(19)

(11)

EP 1 390 554 A1

(12)

(43) Date of publication: 25.02.2004 Bulletin 2004/09 (21) Application number: 02726033.0 (22) Date of filing: 15.05.2002

(51) International Patent Classification (IPC)7: C22F 1/04, C22F 1/047, C22F 1/05, C21D 9/573 (86) International application number: PCT/CA2002/000709 (87) International publication number: WO 2002/092870 (21.11.2002 Gazette 2002/47)

(84) Designated Contracting States: AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR Designated Extension States: AL LT LV MK RO SI (30) Priority: 15.05.2001 US 859017 (71) Applicant: ALCAN INTERNATIONAL LIMITED MontrealQuebec H3A 3G2 (CA)	(72) Inventor: DAVENPORT, Christopher, John Rugby, Warwickshire CV22 7RS (GB) (74) Representative: Gaunt, Robert John  Stevens, Hewlett & PerkinsHalton House20/23 Holborn London EC1N 2JD London EC1N 2JD (GB)