(19)

(11)

EP 0 059 742 A1

(12)

(43) Date of publication: 15.09.1982 Bulletin 1982/37 (21) Application number: 81902622.0 (22) Date of filing: 09.09.1981

(51) International Patent Classification (IPC):  C22C 21/ 00( . ) C22F 1/ 04( . ) (86) International application number: PCT/FR1981/000116 (87) International publication number: WO 1982/001014 (01.04.1982 Gazette 1982/09)

(84) Designated Contracting States: AT DE GB NL (30) Priority: 11.09.1980 FR 19800019876 (71) Applicant: CEGEDUR SOCIETE DE TRANSFORMATION DE L'ALUMINIUM PECHINEY F-75361 Paris Cédex 08 (FR)	(74) Representative: Pascaud, Claude  PECHINEY 28, rue de Bonnel F-69433 Lyon Cédex 3 F-69433 Lyon Cédex 3 (FR)