Alcan International Limited

Alcan Research and Development Limited

Nigel P Fitzpatrick

Pervez J Bamji

John F Evans

James Neville Byrne

Richard E Lee

Angus James MacDonald

Solid scrap metal particles are ingested into molten metal by use of a linear induction motor which establishes a strong upstream in the molten metal adjacent one boundary wall to establish a standing wave at the surface and a corresponding downstream adjacent the opposite boundary, which is preferably in the form of a baffle having a metal outlet passage beneath it. The linear induction motor is conveniently positioned at a sidewell of a melting furnace and a continuous flow of molten metal through the sidewell is established in any convenient way.

Melting scrap metal and ingestion of solids in molten metal

A method of removing organic coatings from scrap aluminum which includes passing a bed of the scrap metal supported on a gas-permeable conveyor through a pyrolysis zone and passing an oxygen-containing hot gas downwardly through the scrap metal bed, the conveyor advancing continuously through the pyrolysis zone, the hot gas being at a temperature to raise the upper surface of the bed of scrap to a temperature in the range of 500.degree.-600.degree. C.; and the temperature and rate of supply and oxygen content of such gas and the rate of travel of the bed of scrap being adjusted to ensure that a reaction front at which the organic material is pyrolysed and residual carbon is burned travels from top to bottom of the bed within the pyrolysis zone and to allow the scrap to be retained within the pyrolysis zone for up to 10 minutes after the reaction front reaches the bottom of the bed.

Decoating of aluminum scrap

Apparatus for melting scrap metal and ingestion of solids in molten metal

In a process for recovery of aluminium metal from coated light gauge aluminium scrap the scrap fragments are first decoated and then fed substantially continuously onto the surface of a body of molten metal above a channel-type induction heater. The molten metal is stirred to produce strong down flows at the molten metal surface to submerge the decoated scrap particles. The submergence may be effected by a coreless induction heater acting on the body of molten metal or other electromagnetic device such as one or more linear induction motors which are employed to set up a strong axial down flow at the center of the metal surface or to generate a vortex at that location.

Recovery of aluminium scrap

For stirring molten metal such as aluminum in a furnace, metal is alternately withdrawn from and discharged as a jet into the body of molten metal, such being effected by successive application of suction and gaseous pressure to a tubular vessel which projects beneath the surface of the molten metal for advantageously delivering the successive quantities in a horizontal direction over a preferably long path. Effective, reliable stirring of the entire body of metal is achieved with one or more such means, the extent of stirring being controllable; the results include saving of energy and of time for furnace operation, and reduction of melt loss.

Growing community of inventors

Kingston, Canada

Nigel P Fitzpatrick