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EP 4 065 738 A1

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(43) Date of publication: 05.10.2022 Bulletin 2022/40 (21) Application number: 20894864.6 (22) Date of filing: 25.11.2020

(51) International Patent Classification (IPC):  C22B 3/20(2006.01) B01D 29/00(2006.01) B01D 11/02(2006.01) C22B 3/12(2006.01) (52) Cooperative Patent Classification (CPC): B01D 37/02; B01D 37/03; B01D 37/048; Y02P 10/20; B01D 11/0446; B01D 11/0492; B01D 11/0488; C22B 21/0023; C01F 7/473; C01F 7/47 (86) International application number: PCT/IB2020/061113 (87) International publication number: WO 2021/105889 (03.06.2021 Gazette 2021/22)

(84) Designated Contracting States: AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR Designated Extension States: BA ME Designated Validation States: KH MA MD TN (30) Priority: 25.11.2019 AU 2019904448 (71) Applicant: Rio Tinto Alcan International Limited Montréal, Québec H3B 0E3 (CA)

(72) Inventors: VANWYK, Sanelle Melbourne, VIC 3000 (AU) GERRELL, Brian Craig Melbourne, VIC 3000 (AU) REN, Yaqiong Melbourne, VIC 3000 (AU) MACH, Tomas Montréal, Québec H3B 0E3 (CA) STAKER, Warren Montréal, Québec H3B 0E3 (CA) MULLINS, Adrian Richard Montréal, Québec H3B 0E3 (CA) FELL, Howard Montréal, Québec H3B 0E3 (CA) (74) Representative: Dekker, Henrike Cornelie Christine et al Kilburn & Strode LLP Lacon London 84 Theobalds Road London WC1X 8NL London WC1X 8NL (GB)