(19)

(11)

EP 0 400 059 A1

(12)

(43) Date of publication: 05.12.1990 Bulletin 1990/49 (21) Application number: 89902718.0 (22) Date of filing: 10.02.1989

(51) International Patent Classification (IPC):  B22D 21/ 04( . ) C22C 1/ 02( . ) C22C 21/ 04( . ) C22C 1/ 00( . ) C22C 21/ 02( . ) C22F 1/ 047( . ) (86) International application number: PCT/AU1989/000054 (87) International publication number: WO 1989/007662 (24.08.1989 Gazette 1989/20)

(84) Designated Contracting States: AT BE CH DE FR GB IT LI LU NL SE (30) Priority: 10.02.1988 AU 19880006681 (71) Applicant: COMALCO LIMITED Melbourne, VIC 3000 (AU)	(72) Inventors: EADY, John, Alan East Doncaster, VIC 3109 (AU) HEATHCOCK, Christopher, John Kew, VIC 3101 (AU) KEAN, Peter, Lawrencer Worcester (GB) ROGERS, Kevin, Phillip Ringwood, VIC 3134 (AU) LEGGE, Rodney, Alan Gloucester GL2 8AB (GB) (74) Representative: Gordon, Michael Vincent, et al  GILL JENNINGS & EVERY, Broadgate House, 7 Eldon Street London EC2M 7LH London EC2M 7LH (GB)