Abstract: A support structure for supporting continuous prebaked anodes in an aluminium smelting cell comprises a pair of side plates (3) and a pair of end plates (4) connected together to form an enclosed superstructure. The supporting structure includes at least one pair of spaced cross-plates (8, 9) that are configured to provide wedging surfaces which act to support an anode (14) therebetween. Electrical current is fed to the anodes via the cross-plates. Respective pairs of cross-plates supporting adjacent anodes may be spaced to define heat exchange passages which can be used to control the temperature of the support structure. A method for operating an aluminium smelting cell at variable amperage by positive and controlled extraction of heat from the cell is also described.

Abstract: Aluminum-base alloys in a peak-aged condition and magnesium-base alloys in the form of cast products and wrought products capable of having improved combinations of yield strength and fracture toughness are disclosed. The aluminum-base alloy products are comprised of 0.5 to 4.5 wt %. lithium, about 0.01 to 1 ppm Na, about 0.01 to 1 ppm K, less than 0.1 ppm Rb, less than 0.1 ppm Cs, and the remainder comprising aluminum. Aluminum-base alloy products in a peak-aged condition have: (i) a grain boundary region substantially free of liquid phase eutectics comprised of Na and K that form embrittlement phases at room temperature; and (ii) an increase in fracture toughness compared to an aluminum-lithium alloy having greater than 5 ppm aggregate alkali metal.

Abstract: A method of operating an aluminum smelting cell during the start-up phase of the cell is described. The method includes forming a layer of boron oxide on the exposed surface of the cathode of the cell, forming a layer of aluminum on the boron oxide layer, and starting the cell. This melts the boron oxide layer to form a barrier impervious to oxygen at a temperature from about 400.degree. C. to about 650.degree. C., and the aluminum layer is melted to form a barrier to oxygen at temperature above about 600.degree. C. to about 1000.degree. C. to reduce the development of oxidation products.

Abstract: Process for the recovery of aluminum and fluoride values from spent pot lining materials comprising the steps of calcining spent pot lining material to produce an ash having environmentally acceptable levels of cyanide contamination, subjecting the ash to a leaching step in a solution containing a mineral acid and a corresponding aluminum salt in such proportions as to dissolve the aluminum and fluoride values, and subjecting the leached liquid to thermal hydrolysis to cause precipitation of an aluminum fluoride product.

Abstract: An aluminium smelting cell comprising a floor defining a cathode surface (4) which is substantially horizontal in the longitudinal direction of an overlying anode (1), shaped structures (2,3) projecting from the cathode surface (4) and having exposed surfaces of aluminium wetted material, the shaped structures being positioned to cause preferential contouring of the anode (1), particularly at its longitudinal edges (5,6) to allow for improved bubble release and to minimize cell resistivity.

Abstract: The toughness of Al-Li, Al-Mg and Mg-Li alloys is increased by a melting and refining process designed to reduce the concentration of alkali metal impurities below specified levels. The hydrogen and chlorine gas constituents are also significantly reduced.

Abstract: The mould assembly comprises mould segments of generally non-thermally conductive material which define a mould cavity for receiving liquid metal through at least one in-gate. A thermal extraction member of a high thermally conductive material contacts a portion of the mould cavity through which heat can be extracted rapidly to establish positive thermal gradients in the casting and thereby promote directional solidification. The mould assembly is also provided with a seal to selectively isolate the mould assembly from the liquid metal source to allow the mould assembly to be removed from the casting station to the cooling station before any substantial solidification has occurred, providing a more efficient use of the casting station.

Abstract: A calcined microsphere of ultrafine bauxite particles having a mean particle size in the range 0.01 to 0.3 micrometers, said microsphere having a particle size less than 30 micrometers and being characterized by a substantially solid form having a pycnometric density substantially falling in the range 3.2-3.0 g/cm.sup.3, a BET surface area substantially falling in the range 0.05 to 0.5 m.sup.2 /g and a crystal grain size less than 4 micrometers, the surface chemistry of the microsphere being modified to enhance the wettability of the microsphere and to improve its ability to bond strongly with matrix materials in use.

Abstract: A calcined microsphere of ultrafine bauxite particles having a mean particle size in the range 0.01 to 0.3 micrometers, said microsphere having a particle size less than 30 micrometers and being characterized by a substantially solid form having a pycnometric density substantially falling in the range 3.2-3.9 g/cm.sup.3, a BET surface area substantially falling in the range 0.05 to 0.5 m.sup.2 /g and a crystal grain size less than 4 micrometers, the surface chemistry of the microsphere being modified to enhance the wettability of the microsphere and to improve its ability to bond strongly with matrix materials in use.

Abstract: A superior proppant having very high permeability at formation pressures up to 20,000 psi, very high compressive strength, low specific gravity, and good acid resistance, is produced by a process comprising: (a) separating a fine fraction from a naturally occurring bauxite containing same; (b) pelletizing the separated fine fraction in the presence of water; (c) treating the pellets produced in step (b) to remove water therefrom; and (d) sintering the product of step (c) to produce a low density material suitable for use as a proppant.