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.