Abstract: A method of model-based ingot solidification control for the vacuum arc remelting process is presented. Specifically, the model predicts the pool depth as a function of radial position from ingot centerline and time, given melting current, and electrode melting efficiency. The analysis leading to the model assumes that the electrode gap is being accurately controlled during the melting process. The controller has both 2-dimensional and 3-dimensional embodiments.

Abstract: A homogeneous electrode of reactive metal alloy comprises an ingot with an axially disposed core made from one induction melted heat of the reactive metal alloy and having a diameter “d” and a length “L” and a body having an outer diameter at least 2 times “d” and a length “L”. The ingot body is disposed about the core, and comprises a plurality of induction melted heats of the reactive metal alloy to provide an electrode of the required size. The electrode also includes features for receiving electrical current for arc remelting of the reactive metal alloy to produce a large homogeneous ingot. Remelting may be conducted under vacuum or controlled atmosphere conditions, as required.

Abstract: A fused magnesia ingot being discharged from an electric furnace at extremely elevated temperatures is thermally insulated to improve product yield. Thermal insulation provided with a blanket covering of refractory material can be used for this purpose.

Abstract: The invention relates to improved apparatuses and methods for remelting metal alloys in furnaces, particularly consumable electrode vacuum arc furnaces. Excited reactive gas is injected into a stationary furnace arc zone, thus accelerating the reduction reactions which purify the metal being melted. Additionally, a cooled condensation surface is disposed within the furnace to reduce the partial pressure of water in the furnace, which also fosters the reduction reactions which result in a purer produced ingot. Methods and means are provided for maintaining the stationary arc zone, thereby reducing the opportunity for contaminants evaporated from the arc zone to be reintroduced into the produced ingot.

Abstract: Apparatus for recognition of metals in base materials includes an electron beam furnace in which base materials are vaporized by means of an electron beam gun and the vaporized materials are condensed as free atoms or are alloyed with other components of the base materials, and are able to be recovered by conventional recovery techniques once they are recognized. The base material includes the products of smelting processes, pellets of compacted raw material like anode-mud or waste material, and the base materials are remelted utilizing the heat from electron beam guns for the remelting.

Abstract: An apparatus and process for the reduction in a plasma stream of a feed material including a comminuted metal oxide, a slag former and a reductant utilizing an enclosed horizontal reactor having a reduction chamber and a filter chamber therein separated by an either common partition having a plurality of holes therethrough or a refractory lined passageway. Coke filter media in the filter chamber act to filter out entrained molten metal contained in the plasma stream with the partition or passageway preventing entry of the coke from the filter chamber into the metal bath contained in the reduction chamber thereby limiting the amount of carbon entering the metal produced. Unreduced metal oxide is provided in the slag layer of the metal bath to maintain the stoichiometric ratio between the metal and reductant in the reduction chamber.