Electrochemical Technology Corp.

Brooks Rand, Ltd.

Other

Northwest Aluminum Technologies

Rohrback Technology Corporation

Theodore R Beck

Richard J Brooks

Craig W Brown

Robert T Ruggeri

Patrick B Frizzle

Low temperature cell for electrolytic production of aluminum.

Aluminum production cell

A method of producing aluminum in an electrolytic cell containing alumina dissolved in an electrolyte. The method comprises the steps of providing a molten salt electrolyte in an electrolytic cell having an anodic liner for containing the electrolyte, the liner having an anodic bottom and walls including at least one end wall extending upwardly from the anodic bottom, the anodic liner being substantially inert with respect to the molten electrolyte. A plurality of non-consumable anodes is provided and disposed vertically in the electrolyte. A plurality of cathodes is disposed vertically in the electrolyte in alternating relationship with the anodes. The anodes are electrically connected to the anodic liner. An electric current is passed through the anodic liner to the anodes, through the electrolyte to the cathodes, and aluminum is deposited on said cathodes. Oxygen bubbles are generated at the anodes and the anodic liner, the bubbles stirring the electrolyte. Molten aluminum is collected from the cathodes into a tubular member positioned underneath the cathodes. The tubular member is in liquid communication with each cathode to collect the molten aluminum therefrom while excluding electrolyte. Molten aluminum is delivered through the tubular member to a molten aluminum reservoir located substantially opposite the anodes and cathodes. The molten aluminum is collected from the cathodes and delivered to the reservoir while avoiding contact of the molten aluminum with the anodic bottom.

Aluminum low temperature smelting cell metal collection

Cathode connector means for low temperature aluminum smelting cell for connecting titanium diboride cathode or the like to bus bars.

Cathode connector for aluminum low temperature smelting cell

An oxidation resistant, non-consumable anode, for use in the electrolytic reduction of alumina to aluminum, has a composition comprising copper, nickel and iron. The anode is part of an electrolytic reduction cell comprising a vessel having an interior lined with metal which has the same composition as the anode. The electrolyte is preferably composed of a eutectic of AlF.sub.3 and either (a) NaF or (b) primarily NaF with some of the NaF replaced by an equivalent molar amount of KF or KF and LiF.

Non-consumable anode and lining for aluminum electrolytic reduction cell

Finely divided particles of alumina are electrolytically reduced to aluminum in an electrolytic reduction vessel having a plurality of vertically disposed, non-consumable anodes and a plurality of vertically disposed, dimensionally stable cathodes in closely spaced, alternating arrangement with the anodes. A horizontally disposed, gas bubble generator is located at the vessel bottom, underlying the cathodes and the spaces between each pair of adjacent electrodes. The vessel contains a molten electrolyte bath composed of (1) NaF+Alf.sub.3 eutectic, (2) KF+AlF.sub.3 eutectic and (3) LiF. The alumina particles are maintained in suspension in the molten electrolyte bath by rising gas bubbles generated at the anodes and at the gas bubble generator during the reduction process.

Electrolytic reduction of alumina

Alumina is reduced to molten aluminum in an electrolytic cell containing a molten electrolyte bath composed of halide salts and having a density less than alumina and aluminum and a melting point less than aluminum. The cell comprises a plurality of vertically disposed, spaced-apart, non-consumable, dimensionally stable anodes and cathodes. Alumina particles are dispersed in the bath to form a slurry. Current is passed between the electrodes, and oxygen bubbles form at the anodes, and molten aluminum droplets form at the cathodes. The oxygen bubbles agitate the bath and enhance dissolution of the alumina adjacent the anodes and inhibit the alumina particles from settling at the bottom of the bath. The molten aluminum droplets flow downwardly along the cathodes and accumulate at the bottom of the bath.

An electrochemical system for determining the concentration of a bacteria or other enzymatic agents in a liquid sample (14). The system includes mounting means (20) for mounting an electrode assembly (16), and drive means for rotating the electrode assembly. The electrode assembly comprises a shaft (22) having a longitudinal axis and a longitudinally extending interior passage (40), an electrode (24) mounted at the lower end of the shaft, and sparging means (26) extending laterally from the lower end of the shaft. The sparging means is in communication with passage (40) through openings (50). The electrode and sparging means are mounted such that they are immersed in the sample when the shaft is mounted by the mounting means. The electrode assembly further comprises conductor means (44, 46) for electrically connecting the electrode to the electrochemical system. The electrode assembly is rotated during measurement of the concentration of the enzymatic agent. Prior to such measurement, dissolved oxygen may be rapidly removed from the sample by rotating the electrode assembly and introducing an inert gas into the passage, such that the inert gas passes from the rotating sparging means into the sample.

Electrochemical system with rotating electrode/sparger assembly

A cell for the electrolytic reduction of alumina to aluminum comprises an electrolyte bath composed of halide salts having a density greater than aluminum but less than alumina. A non-consumable anode is located at the bottom of the bath, and a dimensionally stable cathode coated with titanium diboride is spaced above the anode and totally immersed in the bath. Particles of alumina are introduced into the bath where the alumina dissolves and forms ions of aluminum and oxygen. The oxygen ions are converted at the anode to gaseous oxygen which bubbles upwardly through the bath, agitating the bath. As a result, the bath is substantially saturated with dissolved alumina in the region of the anode, and the build-up of a layer of undissolved alumina on the anode is prevented. The aluminum ions are converted to metallic aluminum at the cathodes, and molten aluminum accumulates as a pool atop the bath above the cathodes. In one embodiment, the upwardly rising gaseous oxygen bubbles are prevented from mixing with the pool of molten aluminum.

Method and apparatus for electrolytic reduction of alumina

A shaft rotatably mounted within a housing. The shaft extends through a pair of annular seal elements one of which is mounted on the shaft for rotation therewith. The other seal element is associated with the housing and is stationary relative to the shaft. The seal elements have respective mating surfaces which rub together during rotation of the shaft. One seal element is composed of relatively hard material, and the other seal element is composed of relatively soft material so that the mating surface of the latter is conformed to the mating surface of the former when the two mating surfaces are initially rubbed together. There is a minute gap between the mating surfaces, and this gap contains a film of liquid which acts as a lubricant. Both seal elements are composed of a material which will not support an electrochemical reaction, e.g., an electrically insulating material, to prevent electrokinetic corrosion of the mating surfaces when the film therebetween is an electrolytic liquid.

Shaft seal resistant to electrokinetic corrosion

A prosthesis electrode for electrically stimulating body tissue. The electrode has a metal tip covered by a non-metallic coating composed of a compound of the metal in the tip. Covering the non-metallic coating is an ion-conducting membrane which prevents the metal tip and the non-metallic coating from contacting the body tissue. The membrane comprises a specific ion-conducting inner membrane layer which prevents transference to the body tissue of ions in the coating which enter into undesirable reactions with the body tissue. On the outside of the inner membrane is a non-specific ion-conducting outer membrane layer which is non-toxic to body tissue and which prevents changes in salt concentration in the body tissue adjacent the electrode during a biphasic pulse of the electrode.

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Seattle, WA, United States of America

Theodore R Beck