Alcoa Inc.

Aluminum Company of America

Alcoa USA Corp.

Alcon, Inc.

David H DeYoung

Xinghua Liu

Ray T Richter

James Wiswall

William F McGinnis

Jeffrey J Wiesner

Brent L Mydland

Siba P Ray

Larry F Wieserman

Melvin H Brown

Diran Apelian

Edward D Williams

Gerald E Carkin

Patricia Stewart

Robert W Woods

Paula L Kolek

Michael A Easley

David J Roha

John D Weyand

Ronald M Dunlap, Sr

Marshall J Bruno

Rajakkannu Mutharasan

K Dean Vinnedge

Donald L Stewart

Jorge A Ramos Cruz

Mark J Dunlay

Dennis R Moeller

Grant G Owen

Dawn Corleen Chesonis

The application is directed towards methods for purifying an aluminum feedstock material. A method provides: (a) feeding an aluminum feedstock into a cell (b) directing an electric current into an anode through an electrolyte and into a cathode, wherein the anode comprises an elongate vertical anode, and wherein the cathode comprises an elongate vertical cathode, wherein the anode and cathode are configured to extend into the electrolyte zone, such that within the electrolyte zone the anode and cathode are configured with an anode-cathode overlap and an anode-cathode distance; and producing some purified aluminum product from the aluminum feedstock.

Systems and methods for purifying aluminum

A method of recovering aluminum is provided. An alloy melt having AlCand aluminum is provided. This mixture is cooled and then a sufficient amount of a finely dispersed gas is added to the alloy melt at a temperature of about 700&#xb0; C. to about 900&#xb0; C. The aluminum recovered is a decarbonized carbothermically produced aluminum where the step of adding a sufficient amount of the finely dispersed gas effects separation of the aluminum from the AlCprecipitates by flotation, resulting in two phases with the AlCprecipitates being the upper layer and the decarbonized aluminum being the lower layer. The aluminum is then recovered from the AlCprecipitates through decanting.

Decarbonization process for carbothermically produced aluminum

A method and apparatus for melting aluminum uses a dense metal salt of Rubidium, Cesium, or Strontium. The salt is melted by a stinger and then superheated by AC applied to electrodes immersed in the salt. Aluminum in contact with the salt melts and floats on the salt. In continuous scrap melting, inflows and outflows of aluminum are comparable and may be shielded by inert gas. The superheated salt may be purified and may be heated in a separate reservoir and pumped to and from another reservoir containing salt and/or metal. The salt may be used to supplement the heating of an existing furnace.

Aluminum melting apparatus

An in-line deep box treatment of molten metal wherein, instead of gaseous Cl, a solid salt reactant containing a halide salt (e.g., MgCl) as one of its components may be injected into the molten metal along with an inert gas (typically argon) through the existing degasser impellor. The salt flux may be metered into the inert gas stream at a controlled rate. A salt injector flux tank may be retrofitted to current rotary degassing equipments without requiring a specialized rotor design or changes in the degasser unit design. Using the halide salt-based solid flux, the benefits of alkali, alkaline earth, and inclusion removal may be achieved without the industrial hygiene, environmental, and safety issues associated with storing and using the gaseous and hazardous Clduring molten metal degassing.

System and method for in-line molten metal processing using salt reactant in a deep box degasser

A method of producing aluminum castings which includes the steps of casting a molten alloy, contacting the surface of the molten alloy with a humidified atmosphere and solidifying the alloy. The method is particularly suited for aluminum-magnesium alloys such as AA 5XXX and 7XXX series alloys. In addition to reducing the thickness of the surface oxide layer formed during casting, the method also provides improved surface quality of cast products and reduces subsequent remedial re-work or scalping. An improved aluminum-magnesium cast alloy product is also disclosed.

Control of oxide growth on molten aluminum during casting using a high moisture atmosphere

Aluminum alloy compositions are disclosed, which include small amounts of calcium that result in improved surface properties of the cast aluminum. The calcium, and up to 0.25% grain refiners, are added along with alkaline earth metals, transition metals and/or rare earth metals to the aluminum alloy as a melt. The addition results in improved appearance, substantially reduced surface imperfections and reduced surface oxidation in cast ingot aluminum and aluminum alloys. The addition of small amounts of these additives, surprisingly were found to substantially eliminate vertical folds, pits and ingot cracking in more than one ingot casting technique. The additions also improved the appearance of the ingots, including reflectance. As a result, the ingots could be reduced or worked essentially right out of the casting without first conditioning the surface by, for example, scalping. Also disclosed is a method of improving the surface properties and preventing surface imperfections and cracking of cast aluminum alloys. The method includes the steps of adding calcium to a molten aluminum alloy that is essentially free of Be and casting the aluminum alloy using any commonly used technique.

Aluminum alloys having improved cast surface quality

The present invention is directed to the additions of alkaline earth metals, in particular strontium and optionally combinations with other metals, to aluminum and aluminum alloys to improve the appearance of, eliminate surface imperfections, and reduce the surface oxidation of the as-cast ingots.

Cast alloys

Molten metal containing suspended liquid and solid particles is passed preferably generally upwardly through a porous media so constructed and arranged such that the movement of the molten metal therethrough renders the suspended liquid particles gravity separable. The gravity separable liquid particles rise upwardly or settle downwardly so as to be removable from said molten metal for subsequent removal therefrom. An associated apparatus is also provided.

Removal of suspended particles from molten metal

Molten metal containing suspended liquid particles is passed preferably generally upwardly through a porous media so constructed and arranged such that the movement of the molten metal therethrough renders the suspended liquid particles gravity separable. The gravity separable liquid particles rise upwardly or settle downwardly so as to be removable from said molten metal for subsequent removal therefrom. An associated apparatus is also provided.

Method for separation and removal of suspended liquid particles from

A method of electrolytically producing lithium includes providing an electrolytic cell having an anode compartment and a cathode compartment. The compartments are separated by a porous electrically nonconductive membrane which will be wetted by the electrolyte and permit migration of lithium ions therethrough. Lithium carbonate is introduced into the anode compartment and produces delivery of lithium ions from the anode compartment to the cathode compartment where such ions are converted into lithium metal. The membrane is preferably a non-glass oxide membrane such as a magnesium oxide membrane. The membrane serves to resist undesired backflow of the lithium from the cathode compartment through the membrane into the anode compartment. Undesired communication between the anode and cathode is further resisted by separating the air spaces thereover. This may be accomplished by applying an inert gas purge and a positive pressure in the cathode compartment. The apparatus preferably includes an electrolytic cell with an anode compartment and a cathode compartment and an electrically nonconductive membrane which is wettable by the electrolyte and will permit migration of the lithium ion therethrough while resisting reverse passage of lithium therethrough.

Production of lithium by direct electrolysis of lithium carbonate

A three-stage combustion process is disclosed for burning a fuel containing sulfur characterized by low sulfur emission and good ash removal. 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; removing at least a portion of the sulfur compounds formed in the first stage; passing combustible gases from the first stage to a second stage; burning the gases in the second stage with less than 100% theoretical air at a temperature above the melting point of the ash to form a liquid slag which is removable from the second stage; and burning combustible gases from the second stage in a third stage with an excess of air to ensure complete combustion of the fuel.

Three-stage process for burning fuel containing sulfur to reduce

An inert electrode connection is disclosed wherein a layer of inert electrode material is bonded to a layer of conductive material by providing at least one intermediate layer of material therebetween comprising a predetermined ratio of inert material to conductive material. In a preferred embodiment, the connection is formed by placing in a die a layer of powdered inert material, at least one layer of a mixture of powdered inert material and conductive material, and a layer of powdered conductive material. The connection is then formed by pressing the material at 15,000-20,000 psi to form a powder compact and then densifying the powder compact in an inert or reducing atmosphere at a temperature of 1200.degree.-1500.degree. C.

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Export, PA, United States of America

David H DeYoung