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AUGMENTING USE OF NON-COKING COAL IN STEEL INDUSTRY:
A C R DasIndustrial AdviserMinistry of Steel
Government of IndiaNew Delhi
4th Coal Summit19-20th November
Hotel The Ashok, New Delhi
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An Overview of Indian Iron & Steel Industry
• World Production of Crude Steel(2011): 1527 MT• Chinese production (46%) : 695.5 MT • India’s Crude Steel Production( 2011) : 72 MT• India is the 4th Largest Producer in the world.• India is the largest producer of Sponge Iron.• Indian Steel Production Increasing @ 8-10%(Decadal)• India to reach to 2nd position by end of 12th Five Yr. Plan• Present & Projected Steel Capacity in India:
2011-12- 90 MT2016-17- 149 MT2019-20- 180-200MT2020-50- 500 MT by 2050
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STRUCTURE OF INDIAN STEEL INDUSTRY
• There are 11 Integrated Steel Plants (ISP)• ISPs adopt different process routes namely, BF-BOF, BF-
BOF/THF, BF/Corex-BOF, DRI/HBI-EAF and DRI/BF-EAF plants• There are a large number of Mini Steel Plants(MSPs)
comprising of Electric Arc Furnace (EAF)/ Energy Optimising Furnace (EOF) and Electric Induction Furnace (EIF) units.
• MSPs includes: Stand-alone plants dependent on purchased inputs (steel scrap and sponge iron) and composite plants having captive sponge iron making facilities.
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TECHNOLOGY MIX OF IRON & STEEL MAKING
Process Route World IndiaOxygen Route (%) 70 BF/COREX/BOF/THF/EOF: 40
Electric Route (%) 30 EAF/DRI-EAF : 25
EIF/DRI-EAF : 35
NB: As per future projections, proportion of steel production through BF-BOF route in expected to increase in years to come
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Techno-Economic Efficiency ParametersItem Global Benchmark Indian Iron & Steel sector
BF Productivity (t / day / m3 of working
volume
2.5-3.5 1.5-2.5/2.8
Coke rate (Kg / t HM) 350-400 400-520
PCI (kg / t HM) 150-250 50-150
Energy Consumption (G cal / TCS
4.5-5.5 6-6.5
CO2 emission (t / TCS)
1.7 – 1.9 2.8 – 3.0
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INDIAN STEEL INDUSTRY: CHALLENGES
• Poor techno-economic performance parameters of Indian steel industry reflects that it is trailing behind the global standards
• Main problems relate to:– technological obsolescence in principle process sand– Lack of timely technological intervention and R&D – Lack of dedicated technologies for harnessing waste heat/
energy• Inferior quality of Raw Materials/ Inputs:
– High Alumina and high Alumina/Silica Ratio in Iron Ore – High ash in Coking/ Non-Coking Coal
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Overview of Blast Furnace(BF) Iron making• BF is the oldest and most established and also most efficient process
of iron making • Over 90% of total iron produced in the world comes from BF process• Blast Furnace essentially requires coke made from cooking coal.• Coke is made in coke oven (by-product/heat recovery)• Coke has three important functions in Blast Furnace:
Thermal (source of heat) Chemical (reductant) Physical (Supporting Burden & Imparting Bed Permeability)
• Coke must satisfy some basic minimum quality parameters viz., composition (high FC & low ash), proper size range, high strength (Cold & Hot), good reactivity etc. to ensure efficient BF operation with maximum productivity & minimum coke rate/energy consumption.
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Problems and issues with Indian Coking Coal
• BF Coke-making requires good quality of cooking coal usually prime cooking coal.
• Prime Coking-Coal is relatively scarce and costly and its availability is depleting sharply
• Prime Coking coal reserves limited and constitute only about 14 % of the total coal reserves of 252 Billion Tonnes in India
• The ash content in ROM Coking is very high (30-45%) and washing/ beneficiation is difficult because of techno-economic reasons
• Poor coke and iron ore quality are primarily responsible for poor performance of Indian BFs and higher energy consumption.
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Development of Alternative technlogies/ Practices for substitution of Coking-Coal
• Pulverised Coal Injection (PCI)/ Coal Dust Injection (CDI) to partially substitute Coking-Coal (Coke) in Blast Furnace by Non-Coking Coal/ other reductants.
• Alternative Iron Making Technologies: Direct Reduction of Iron Ore to produce sponge iron/
DRI using non-coking coal/ natural gas.Smelting Reduction (SR) of Iron Ore using non-coking
coal.
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Effect of PCI/CDI in BFs• CDI/PCI has picked up over the years across the world
to minimise coking coal use in BFs in view of its scarcity and cost
• 1 ton of coal dust/ pulverised coal replaces about 1 ton of coke resulting in saving of approx 1.4 ton of coking coal and equivalent coke making capacity thereby avoiding emission of pollutants/ GHGs
• PCI also helps in smooth operation of Blast Furnace with improvement in productivity
• PCI in Indian BFs is low, varying in the range of 50-150 kg/thm as compared to 250 kg/thm (max) in the world.
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Techno-Economic Parameters in EuropeCountry Belgium France Finland Germany Germany Germany Netherland Netherland
Works AM Gent AMDunkerqu
e
Ruukki Raahe
HKM TKS TKS Corus Corus
Coke Rate Kg/t/HM 261.9 266.1 319.0 289.0 262.6 289.5 245.6 271.1
Nut Coke Kg/t/HM 66.5 47.8 39.0 66.8 70.9 53.5 35.3 32.1
Total Coke Kg/t/HM 328.4 313.9 358.0 355.8 333.5 343.0 280.9 303.2
Coal
Injection
Kg/t/HM 169.7 171.5 - - 165.4 159.8 235.1 214.9
Oil Injection Kg/t/HM - - 100.5 23.5 - - 0.9 -
Natural Gas Kg/t/HM - - - 84.9 - - - -
Oxygen in
blast
% 26.2 24.3 27.2 28.1 26.5 26.4 36.2 32.3
Blast
Furnace
Productivity
t/m3
(WV) x
24 hr
2.18 2.24 3.44 2.57 2.80 2.49 3.18 2.64
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Enablers for High PCI rate in BFs• Injection of High PCI in BFs is dependant on several
factors: Good Coke quality (Coke M10 value 7 (max), M40 value 81-
88%, CSR 66% (min) Slag Rate (max): 300 kg/thm (preferably 280 Kg/thm) Hot Blast Temperature: 1150 C (min) Oxygen enrichment: 3-5% or more
• PCI coal essentially requires appropriate quality of non-coking coal characterized by low Ash: 12%, VM: 12-15%, CSN: (-) 3%, HGI: (+) 75%, Ash Fusion Temp: IDT- 1300°C and Final Flow Temp: 1500°C
• Such PCI coal is not readily available in India and is being imported
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ALTERNATIVE IRON MAKINGDirect Reduction of Iron Ore Process of directly reducing iron ore (lumps/ Pellets)
in solid form itself Product known as Direct Reduced Iron (DRI) or
Sponge Iron Two main Processes:
Non-Coking Coal based Rotary KilnsNatural Gas Based Shaft FurnacesSyn-Gas Based Shaft Furnaces
Modular Sizes of Rotary Kilns: low (100 – 500 TPD) Modular Size of Gas Based Plants: high (upto 2 MTPA)
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DRI PRODUCTION IN INDIA/WORLDCountry Production, MT
2008 2009 2010
India 21.1 22.03 23.81
Venezuela 6.87 5.6 5.80
Mexico 6.01 4.15 5.22
Iran 7.46 8.2 9.10
Saudi Arabia 4.97 5.03 5.96
Russia 4.56 4.67 4.60
World 66 65 71
India is the largest DRI producer (75% Coal Based & 25% gas based)
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Midrex Process Flow Sheet – DRI/HBI Production
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Syn-Gas Based Midrex DRI/HBI Production
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Alternate Iron Making – Smelting Reduction• Process of converting Iron Ore into Hot Metal/ Pig Iron using
non-coking coal directly bypassing conversion of coal into coke• Also known as Direct Smelting • Several Processes have been developed, some of which are
commercially available and others are in the process of development
• Commonly known SR Processes are:CorexFinexITmk3HISmeltHIsarnaFastMeltTechnored
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A schematic diagram of COREX process
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FINEX Process
CO2
RemovalPower Plant
Oxygen Plant
Fine Ore Non-coking Coal
R4
R3
R2
R1
Fluidized BedReduction
CoalBriquetting
Hot DRICompaction
ProcessOptimization
CO2
RemovalPower Plant
Oxygen Plant
Fine Ore Non-coking Coal
R4
R3
R2
R1
Fluidized BedReduction
CoalBriquetting
Hot DRICompaction
ProcessOptimization
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Production of Iron nuggets
• Ore + coal composite pellets: Reduction & melting at 1500C in RHF
• It produces almost low sulphur pure iron nuggets (& slag globules)
• Technology: Kobe Steel, Japan
• 0.50 MT: Minnesota, USA • 0.50 MT: ASP, Durgapur
(Proposed): Rs 1500 Crores
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ITmk3 Process
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Key features of HIsarna Smelter Technology of ULCOS
ULCOS: Ultra-low Carbon di-oxide Steeelmaking:
European consortium of 48 companies: Cooperative
R&D Programme: Develop processes for reducing CO2
emission of today’s best routes by at least 50%:
HIsarna for ironmaking (HIsarna for the process ("HI" from HIsmelt and "sarna" from Isarna, a celtic word for iron).
BF Top gas recycling, etc.
HIsarna is a single-step technology based on bath-
smelting of iron ore to produce liquid iron like HM of BF.
The main purpose is to improve energy efficiency by at
least 20%.
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Hisarna Ironmaking Technology
Coal Iron Ore Fines
CO2 gas
Oxygen
Smelting Converter
Hot Metal
Melting cyclone
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Discussions & Conclusions• BF has been and will continue to be the workhorse for Hot Metal
production.• BF process has undergone substantial improvements in terms of
size, capacity, efficiency, use of coke, waste heat recovery etc. • Coke-making has also undergone several changes to produce
good quality coke from inferior coking coal/ non-coking coal.• From 100% use of coke in the past, modern BFs use only 50-60%
coke, balance being non-coking coal (PCI/CDI).• Indian BFs need to bring in Technological upgradations to
introduce/ improve PCI/ CDI rate. • Good quality coke/coal is key to BF operation and also to reduce
coke rate in BF. Good quality NCC is also necessary to enhance PCI/CDI rate
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Discussions & Conclusions (Contd.)
• Overall DRI production (and particularly natural gas based DRI production in middle east countries) increasing
• DR & SR process will continue to play complementary/ supplementary role in overall iron/steel production.
• Coal /Coke consumption cannot be reduced below a theoretical minimum. Worldwide R&D in progress for development of path breaking processes to further reduce use of fossil fuel in BF and /or substitute use of coal by non-fossil fuel for addressing climate change issues.
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“THANK YOU”