Augmenting use of Non- Coking Coal in Steel Industry

Report
AUGMENTING USE OF NON-COKING COAL
IN STEEL INDUSTRY:
A C R Das
Industrial Adviser
Ministry of Steel
Government of India
New Delhi
4th Coal Summit
19-20th November
Hotel The Ashok, New Delhi
1
An Overview of Indian Iron & Steel Industry
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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 MT
2016-17- 149 MT
2019-20- 180-200MT
2020-50- 500 MT by 2050
2
STRUCTURE OF INDIAN STEEL INDUSTRY
• There are 11 Integrated Steel Plants (ISP)
• ISPs adopt different process routes namely, BF-BOF, BFBOF/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.
3
TECHNOLOGY MIX OF IRON & STEEL MAKING
Process Route
World
India
Oxygen 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
4
Techno-Economic Efficiency Parameters
Item
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
5
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
6
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.
7
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.
8
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.
9
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 50150 kg/thm as compared to 250 kg/thm (max) in the
world.
10
Techno-Economic Parameters in Europe
Country
Works
Belgium
France
Finland
Germany
Germany
Germany
Netherland Netherland
AM Gent
AM
Dunkerque
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
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
-
-
-
-
%
26.2
24.3
27.2
28.1
26.5
26.4
36.2
32.3
t/m3
2.18
2.24
3.44
2.57
2.80
2.49
3.18
2.64
Injection
Oxygen in
blast
Blast
Furnace
Productivity
(WV) x
24 hr
11
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
12
ALTERNATIVE IRON MAKING
Direct 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 Kilns
Natural Gas Based Shaft Furnaces
Syn-Gas Based Shaft Furnaces
 Modular Sizes of Rotary Kilns: low (100 – 500 TPD)
 Modular Size of Gas Based Plants: high (upto 2 MTPA)
13
DRI PRODUCTION IN INDIA/WORLD
Country
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)
14
Midrex Process Flow Sheet – DRI/HBI Production
15
Syn-Gas Based Midrex DRI/HBI Production
16
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:







Corex
Finex
ITmk3
HISmelt
HIsarna
FastMelt
Technored
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A schematic diagram of COREX process
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20
FINEX Process
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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
23
ITmk3 Process
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25
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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 bathsmelting 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
CO2 gas
Coal
Melting
cyclone
Iron Ore
Fines
Oxygen
Smelting Converter
Hot Metal
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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 5060% 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
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enhance PCI/CDI rate
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”
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