Abstract: An enlarged and generally cup-shaped front section of the central passageway of the main body of the electrode has a rearwardly and inwardly sloping wall that extends at an angle within the range of approximately twenty to forty degrees relative to a plane perpendicular to the central axis of the electrode. The front section of the passageway has a readily replaceable and forwardly disclosed choke member having a central opening of a diameter within the range of 1.25 to 1.9 times the diameter of a rear section of the passageway. The rear section of the electrode passageway increases in diameter along a forward part of its length. The choke member comprises one of a set of similar choke members that differ from each other in the diameter of their central openings and/or in the electrically conductive material of which they are formed.

Abstract: An assembly for the recovery of aluminum metal from aluminum dross comprising a rotary furnace, a plasma arc torch, and a supervisory control system for tying together and automatically controlling the operation of the rotary furnace and plasma arc torch is described. The invention provides recovery of aluminum metal from dross in an efficient and economical process.

Abstract: A process for recovering free aluminum and aluminum compounds such as aluminum oxide from aluminum dross in a rotary furnace heated with a plasma arc torch wherein air is preferably utilized as the arc gas is described. The use of the rotary furnace heated with plasma energy eliminates the need for a salt flux, providing a process which is ecologically safe and cost effective. A process of converting non-metallic aluminum compounds to substantially pure aluminum oxides by heating the compounds with a plasma torch operating with an oxidizing gas as the plasma torch arc gas is also described.

Abstract: As apparatus and method is disclosed which is adapted to melt metallic fines, and which is useful for processing metallic fines into a useful form. The apparatus may also be used in the smelting of metallic oxides, and in combining metals in an alloying process. The disclosed embodiment of the apparatus includes a furnace having a hearth, a pair of tubular residence chambers each extending upwardly from the hearth, a first plasma torch mounted at the upper end of each residence chamber, and a second plasma torch mounted for heating the material on the hearth. The powdered or granular material is fed into the upper end of each residence chamber, such that the material is at least partially melted from the heat of the first torch while falling through the residence chamber, and the material is further heated and completely melted on the hearth by the second torch.