(19)

(11)

EP 1 794 333 A2

(12)

(88) Date of publication A3: 14.12.2006 (43) Date of publication: 13.06.2007 Bulletin 2007/24 (21) Application number: 05794450.6 (22) Date of filing: 01.09.2005

(51) International Patent Classification (IPC):  C22B 4/02(2006.01) (86) International application number: PCT/US2005/031521 (87) International publication number: WO 2006/026771 (09.03.2006 Gazette 2006/10)

(84) Designated Contracting States: AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU LV MC NL PL PT RO SE SI SK TR Designated Extension States: AL BA HR MK YU (30) Priority: 01.09.2004 US 932846 (71) Applicants: Alcoa Inc. Pittsburgh, PA 15212-5858 (US) Elkem AS 0377 Oslo (NO)	(72) Inventor: FRUEHAN, Richard, J. Murrysville, Pennsylvania 15668 (US) (74) Representative: Parry, Simon James  Forrester & Boehmert Pettenkoferstrasse 20-22 80336 München 80336 München (DE)