Presentation by Yiannis Pontikes at TMS 2016, Nashville, Tennessee

1. Valorization of Bauxite Residue
in a Technologically Realistic,
Financially Viable Process:
Are We Getting There?
Yiannis Pontikes, Efthymios Balomenos,
Peter Tom Jones, Koen Binnemans
February 2016

2. Disclaimer
• This is a biased presentation, that goes beyond presenting
facts
• It is based on the assumption that reality is a choice and
that depending on effort allocated, this can change
• It is also based on the assumption that there is a sincere
interest in all stakeholders in creating this alternative reality
• Which alternative reality, requires robust science and
technology, and “financial numbers that make sense”
• Which will eventually happen, by leaders taking
(calculated) risk, when others will just try to defend
business as usual

3. 3
Summary of what will follow
I. R5: revisiting “reality” via realistic and reliable
research.
II. Getting things done
III. Where BR becomes an asset.

4. Example 1
Red mud can not be filter-pressed to a cake
25 April 2006
“A Success Story”. Aluminium de Grece (AdG) has installed
a High Pressure Filter Press early this year, in order to
progressively cease sea disposal for Red Mud. The overall
cost exceeded 2 million euros. In the near future a second
Filter Press is expected to be installed and then the whole
quantity of produced Red Mud will be processed in this
manner. The resulting semi-dry product, is named “Ferro-
alumina” and there are concrete hopes for its marketing.

5. Example 2
Red mud is a waste
From 2007 onwards, Ferroalumina is used in cement
production in Greece and the same applies for many other
countries. Other applications are in heavy clay ceramics,
filler in plastics, roads etc. Yes, indeed, the total volume is
still low…

6. Example 3
Red mud cannot find high added value applications
High purity multi-wall carbon nanotubes
(MWCNTs), diam. 20nm to 55nm were produced
via Chemical Vapour Deposition at 700°C, in 30%
C2H4/He.
Karachalios, T., Pontikes, Y., Kouravelou, K., Nitodas, S. Bayer’s process bauxite residue
(“red mud”) as catalyst for the production of low cost carbon nanotubes. International
Conference and Exhibition of the European Ceramic Society. June 2009.
Alkaline & non-
magnetic, sodicity:
51.4 mg/g
Non-alkaline & magnetic
33 % carbon content,
sodicity: 28.9 mg/g
Stabilized, non-
acidic high-
energy density
oil
Pressure, temp
Pyrolysis bio-oil from
ligno-cellulosic
biomass
See work by Schlaf group at Guelph University, Canada

7. Example 4
Use of red mud cannot really go beyond laboratory scale
AoG pilot plant facility for pig iron production and mineral wool in Greece
during the FP7 ENEXAL project.

8. The message to take home is that there is work being done and that
reality is region/plant specific.
Some claim red mud is a residue that waits (who? what?) to be used,
others develop processes for recovering Na (and the rest?) or use a
fraction as an aggregate (the rest? Is that financially sound?), others
develop processes that will be upscaled (maybe) in the next decades.
In the meantime, the major red mud producer is China and by the
time “something that works” is developed, (some?) alumina refineries
in Europe (US? Australia?) will be only dealing with legacy sites.
Can we develop something
in the next decade?
Yang Cao, Metal Bulletin Research

9. Let’s start by communication…

10. We are building an open, inclusive
and respectful network of
knowledgeable individuals, the
LinkedIn Coalition of the Willing
:-)
There are >600 members…
and find like-minded ones

11. A number of exceptional people work on bauxite residue
and we try collectively to mobilize more resources.
and research partners

12. We underestimate serendipity,
luck, coincidence and the likes…
(and be open to the surprises of life...)
• The accident at Ajka created a
sequence of events and brought
in the surface other accidents
also.
• The Chinese put REE export
quota > to be replaced by a
resources tax (?)

13. …while building critical mass through projects
“EURARE: Development of a
sustainable exploitation
scheme for Europe’s REE ore
deposits”
NOVEL TECHNOLOGIES FOR
ENHANCED ENERGY AND EXERGY
EFFICIENCIES IN PRIMARY ALUMINIUM
PRODUCTION INDUSTRY
2 x DBOF scholarships
15 PhD thesis all over Europe

14. 15 PhD thesis all over Europe
Partners: KU Leuven, UHelsinki, RWTH Aachen, KTH, NTUA, UTartu, MEAB, Aluminium of
Greece, Titan
Partner Organisations: UPatras, UAveiro, Bay Zoltan, Tasman Metals
Funding: 3,7 M EURO
…while building critical mass through projects

15. …where we set principles
Mud2Metal H2020 proposal
Building materials industry
Zero-waste
Industrial symbiosis

16. …fighting perception

17. …and results are disseminated
CR3
SIM2
EIT KIC
JSM

18. …and indeed we produce results
Nuccetelli, C., Pontikes, Y., Leonardi, F., Trevisi, R. (2015). New perspectives and issues arising from the introduction of (NORM)
residues in building materials: a critical assessment on the radiological behaviour. Construction & Building Materials.
Country
(25 MS)
4 brick walls +concrete (f+c) in standard room (nGy h-1)
*RM%=0 *RM%=10 *RM%=20 *RM%=30
Austria 73 101 129 157
Belgium 77 106 134 162
Bulgaria 94 122 150 178
Cyprus 17 49 81 113
Czech Rep. 104 132 159 187
Denmark 142 172 202 232
Estonia 58 88 119 149
Finland 130 157 185 212
France 88 117 146 175
Germany 134 162 190 218
Greece 79 107 135 163
Hungary 91 118 146 173
Ireland 71 100 129 158
Italy 78 106 135 164
Lithuania 92 120 148 176
Luxembourg 211 233 256 278
Netherlands 90 119 147 176
Poland 152 182 212 242
Portugal 155 181 208 234
Romania 135 163 191 219
Slovakia 104 132 159 187
Slovenia 160 185 209 234
Spain 105 132 159 185
Sweden 267 291 316 340
UK 112 141 169 198
Gamma dose rate in EU-MS assuming different bauxite residue addition to the mixture of bricks; * RM average activity concentrations

19. …and results
Borra, C., Pontikes, Y., Binnemans, K., Van Gerven, T. (2015). Leaching of rare earths from bauxite residue
(red mud). Minerals Engineering

20. …and results
Borra, C. R. E, et al, Smelting reduction of iron oxides from bauxite residue in view of improved rare earths leaching, Journal of
Sustainable Metallurgy (accepted)
Reduced BR (mixed with 20 wt.%
wollastonite, 5 wt.% graphite, 1500 °C).
Effect of acid concentration on leaching of REEs and iron
(HCl, T: 90 °C, t: 1 h, L/S: 50)

21. …and results
• Increase in acid amount increases the
recovery
• No increase in REEs recovery beyond
H2SO4 to BR ratio 1
• REE dissolution except Sc is >80%. Sc
dissolution is max. 65%
• Increase in recovery of Al, Ti and Fe with
increase in amount of acid
• No change in the Na and Ca dissolution
with acid amount
• Ca dissolution is low due to solubility limit
Borra, C.R. et al., Bauxite Residue Valorisation and Best Practices Conference, 5-7 October, 2015, Leuven, Belgium

22. …and results
In the paper of Gamaletsos et al., the crystal that hosts Th is identified for
the first time ever
Th
Ca
Ti
O
Gamaletsos et al. The role of nano-perovskite in the negligible thorium release in seawater from Greek bauxite residue (red
mud), Scientific Reports, accepted (2016)

23. …and results; focus on binders
Binders are used as an inorganic “glue” to keep together
aggregates and form a monolith. The use of the monolith can
be from a surface coating finish to a bulk, voluminous wall
structure.
Although they are “low value” stream compared to metal
production, they can accommodate substantial volumes of
BR.
Two areas are explored:
cementitious binders
(ask me!)
inorganic polymers
(slides follow)

24. …and we produce results; focus on IP
Ways to make IP from BR
• With additives (e.g. fly ash, silica fume etc)
• After heating (at 500-800 deg. C)
• After melting > our process under development at SREMat;
there is a second process also explored

25. …and we produce results; focus on IP

26. …and we produce results; focus on IP
Hertel, T. et al., Bauxite Residue Valorisation and Best Practices Conference, 5-7 October, 2015, Leuven, Belgium

27. …and we produce results; focus on IP
Hertel, T. et al., Bauxite Residue Valorisation and Best Practices Conference, 5-7 October, 2015, Leuven, Belgium
Compressive 13 MPa 20 MPa 44 MPa
Flexural 4 MPa 6 MPa 10 MPa

28. …and we produce results; focus on IP
BR slurry Filterpressing
BR “dry” Alkali solution
Optional addition of
<15wt% SiO2/CaO/C
Firing in rotary kiln at
1100-1200 °C
Boiling/additives for
alkalinity increase
Mixing and
casting
New product!

29. …and we produce results; focus on IP
BR slurry Filterpressing
BR “dry” Alkali solution
Addition of >20wt%
Na2CO3
Firing in rotary kiln at
1100-1200 °C/
or sinterbed…
Boiling/additives for
alkalinity increase
Mixing and
casting
New product!
Recovery of water-
leached Al, Na
Magnetic recovery of Fe

30. In summary
Typically, wt%
SiO2 8
Al2O3 20
CaO 15
Fe2O3 45
others 12
Beneficiate bauxite.
Remove FeOx in
bauxite, either by
magnetically separating
after milling (under
CO/CO2) or by acid
leaching. Flotation to
separate silica, others?
Towards
zero-waste
Remove FeOx in the slurry,
either by electrolysis or
magnetic separation
Remove FeOx after roasting
(alkali added or not)
Remove FeOx
after smelting
Sequential “Bayer”
like process to recover Al
• Mineral wool
• Sc extraction and ?
• Inorganic Polymers
• Calcium Aluminate
Cements
Fe smelting, Sc leaching and ?
Water leaching for Al
Bayer process
Acid leaching to
separate Th (Ca-
titanates) and (?) REE
Can be a whole
hydrometallurgical acid-
based process to
separate Fe, Al, REE…
Use FeOx as a “flux”
in a roasting process
• Extract Al, Na
(water leaching)
• Extract Fe
(magnet)
• Use the residue
for Inorganic
Polymers

31. Instead of conclusions
• Reality is a convention, a photograph in time.
• We have moved within few years only, from sea disposal
creating an azoic zone, to filter-presses and valorisation of
a fraction of BR.
• It seems that there is momentum and some solutions will
be implemented in the next decade, leading to less
disposal and more products with BR.
• Stewardship from industrial partners will accelerate the
transition.
• All is left, is for us to demonstrate the process…and things
will happen!

32. Thank you!