Panias Dimitrios Associate Professor in Extractive Metallurgy National

Panias Dimitrios Associate Professor in Extractive Metallurgy National Technical University of Athens

SOCIETY AND THE CONSUMPTION OF METALS Global Copper Production Global Iron and Steel Production Million tonnes Global Aluminum Production 9/25/2020 2

HUMAN WEALTH & THE VALUE OF METALS 9/25/2020 3

HUMAN WELFARE VS ECOLOGICAL FOOTPRINT 9/25/2020 4

CONCEPT OF SUSTAINABILITY i n n o v at I o Social n Be ar ble a t ui ab le Eq Environment on in no va ti Viable Sustain able in Economic n ov at io n 9/25/2020 5

HOW CAN INNOVATIONS EMERGE? MASS & ENERGY BALANCES PRIMARY ALUMINA AND ALUMINUM PRODUCTION 9/25/2020 ENEXAL PROJECT 6

INNOVATIONS IN BAYER PROCESS MASS & ENERGY BALANCES EXERGY ANALYSIS Bauxite 5. 1 kg Red Mud 2 kg Al 2 O 3 1. 93 kg RED MUD IS A VALUABLE BY-PRODUCT AND NOT A WASTE 9/25/2020 ENEXAL PROJECT 7

EMERGING INNOVATION I : RED MUD AS A FEEDSTOCK Common Resources for Mineral Wool production Chemical Species %wt (dry basis) Fe 2 O 3 47. 74% Al 2 O 3 16. 22% Ca. O 10. 73% Si. O 2 6. 09% Ti. O 2 5. 93% Na 2 O 2. 51% V 2 O 5 0. 21% -SO 3 0. 60% -CO 2 1. 63% H 2 O(cry) 8. 35% Resource for Pig. Iron Production 9/25/2020 ENEXAL PROJECT 8

EMERGING INNOVATION I : RED MUD AS A FEEDSTOCK TECHNOLOGY DEVELOPMENT CO 2 offgases Red Mud Ø Total Utilization of Bauxite Residue Ø No Solid/Liquid Wastes Pig Iron Mineral Wool 9/25/2020 ENEXAL PROJECT 9

EMERGING INNOVATION I : RED MUD AS A FEEDSTOCK PILOT SCALE TESTING 1 MVA dust treating AC EAF with 1 ton Batch Capacity 25 tons of BR has been treated Melt Spinning Fiberizing Line 9/25/2020 ENEXAL PROJECT 10

EMERGING INNOVATION I : RED MUD AS A FEEDSTOCK PRODUCTS EVALUATION – PIG IRON Pig Iron Fe (%wt) C (%wt) S (%wt) P (%wt) Si (%wt) Cr (%wt) Total %w/w 93. 44 4. 59 0. 07 0. 22 1. 12 0. 50 99. 94 Used in Secondary Steel Industry as 21% w/w substitution of Steel scrap White Iron Grinding Balls 9/25/2020 ENEXAL PROJECT 11

EMERGING INNOVATION I : RED MUD AS A FEEDSTOCK PRODUCTS EVALUATION – MINERAL WOOL wool Fe 2 O 3 Si. O 2 Ca. O Al 2 O 3 Cr 2 O 3 Mg. O Ti. O 2 Na 2 O %w/w 1. 1 26. 5 23. 4 31. 1 0. 1 8. 3 6. 1 1. 8 Wool of excellent quality q λ = 0, 034 W/m. K q Mean Fiber Diameter 7 μm q Bright white color (low Mn content) q High Mechanical resistance due to high Ti. O 2 Industrial pipes insulation 9/25/2020 ENEXAL PROJECT 12

EMERGING INNOVATION I : RED MUD AS A FEEDSTOCK PROCESS ECONOMIC EVALUATION q Extrapolation for a 5. 0 MVA EAF treating 1300 tons of bauxite residues and producing 442 tons of pig iron and 931 tons of mineral wool per month q Pig Iron revenues (calculated at a market price of 415€/t) amount to 25% of operational costs q Mineral wool revenues depend on market price (depends on product quality and market demand) 9/25/2020 ENEXAL PROJECT 13

THE NEW BAYER PLANT IS MORE RESOURCE EFFICIENT AND SUSTAINABLE PROCESS 9/25/2020 ENEXAL PROJECT 14

INNOVATIONS IN ALUMINUM PRODUCTION DRAWBACKS OF MOLTEN SALTS ELECTROLYSIS q High Electrical Energy consumption (an upgraded energy form with high cost and exergy content) for production of chemical work and heat Typical Aluminum Smelter Salts Electrolysis - around. Molten 300 electrolytic cells + + 3 O 2 O 3 = 2 Al 3 ton/y -Al 2125. 000 Al production New generation smelters Cathode: 4 Al 3+ + 12 e- = 4 Al 400 -500 kton/y Al production q Increased Environmental Impact due to mainly CO 2 emissions q Low volumetric efficiency due to 2 Dimensional Electrolytic Reactor. That means, for a given production capacity, a big number of cells and therefore big industrial space are necessary 2 - Middle Located East, China, Russia, Anode: 6 Oin + 3 Cgraphite = 3 CO 2(g) + 12 e India, Malaysia and Africa 9/25/2020 ENEXAL PROJECT 15

EMERGING INNOVATION II : CARBOTHERMIC AL PRODUCTION THE CONCEPT OF CARBOTHERMIC PROCESS Cathode: 4 Al 3+ + 12 e- = 4 Al Anode: 6 O 2 - + 3 Cgraphite = 3 CO 2(g) + 1. 93 kg Al 2 O 3 44. 73 MJ 56. 24 MJ Electricity 20% decrease Reduction in indirect CO 2 emissions q Substitution of a part of Electrical Energy with the chemical and thermal energy of Recovery carbon of 12 e- 2. 6 kg CO 2 Carbothermic Electrolytic Process ADVANTAGES OF CARBOTHERMIC PROCESS 15. 82 MJ 1. 66 kg 7. 42 kg CO CO 2 1 kg Al 24. 23 MJ 15. 3 MJCCReductant anode Al 2 O 3 + 3 C = 2 Al + 3 CO(g) q Decrease of waste heat q Potential for waste heat recovery q Decrease of CO 2 emissions q Higher volumetric efficiency due to 3 Dimensional Reactor q For a given production capacity - smaller reactor size and thus industrial space - less capital cost 9/25/2020 ENEXAL PROJECT 16

EMERGING INNOVATION II : CARBOTHERMIC AL PRODUCTION MODES OF PERFORMING THE CARBOTHERMIC AL PRODUCTION 1. Co-Reduction of Alumina and Silica is now tested in Pilot Scale 2 Al 2 O 3 + Si. O 2 + 8 C = 4 Al. Si 0. 25(l) + 8 CO(g) 2. Gaseous aluminum production q Under high temperatures (>2500 o. C) Al 2 O 3 + 3 C = 2 Al(g) + 3 CO(g) all are proven in Laboratory Scale q Under vacuum (1500 o. C) Al 2 O 3 + 3 C = 2 Al(g) + 3 CO(g) 9/25/2020 ENEXAL PROJECT 17

EMERGING INNOVATION IIA : HIGH TEMPERATURE CARBOTHERMIC AL-SI ALLOY PRODUCTION ELECTRIC ARC FURNACE Identification Number Ex. 1: Si/Al=0. 26 (T=1300°C) Ex. 1: Si/Al 0. 26 (T=700°C) 2 Al O + Si. O + 8 C = 4 Al. Si 0. 25(l) + 8 CO(g) Al 2 3 Si 2 wt. -% Carbonwt. -% Source: 72. 53 Wood 25. 58 charcoal 71. 37 Binder: 25. 95 7% corn starch q 33% of 42 Mt of Global Al. Castings are Al. Si Castings Molded Al-Si Alloy Al 77. 07 wt. -% Si 22. 93 wt. -% <1000 o. C 2600 o. C 9/25/2020 ENEXAL PROJECT 18

EMERGING INNOVATION IIB : HIGH TEMPERATURE CARBOTHERMIC GASEOUS AL PRODUCTION Concept: • Hollow electrode EAF • Feeding Alumina-Carbon pellets directly in the arc zone No Liquid Phase Homogeneous Condensed Material with • Controlled feeding rate Metallic Shine • No liquid phase formation • Water cooled lid acts as condenser Pure • Argon. Almost Overpressure Aluminum CHALLENGES 1. PROPER VERY FAST ALUMINUM CONDENSER 2. PLASMA FURNACE INSTEAD OF EAF ENEXAL PROJECT 9/25/2020 19

EMERGING INNOVATION IIC : VACUUM CARBOTHERMIC GASEOUS AL PRODUCTION Concept: Quartz Window • Reactor under vacuum • Concentrated Solar Radiation provides process heat ZIrconia • Condenser before vacuum pumps collects the metal. Condensed Deposit Energy of the process = pumping CHALLENGES work (electricity) + concentrated 1. solar PROPER VERY FAST ALUMINUM CONDENSER radiation. After. REACTOR test Before 2. DEVELOPMENT OF Atest HYBRID SOLAR-ELECTRICAL 9/25/2020 ENEXAL PROJECT 20

THE NEW ALUMINA SMELTER Estimated gains of the new Alumina Smelter in Comparison to the Hall-Heroult Energy Source Energy Savings Reduction in GHG Emissions Exergy Efficiency Increase Coal based electricity 16% 35% 3% Hydroelectricity 10% 65% 5% Hydroelectricity for H-H and Concentrated Solar for New Smelter 68% 65% 82% A SUSTAINABLE PERSPECTIVE FOR THE EUROPEAN ALUMINUM INDUSTRY ALUMINUM MILLS VERSUS HALL-HEROULT MEGAPLANTS 9/25/2020 ENEXAL PROJECT 21

CAN THE NEW ALUMINA & ALUMINUM PLANT BECOME A REALITY? 9/25/2020 22

Thank you for your attention 9/25/2020 23