Abstract: A self-baking, Soderberg type carbon anode (40) for use in an aluminum electrolyses cell (1) to form product aluminum (11), where the anode (40) is consumable in molten electrolyte (12) in the cell, the anode having top, bottom and side surfaces and at least four layers of vertically disposed plate inserts (48) meltable in the molten electrolyte, the plate inserts (48) preferably made of aluminum and are capable of melting to create hollow vertical slots (52) at the bottom of the anode facilitating any gas bubbles (60) generated to channel to the side of the anode into the electrolyte (12).

Abstract: An electrolytic cell for the reduction of aluminum having a layer of interlocking cathode tiles positioned on a cathode block. Each tile includes a main body and a vertical restraining member to prevent movement of the tiles away from the cathode block during operation of the cell. The anode of the electrolytic cell may be positioned about 1 inch from the interlocking cathode tiles.

Abstract: An electrolytic cell for the reduction of aluminum having a layer of interlocking cathode tiles positioned on a cathode block. Each tile includes a main body and a vertical restraining member to prevent movement of the tiles away from the cathode block during operation of the cell. The anode of the electrolytic cell may be positioned about 1 inch from the interlocking cathode tiles.

Abstract: An electrolysis cell for producing metals by electrolytic reduction of molten baths which includes non-consumable inert anodes and refractory hard metal cathode elements. The cathode elements are replaceably mounted in the electrolysis cell and have inclined planar working surfaces which have grooves therein. A method for producing metals by use of the electrolysis cell includes utilizing the grooves to control the release of anode gases.

Abstract: The density of various refractory hard metal articles are controlled so that articles made from the refractory hard metals are able to float on the surface of molten aluminum. Floating such articles on aluminum has been found to both stabilize and protect the surface of molten aluminum. Floating cathodes for use in aluminum reduction cells is a particular application for the floating refractory hard metals.

Abstract: A composition and method is disclosed for the production of aluminum. A modified cryolite electrolyte bath is shown comprising, by weight: 0.5 to 1.5% LiF; 0 to 2% MgF.sub.2 ; 3 to 5% CaF.sub.2 and 8 to 12% excess AlF.sub.3. Also, Al.sub.2 O.sub.3 in an amount of 1 to 6%; preferably 1 to 3% by weight, is present in the bath.

Abstract: An improved alumina reduction cell is disclosed. The anode channels through which the anode pins are located include openings for the pins which locate the pins to conform more closely to the carbon bake-out zone and line of constant current distribution of the cell.

Abstract: The present invention describes a method for controlling alumina additions to reduction cells employing point feeders referred to as automatic feed. Automatic feed reduces the possibility of operating the cell at either too low or too high levels of alumina in the bath, and eliminates all anode effects except those desired, thus resulting in increased metal production.

Abstract: An improved alumina reduction cell is described in which the carbonaceous cathode includes refractory hard metal shapes projecting upwardly from the cell surface thereof, forming the true cathode surface, and permanently mounted and replaceable protective sleeves formed of inert refractory material surrounding the refractory hard metal shapes and protecting these shapes from accidental contact by the anode.

Abstract: A protective barrier for alumina reduction cell cathodes is disclosed. This barrier layer comprises a layer of borosilicate glass which may optionally be surrounded by layers of alumina silicate glass. The barrier prevents cryolitic salts from attacking the reduction cell insulation, preventing degradation of the insulation and improving cell efficiency.

Abstract: An improved alumina reduction cell is disclosed. Vapor barriers, formed from a castable refractory and a silicon carbide mortar protect the bottom and sidewall insulation material of the cell from attack by the corrosive materials contained within the cell.

Abstract: An alumina reduction cell is described in which a bed of holow refractory hard metal (RHM) shapes form a packed cathode bed above the carbonaceous cell cathode and within the molten aluminum pad. This packed bed permits free flow of the molten aluminum and reduces RHM material usage as compared to known packed bed cells.

Abstract: An improved probe for an alumina concentration meter is disclosed. The active anode and cathode surfaces of the probe lie on a common surface. A bath temperature measuring device is included within the probe.

Abstract: An improved alumina reduction cell is described in which the carbonaceous cathode includes refractory hard metal tiles projecting upwardly from the cell surface thereof, forming the true cathode surface and inert refractory sleeves imbedded in the cathode into which the refractory hard tiles are mounted.

Abstract: An improved alumina reduction cell is described in which the carbonaceous cathode includes refractory hard metal tiles projecting upwardly from the cell surface thereof, forming the true cathode surface, and inert refractory anode stops protecting the tiles from accidental contact by the anode. These anode stops protect the refractory hard metal shapes from breakage, increasing the useful life of the cell.

Abstract: A method of controlling alumina additions to aluminum reduction cells is disclosed. Changes in cell resistance with respect to time are measured and compared to historical values. Alumina is fed to the cell only under conditions which, based upon a statistically reliable sampling of resistance values, give a substantial reliability that an electrode upset will occur if an alumina feed is not performed.

Abstract: The disclosure pertains to alumina reduction cells which employ refractory materials to provide a molten-aluminum contacting surface for the cathode. Specifically, configurations and methods are described according to which refractory hard metal tiles are secured to a carbonaceous substrate to produce composites suitable for constructing a molten-aluminum contacting surface for the use stated. The tiles are wettable by molten aluminum and are inert chemically to the reduction cell electrolyte. Configurations for coupling and interlocking such tiles are also described. When the tiles are coupled or interlocked in the manner taught, it is possible to achieve a built-up refractory surface which remains chemically and mechanically stable in a reduction cell environment.