(19)

(11)

EP 0 839 118 A1

(12)

(43) Date of publication: 06.05.1998 Bulletin 1998/19 (21) Application number: 96922684.0 (22) Date of filing: 11.07.1996

(51) International Patent Classification (IPC):  C01F 7/ 14( . ) (86) International application number: PCT/AU1996/000435 (87) International publication number: WO 1997/003022 (30.01.1997 Gazette 1997/06)

(84) Designated Contracting States: ES IE (30) Priority: 11.07.1995 AU 1995PN04107 14.08.1995 AU 1995PN04785 (71) Applicant: COMALCO ALUMINIUM, LTD. Melbourne Victoria 3000 (AU)	(72) Inventor: BROWN, Gregory, Patrick Buderim, QLD 4556 (AU) (74) Representative: Gorman, Francis Fergus  F. F. Gorman & Co. 54, Merrion Square Dublin 2 Dublin 2 (IE)