Abstract: The invention relates to a multi-polar reduction cell for production of a light metal by electrolysis. The cell has an anode, a cathode, and at least one current-conducting multi-polar electrode interposed between the anode and the cathode. The cell has a molten electrolyte containing a metal salt to be electrolyzed held within the cell and preferably has means to maintain an upper surface of the electrolyte at a predetermined level within the cell. The level is preferably maintained above the upper end of the multi-polar electrode(s), at least in use of the cell. The multi-polar electrode has an electrically insulating surface at its upper end that minimizes or eliminates by-pass current between the anode and cathode when the cell is operated. The invention also relates to the method of minimizing or eliminating the by-pass current.

Abstract: An electrolysis cell (10) for producing a molten metal having a density less than a density of a molten electrolyte used for producing the metal in the cell. The cell includes a section (14) for the electrolysis of a salt of the the metal contained in a molten electrolyte to form droplets of the metal in molten form contained in the electroylte; electrodes (18) within the electrolysis section for effecting the electrolysis; a metal recovery section (15) for separation of the metal from the electrolyte to form a molten metal layer, having an upper suface, floating on an upper surface of the molten electrolyte; a tapping device for periodically removing molten metal from the cell; and a reservoir (25) for withdrawal and temporary holding of molten metal separated from the electrolyte in the metal recovery section. The reservoir has a means to remove liquid from the reservoir without permanently removing the liquid from the cell.

Abstract: An electrolysis cell for recovery of metals that are lighter than the electrolyte used in the cell. The cell makes use of multiple electrode assemblies, and each assembly is provided with an individual hood at the top forming a gas collection chamber. The hood of each assembly collects gas generated by the assembly and isolates the gas thus generated from gas generated by other assemblies and from metal collecting in the cell outside the hoods. The invention also relates to an integrated unit made up of an electrode assembly and an associated hood for use in a cell of the above kind, and a method of recovering metal by operating a cell of the above kind.

Abstract: The present invention relates to self-supporting ceramics or ceramic composite bodies which include a polycrystalline ceramic material comprising the oxidation reaction product of a silicon parent metal with a nitrogenous oxidant, including a nitrogenous vapor-phase oxidant, and optionally, one or more metallic constituents dispersed throughout the polycrystalline ceramic material. A barrier means comprising, for example, at least one of titanium nitride, zirconium nitride, aluminum nitride and boron nitride or a barrier means that has undergone chemical changes or alterations may be removably attached to the self-supporting ceramics or ceramic composite bodies of the present invention.

Abstract: In the present invention, there is provided a method for producing a self-supporting ceramic or ceramic composite body by the oxidation of a parent metal to form a polycrystalline ceramic material comprising the oxidation reaction product of said parent metal with an oxidant, including a vapor-phase oxidant, and optionally one or more metallic constituents dispersed throughout the polycrystalline ceramic material. The method comprises the steps of providing at least a portion of said parent metal with a barrier means at least partially spaced from said parent metal for establishing at least one surface of the ceramic body, and heating said parent metal to a temperature above its melting point but below the melting point of the oxidation reaction product to form a body of molten metal. At that temperature, the molten metal is reacted with the oxidant, thus forming the oxidation reaction product.

Abstract: A method of producing a composite comprising a self-supporting polycrystalline material obtained by oxidation reaction of a molten parent metal with a vapor-phase oxidant comprising infiltrating a filler exhibiting inter-particle pore volume with a parent metal under conditions which control the respective rates of said metal infiltration and said oxidation reaction.