Concept for an industrial scale HCl-based bauxite residue valorization and idea for using available technology for piloting at batch scale David Konlechner, Egon Sehner, Ernst Pichler, Mario Stein 07/05/18

The idea of producing Alumina via a HCl route is not novel History The idea of producing Alumina via a HCl route is not novel Camille Jenatza a Belgian race driver reached 100 km/h 29th April 1899 in an electric car 07/05/18

Single treatment steps follow known chemistry Vision Single treatment steps follow known chemistry 21st century materials make HCl process possible Target is a zero waste approach 07/05/18

Process Overview Industrial Scale Assumed Process ~ 77,6 kt BR 9,6 kt SiO2 TiO2 12 kt Al2O3 39,2 kt Fe2O3 Simple PFD Required process equipment, preliminary summary 07/05/18

Step 1: Bauxite Residual Leaching with HCl Leaching BR 15,6 wt% Al2O3 6,5 wt% SiO2 50,6 wt% Fe2O3 6,3 wt% TiO2 8,7 wt% CaO 3,5 wt% Na2O Batch operation Acidic filtration 31,9 t/h HCl conc. 9,7 t/h BR Step 1: Leaching 40,2t/h Solution 1,4 t/h (wet) SiO2 TiO2 07/05/18

Step 2: ACH Precipitation by using HCl gas 11,3 t/h HCl >95% 40,2 t/h Solution Step 2: Precipitation 43,8 t/h Solution 7,7 t/h ACH 07/05/18

Step 3: AlCl3.6H2O Calcination and Step 4: Al2O3 Washing ACH is decomposed AlCl3.6H2O  Al2O3 +3H2O + 6HCl recycling high concentrated HCl gas Al2O3 / NaCl separation by washing 7,7 t/h ACH Step 3/4: Calcination & Washing 5,6 t/h HCl/H2O 2,1 t/h Al2O3 & NaCl 1,5 t/h Al2O3 07/05/18

Step 5: Fe2O3 Precipitation Only Fe2O3 is precipitated at process conditions 2FeCl3 + 3H2O  Fe2O3 + 6 HCl Remaining elements are concentrated 37,3 t/h HCl/H2O 43,8 t/h Solution Step 5: Fe2O3 Precipitation 44,1 t/h Solution 42,5 t/h Backfl. 4,9 t/h Fe2O3 07/05/18

Step 6: REE and Trace Element Removal Step 7: HCl Purification 19,3 t/h H2O 44,1 t/h Solution Step 6: Trace Element Removal 42,5 t/h Backfl. 37,3 t/h HCl/H2O Step 7: HCl Drying 18 t/h HCl > 95% 1,6 t/h Rest, incl. REE, Ca 07/05/18

Nobody wants to be the guinea pig Industry available process Concept to Industry Valley of death Nobody wants to be the guinea pig Lab proven process Industry available process 07/05/18

Using a customized CARLA as Pilot Compact Acid Regeneration Liquid Assembly (CARLA) Originally designed with the steel industry Including key equipment suitable for HCl Ready for process Step 1, 2, 5 and 6 Smart possibility for batch demonstration / piloting Operating at site Using original feedstock material 07/05/18

CARLA Concept 07/05/18

CARLA Concept 07/05/18

Summary HCl based BR treatment a possible solution for sustainable alumina CARLA an opportunity for straight forward piloting and demonstration activities Outlook Process has to be demonstrated Further upscaling and equipment availability has to be investigated REE enrichment and behavior has to be studied 07/05/18

Thank you for your attention! David KONLECHNER Owner KON Chemical Solutions e.U.   Obermuellnerstrasse 2A/4/2 1020 Vienna, Austria T: +43 699 11 77 99 33 david.konlechner@kon-chem.com Egon SEHNER Product Line Manager CMI Industry CMI UVK GmbH Robert-Bosch-Str. 12 56410 Montabaur, Germany T: +49 2602 9999 140 F: +49 2602 9999 596 M:+49 151 55144984 egon.sehner@cmigroupe.com 07/05/18