregate bonded with from 0.1% to 3% MgSO.sub.4, from 0.1% to 2% sodium gluconate, and from 0.1 to 2% B.sub.2 O.sub.3 in the form of a soluble boron compound, boric acid being a preferred form. To inhibit explosion of the composition upon rapid heating, the sum of the per cent sodium gluconate and boric acid should be over 0.8, preferably over 0.9.

Abstract: Improved low headroom culvert comprised of a plurality of shallow arch-shaped corrugated culvert sections and elongated unitary load transferring stringer stiffener elements, the stringer stiffener elements being arranged in generally spaced parallel relation to each other and secured to the inside surfaces of said sections. The stringer elements extend for substantially the full length of the culvert thereby acting to integrate the culvert sections into a unitary overall culvert structure. Certain of the stringer elements are located a selected distance inwardly from the free bottom edges of the culvert sections and provide combination culvert reinforcing stringer elements and elongated footings and soil supports.

Abstract: Improved depressible tab provided with a nose for easy open end closure members and the like, wherein an improved pressure relief means in the form of a unique vent arrangement is incorporated in the nose portion of the depressible tab.

Abstract: A vibration damper attachable to a pole structure and comprised of a plurality of individual vibration damping discs or weights mounted for controlled and limited movement within a housing together with rods insertable in an improved fashion through openings in the discs and separator washers for vertically stacking the discs along with separator washers within the housing.

Abstract: Improved sectionalized depressible opener tab for easy open containers wherein one of the sections can be relatively small as compared to the dimensions of the overall tab while being connected by an improved hinge arrangement to the remainder of the tab. This hinge arrangement permits either a simultaneous selective depression of multiple tab sections or depression of only one tab section to obtain initial separation of the tab from the container component with which the tab is associated and a controlled release of internal container pressure.

Abstract: A magnesium aluminate spinel-bonded refractory can be formed which does not exhibit undue expansion (due to the reaction of magnesia and alumina to form magnesium aluminate spinel) between the raw, compacted state and the fired, ceramically bonded state when fired to a temperature of 1400.degree. C if a very finely divided alumina with dense particles is used. More specifically, the alumina used has an average particle size of less than 5, preferably less than 2, microns, and a specific surface of less than 30 m.sup.2 /g, preferably about 5 m.sup.2 /g (i.e., the small crystallites or particles are dense and do not have a high surface area, as do finely divided active aluminas).

Abstract: A high purity periclase grain having less than 8 volume % porosity, less than 2% SiO.sub.2, and a CaO:SiO.sub.2 weight ratio not over 1.0 is produced in a single fire process by mixing from 0.5 to 1.5% finely divided SiO.sub.2 with a magnesium hydroxide containing (on the ignited basis) at least 98% MgO, not over 1.5% CaO, and not over 1.0% SiO.sub.2, drying the admixture, compacting it at a pressure of at least 10 tons/in.sup.2 (1400 kg/cm.sup.2), and firing the compacts at a temperature of at least 1700.degree. C.

Abstract: Synergistically performing flame retarding compositions are provided for cellulosic boards, such as hardboards, particleboards and fiberboards. The synergistically performing compositions consist of three components, namely, an aluminous material, a naturally occurring borate-containing mineral and a phosphate or sulfate salt. Incorporation of these compositions in the boards allows consistent production of flame-retarded products with a Class I or better fire rating.

Abstract: A jacketing system for cylindrical storage tank structures of the type used for oil, water, etc., wherein vertically disposed insulated panel sections are affixed to wire cable members or the like on the outside walls of the tank structures and improved articulated fasteners are provided for securing the panel sections to the wire cable members.

Abstract: A fully integrated process is provided for the recovery of valuable components from waste materials generated in electrolytic aluminum reduction systems. The waste materials, such as spent pot linings, channel and trench cleanings, floor sweepings and spent alumina from offgas purifying dry scrubbers, are combined, then pyrohydrolyzed at elevated temperature. Fluoridic values, such as NaF and HF can be recovered from the offgas generated by pyrohydrolysis, while alumina and Na.sub.2 O values, or if desired, sodium aluminate, is reclaimed from the solid residue of pyrohydrolysis.The fluoridic values from the pyrohydrolysis offgas can be used for the manufacture of both electrolytes for aluminum reduction cells and also for the production of anhydrous HF. The alumina from the pyrohydrolysis residue can be reclaimed by a Bayer process-type leach with a caustic solution and the recovered high purity alumina utilized, for example, as reduction cell feed and/or for scrubbing reduction cell offgases.

Abstract: This invention relates to a method of forming an oxide coating on an aluminum surface having a controlled surface resistance and if sufficiently thick have an integral color by treating the aluminum surface with a neutral or slightly basic aqueous solution containing at least 0.001 gm/liter of a difficultly soluble magnesium compound expressed as MgCO.sub.3. The temperature of the bath should exceed 65.degree. C and the pH should range from about 7 to 9.

Abstract: A pretreatment system is provided for transforming the goethite constituent [FeO(OH)] of goethitic bauxites to hematite and/or magnetite at high temperatures and pressures. The system employs a number of float-type, liquid displacement pressure pumps, both for charging caustic-containing bauxite slurries of high solids concentration to the system and for discharging the treated slurries. The system operates at temperatures in excess of 250.degree. C and up to temperatures required for the total conversion of the goethite content to hematite or magnetite which, in turn, significantly increases the yield of recoverable alumina. Since the slurry to be pretreated is of high solids concentration, e.g.

Abstract: This invention is directed to the formation of massive aluminum-magnesium alloy plate wherein the plate is cast directly to size then homogenized at a temperature greater than 1020.degree. F for more than 12 hours to provide good mechanical properties and excellent weldment characteristics.