Abstract: High molecular weight organic compounds, such as humic acid derivatives, are removed from Bayer process caustic liquors by oxidation of these compounds. The process involves addition of oxygen to the caustic liquor in quantities in the range established by the solubility of the oxygen in the liquor under the oxidation conditions.

Abstract: A low headroom culvert is provided wherein a series of shallow arch-shaped flat metallic sections are overlappingly secured together. Torsion and buckle resistant reinforcing cross ribbing elements are affixed to the exterior culvert sections at selected points along the culvert to form girder-like beams. The improved culvert structure provides reduced hydraulic flow resistance, can be easily installed and requires less metal for its manufacture in comparison to culverts made of corrugated sheet.

Abstract: HCl-contaminated gas streams are purified by contacting the contaminated gas with an alumina-containing material which has been promoted with an alkaline earth metal salt.

Abstract: A metallurgical bond at the interface between an aluminum-lithium core alloy and a metallic liner is achieved by first forming a mechanical bond along the interface between the core and liner under moderated temperature and reduction conditions, and then heating the composite without simultaneous reduction to cause diffusion of the elements across the core-liner interface. The result is a metallurgical bond securing the layers together to form a composite which can be worked, shaped, and fabricated by normal reduction techniques into a full range of products without the discoloration and fouling problems otherwise typical of aluminum-lithium alloys.

Abstract: Powder metallurgy products of high tensile strength are formed in a pore-free state by a novel process which entirely avoids the use of canisters. An open-pore specimen is purged with depurative gas, backfilled with a reactive gas and, while still immersed in the reactive gas, compressed isostatically to an extent necessary to close the pores. The specimen may then be compressed to full density without the need for either high vacuum or a depurative or reactive gas atmosphere.

Abstract: This invention is concerned with an improved apparatus system and method for removing liquid coolant from the side marginal edges of a continuously moving metal strip or sheet after it exits from a rolling mill and subsequent to the prior diversion and collection by a suitable device of the liquid rolling mill coolant that may otherwise contact and deleteriously rewet the top and bottom surfaces of the moving strip as it exits from the mill. The invention in its preferred embodiment involves use of a pair of improved combination strip edge wiping or contacting roller and vacuum creating units that are located adjacent the path of travel and each of the opposing side marginal edges of the moving strip.

Abstract: High strength and high toughness are combined in an aluminum-based metallic product by dispersing particles of an aluminum-based metal having a toughness of at least about 20 foot-pounds through a matrix of aluminum-based metal having a yield strength of at least about 30 ksi.

Abstract: A novel process for producing aluminum composite sheet products for roll forming and vacuum brazing is disclosed, which provides an unexpected improvement in the corrosion resistance of the brazed product. According to the process, a composite sheet is annealed to a strain-free state after having been rolled to a thickness which is a critical amount greater than the thickness ultimately sought. Following the annealing step, the sheet is cold worked to the desired thickness, the degree of reduction in this final step being within a critical range which provides the improvement in corrosion resistance to the final product after vacuum brazing.

Abstract: A cover for a top charged melting furnace includes an annular ring of downwardly extending blocks or modules of ceramic fiber insulating material. A plurality of T-bar anchors cooperate with the blocks to provide an anchor system for the annular ring. This anchor system allows the ring's attachment to the cover to be tightened in compensation for heat and compressionally related block size reductions. The anchoring system prevents the ring of blocks from sagging during cover elevation while not interfering with upward movement of the blocks during cover positioning on the furnace. The annular ring of blocks protects the main portion of the cover's insulation from damage and any damaged blocks in the ring are readily replaceable.

Abstract: Bayer process liquors derived from the digestion of bauxites with a caustic solution are purified by removing at least a portion of the organic impurities present in the liquors. Removal of these impurities is accomplished by treating liquor containing dispersed therein solids generated by the Bayer process or added thereto, such as red mud particles, alumina trihydrate, oxalate salt, or filter aid with an organic polymeric, water-soluble cationic quaternary ammonium salt (POLYQUAT salt) which due to its cationic nature will adhere to the surface of the dispersed solids. The organic coating or layer adhered to the solids provides a receptive surface for the organic impurities, thus allowing formation of a solid-Polyquat-organic Adduct which is easily removed from the Bayer system.

Abstract: A mechanical seal mounting assembly for a centrifugal high solids concentration slurry pump is disclosed. A rotating seal ring adapter is secured to the pump's impeller drive shaft for rotation with the shaft. A stationary seal ring adapter is secured to a first end of a seal carrier which extends through the pump's back plate. A split gland ring is attached to a second end of the seal carrier and is supported by gland nuts threadedly carried on gland bolts. The gland bolts are attached to a bearing assembly for the pump shaft. Axial movement of the pump shaft to effect impeller clearance seal adjustment is possible without disturbing the mechanical seal adjustment. An O-ring is interposed between the pump back plate and the seal carrier and is held in place by an O-ring retainer secured to the back plate of the pump.

Abstract: This invention is directed to the process and system for controlling the level of molten metal in a plurality of vertically oriented, continuous or semicontinuous casting units, particularly electromagnetic casting units. The flows of molten metal to the individual casting units are adjusted automatically in response to a control set point signal from a master controller in order to maintain essentially the same molten metal level in all of the casting units. Improved startup and termination procedures are also given.

Abstract: A method and system for continuously or semicontinuously casting a composite metal article, such as a structurally composite ingot or the like, wherein one of the principal structural components of the ingot comprises an aluminum-lithium alloy. During such casting by a D.C. (direct chill) conventional tubular mold or electromagnetic process, the aluminum-lithium structural component of a structurally composite ingot is encircled or peripherally encased by a further outer metal cladding component that can be cast simultaneously with the aluminum-lithium component such as another outer aluminous alloy from which lithium is absent as a constituent or impurity, although it may be present and tolerated as a trace element. In this arrangement the aluminum-lithium structural component is prevented during casting from coming into direct contact with the chilling coolant, normally water, with which lithium can react violently.

Abstract: Finely divided alumina, recovered from the dust recovery systems of alumina hydrate calcination facilities, is employed as seed for the precipitation of alumina hydrate from pregnant Bayer process liquors. The finely divided alumina dust can either be used as seed in as-is condition, or, if desired, agglomerated to coarse and strong particles prior to use as seed. Agglomeration is accomplished by combining the dust in a predetermined weight ratio with alumina trihydrate seed under controlled conditions. The process allows the utilization of an otherwise undesirable and unacceptable by-product of alumina hydrate calcination.

Abstract: Anodized aluminum-based metal workpieces are colored in a nickel-based electrolytic coloring process in which the nickel ion is supplied in the form of nickel sulfate in acidic solution. Improvements in both throwing power and coloring rate are observed at elevated temperatures and nickel concentrations.

Abstract: A covered trough for conveying molten metal, wherein the trough includes a channel of refractory material within a metal shell, and the cover includes a layer of refractory insulation to reduce heat loss and means for preheating the trough such as a gas-fired radiant heater. Adjacent trough modules are joined together in an abutting end-to-end fashion, so that metal may flow between modules, by resilient joining means which elongate or contract to absorb differences in thermal expansion between parts of each trough module, to avoid the build up of large thermal stresses which might cause premature failure of the refractory parts.

Abstract: A heat exchange structure is constructed from refractory blocks having three linearly aligned flue-forming openings extending from top to bottom of the block. The central opening is surrounded on four sides by refractory and the two end openings are surrounded on three sides. These refractory shapes are assembled in an open basketweave structure to form the heat exchanger. The resulting structure contains vertically extending, interconnected flues of two types, (1) flues of a first type interconnected at alternate layers in the structure to each of the four contiguously adjacent flues and (2) flues of a second type connected to opposed pairs of contiguously adjacent flues at alternate levels and to the other pair of contiguously adjacent flues at the intermediate levels. The net result is a stable heat exchange structure with relatively thin walls, relatively large flues, and means for creating turbulence in gas passing through the exchanger, thus increasing the rate of heat exchange.

Abstract: A process and apparatus for on-line measurement of unflatness of hot or cold rolled strip products, wherein the longitudinal bending of a shape roll over which the strip passes provides a measure of the unflatness of the strip. Actual values of force, displacement or bending moment near the ends of the shape roll may be compared to theoretically predicted values for a flat product and for product having various out-of-flatness conditions. Preferably, the shape roll is supported at its ends by two pairs of supports, and the measurements at the supports are used in determining roll bending and then strip unflatness. Other conditions such as off-center strip and asymmetric operation of the rolling mill may also be determined from the measurement.

Abstract: A device for applying coolant/lubricant to the surface of the rolls of the rolling mill and/or the workpiece being rolled. The device comprises a housing having a plurality of nozzles associated therewith, a rotating inner manifold having a plurality of apertures therein in a particular array for directing liquid to the nozzles and sealing means between the manifold and housing which provides a leak-free passageway for the liquid. The manifold is rotated to align the apertures therein with the leak-free passageway to supply liquid to the desired nozzles.

Abstract: An improved precipitation system is provided for the Bayer process production of alumina hydrate. In order to produce coarse and strong alumina hydrate at high yield, supersaturated Bayer process sodium aluminate liquor is seeded with a relatively small seed charge in a first precipitator at a relatively low temperature and the produced slurry is transferred to a second precipitator where without additional seeding, the solids content of the slurry is allowed to increase to about 250-700 g/l by accumulating solids in the line until the desired solids content is reached. After a suitable residence time, a coarse, strong product hydrate can be recovered in yields of or exceeding 80 g/l based on the alumina (Al.sub.2 O.sub.3) content of the supersaturated sodium aluminate liquor subjected to precipitation.