Abstract: The invention relates to a metal boride precursor mixture comprising a metal oxide and a boric oxide combined in such a manner so as to produce intimately linked clusters wherein the boric oxide is found within the metal oxide. Furthermore, the invention discloses a carbon composite material made with the metal boride precursor mixture and a carbonaceous component. Finally, the invention also teaches the process for preparing the metal boride precursor mixture comprising steps of providing a metal oxide and a boron oxide, mechanically mixing the metal oxide and the boron oxide at a temperature that liquefies the boron oxide and may impregnate the metal oxide to produce an intimately linked cluster of metal oxide and boric oxide.

Abstract: A refractory coating is provided for a component of an electrolytic cell for the production of aluminum in which an aqueous slurry is prepared comprising particulate refractory material, e.g. TiB2, dispersed in an aluminum oxalate complex. The slurry is applied as a coating to the surface of the component, e.g. a cathode block, and dried to form a hard refractory surface on the component. The aluminum oxalate complex may be formed in situ during production of the slurry by mixing together oxalic acid and electrostatic precipitator dust comprising aluminum oxide. After the refractory coated component is immersed in a high temperature cryolite bath of an aluminum electrolysis cell, the aluminum oxalate complex is converted to alumina which bonds the refractory particles to the surface of the cell component.

Abstract: The invention relates to a system for cooling and reducing fluoride emissions from a hot, spent anode butt removed from an electrolysis cell. The system comprises an elongated fluidised bed cooling chamber comprising particles of alumina and conveyor means for transporting a hot, spent anode butt through the fluidised bed. A lower air distributor is provided for injecting fluidising air into the chamber to create the fluidised bed and an upper air distributor is provided which is adapted to direct fluidised particles into contact with the top surface of the hot anode butt, whereby the fluidised bed surrounds the hot anode butt and serves to simultaneously uniformly cool the hot anode butt and significantly reduce fluoride emissions from the hot anode butt.

Abstract: A method and apparatus for treating non-ferrous metal drosses in order to recover the free metal contained therein. The dross is heated by a plasma torch in a rotary furnace, preferably to a temperature above 800.degree. C. The plasma heating and rotary motion make it possible to recover metal from the dross without employing the conventional salt bath. This means that the gases exiting the furnace can be treated more easily to remove pollutants and the solid residues can be discarded without risk of causing environmental pollution. By controlling the speed of rotation of the furnace, large dross lumps can be accommodated and so the conventional grinding and screening procedure of the dross can advantageously be eliminated.

Abstract: A method and apparatus for treating non-ferrous metal drosses in order to recover the free metal contained therein. The dross is heated by a plasma torch in a rotary furnace, preferably to a temperature above 800.degree. C. The plasma heating and rotary motion make it possible to recover metal from the dross without employing the conventional salt bath. This means that the gases exiting the furnace can be treated more easily to remove pollutants and the soild residues can be discarded without risk of causing environmental pollution. By controlling the speed of rotation of the furnace, large dross lumps can be accommodated and so the conventional grinding and screening procedure of the dross can advantageously be eliminated.

Abstract: A method and apparatus for treating non-ferrous metal drosses in order to recover the free metal contained therein. The dross is heated by a plasma torch in a rotary furnace, preferably to a temperature above 800.degree. C. The plasma heating and rotary motion make it possible to recover metal from the dross without employing the conventional salt bath. This means that the gases exiting the furnace can be treated more easily to remove pollutants and the solid residues can be discarded without risk of causing environmental pollution. By controlling the speed of rotation of the furnace, large dross lumps can be accommodated and so the conventional grinding and screening procedure of the dross can advantageously be eliminated.

Abstract: A method and apparatus for treating non-ferrous metal drosses in order to recover the free metal contained therein. The dross is heated by a plasma torch in a rotary furnace, preferably to a temperature above 800.degree. C. The plasma heating and rotary motion make it possible to recover metal from the dross without employing the conventional salt bath. This means that the gases exiting the furnance can be treated more easily to remove pollutants and the solid residues can be discarded without risk of causing environmental pollution. By controlling the speed of rotation of the furnace, large dross lumps can be accommodated and so the conventional grinding and screening procedure of the dross can advantageously be eliminated.

Abstract: A process for forming carbides of silicon or metals in fine powder or whisker form. The process comprises forming a substantially uniform and non-agglomerated dispersion of a microfine powder of an oxide of silicon or a carbide-forming metal within a matrix of a polymer, carbonizing the oxide-containing polymer in an inert atmosphere and heating the carbonized product at high temperature to cause the oxide to react with carbon to form a carbide. The polymer must have a molecular weight of at least 10,000, a high carbon yield of at least 30% by weight, and a chemical structure which is infusible or capable of being rendered infusible. The preferred polymers are polyacrylonitrile, cellulose and polyvinyl alcohol, but other polymers with similar characteristics can be employed. The process is relatively inexpensive and gives an extremely finely divided product of high purity.