Importance of disposal, storage and recovery of Red mud in the present scenario.

1. Red mud processing and utilization
KISHAN KUMAR MAHILANGE
16MS06013
MATERIAL SCIENCE & ENGINEERING
IIT BHUBANESWAR
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2. CONTENTS
Introduction to red mud
Composition of red mud
Environmental problems associated with
disposal of red mud
Storage and disposal of red mud
Neutralization of red mud
Utilization of red mud
Conclusion
References
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3. INTRODUCTION
 Red mud or red sludge is a
high alkaline waste product
that is generated in the
production of alumina from
bauxite in the Bayer process.
 Depending on the raw
material processed, 1–2.5 tons
of red mud is generated per
ton of alumina produced..
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4. What does Red mud consist of?
Red mud from
alumina production
(70% NaOH
solution+ 30% BR)
Disposed and settled red mud Dry bauxite residue
(>65% solid content)
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5. Bayer’s process of alumina production 5

6. Typical composition of red mud:-
Composition Percentage
Fe2O3 30-60%
Al2O3 10-20%
SiO2 10-20%
Na2O 2-10%
CaO 2-8%
TiO2 trace-25%
Company Al2O3
(%)
Fe2O3
(%)
SiO2
(%)
TiO2
(%)
Na2O
(%)
CaO
(%)
BALCO, Korba 18.10-21.0 35.0-37.0 6.0-6.5 17.0-19.0 5.2-5.5 1.7-2.2
HINDALCO,
Renukoot
17.5-19.0 35.5-36.2 7.0-8.5 16.3-14.5 5.0-6.0 3.2-4.5
HINDALCO,
Muri
19.0-20.5 44.0-46.0 5.5-6.5 17.0-18.9 3.3-3.8 1.5-2.0
HINDALCO,
Belgaum
17.8-20.1 44.0-47.0 7.5-8.5 8.2-10.4 3.5-4.6 1.0-3.0
MALCO,
Metturdam
18.0-22.0 40.0-26.0 12.0-16.0 2.5-3.5 4.0-4.5 1.5-2.5
NALCO,
Damanjodi
17.7-19.8 48.2-53.8 4.8-5.7 3.6-4.1 3.8-4.6 0.8-1.2
Chemical composition of Indian red mud:-
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7. Environmental problems of red mud:-
 Disposal of red mud is typically problematic for most alumina refineries.
Red mud is disposed as dry or semi dry material in red mud pond or
bauxite mines. Untreated red mud has such high pH (typically 11-13) that
plant growth is impossible and this posses a very serious and alarming
environmental problem.
The environmental problems associated with the disposal of red mud are:
• Its high pH
• Alkali seepage into underground water
• Safety storage problem
• Alkaline airborne dust emissions
• Vast area of land required for disposal.
• Minor and trace amounts of heavy metals and radionuclides seepage into
ground water.
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8. Red mud spill/disaster in Hungary drew world attention in
2010 - Ajka Alumina plant accident,Hungary
In October 2010, approximately one million cubic meter of red mud from an
alumina plant near ‘Kolontar’ in ‘Hungary’ was accidently released into the
surrounding contryside and flooding several nearby localities, including the
village of Kolontár and the town of Devecser. Known as big “red mud
disaster" claimed 10 lives, 150 were seriously injured.
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9. STORAGE AND DISPOSAL OF RED MUD
 Most of the bauxite residue produced is stored on land for
future rehabilitation or use called red mud ponds/stacks or
bauxite residue disposal areas (BRDAs).
 Disposal methods:
• CCD- closed cycle disposal (traditional method)
• MCCD- Modified closed cycle disposal
 Current methods:
• Sea water discharge
• Lagooning
• Dry stacking method
• Dry disposal
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10. Traditional method-CCD
Modified-MCCD
Red mud disposal lake in the vicinity
of Kashipur region of Orissa,India
The pond of NALCO factory in Damandjodi
(India)
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11. Dry disposal:
• Dry filtered cake
• Solid content:>65%
• Transported by trucks
• minimizes the land area
required for storage
• Minimizes the risk of leakage
to groundwater
Dry stacking:
• Paste like, thixotropic
• Solid content:>48-55%
• Pumped via pipeline
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12. Sea water discharge:
• From the mud washing
circuit
• Solid content: 30-40%
• Via pipeline or ships
• reduce caustic soda levels
Lagooning:
• From the mud washing
circuit
• Solid content: 30-40%
• Via pipeline or ships
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14.  Acid neutralization: :
 Carbon dioxide
treatment :
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NEUTRALIZATION OF RED MUD

15. UTILIZATION OF RED MUD
 Building and chemical industries:
• Building materials, engineering constructions
• Paving blocks
• As a feedstock for manufacturing Adsorbents
and catalyst supports
• Ceramics, glasses, paints, polymers, coatings
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16. Continued….
 Waste water treatment:
• For removal of toxic heavy metal and metalloid ions,
inorganic anions such as nitrate, fluoride, and
phosphate, as well as organics including dyes, phenolic
compounds and bacteria.
 Metallurgy:
• Steel making, additives for slags
• Selection of main components (Fe, Al)
• Selection of other metals (Ti, V, RM)
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17. Recovery of metals
 Two main approaches which have been generally
investigated to recover iron values are based on :
a) Solid state reduction of red mud followed by
magnetic separation to recover iron; and
b) Reduction smelting in a blast/electric/low shaft
furnace (with or without pre reduction) to produce pig
iron.
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18. Continued…
 National Metallurgical Laboratory (NML), Jamshedpur
has evaluated technical feasibility of Al2O3 extraction,
along with Vanadium oxide, from Muri red mud by
Soda-Lime sinter process.
 Prasad and co-workers have explored the production of
ferrotitanium to utilize both iron and titanium values
of Indian red muds.
 Recovery of Fe, Al2O3,V and Cr from red mud has
been developed by Regional Research Laboratory
(RRL), Bhubaneswar.
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19. CONCLUSION
 Red mud has wide range of application from building material to
metal recovery.
 Developments in dry disposal methods will lead to better
management of residue but neutralization of red mud will be an
essential ingredient of any permanent solution.
 Continuous research is required by studying residue neutralization
technologies to reduce alkalinity of red mud which is the most
important barrier for its reuse and disposal management.
 Red mud ponds can be rehabilitated by growing suitable flora and
fauna on it.
 Depending on mud characteristics, a systematic strategy should be
taken up by each alumina plant and a zero waste alumina refinery
may be realized by developing a universal technique of disposal,
management and full utilization of red mud.
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20. References
 Current Status of an Industrial Waste: Red Mud an Overview by
Sucharita Patel, B.K. Pal, Nit Rourkela, Orissa
 Neutralization and Utilization of red mud for its better waste
management by Suchita Rai, Kailas L. Wasewar , Changkyoo
Yoo.
 Agrawal, A., Sahu, K.K.., Pandey, B.D., (2004). Solid waste
management in non-ferrous industries in India. Resources,
Conservation and Recycling 42 99–120.
(http://www.sciencedirect.com/science/article/pii/S092134490300
168X).
 U.S. Geological Survey, Mineral Commodity Summaries (2015).
(http://minerals.usgs.gov/minerals/pubs/mcs/2015/mcs2015.pdf)
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21. Waste is waste if you waste it.
Otherwise it is a resource. 21

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