Abstract: A process for converting silicon intermediates to high purity silicon by an arc heater characterized by the steps of preliminarily reacting gaseous silicon intermediate, such as a silicon halide, with a metal reductant, such as sodium, to form preliminary reaction products including small solid silicon particles and droplets of salt of the metal reductant, at temperatures below the boiling point of the metal reductant, subsequently heating the reaction products to temperatures above said boiling point in an arc heater chamber to convert the reaction products to droplets of silicon to merge and form larger silicon droplets, and thereafter separating the mixture of silicon droplets and salt vapor.

Abstract: Apparatus for melting metal chips comprising a preheating chamber, a prereducing chamber, and a melting chamber, the latter comprising a metallurgical vessel having a refractory wall with arc heater means mounted on the wall and extending therethrough which arc heater means provides an electric plasma arc which extends through an opening in the refractory wall, and the arc heater means comprising a downstream cylindrical electrode extending through the refractory wall for improved heating efficiency.

Abstract: A method for melting machine chips characterized by a preheating zone, a prereducer zone, and a melting zone the latter of which is heated by an arc heater through which a reducing inert gas is introduced into the communicating zones, whereby metal chips entering the preheating zone move through the subsequent zones in counterflow to the reducing gas flow.

Abstract: This is a method of producing silicon nitride in a plasma arc furnace utilizing silicon metal or silicon dioxide as a starting material. When silicon metal is used it is reacted directly with a nitrogen bearing gas to produce silicon nitride. When silicon dioxide is used a two-step process is performed wherein the silicon dioxide is first reacted with hydrogen to produce silicon monoxide gas and water and thereafter the silicon monoxide gas is reacted with hydrogen and nitrogen to produce silicon nitride and water.

Abstract: A method and apparatus for melting metal chips characterized by a preheating zone, a pre-reducer zone, and a melting zone in conjunction with an arc heater through which a reducing or inert gas atmosphere is introduced into the communicating zones, whereby metal chips entering the preheating zone move through the preheating, pre-reducing and melting zones in counterflow to the reducing or inert gas movement.

Abstract: A process for producing high purity silicon characterized by the employment of an electric arc heater into which a silicon halide is injected together with a metal reductant such as an alkali metal or an alkaline-earth metal which are reacted together by projecting them tangentially into a reaction chamber to cause the formation of liquid silicon and a gaseous metal halide salt which are separated in a suitable manner such as centrifugally or by condensation.

Abstract: A process for the production of aluminum characterized by the steps of chlorinating a material containing chemically combined aluminum and silicon with chlorine to produce aluminum trichloride and silicon tetrachloride, reacting aluminum trichloride with manganese to produce elemental aluminum and manganese chloride, reducing silicon tetrachloride to yield silicon, oxidizing the manganese chloride to produce manganese oxide, and reducing the manganese oxide with silicon to produce manganese which is recycled to the second step for reducing aluminum trichloride.

Abstract: A process for the production of high purity silicon characterized by the employment of an electric arc heater in which a silicon halide is reacted with hydrogen to produce liquid silicon and gaseous co-products.

Abstract: A process for converting silicon intermediates to high purity silicon by an arc heater characterized by the thermal reduction of one of several potential purified silicon intermediate compounds using an arc heater as the reduction energy source and using hydrogen as the reductant.

Abstract: A method for the production of single crystal silicon characterized by the steps of feeding into an arc heater a quantity of uncontaminated silicon halide to react with hydrogen or a metal reductant, such as sodium, to produce reaction products including liquid silicon and a gaseous salt of the reductant, depositing the liquid silicon on a downwardly inclined surface, and attaching a single seed crystal of silicon to the liquid silicon and withdrawing the single seed crystal from the liquid silicon so as to propagate a large single crystal.

Abstract: A process for producing high purity silicon characterized by the employment of an electric arc heater into which a silicon halide is injected together with a metal reductant such as an alkali metal or an alkaline-earth metal which are reacted together by projecting them tangentially into a reaction chamber to cause the formation of liquid silicon and a gaseous metal halide salt which are separated in a suitable manner such as centrifugally or by condensation.

Abstract: A process for the production of magnetic spheres from grit of magnetite ore by introducing the grit into an arc heated gas jet, thus heating the grit to a temperature of at least 1600.degree. C, and allowing the melted magnetite droplets to spheroidize and cool to a solid state.

Abstract: A process for the reduction of zinc roast in which pulverized particles of zinc roast are fed into an arc heated jet of carbon monoxide, whereby the particles are heated and reduced from zinc oxide to zinc vapor which in turn is quenched with pulverized carbon in an endothermic reaction to yield additional carbon monoxide, after which the vaporized zinc is cooled to room temperature.