Patent ID: 7655067

Claim:
A method for processing aluminum in a furnace having at least first and second phases, in which an aluminum-containing material is introduced into the furnace, comprising: melting the material by heating using at least one burner supplied with oxidizer and with fuel, in order to obtain molten aluminum: measuring at least one of carbon monoxide CO and hydrogen H 2 concentration in at least one of a furnace atmosphere and flue gases, wherein the oxidizer supplied to at least one burner comprises over about 10% by volume of oxygen; during the first phase, regulating at least one of the carbon monoxide and hydrogen concentration to a setpoint C 1 of between about 0.1 vol % and about 5 vol % by varying the flow rate of the oxidizer or of the fuel; and decreasing oxidation of the molten aluminum in the second phase which is an oxidation limitation phase, during which (i) flow rate of the oxidizer is substantially constant while flow rate of the fuel injected into the at least one burner is a function of at least one of the carbon monoxide and hydrogen concentration in at least one of atmosphere or the flue gases or (ii) the flow rate of the fuel is substantially constant while the flow rate of the oxidizer is a function of at least one of the carbon monoxide and hydrogen concentration in at least one of the atmosphere and the flue gases, at least one of the carbon monoxide and hydrogen concentration being regulated upon the decreasing in the second phase to a setpoint C 2 of between about 3 vol % and about 15 vol %, wherein the setpoint C 1 is less than the setpoint C 2 .