DROSS TREATMENT IN A ROTARY ARC FURNACE WITH GRAPHITE-ELECTRODES

Aluminum baths are always covered with a layer of dross resulting from the aluminum surface oxidation. This dross represents 1-10% of the me lt and may contain up to 75 wt.% aluminum. Since aluminum production i s highly energy intensive, dross recycling is very attractive from bot h energy and economic standpoints. The conventional recycling process using salt rotary furnaces is thermally inefficient and environmentall y unacceptable because of the production of salt slags. Hydro-Quebec h as developed a new technology using a rotary arc furnace with graphite electrodes. This process provides aluminum recovery rates of 80-90%, using a highly energy efficient, environmentally sound production meth od.