Application of organic polymer in coke making-Tata Steel Scenario
Debjani Nag, Bidyut Das & P. S. Dash
Tata Steel, India
What We Have For Today
2
Tata Steel India- Overview
Coke Making Process in Tata Steel, India
Background
Challenges
Innovation
Idea to Innovation- The Journey
Results
Impact
Tata Steel India- Overview
3
Coke Making Process- Tata Steel
4
Recovery Non-recovery
CP1 CP2 Battery 10& 11 KPO HMC
Battery 5 6 7 8 9
No of ovens
144 70 176(88*2) 176(88*2) 352(88*4)
mtpa 1 1 1.4 1.4 1.2
Stamp charging technology
5
• Installed in Tata Steel, in January 1989
• Crushing fineness : 90% below 3.2 mm
• Bulk density: 1150 Kg/m3
• Utilization of inferior coal (increment of semi soft coal from 60 to 80%)
• Widens the choice of coal
• Improved coke quality
Concern-Coal cake stability; swelling/shrinkage of coal cake
Background
6
65%33%
25%
Cost
Energy
CO2emission
Role of coke in blast furnace iron making
Act as a fuel by providing thermal energy. Provides CO for the reduction of iron oxides. It provides the permeability and the mechanical
support to the burden.
Important properties of coke
Hot strength (CSR-coke strength after reaction) Cold strength (M40 and M10- micum indices) Size (AMS-arithmetic mean size) Chemical (Ash etc) GCQI – Composite index of CSR/M40
Tata Steel , India scenario ~12 MT coal charged/anum in which ~ 7.5 MT is imported
Import of coking coal in India FY 16-17 ~ 160 Mt
Background
7
Challenges
• Improvement in Coke Quality
60
65
70
75
Coke
Str
engt
h Af
ter R
eact
ion …
Present
Target
• Use of Cheaper Raw Material
10
50
90
50
0102030405060708090
100
Present Target
%
Inferior/Non-coking…
Key Challenges
Improvement of Blast Furnace Productivity
Hot Metal Cost Reduction
Ideas Improvement in Coke
Quality
Use of Cheaper coal
Typical Blast Furnace
8
Option for Coke Quality Improvement & Effects
By using more Prime Hard coking coal in the blend --- Increase Cost of coke
By increasing soaking period and reducing oven temperature – Loss of coke production and cost increase
Optimizing coal crushing – Infrastructure to be built
Maximizing coal bulk Density-- battery health will effect
Use of chemicals in the coal – Easy to implement – overall benefit to be seen
Addition of specific organic chemicals to mimic the useful part of coal
9
Overview of Coal Carbonization
10Only semi-coke
& coke
Plastic Mass, Semi-Coke &
Coke
Few hours after charging
Semi coke
Tar & gas
Plastic mass
Just after charging
Steam formation
Steam condensation
Coal
Coke at Pushing
Coke
1 2 3
45
The Innovation
Why Phenolic Resin?
I. Mimics “Liptinite” of coal
II. Improves fusion between
coal macerals
402.4
411.1
435.6
445.2
505.4
691.6
757.8
814.2
913.
2
1014
.510
46.5
1101
.4
1235
.71370
.7
1511
.3
1594
.5
1784
.7
1885
.2
2016
.9
2923
.3
3319
.6
3847
.138
76.7
RESIN
-15
-10
-5
0
5
10
15
20
25
30
35
40
45
50
55
60
%Tr
ansm
ittan
ce
500 1000 1500 2000 2500 3000 3500 4000 Wavenumbers (cm-1)
411.5
430.4
472.5
540.2
699.6
750.5
811.3
872.1
914.1
1032
.51374
.1
1446
.11603
.516
57.0
1904
.6
2922
.2
3044
.5
3542
.5
3619
.736
65.7
3693
.4
3847
.2
RC/129/14-OK AY NORTH
10
15
20
25
30
35
40
45
50
55
60
65
70
%Tr
ansm
ittan
ce
500 1000 1500 2000 2500 3000 3500 4000 Wavenumbers (cm-1)
Resin
HCC
Comparative FTIR of Resin and Hard Coking Coal (HCC)
11
Liptinite
Phenolic Resin- Characterization
12
@ 2
5 de
gC
@ 4
20 d
egC
A: 100%H: 100%W: 100.%
A: 109%H: 108%W: 113.%
A: 100%H: 100%W: 100.%
A: 126%H: 117%W: 127.%
Phenolic Resin- Characterization
13
TGA-DTA profile MS profile
Idea to Innovation- The Journey
Idea Lab Top Charge
Heat-Recovery
FY 13- 14 FY 14-15
Idea
Gen
erat
ion
Labo
rato
ry
Stud
y
Plan
t Tri
al I
Plan
t Tri
al II
Lab scale study was conducted in 7 kg Carbolite oven
Plant Trial I was carried in 5 top charge ovens at Jamshedpur
Plant trial II was conducted at HMC for complete I row (88 Ovens) for continuously 7 days
14
Results- Lab Scale
Proximate
Analysis , wt%
(db)
Fluidity Dilation, % Coke properties
Ash VM CSN Max
fluidity
(ddpm)
Fluid
range
(0C)
Contraction Expansion CSR Porosity
Blend 1 10.72 24.20 6.5 22 48 20 -7 48.18 45.8
Blend 2 10.66 24.94 7 144 63 21 12 52.32 28.1
Coal blend & Coke Properties
Blend1
Blend 2
* Blend 2 contains 0.3% Phenolic resin15
Results- Lab Scale
Utilization of inferior and or non-coking coal
CSR CSRCSR
CRI CRI CRI
Ash Ash Ash
0
10
20
30
40
50
60
70
1 2 3
Prop
ertie
s of
cok
e
Blend
Blend Details
1 Base blend
2 Base blend containing 5% of non-coking coal
3 Base blend containing 5% of non-coking coal and 0.3% phenolic resin
Utilization of non-coking coal without detorioration of coke quality16
Results- Trial @ Top Charge Oven, Jamshedpur
58
59
60
61
62
63
64
65
0 5 10 15
CSR
Trial Period
Aug Sept Oct
17
GCQI = 0.5*((M40-3.42*M10+100)+(CSR-2.6*CRI+100))
Trials at non-recovery oven, HMC, Haldia
Current Coke Making
Process
Addition of Binder
Air Lock Screw Feeder 18
19
Facts- Trials at non-recovery oven, HMC
No of ovens 230
BD, Kg/m3 1050
Blend composition Captive medium coking coal- 20Captive prime coking coal- 26Imported medium coking coal- 10Imported prime coking coal- 44
Average ash, % (db) 12.5
Average VM, % (db) 22.4
Coal Ash, % (db) 16.07
% of resin (average) 0.4
CSN 6.1
Fluidity, ddpm 1605
Results- Trials at HMC, Haldia
62
64
66
68
70
72
0 10 20 30 40 50 60
CSR
No. of Days
GCQI = 0.5*((M40-3.42*M10+100)+(CSR-2.6*CRI+100)) Trial Period
20
Parameter M40 M10 AMS CSR CRI
During trial
89 4.2 58.9 67.8 22.3
Before trial 88 4.8 56.7 65.9 23.6
Impact $$
$ $
$$
$$
$$
21
Use of non-coking coal in metullurgical coke making
Lesser dependency on prime coking coal
Improvement of mine life
IMPROVEMENT IN HOT STRENGTH - ENABLE TO OPERATE WITH HIGHER PCI
22