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