Abstract: In accordance with the invention, apparatus for the production of atomized metal is provided comprising a containment vessel having a sidewall terminating in an end wall through which atomizing gas and molten metal from a molten metal source enter the vessel through nozzle means sealed thereto. A restricted air ingress port is provided in the vessel spaced from the end plate, the sidewall and the end plate cooperating with the nozzle means to seal off the interior of the vessel and the metal particles therein from the area adjacent the source of molten metal. The source of molten metal includes a reservoir having at least a portion above the nozzle means whereby the metal level in the reservoir provides an adjustable pressure head for the metal entering the vessel through the nozzle means which is adjusted by varying the level of the molten metal in the reservoir.
Abstract: In a process for producing aluminum by electrolysis of alumina dissolved in a cryolite-based molten salt contained between a cathode and a plurality of previously baked carbon anodes which are consumed with evolution of oxides of carbon, the improvement including setting all anodes at the same time.
Abstract: In a process of fragmenting and segregating shredded metallic components fabricated from different aluminum alloys in which a fragmented component is provided, a method of removing fines for purposes of enhancing segregation of the alloys, the method comprising the steps of providing a feedstock comprised of said metallic components, said alloys having different incipient melting temperatures, the feedstock is shredded and thereafter screened to remove fines therefrom having at least sizes in a size range of the fragment component. The feedstock is heated to effect incipient melting of the component having the lowest incipient melting temperature and agitated sufficiently to cause the component having the lowest incipient melting temperature to fragment. The fragmented components are segregated from the unfragmented feedstock.
Abstract: Improved aluminum alloy products are fabricated from an improved alloy broadly containing 0.4 to 1.2% silicon, 0.5 to 1.3% magnesium, 0.6 to 1.1% copper and 0.1 to 1% manganese. The alloy is treated at very high temperatures, approaching the solidus or initial melting temperature, to provide the improved performance. Thereafter, the alloy is shaped as by rolling, extruding, forging and other known aluminum wrought product-producing operations. In the solution heat treated, quenched and artificially aged temper products so produced exhibit very high strength in comparison with 6XXX aluminum alloys, together with very high toughness and impact and dent resistance along with substantial corrosion resistance properties. In addition, the artificial aging response of the improved products enables use of high temperature, low cost aging treatments without risk of overshooting or undershooting the required or desired properties.
Abstract: An improved system for the production of particulate metal is disclosed. The system comprises a containment vessel having a sidewall extending to an endwall, a source of metal external to said vessel and nozzle means carried by said endwall, said nozzle means including a central bore and providing communication between said vessel and said external source of metal, the sidewall and endwall cooperating with the nozzle means to seal off the interior of said vessel and the metal particles therein from the area adjacent said source of molten metal. Further, the system comprises a source of atomizing gas flowing through said nozzle means into said vessel and means for redirecting said atomizing gas flowing into said vessel into said central bore to remove deposition in said bore.
Type:
Grant
Filed:
May 3, 1984
Date of Patent:
April 29, 1986
Assignee:
Aluminum Company of America
Inventors:
A. David Booz, Kalman E. Buchovecky, Walter S. Cebulak, Ray A. Kuchera, David D. White, Jr.
Abstract: A process for transforming alumina hydrate into an anhydrous product comprising at least 10 wt % alpha alumina. Alumina hydrate is dehydrated, heated and transferred to a reactor where it is fluidized with steam and maintained at a temperature of about 900.degree.-1350.degree. C. Steam fluidization enhances crystal growth and results in a product having uniform quality and superior grinding characteristics.
Abstract: A lubricant composition comprising a major proportion of mineral oil and a minor proportion of an alkoxyalkyl ester having the general formula R.sub.2 COO(CH.sub.2 CH.sub.2 O).sub.n R.sub.1 wherein n=1 or 2, R.sub.1 is a C.sub.1 to C.sub.8 alkyl group and R.sub.2 is a C.sub.7 to C.sub.19 alkyl or alkenyl group. A particularly preferred composition comprises about 30 wt % butoxyethyl stearate dissolved in about 70 wt % mineral oil.A metalworking lubricant emulsion is formed by emulsifying about 2-10 wt % of the composition in about 90-98 wt % water. A particularly preferred emulsion comprises about 5 wt % of the composition in about 95 wt % water. The emulsion is suitable for hot rolling and cold rolling aluminum and aluminum alloys.
Abstract: A method for reducing the thickness of a slab of metal under conditions which tend to cause alligator defects to occur. The method comprises the steps of directing a relatively thick slab of metal several times through a rolling mill or mills to incrementally reduce the thickness of the slab until the thickness approaches a value that tends to produce a longitudinal and lateral fracture in one or both ends of the slab. The thickness of the slab is further reduced by passing the same several times again through a rolling mill or mills, with each of the passes of the slab taking a decreasing amount of reduction in thickness until a predetermined thickness value is reached. The next step involves passing the slab again through a rolling mill to further reduce the thickness thereof, the amount of reduction in this step and pass being substantially greater than that of the last pass immediately preceding this step.
Abstract: An improved inert electrode composition is suitable for use as an inert electrode in the production of metals such as aluminum by the electrolytic reduction of metal oxide or metal salt dissolved in a molten salt bath. The composition comprises one or more metals or metal alloys and metal compounds which may include oxides of the metals comprising the alloy. The alloy and metal compounds are interwoven in a network which provides improved electrical conductivity and mechanical strength while preserving the level of chemical inertness necessary for such an electrode to function satisfactorily.
Abstract: A combustion process is disclosed for burning a fuel containing sulfur characterized by low sulfur and particulate emission and formation of solid, non-toxic sulfur compounds. The process comprises mixing the sulfur containing fuel with an additive capable of reacting with sulfur; burning the mixture in a first combustion stage with less than 75% theoretical air and at a temperature below the melting point of the ash, but sufficiently high to cause reaction between the additive and any sulfur in the fuel to facilitate removal of the sulfur compounds formed; passing combustible fuel gases and particulates from the first stage to one or more further stages to complete the combustion of the fuel; and oxidizing, in a separate zone, sulfur compounds formed in the first reaction zone by reaction between the additive and the sulfur in the fuel to form non-toxic sulfates.
Abstract: Calcium is produced by a thermal reduction process in a reaction-condensation system having a reaction zone and a condensation zone. According to the process, a reducing agent is contacted or reacted in the reaction zone with at least a partially molten slag to produce calcium vapor. The calcium vapor is transported from the reaction zone to the condensation zone and condensed therein.
Abstract: A method and apparatus for heating and melting electrically conductive material are disclosed. The method includes the steps of heating a jet of gas or gaseous mixture, directing a heated jet of gas or gaseous mixture to the material, and drawing a diffuse current through said gas jet to said material by seeding it with an additive having a low ionization potential so as to increase the rate at which the material is heated. The apparatus includes means for heating gas(es), means for directing a jet of said gas(es) to the material, means for introducing an additive having a low ionization potential into the gas(es) for purposes of ionizing said gas(es), and means for drawing a diffuse current through the jet of ionized gas to the material.
Abstract: A method for continuously casting lithium-containing alloys by a direct chill process includes cooling the alloy to form a continuous ingot having a solid shell, further cooling the ingot by direct chill with an organic coolant, and inhibiting fire by covering the coolant with fire retardant atmosphere.
Type:
Grant
Filed:
October 9, 1984
Date of Patent:
April 15, 1986
Assignee:
Aluminum Company of America
Inventors:
John E. Jacoby, Ho Yu, Robert A. Ramser
Abstract: An improved inert electrode composition is suitable for use as an inert electrode in the production of metals such as aluminum by the electrolytic reduction of metal oxide or metal salt dissolved in a molten salt bath. The composition comprises one or more metal alloys and metal compounds which may include oxides of the metals comprising the alloy. The alloy and metal compounds are interwoven in a network which provides improved electrical conductivity and mechanical strength while preserving the level of chemical inertness necessary for such an electrode to function satisfactorily. The electrode composition further includes a metal compound dopant which will aid in controlling the thickness of a protective oxide layer on at least the bottom portion of an electrode made therefrom during use.
Abstract: A snap-type cap for sealing against escape of gases through an opening in an end closure of a container having contents therein which dissociate a gas therefrom. The cap includes a seal portion to engage with a sealing lip around the opening in the container end to provide an initial low pressure seal and a second high pressure seal as progressively higher pressures within the container exceed the sealing limit of the initial low pressure seal. The cap may further include an opening portion adapted for contacting an opening panel in the container end and effecting an opening in the container by applying pressure against the opening panel through the opening portion. An improved easy open container end having a smooth sealing lip for cooperating with the cap for resealing and a method of making such an end are also disclosed.
Abstract: A master alloy compacted mass of particulate metal is fabricated using non-spherical particulated aluminum, such as aluminum sawdust from production operations, in combination with metal particles of a brittle and friable principal metal of the master alloy which is non-malleable and, therefore, non-compactable. The compacted mass retains its homogeneity by the interlocking action of the aluminum sawdust and thereby obviates the need for additional binder despite the non-compactability of the metal particles of the non-malleable principal metal of the master alloy.
Abstract: Wet oxidation of organic contaminants in aqueous sodium aluminate solutions is enhanced when a heated and oxygenated solution is passed through a packed bed containing a metal packing member that is chemically inert to sodium aluminate solutions at elevated temperatures. Process temperature is about 180.degree.-300.degree. C. and oxygen partial pressure is at least about 345 kPa. The packed bed has a packing surface of at least 100 square meters per cubic meter bed volume and preferably at least 50% free space.
Type:
Grant
Filed:
June 26, 1985
Date of Patent:
April 8, 1986
Assignee:
Aluminum Company of America
Inventors:
Paul J. The, Fred S. Williams, Thinnalur J. Sivakumar
Abstract: A process for the purification of spent liquor from an alumina precipitation stage is disclosed wherein the spent liquor is first contacted with 50 volume % or less ethanol to form a sodium oxalate precipitate and the, after removal of the sodium oxalate precipitate is contacted with over 50 volume % of ethanol extraction fluid to separate the mixture into a first layer comprising the ethanol and at least a portion of the caustic from the spent liquor and a second layer which comprises the remainder of the spent liquor. The spent liquor may then be subjected to a further precipitation to recover further alumina. The spent liquor remaining may be further treated in subsequent extraction steps to concentrate and dispose of undesirable impurities remaining.
Abstract: A refractory assembly for containment of molten aluminum-lithium alloys, comprising a nitride bonded silicon carbide refractory brick and a seam joined to the brick. The seam is formed from a mortar mix comprising particulate nitride refractory filler and colloidal sol binder. The brick and seam both exhibit good resistance to attack by molten aluminum-lithium alloys at elevated temperatures.
Type:
Grant
Filed:
April 3, 1985
Date of Patent:
April 8, 1986
Assignee:
Aluminum Company of America
Inventors:
Evelyn M. DeLiso, Frankie E. Phelps, Robert A. Gilbert, Douglas G. Graham, Ronald A. Kois, Thomas L. Francis