Abstract: A kiln system for a process for treatment of aluminum dross residue (NMP) having available aluminum nitride (AlN) and/or free aluminum (Al) and/or aluminum chlorides (AlCl.sub.3) having a particle size within the range of 0.3 to 300 microns, i.e., "fines" to produce a high alumina lightweight aggregate is described. The process is characterized in that the NMP is fed into a rotating sealed kiln and heated to a temperature in the range of 2000.degree. to 4000.degree. F. while feeding oxygen or a mixture of oxygen and water into the kiln with less than about 20% of the total heat energy input for heating the NMP to a temperature between 2000.degree. and 4000.degree. F. being supplied from an external source. The process does not require prior agglomerization of the fines.

Abstract: A process for treatment of aluminum dross residue (NMP) having available aluminum nitride (AlN) and/or free aluminum (Al) and/or aluminum chlorides (AlCl.sub.3) having a particle size within the range of 0.3 to 300 microns, i.e., "fines" to produce a high alumina lightweight aggregate is described. The process is characterized in that the NMP is fed into a rotating sealed kiln and heated to a temperature in the range of 2000.degree. to 4000.degree. F. while feeding oxygen or a mixture of oxygen and water into the kiln with less than about 20% of the total heat energy input for heating the NMP to a temperature between 2000.degree. and 4000.degree. F. being supplied from an external source. The process does not require prior agglomerization of the fines.

Abstract: A process for recovering free aluminum and aluminum compounds such as aluminum oxide from aluminum dross and aluminum scrap in a furnace heated with a plasma arc torch followed by oxygen injection after significant aluminum separation has occurred is described. The injected oxygen reacts with aluminum nitrides and unrecoverable aluminum in the dross to provide processing energy. High aluminum recovery is obtained with greatly reduced cycle times at lower overall operating costs.

Abstract: A process for recovering free aluminum and aluminum compounds such as aluminum oxide from aluminum dross and aluminum scrap in a furnace heated with a plasma arc torch followed by oxygen injection after significant aluminum separation has occurred is described. The injected oxygen reacts with aluminum nitrides and unrecoverable aluminum in the dross to provide processing energy. High aluminum recovery is obtained with greatly reduced cycle times at lower overall operating costs.

Abstract: A process for recovering free aluminum and aluminum compounds such as aluminum oxide from aluminum dross and aluminum scrap in a furnace heated with a plasma arc torch wherein air at high enthalpy is used as the arc gas. The use of air at high enthalpy as the arc gas provides for more rapid heat output, causing the outer surface or shell of dross to heat rapidly, thereby rupturing the oxide shell releasing free aluminum from within the shell. A higher aluminum recovery is obtained. In a plasma torch high enthalpy is obtained by adding a gas such as CO.sub.2, methane or hydrogen to the air arc gas at a fixed current level or by operating the plasma torch with higher current at a fixed air flow.

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: A process for recovering free aluminum and aluminum compounds such as aluminum oxide from aluminum dross and aluminum scrap in a furnace heated with a plasma arc torch wherein air is utilized as the arc gas is described. The use of air as the arc gas provides greater heat output per kilowatt hour of electricity and provides for greater dross throughput. Moreover, the process is ecologically safe.

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.