Alcoa Inc.

Aluminum Company of America

Alcoa USA Corp.

Elysis Limited Partnership

Robert L Kozarek

David D Leon

Leroy E D'Astolfo

Siba P Ray

Alfred F LaCamera

Adel B Mansour

Thomas R Hornack

Yimin Ruan

William J Steiner

Norman Chigier

Eric C Moreland

Roberto J Rioja

Xinghua Liu

Men Glenn Chu

Robert K Dawless

Robert B Hosler

Gregory J Hildeman

Noel Jarrett

William D Straub

Raymond Miller

Gene S Miller

Jerry L Roddy

Christopher M Seaman

William M Hall

Kevin G Christian

William D McGraw

Joern E Fischer

Alfred F Lacamera

Leroy E D'astolfo

Leroy E D'ASTOLFO

A method of monitoring an electrolytic cell including detecting information indicative of a thermite reaction, comparing the information indicative of a thermite reaction to a threshold, generating a thermite response signal according to the comparison, and reacting to the thermite response signal by adjusting the operation of the electrolytic cell.

Systems and methods for preventing thermite reactions in electrolytic cells

Methods and apparatus are disclosed for reducing sulfur impurities in aluminum electrolytic production cells in order to significantly increase current efficiency of the cells. An impurity reduction zone may be created in the bath of an inert anode cell by submerging a purifying electrode in the bath. In another embodiment, an oxygen barrier tube may be disposed in a portion of the bath. In a further embodiment, reductants such as aluminum, CO and/or COare added to the bath. In another embodiment, electrode current is interrupted or electrodes are removed from selected regions of the cell in order to allow gaseous impurities to escape from the bath. Sulfur impurity levels may also be reduced in inert anode cells by scrubbing bath emissions from the cell before they are reintroduced into the cell, and by controlling sulfur impurity contents of materials added to the cell.

Methods and apparatus for reducing sulfur impurities and improving current efficiencies of inert anode aluminum production cells

Insulation assemblies provide reduced heat loss from electrolytic metal production cells such as inert anode aluminum production cells. The insulation assemblies may be located at the end, side and/or center aisles of the cell, and may be supported by the anodes and deckplate of the cell. The assemblies reduce heat loss and bath vaporization losses, and permit stable operation of the inert anode cell.

Insulation assemblies for metal production cells

There is claimed a method for depositing fluid material from a linear nozzle in a substantially uniform manner across and along a surface. The method includes directing gaseous medium through said nozzle to provide a gaseous stream at the nozzle exit that entrains fluid material supplied to the nozzle, said gaseous stream being provided with a velocity profile across the nozzle width that compensates for the gaseous medium's tendency to assume an axisymmetric configuration after leaving the nozzle and before reaching the surface. There is also claimed a nozzle divided into respective side-by-side zones, or preferably chambers, through which a gaseous stream can be delivered in various velocity profiles across the width of said nozzle to compensate for the tendency of this gaseous medium to assume an axisymmetric configuration.

Linear nozzle with tailored gas plumes

A device for adjusting the distance between the anode and the cathode of an electrolytic cell having a compartment, at least one anode partially disposed in a molten metal producing salt bath and a layer of molten metal above a cathode. The device includes a displacement device partially disposed within the layer of molten metal, and an actuator to move the displacement device generally vertically.

Anode cathode distance adjustment device

A method and apparatus is provided for producing a porous metal. The method broadly includes the steps of first, providing a molten metal and second, introducing a gas into said molten metal. The method then includes spray casting the molten metal containing the gas onto a surface thereby producing the porous metal. The method further provides for controlling the amount and size of the porosity contained within the porous metal by controlling the parameters at which the gas is introduced into the molten metal, as well as, controlling the parameters surrounding the spray casting of the molten metal. Additionally, the method also provides for producing a porous metal having either an isolated or interconnected pore structure. The present invention also provides for a porous metal product, as well as a porous aluminum alloy product, made by the described method. The apparatus includes a means for containing the molten metal wherein the containing means has a discharge end. A means for introducing a gas into the containing means is also provided. The apparatus further includes molten metal discharge means positioned adjacent the discharge end of the containing means for atomizing the molten metal that is discharged from the discharge end into metal droplets, and a substrate on which the metal droplets are deposited in order to form the porous metal.

Method and apparatus for producing a porous metal via spray casting

Aluminum is produced by electrolytic reduction of alumina in a cell having a cathode, an inert anode and a molten salt bath containing metal fluorides and alumina. The inert anode preferably contains copper, silver and oxides of iron and nickel. Reducing the molten salt bath temperature to about 900-950.degree. C. lowers corrosion on the inert anode constituents.

Reduced temperature aluminum production in an electrolytic cell having

Linear nozzle with tailored gas plumes and method

A method of estimating and controlling the concentration of alumina in the bath of a Hall cell. The method includes the use of an estimator that employs two sets of equations, namely, a time update algorithm that contains a dynamic model of the alumina mass balance of the cell and provides estimates of alumina concentration, and a measurement algorithm that uses a process feedback variable from the cell to modify the alumina estimate. In addition, the method includes the use of one or more tuning parameters, such as state noise variance and measurement noise variance. The measurement noise variance is modified by the process noise variance in a manner that increases measurement noise variance for high values of process noise and decreases measurement noise variance for low values of process noise. In addition, one or more of the parameters of the model are modified by the feed history of the cell.

Estimation and control of alumina concentration in hall cells

An electrolytic cell is disclosed including means for holding a first electrode in position relative to a second electrode to form an inter-electrode zone of specified dimension for containing the electrolyte; the means for holding including float means adapted for supporting the first electrode essentially free from support by internal surfaces of the cell; and conductive means for electrically connecting one electrode to a separate liquid pad of higher conductivity than the electrolyte. An electrolytic method is disclosed including floating a first electrode essentially free from support by the internal surfaces of an electrolytic cell; arranging a second electrode spaced from the first electrode to form an inter-electrode zone for containing electrolyte; and connecting one electrode electrically with a separate liquid pad of higher conductivity than the electrolyte.

Apparatus and method for electrolysis and float

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Apollo, PA, United States of America

Robert L Kozarek