Abstract: A high strength low density opaque shaped aluminum borate product is disclosed characterized by an MOR of at least 45,000 psi and a density of approximately 2.9 g/cm.sup.3. The shaped aluminum borate may be formed by reacting an aluminum oxide with a boron oxide at a temperature of at least 800.degree. C., grinding the reaction product, pressing the resulting particulate into a shaped form and sintering the shaped particulate at a temperature of from 800.degree. to 1400.degree. C. while maintaining the shaped particulate under a pressure of 2500 to 3500 psi.

Abstract: Provided is a sintering air suitable for use in forming aluminum borate into a ceramic product, the sintering aid comprised of an aluminum borate compound having a melting point lower than the sintering temperature of aluminum borate.

Abstract: An improved process is disclosed for carbothermically producing an alkaline earth metal aluminide from an aluminum-bearing material which, in one aspect comprises forming a mixture of a carbonaceous reducing agent and a slag comprising the aluminum-bearing material, the alkaline earth metal compound; forming, at a first temperature, an alloy containing impurities in the slag; removing the alloy containing the impurities from the slag; and then heating the slag to a higher temperature to form the alkaline earth metal aluminide. The alkaline earth metal compound used in the process may comprise calcium carbide. Alternatively, both the alkaline earth metal compound and the aluminum-bearing material may be obtained using a calcium aluminate slag such as a byproduct from the steel industry. The calcium aluminate slag is purified in a preliminary step to remove silicon by alloying it with iron and then removing a ferrosilicon alloy formed in this step.

Abstract: A porous refractory hard metal composition is disclosed which is formed by removing the metal compound from a substantially interwoven matrix composition comprising one or more refractory hard metals and a metal compound. The interwoven matrix composition, in a preferred embodiment, may comprise Al.sub.2 O.sub.3 and TiB.sub.2, ZrB.sub.2, or a mixture of the two refractory hard metals.

Abstract: A composite is disclosed which comprises one or more interwoven matrix compositions, each containing a refractory hard metal; and from 0 to 80 wt. % of at least one previously formed refractory hard metal. In one embodiment, the composite may comprise two interwoven matrix compositions which were formed by mixing the reactants together prior to forming the interwoven matrix compositions whereby the exothermic heat of react may be controlled by selection of proper ratios of reactants. In another embodiments, previously formed refractory hard metals or previously formed interwoven matrix compositions may be used in the formation of the composite to control the exothermic heat liberated during formation of the interwoven matrix composition or for other purposes such as densification of the composite.

Abstract: A densified composite is disclosed which comprises one or more substantially interwoven matrix compositions, which have been densified either during formation of the interwoven matrix composition to provide a composite having a low porosity and a density of at least 75% of the theoretical density. The interwoven matrix composition may be densified during formation either by the addition to the reactants of a densification agent or by maintaining sufficient pressure on the reactants during the formation of the interwoven matrix. The densification of the interwoven matrix may be carried out after formation of the interwoven matrix composition either by heating the composition to a sufficient temperature for a sufficient time period to achieve the desired densification or by immersing the interwoven matrix composition in a molten metal or a molten metal salt to impregnate the interwoven matrix composition to achieve the desired densification.

Abstract: The invention discloses an improvement in a process wherein a first reactant comprising one or more metals or metal compounds exothermically reacts with a second reactant comprising at least one or more metals or metal compounds in the presence of a third reactant to form an interwoven matrix of a conductive material and an insulating material. The improvement comprises locally applying, to a selected region of a shaped body formed from a mixture of the reactants, sufficient energy to initiate an exothermic reaction which then propagates throughout the remainder of the body to form the interwoven matrix.

Abstract: An electrolytic process comprising evolving oxygen on an anode in a molten salt, the anode comprising an alloy comprising a first metal and a second metal, both metals forming oxides, the oxide of the first metal being more resistant than the second metal to attack by the molten salt, the oxide of the second metal being more resistant than the first metal to the diffusion of oxygen. The electrode may also be formed of CuAlO.sub.2 and/or Cu.sub.2 O.

Abstract: An improved inert electrode composition is suitable for use as an inert electrode in the production of metals such as aluminum by the electrolytic reduction of metal oxide or metal salt dissolved in a molten salt bath. The composition comprises one or more metals or metal alloys and metal compounds which may include oxides of the metals comprising the alloy. The alloy and metal compounds are interwoven in a network which provides improved electrical conductivity and mechanical strength while preserving the level of chemical inertness necessary for such an electrode to function satisfactorily.

Abstract: An improved inert electrode composition is suitable for use as an inert electrode in the production of metals such as aluminum by the electrolytic reduction of metal oxide or metal salt dissolved in a molten salt bath. The composition comprises one or more metal alloys and metal compounds which may include oxides of the metals comprising the alloy. The alloy and metal compounds are interwoven in a network which provides improved electrical conductivity and mechanical strength while preserving the level of chemical inertness necessary for such an electrode to function satisfactorily. The electrode composition further includes a metal compound dopant which will aid in controlling the thickness of a protective oxide layer on at least the bottom portion of an electrode made therefrom during use.

Abstract: An inert electrode connection is disclosed wherein a layer of inert electrode material is bonded to a layer of conductive material by providing at least one intermediate layer of material therebetween comprising a predetermined ratio of inert material to conductive material. In a preferred embodiment, the connection is formed by placing in a die a layer of powdered inert material, at least one layer of a mixture of powdered inert material and conductive material, and a layer of powdered conductive material. The connection is then formed by pressing the material at 15,000-20,000 psi to form a powder compact and then densifying the powder compact in an inert or reducing atmosphere at a temperature of 1200.degree.-1500.degree. C.

Abstract: An inert type electrode composition suitable for use in the electrolytic production of metals such as aluminum is disclosed. The aluminum is produced from an aluminum-containing material dissolved in a molten salt. The electrode composition is fabricated from at least two metals or metal compounds combined to provide a combination metal compound containing at least one of the group consisting of oxide, fluoride, nitride, sulfide, carbide or boride, the combination metal compound defined by the formula: ##EQU1## Z is a number in the range of 1.0 to 2.2; K is a number in the range of 2.0 to 4.4; M.sub.i is at least one metal having a valence of 1, 2, 3, 4 or 5 and is the same metal or metals when M.sub.i is used in the composition; M.sub.j is a metal having a valence of 2, 3 or 4; X.sub.r is at least one of the elements from the group consisting of O, F, N, S, C and B; m, p and n are the number components which comprise M.sub.i, M.sub.j and X.sub.r ; F.sub.M.sbsb.i, F'.sub.M.sbsb.j, F'.sub.M.sbsb.i or F.sub.x.

Abstract: A nonconsumable electrode assembly suitable for use in the production of metal by electrolytic reduction of a metal compound dissolved in a molten salt, the assembly comprising a metal conductor and a ceramic electrode body connected by a friction weld between a portion of the body having a level of free metal or metal alloy sufficient to effect such a friction weld and a portion of the metal conductor.

Abstract: A nonconsumable electrode assembly suitable for use in the production of metal by electrolytic reduction of a metal compound dissolved in a molten salt, the assembly comprising a metal conductor attached to a ceramic electrode body by a metal bond on a portion of the body having a level of free metal or metal alloy sufficient to effect a metal bond.

Abstract: An inert electrode composition suitable for use in the production of metal by the electrolytic reduction of a metal compound dissolved in a molten salt is disclosed. The composition is formulated from a body containing metals and metal compounds designed to undergo displacement reaction upon sintering to form an interwoven network. The body also contains at least one non-reactive material, e.g., metal compound or metal. The interwoven network contains at least a metal compound and a second material, both resulting from the displacement reaction, the second material selected from the group consisting of free metal and a metal alloy or a mixture thereof.

Abstract: An improved inert electrode composition is suitable for use as an inert electrode in the production of metals such as aluminum by the electrolytic reduction of metal oxide or metal salt dissolved in a molten salt bath. The composition comprises one or more metals or metal alloys and metal compounds which may include oxides of the metals comprising the alloy. The alloy and metal compounds are interwoven in a network which provides improved electrical conductivity and mechanical strength while preserving the level of chemical inertness necessary for such an electrode to function satisfactorily.

Abstract: Disclosed is a composition suitable for fabricating into an inert electrode for use in the electrolytic production of metal from a metal compound dissolved in a molten salt. The electrode comprises at least two metal oxides combined to provide a combination metal oxide consisting essentially of a composition defined by the formula M(M'.sub.y M.sub.1-y).sub.z O.sub.K where y is a number less than one and greater than 0 and M is a metal having a valence selected from the group consisting of 2, 3, 4 and 5 and M' is a metal having a valence selected from the group consisting of 2, 3, 4 and 5, z is a number selected from the group consisting of 2, 3 and 4 and K is a number in the range of 2 to 4.4, the electrode being highly conductive and being substantially inert with respect to the molten salt.

Abstract: Disclosed is an inert electrode composition suitable for use in the electrolytic production of metal from a metal compound dissolved in a molten salt. The electrode comprises a ceramic oxide composition and at least one metal powder dispersed through the ceramic oxide composition for purposes of increasing its conductivity, the metal powder selected from the group consisting of Ni, Cu, Co, Pt, Rh, In and Ir.

Abstract: An inert type electrode composition suitable for use in the electrolytic production of metals such as aluminum is disclosed. The aluminum is produced from an aluminum-containing material dissolved in a molten salt. The electrode composition is fabricated from at least two metals or metal compounds combined to provide a combination metal compound containing at least one of the group consisting of oxide, fluoride, nitride, sulfide, carbide or boride, the combination metal compound defined by the formula: ##EQU1## Z is a number in the range of 1.0 to 2.2; K is a number in the range of 2.0 to 4.4; M.sub.j is at least one metal having a valence of 1, 2, 3, 4 or 5 and is the same metal or metals when M.sub.i is used in the composition; M.sub.j is a metal having a valence of 2, 3 or 4; X.sub.r is at least one of the elements from the group consisting of O, F, N, S, C and B; m, p and n are the number components which comprise M.sub.i, M.sub.j and X.sub.r ; F.sub.M.sbsb.i, F'.sub.M.sbsb.j, F'.sub.M.sbsb.i or F.sub.x.