Recycled Alumina from Aluminium Salt Slag: Origins & Applications. Howard Epstein

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1 Recycled Alumina from Aluminium Salt Slag: Origins & Applications Howard Epstein

2 Recycled Alumina - Agenda Where it comes from What it is How it may be applied The drivers of demand October 2012

3 RVA s Business The conversion of salt slag, a hazardous waste of the aluminium industry, into sustainable, value-added materials: Aluminium Granules Returned to secondary aluminium production cycle Salt Returned to refiners for melting process Recycled Alumina (Valoxy) Non-metallurgical applications as substitute bauxite/alumina

4 RVA located at the Heart of Europe

5 RVA Sustainably Developed

6 Aluminium Value Chain and Life Cycle

7 Life Cycle Origins of Recycled Alumina Scrap Al Al users Secondary Al

8 Life Cycle Origins of Recycled Alumina Scrap Al Salt slag Al users Secondary Al Al granules & regenerated salt

9 Life Cycle Origins of Recycled Alumina Scrap Al Salt slag Al users Secondary Al Al granules & regenerated salt VALOXY

10 RVA Process Salt Slags Heat recovery Regenerated Salt Mill Screen Magnet Salt residues Dissolution Reaction Filtration Brine Crystallization Water recirculation Al granules VALOXY

11 Million Tonnes Slag arisings as a function of 2 Y Al production Y Al Output October 2012

12 Million Tonnes Slag arisings as a function of 2 Y Al production Y Al Output Slag Arisings October 2012

13 Secondary Aluminas Production Global Potential 1 tonne 550 kg 300 kg Secondary Aluminium 10.3 million Tpa Salt Slag 5.7 million Tpa Secondary Aluminas 3.1 million Tpa October 2012

14 Drivers for Development of Secondary Aluminas Regulatory Salt slag: prohibition of landfill Waste processing into useful products Economic Secondary aluminas: potential savings in operating cost Conventional aluminas: comparatively higher production cost October 2012

15 Typical Al Salt Slag Composition NaCl/KCl 40% Oxides 55% Aluminium metal 5%

16 VALOXY Chemical Composition Typical composition dry weight (%) Al 2 O 3 67% MgO 8% SiO 2 4% CaO 2% Cl <0.5%

17 VALOXY - Applications, Current & Potential 1. Cement 2. Insulation products 3. Stainless steel slag stabilization 4. Fire resistant geopolymers 5. Calcium aluminate steel refining powder October 2012

18 VALOXY: A source of alumina in cement production VALOXY February 2012 October 2012

19 VALOXY in Cement Production - Benefits More efficient combination of raw materials Facilitates formation of clinker minerals Improved early age strength development Lower milling costs October 2012

20 VALOXY in Insulation Products % Water Absorption at 1250 C % fireclay 20% 30% 40% 50% Valoxy substitution October 2012

21 VALOXY in Insulation Products - Benefits Strengthening of ceramic lattice Increased resistance to volume shrinkage More open and stable ceramic structure Application in insulating firebricks October 2012

22 VALOXY in Slag Conditioning The Problem Stainless Steel Converter Slags: 7 MT and growing at >5% p.a.

23 Argon-Oxygen Decarburization

24 AOD Slag Stability - a function of C 2 S form

25 AOD Slag Stability - a function of C 2 S form

26 AOD Slag Stability - a function of C 2 S form Volume increase: 12%

27 AOD Slag Stability - a function of C 2 S form Conversion of β-c 2 S to ϒ-C 2 S causes structural collapse (dusting) of the slag making it difficult to: handle store valorize Volume increase: 12%

28 AOD Slag Stability - a function of C 2 S form Conversion of β-c 2 S to ϒ-C 2 S causes structural collapse (dusting) of the slag making it difficult to: handle store valorize Potential for Cr leaching Volume increase: 12%

29 AOD Slag Stabilization Current Solution Add boron compounds after tapping the slag. But Borax is expensive Boron usage may be restricted in the future

30 Alternative Solution Stabilize with Alumina

31 Properties of VALOXY-treated AOD Slag Valoxy addition (w/w) 5% 10% 12.5% 15% γ-c 2 S 4.4% 3.9% 3.3% 1.9% Volumetric stability Unstable Stable Stable Stable Micro-hardness (HV) Spinel 6.1% 13.0% 12.1% 12.2% AOD slag stabilized by Valoxy 12.5% w/w

32 VALOXY as Slag Stabilizer Compared to conventionally treated slag: Improved mechanical properties Improved health and environmental properties Implying: Higher market value for the slag

33 VALOXY in Fire Resistant Geopolymers -Si-O-Si-O- -Si-O-Al-O- -Si-O-Al-O-Si-O- -Si-O-Al-O-Si-O-Si-O- -P-O-Si-O-Al-O-P-O- -(R)-Si-O-Si-O-(R) -Al-O-P-O- -Fe-O-Si-O-Al-O-Si-O-

34 VALOXY in Fire Resistant Geopolymers Geopolymer System KOH / SiO 2 K 2 SiO 3 Valoxy (w/w) 27% 16% Compressive strength 10 MPa Water absorption (24 hr) 14% 15% Fire resistance No damage, no creep

35 VALOXY in Fire Resistant Geopolymers Geopolymer formulations based on Valoxy met Europe s most rigorous standards for fire resistance. Low water absorption High compressive strength No fire damage

36 VALOXY in Steel Refining Powder Heated to 1500⁰C Cooled to 1350⁰C Valoxy Calcium aluminate pre-melted slag

37 VALOXY in Steel Refining Powder Calcium aluminate samples successfully synthesized from VALOXY and calcined lime. Melting pt. 1350⁰C excellent for steel refining. Chemical analysis suitable for intended application (CaO/Al 2 O 3 ratio 70%)

38 VALOXY Technical Benefits Application Cement Benefit Improved sintering Early setting Insulation Products Stainless Steel Slag Fire-resistant Geopolymers More robust ceramic lattice Stable micro-structure Reduce shrinkage Phase transformation inhibited Increased micro-hardness Cr (III) containment reduced leaching Met RWS standards for fire protection Refining powder for steel Suitable calcium aluminate produced October 2012

39 Recycled Alumina: Economic Drivers of Demand Supply stability Long-term fixed price structures Inexpensive compared to conventional raw materials Potential savings in operating costs October 2012

40 Recycled Alumina: Health, Safety and Environmental Sustainable product derived from existing industrial process Eliminates need for extraction of nonrenewable raw materials Pre-empts future health & safety concerns (borax) Drivers of Demand October 2012

41 VALOXY Recycled Alumina - Conclusion Commercial Benefits Environmental + Benefits = A Cost-Effective, Sustainable Alumina Source October 2012

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43 Profitability

44 Sustainable Development Profitability

45 Valoxy: turning a tug of war.. Profitability Sustainable Development

46 ...into a handshake Sustainable Development Valoxy Profitability

47 Thanks for your attention