Recovery of non-ferrous metals from dross

US5470376A · kind A · utility

Assignee

• Alcan International Limited · CA

Inventors

• Ghyslain Dube · Saguenay, CA
• Marko Litalien · Saguenay, CA
• Roger Pelletier · Saguenay, CA
• Zhou Wang · Aachen, DE

Key dates

• Filing date: Jul 15, 1994
• Grant date: Nov 28, 1995
• Expiry date: Jul 15, 2014

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02P10/20
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

A process of recovering a non-ferrous metal from a dross containing the same. The process involves introducing into a rotary furnace the dross and a fluoride compound which becomes substantially molten above the melting point of the metal, heating the dross and fluoride compound to a maximum temperature above the melting point of the metal, using a heating device which substantially maintains a non-oxiding atmosphere in the furnace, rotating the furnace until the dross reaches the maximum temperature, removing the molten metal thereby separated from a solid dross residue and removing the solid dross residue from the furnace. The fluoride compound, which may be, for example, cryolite, recovered cryolite, AlF.sub.3 or NaF, or a mixture thereof, is such that it remains in the dross during the process and does not make the dross become sticky. The use of the fluoride improves the rate of recovery of the metal content of the dross without producing environmental difficulties either during the heating operation or during the disposal or use of the dross residue.