The production of Liquid Iron by Orbitting plasma technique in a few micro seconds using fine ore such as Taconite(Fe3O4) Concentrates coupled with other technological advancement is a significant breakthrough for quality and cost-effective production of Ironmaking.

1. Plasma Technology for
Quickest Ironmaking
Presenter: Zohaib Akbar
Metallurgical and Materials Engineering
NIT Durgapur

2.  Abstract
 Introduction- Other process of Iron making
 What is Plasma Technology
 Why Plasma Technology
 Design of Plasma Reactor
 Operational Procedures
 Discussion of Mechanism
 Limitations
 Other areas of Plasma Technology in Metallurgy
 Plasma Technology in Relevance to INDIA
 Future scope
 Conclusion
 References
Points to follow……

3. The production of Liquid Iron by Orbitting plasma technique in a
few micro seconds using fine ore such as Taconite(Fe3O4)
Concentrates coupled with other technological advancement is a
significant breakthrough for quality and cost effective production
in the field of Iron making.
Abstract

4. 90% of world Iron production
is obtained through
BLAST FURNACE
route using Iron Ore and
‘COSTLY & SCARCE COKE’
as a raw material.
Introduction…

5. IS EVERYTHING FINE WITH BLAST FURNACE ROUTE OF
IRONMAKING?
NO

6. THREATS FOR BF – COKING COAL
DIMINISHING
RESOURCES
INCREASING
PRICES

7. THREATS FOR BF – LARGE AMOUNT OF FINE ORE
WASTAGE
LARGE AMOUNT OF DISCARDED
ORE FINES

8. THREATS FOR BF – ENVIRONMENTAL
CONSIDERATION & WATER CRISIS
EXTREME POLLUTION
DUE TO TOXIC GASES
LARGE AMOUNT OF
WATER BEING USED
IN PLANT

9. Production of Direct Reduced Iron(DRI) – 64371 ton in 2014
Smelting Reduction for production of liquid Iron
COREX, FINEX, HISMELT etc.
ADVANTAGES:
Using Non-Coking Coal
Eliminating the need for Coke oven plant and Sinter Plant
Smaller land /Area
Environmental pollution decreases.
Alternative Ironmaking processes …

10.  Partial pellet is a must for COREX process
 Large amount of Oxygen Gas Consumption
 Temperature control problem
 Pollution hazards is still significantly high..
DISADVANTAGES OF DRI & SMELTING REDUCTION
PROCESSES

11.  Lower cost
 Better process control
 Better product quality
 Low Noise and other Environmental
hazards
Hence…. Another Technology
evolved called..
“PLASMA TECHNOLOGY”
…..But what Steel Researchers want is…

12. Let us understand the physics of Plasma…..
 Plasma is the 4th state of matter.
 Consists of massive free electrons and positively
charged particles called Cations mixed together.
 Plasma is produced when gas is exposed to either a
high temperature or high voltage electricity is passed
through it.
 Neither specific Shape nor Volume.
 Are Plasma and Gases similar?
 Conduct electricity
 Produces and responds to Magnetic fields.
PLASMA TECHNOLOGY

13. Orbiting plasma technology produces iron directly from fine
magnetite(Fe3O4) concentrates in a few micro seconds in a single
stage.
Eliminating need for BF units, Sinter plant, Coke Oven resulting in
Low energy Consumption.
Low S and Low P metal is obtained because high temperature
within plasma.
Even though Taconite(Fe3O4) contains as high as 6% SiO2 and
lignite char has 2% S . Sulphur in the final product becomes almost
nil and Si around 0.08-0.1% respectively.
Higher thermal efficiency causes elimination of tar, phenol,
aromatic hydrocarbon thus reducing cost of cleaning.
WHY PLASMA TECHNOLOGY ?

14. Design of Orbitting Plasma Reactor
REACTOR CONFIGURATION OF AN ORBITTING PLASMA

15.  Cylindrical upper part of 40⸗ diameter and 26⸗ height
with water cooled roof and slide gate openings for
feeding of charge and gas. For supplying heat to the
melting vessel, a graphite electrode ranging from 0.5 -
4⸗ diameter at the furnace top is installed.
 The lower part is in shape of truncated cone having a
bottom diameter of 30⸗ and height 45⸗.
 The furnace has provision for side injection of solids
through 3 ⸗ diameter hollow graphite electrode. This
hollow electrode is an auxiliary anode for plasma
heating.
Design Contd….

16.  The furnace shell is lined with refractory materials called as
Fibrefrax Duraboard that is reinforced with fire clay and finally
with alumina bricks to withstand the possible thermal and
physical chemical attack.
Design contd….
Cone height(mm) 100
Anode diameter(mm) 100
Volts 150-220
Amperes 350 - 400
Power kW 52 - 88
Plasma gas (Ar) L/min 9-19
Arc rotating RPM 8 - 30000
Feed rate kg/min 150
Operating Condition for Orbitting Plasma is tabulated

17.  Rotating arc plasma is produced
through mechanical, magnetic or
electronics means. In this reactor the
low temperature plasma generated is
made to orbit because of magnetic
influence which is made to energize
the 6 anodic segments sequentially
around 1 central cathode.
 Two distinct charge fields, i) inner
field where the charges are accumulating
ii) outer field where the charges are
dispersed.
 Only at a higher orbiting fields
charges accumulation in the inner field
get well established and whole of the
cone fills with freely ionized highly
turbulent plasma.
Operational Procedures of Orbitting Plasma reactor
Simplified Scheme for Segmented
anodes to effect an Orbitting Plasma

18.  Mixed charge of taconite and
carbon bearing materials was
introduced through the feeder at
the top, it got into the plasma and
particle reacted vigorously while
falling into stream flow pattern
depending on the rotational control.
 Excellent thermodynamics and
kinetic medium for the reduction of
iron ore concentrates.
 Plasma as a medium is utilised
not merely a heat source
Operational Procedures of Orbitting Plasma reactor Contd….
Conceptual representation of falling
charge particles in an orbitting plasma

19.  The smelting particle passed from this free flow zone and get
collected at the bottom crucible.
 It is not cooled if direct production of hot metal is desired
otherwise it will be cooled by jacket assembly containing
de-ionised water.
 The cooling jacket assembly for the main reactor must have
to be extremely non corroding in order to ensure nil leakage.
 Ar is used as Plasma gas.
 The requirement of Ar gas used in the experiment was quite
low i.e. 0.85 m3 per hour for a 100 kW reactor.
Operational Procedures of Orbitting Plasma reactor
Contd….

20. Discussion of mechanism…..
 No Metallization in the product can be obtained with less than
100% stoichiometric level of carbon
Fe3O4+ 4C= 3Fe+ 4CO(ΔH=+ve)
But an increase in power input
from 30 to 60kW for the same
particle feed rate degree of
metallization increases.
 Metallization begins after
30% reduction of the Fe3+ to Fe2+
following conventional
thermodynamics sequence
3 Fe2O3 ----- 2(FeO.Fe2O3)------ FeO ---- 6Fe

21. Discussion of mechanism…..
 To attain more effective product i.e. greater degree of
metallization in shorter time it is important to use particle
loading rate and to charge carbon in excess about 200%
stoichiometric which results in metallization beyond 96%.
 The high particle rate on one hand helps in obtaining highly
turbulent plasma for better reaction kinetics and on the other
hand curtain of falling feed stocks shielded the refractory lining
from excessive wear.
 At high orbiting rates of 30000 rpm needed excess reductant to
be present to prevent re-association of the oxygen with
dissociated oxide immediately on leaving the plasma.

22. Limitation of Plasma Technology
 The increasing cost of electrical power is a huge concern.
 The energy consumption figure will have to be compared with
sufficient power available.
 The plasma technology is still under development and their
industrial application is limited. So large tonnage production is
still not viable.
 Conservative thinking and insufficient financing of big
metallurgical companies.

23. OTHER AREAS OF PLASMA TECHNOLGY IN METALLURGY
 Production of Ferroalloys through plasma technology, an
undergoing project at Bethlehem Steel and the University of
Torronto.
 In the foundry. 2.5 t/hr Cupola is being retrofitted 20MW plasma
torch for attainment of high temperature without combustion.
 In non ferrous extraction e.g. refining of Ni base alloy in plasma
induction furnace, production of Ti Slab ingot, molybdenum
metals. Formation of refractory metals like Nb.

24. In Relevance to INDIA
 Productivity of BF in the world e.g. Japan, USA, Europe
2.0 t/m3/day
 The Productivity of Indian furnaces less than 1.0 t/m3/day .
 The reason behind it is deteriorating quality of raw
materials(high ash coking coals and high gangue ores) out-dated
equipment and technological obsolescence.
 Scarcity of Coal, Pollution creating agents and the world scenario
of steel sector indicates that applying radical technologies for
newer processes are more necessary than modification in BF.
 Evidently at this stage plasmasmelt process of liquid Iron making
appears worthwhile. The utilisation of iron ore fines as the
charge and non-coking coal as the reductant and plasma as heat
energy is beneficial in the national perspective for low cost hot
metal route with a good quality and minimum pollution.

25. CONCLUSION
 The possible development in iron production can’t be viewed in
isolation and has to be measured within the economy and
development in international trade.
 In South Africa Union steel company, 300000 ton/year plant
equipped with a 40MW capacity of plasma arc that will use
plasma for sponge iron making.
 Although the replacement of coke by coal and utilisation of fines
looks attractive but the consumption of energy is a drawback for
plasmasmelt process.

26. FUTURE SCOPE
The lack of Quality ores on one
side and diminishing resources
on the other side are favourable
perspective for future application
for plasma technologies in
metallurgy.

27. REFRENCES
 Ganguly, Amit, Lee, Reid, K J Steel Resin press.
 Orbitting plasma for Direct Smelting of Iron Ore Concentrates by
Dr. Amit Ganguly
 Ganguly, Amit, Paul, A K and Choudhury, B R : paper on
Engineering evaluation for Alternative Iron making
processpresented at International symposium on progress in
metallurgical Research at IIT Kanpur, India, Feb 1985