Abstract: A positioning device is disclosed comprising a jack screw having a stationary guide housing, an externally helically threaded shaft through the housing and a retainer threadably engaged onto the shaft, and a rotatable ratchet having a head mounted on a top portion of the shaft. The positioning device further comprises at least one fluid cylinder and a piston fitting inside a mating chamber in the cylinder, a piston rod extending from the piston and connected to the ratchet and means for reciprocally driving the piston in the chamber. Each stroke of the piston and attached piston rod displaces the ratchet arm rotating the ratchet head and the shaft connected thereto, thereby displacing the retainer along the shaft.

Abstract: Method of operating (and apparatus including) an electrolytic cell for the production of aluminum, in which provision is made for monitoring the cell resistance, producing feed control signals responsive to cell resistance changes, and regulating the feeding of alumina into the bath in accordance with such signals.

Abstract: The invention relates to the feeding of finely divided particulate matter in a fluidized state from a source to a plurality of discharge points wherein discrete quantities of particulate matter are discharged by suitable feeding devices. In more detail, the invention comprises a primary air activated gravity conveyor and a plurality of secondary air activated gravity conveyors leading away from the primary conveyor to direct particulate matter to the feeding units associated with each secondary conveyor. The primary and secondary conveyors are maintained full of fluidized particulate matter at all times.

Abstract: The invention relates to a process and an apparatus for collecting the fumes given off during the production of aluminium in an electrolysis cell with a continuous anode.In the process, the surface of the elecytrolysis bath is closed, on the one hand along the long sides of the cell, by a longitudinal panel which is applied in fluid-tight manner to the anode tube, leaving an air intake free at its base, and on the other hand along the short sides of the cell by a fixed hooding closed laterally by the longitudinal panel.The invention is applicable to cells for the igneous electrolysis of alumina comprising a continuous anode.

Abstract: In a process for producing aluminum, which process conventionally includes electrolytically decomposing alumina to aluminum metal in a molten electrolyte bath between a carbon anode and a cathodic interface formed between a molten aluminum metal pad and sides electrolyte bath, the bathA. being predominantly NaF and AlF.sub.3,b. containing CaF.sub.2 and Al.sub.2 O.sub.3, andC. being covered by a frozen crust,The improvement including providing in the bath 5 to 10 weight-% LiF, while maintaining in the bath a weight ratio NaF to AlF.sub.3 of 1.04 to 1.15, and while maintaining a frozen layer bounding the sizes of the aluminum metal pad and bath.

Abstract: A carriage with a crucible for tapping molten metal from aluminum electrolyzers and the like includes a movable tapping tube adapted to be inserted downwardly into the metal melt from which tapping shall take place, ejector means for sucking molten metal through the tapping tube, and a discharge tube for delivering collected metal from the crucible. There may also be provided compressed air means for discharging collected metal through the discharge tube. The tapping tube is mounted pivotably substantially in an inclined plane parallel to the longitudinal axis of the carriage and extending downwardly and outwardly to the side of the carriage from a tapping opening in a tapping head located on the crucible, to which tapping head the upper end of the tapping tube is coupled in the tapping position.

Abstract: A readily oxidizable metal such as lithium formed along a cathode is collected in an electrolytic tank within a collecting chamber, the level of electrolyte is caused to rise to a predetermined top level at which the lithium leaves the collecting chamber and overflows into a transfer compartment, the level of electrolyte is lowered to a predetermined bottom level at which the poured-off lithium leaves the transfer compartment and passes to the discharge compartment, the level of electrolyte is raised to the top level in order to ensure overflow into a discharge tube. A stream of inert gas is passed into the discharge compartment and the lithium is transferred to a chamber for treatment in an inert atmosphere and conversion to ingots in the pure state.

Abstract: In an aluminum electrolysis furnace provided with an anode structure located above a cathode forming part of the bottom of the furnace chamber, whereby direct electric current between the anode and the cathode causes aluminum to be obtained from aluminum oxide, a portion of the surface of the cathode facing the anode is covered with an electrically nonconductive material to create an electric current distribution which tends to improve the heat distribution within the furnace chamber.

Abstract: Process for operating a cell for the electrolysis of a molten charge, in particular aluminum oxide, with one or more anodes, the working surfaces of which are of ceramic oxide material, and anode for carrying out the process.In the process a current density above a minimum value is maintained over the whole anode surface which comes into contact with the molten electrolyte. An anode for carrying out the process is provided at least in the region of the interface between electrolyte and surrounding atmosphere, the three phase zone, with a protective ring of electrically insulating material which is resistant to attack by the electrolyte. The anode may be fitted with a current distributor for attaining a better current distribution.

Abstract: An interior lining system for aluminum reduction cell anodes comprising strips of flexible sheet material supplied in roll form with adjacent strips disposed in laterally overlapping relationship between the anode and its casing.

Abstract: An electrolyzer for the manufacture of magnesium, which has at least one electrolysis compartment with a cathode in the form of a frame whose members make up a closed loop around an anode in the electrolysis compartment.The present invention relates to electrolyzers for the manufacture of magnesium.Known in the art are electrolyzers for the manufacture of magnesium, comprising two compartments for the electrolysis of magnesium chloride, between which is placed a compartment to collect metallic magnesium. Between the electrolysis compartments and the collecting compartment there are partitions fabricated from refractory materials. The electrolysis compartments hold electrodes. Cathodes are provided in the form of plates with rods passing through a lining to a busbar.However the above-mentioned electrolyzer has a low production rate.