development of ferro-coke process for mitigating co2 ... and steel 2 secured... · kanji takeda...

1 IEAGHG/IETS Iron & Steel IndustryCCUS & Process Integration Workshop, November 2013

Development of Ferro-Coke Process for Mitigating CO2 Emissions in Ironmaking

IEAGHG/IETS Iron & Steel Industry CCUS & Process Integration Workshop

November 2013 Tokyo Tech Front, Tokyo Institute of Technology, Japan

Kanji TakedaKanji Takeda(Project Leader) (Project Leader)

JFE Steel Corp.JFE Steel Corp.Nippon Steel & Sumitomo Metal Corp.Nippon Steel & Sumitomo Metal Corp.

Kobe Steel, Ltd.Kobe Steel, Ltd.


CO2 mitigation and usage of low grade resources in ironmaking process

Forming

Coking coal

Coke ovens

Innovative Ironmaking process

BF

Coke

Shaftfurnace

PJPJ

Conventional Conventional ironmakingironmaking processprocess

Low grade

Lowgrade

Ore fine

Sintering machine SinterHigh grade

Burden 1

Burden 2

Burden 3

Coke reduction

Utilization of low grade ore/coal

Innovative binder

Non-coking coal

Ore fine

InnovativeBF operation

Ferro-coke

Low environmental

risk

Energy savings(CO2 mitigation)

Partial replace

NEDO/METI grant project ： Period: FY2009/10 , FY2011/12 ：Grant ratio : 1/2

Participants: JFE Steel, Nippon Steel, Sumitomo Metals, Kobe Steel, Major Japanese Universities

Concept of Innovative ironmaking process


Development of innovative ironmaking process

Ferro-coke

Direct heating

Innovative binder

Metallic iron Carbon(coke)Binder

Ore particle

Coal particle

Ｆｅ

Ｆｅ

Ｆｅ

Briquette

Coke layer

Sintered ore layer

Blast furnace(Coke mixed charging)

Structure and compositions of agglomerates

Carbonization and reduction

Blast furnace operation using Ferro-

coke

Three key technologies

Low gradeOre and coke

Ferro-coke

Copyright © 2013 JFE Steel Corporation. All Rights Reserved.


Coal Properties

Ore Properties

Coal Ro(％) VM(％) MF(ddpm) Ash(％)

A 0.72 36.1 307 8.4

B 1.80 11.2 0 8.6

T.Fe FeO SiO2 Al2O3 SPCaO MgO Na K

A 67.5 0.21 0.01 0.49 0.73 0.01 0.033 <0.01 <0.01 <0.01

Coal A ：Slightly caking coalCoal B ：Non caking coal

（VM,Ash：ｄｒｙ base）

（mass％）

Properties of coal and ore



Briquette conditionsTotal roll power 30～50tonBriquetting pressure 3～5 t/cm

6 ｒｐｍ

100～120℃

Cup volume 6cc

Roll speedBriquetting temp.

Coal/ore = 7/3Coal/ore（mass%）

20ｋｇ-dry/batchTotal sample weight

Roll diameter 650mm

Binder（mass%） SOP+ASP=5-9%Particle size Coal； -3mm，

Ore A； -250μm B； -1mm

Size：30ｘ25ｘ15mm

Hot briquetting test in bench plant

Briquette machine

Coal Hopper Ore Hopper

Mixer

MixerDischarge



Carbonization test conditionsCarbonization temp (at wall) ；1000℃

Carbonization time ；6ｈ

Packing ；with/without coke breeze

Carbonization temperature

885℃

0

200

400

600

800

1000

0 60 120 180 240 300 360Time （min）

Car

boni

zatio

n te

mp

at c

ente

r（C

)

Briquette

Heater

Schematics of carbonization furnace

T/C

Without coke fine Embedded to coke fine

Packing conditions

Carbonization tests in batch furnace



Adhesion ratio of the ferro-coke at the blending ratio of 30% and 70%

Effect of coal and ore ratio on adhesion and swelling

Coal ： A/B = 70/30（mass％）

Ore； 0mass％ Ore； 10mass％ Ore； 30mass％

Coal A70%

+Coal B

30%

Coal A100%

Carbonized in coke fine



Hypercoal

Residue Coal

coal

Solvent recoverySlurry make up Extraction Solid-Liquidseparation

Pre-heater

ExtractorSettler

Recycle-solvent

DryerFlasher

FlasherEvaporator

Mixer

Hypercoal

Residue Coal

coal

Solvent recoverySlurry make up Extraction Solid-Liquidseparation

Pre-heater

ExtractorSettler

Recycle-solvent

DryerFlasher

FlasherEvaporator

Mixer

Innovative binder

ObjectivesObjectivesTo develop a innovative binder for Ferro-coke by utilizing the KSL’s proprietary coal solvent extraction technology (Hyper-coal)TargetsTargets

Higher Ferro-coke strength compared to a conventional asphalt pitch binder (ASP) Features of the innovative binder processFeatures of the innovative binder process1. No hydrogenation, mild reaction conditions (ca. 400oC, 2MPa)2. Product separation by gravity settling3. Recycled use of naphthalene-based solvent

Photo Test production facility for the innovative binderCapacity: 0.1 ton-coal/day

Development of an innovative binder for Ferro-coke

All Rights Reserved.


- Softening temperature of the binder can be controlled by the extraction conditions. - The innovative binder prepared by extracting a bituminous coal at 410 oC exhibitedlower softening temperature and superior fluidity than the ASP binder.

The enhanced fluidity of the binder may improve the inter-particle adhesion between ore and coal particles under the Ferro-coke carbonization conditions

0

1

2

3

4

5

6

150 200 250 300 350 400 450 500 550

Temperature [℃]

Gie

sela

r flu

idity

, log

ddp

m

380℃ Extaction 410℃ ExtractionRef.(Asphalt pitch)

Effects of the extraction conditions on the binder properties



Briquette ejector Mixer

Mixer

Double roll press

Coal hopper Ore hopperTable Compositions for the feed [wt%]

Table Briquetting conditions

HPC: 23.02.028.539.926.65

HPC: 23.02.028.539.926.64

ASP/HPC: 13.01.01.028.539.926.63

ASP/HPC: 13.01.01.028.539.926.62

Ref.3.02.028.539.926.61

RemarksSOPHPC2HPC1ASPOre ACoal BCoal ANo.

Extraction temperature for the innovative binders: HPC1, 380oC; HPC2, 410oC

20 kg/batchFeed rate

Coal, <2mm; Ore, <250mParticle size

SOP, 3%; ASP (or HPC), 2%Binder content

7/3 (by weight)Coal/ore ratio

6 cc (30x25x15 mm)Pocket volume

170 oCMaterial temperature

6 rpmRotation speed

650 mmRoll diameter

3-5 ton/cmPressure

Experiments for evaluating the innovative binders



Strength of Ferro-coke prepared by the innovative binders

Fig. Drum indices of the Ferro-coke

60

65

70

75

No.1 No.2 No.3 No.4 No.5ID

I（60

0/10

）[-

]

Briquettes

Heater

Fig. A schematic for 3kg-scalecarbonization apparatus

Thermo couple

410oC extractionbinder (HPC2)

ASP380oC (HPC1)

Wall temperature: 1000oCMaterial temperature: 900oCDuration: 6 hour

Table Carbonization conditions

It was demonstrated that the innovative binder prepared by solvent extractionof coal at 410oC improves the Ferro-coke strength compared to the ASP binder



Effect of coking temperature and holding time

Carbonized particle

6ｃｃ

Discharge

Gas pre-heater

Charging BC

Bench scale plant 0.5t/d

Shaft furnaceElectricheater

Coke

Cross section

Metallic iron

0.2mm

Effect of coking temperature on the reduction ratio

Bench scale plant of 0.5 t/d and products.



DEM model development of Ferro-coke plant

1.25m

0.96m

12m

2m

1.25m

1.33m

Width : 1.25mLength : 1.33mHeight : 14.0m

Discrete Element Method

Inter particle

Voigt model


3D images of tracer particle flow

14

Initial charging


Process flow of a pilot plant of 30t/d

Forming

Gas heating

Gas cooler

Iron ore30%

Non-coking coke70%

DryerPre-heater

Mixer/kneader

Crusher

Oven coke

Blast furnaceFerro-cokeBriquette

Shaft furnace

EPPlant

Carbonization/Reduction

Furnace type : Shaft Capacity : 30t/dLocation : JFE Steel Corp.,East Work (Keihin)

Sintered ore



Overview of the 30t/d ferro-coke pilot plant

Briquetting Carbonization

Stockyard

Gas recycle

Crushing and heating



0

50

100

150

200

11:00 12:00 13:00 14:00 15:00 16:00 17:00Tem

p. o

f mix

er [℃

]

0

50

100

150

200

11:00 12:00 13:00 14:00 15:00 16:00 17:00

BQ

forc

e [t]

84

88

92

96

100

① ② ③ ④

Stre

ngth

ID30

/16[

-]

Target

Target DI>88

Start briquetting

Charging start

Continuous operation for 5hr

Briquette for carbonization tests

10mm

Target range of BQ force

Time

Typical continuous briquetting operation



Development of innovative ironmaking process

Ferro-coke

Direct heating

Innovative binder

Metallic iron Carbon(coke)Binder

Ore particle

Coal particle

Ｆｅ

Ｆｅ

Ｆｅ

Briquette

Coke layer

Sintered ore layer

Blast furnace(Coke mixed charging)

Structure and compositions of agglomerates

Carbonization and reduction

Blast furnace operation using Ferro-

coke

Three key technologies

Low gradeOre and coke

Ferro-coke



Tw control

Pre-reduction

O/Ｆｅ

Highly reactive composite forTw decrease

FｅO

Fe

Temp ＣＯ２/（CO+CO2）

W point at800℃

Catalytic effect

RAR reduction

10001000℃℃

800800℃℃

W point W point at 1000at 1000℃℃

Base

②

③

④

①→② RAR reduction in short term・Improve sinter reducibility・Burden distribution control

②→③ Thermal reserve temp. Tw・Highly reactive coke・Carbon contained agglomerates

②→④ Innovative agglomerates③→④

Catalytic effect for high reactivity

①

Basic concept of low carbon technologies



Gas flow

Solid flow

Experimental conditions with BIS and large thickness

Sinter

Coke

Sinter

330mm

330mm

φ65mm

Reducing gas

Ferro-coke

Coke

Blast furnace Inner reaction simulator

30% of conventional coke was replaced with Ferro-coke.

Different mixing conditions with Ferro-coke were tested.

Condition with large layer thickness as plant, 330 mm, was tested.

コークス層

焼結鉱層

フェロコークス

70mm

ベース焼結層に均一混合

焼結層上層に混合

コークス層に均一混合

Ferro-coke

Sinter

Coke

Base Homogeneously mixed

Upper layer

Mixed in coke

© 2013 NIPPON STEEL & SUMITOMO METAL CORPORATION All Rights Reserved.


850

900

950

1000

1050

1100

ベース鉱石層

均一混合

鉱石層

上層混合

コークス層

均一混合

熱保

存帯

温度

(℃）

コークス層

焼結鉱層

BIS testsTemperature of thermal reserve zone was lowered by 100℃ with using Ferro-coke. Proper arrangement of Ferro-coke was homogeneously mixed or segregated in upper layer.

Both reactivity of sinter and Ferro-coke were large in homogeneously mixed.

Evaluation with a large layer thickness as plant, 330 mm

Sinter

Coke

Base Homogeneously mixed

Upper layer

Mixed in coke

Tem

pera

ture

of t

herm

al

rese

rve

zone

(℃)

30

40

50

60

70

80

30

40

50

60

70

80

1 2 3 4

Carbo

n con

sump

tion r

atio

of fer

ro-co

ke (%

)

Redu

ction

degre

e of s

inter

(%)

26

28

32

34

36

30

□ Average of reduction degree of sinter－ Minimum and maximum of reduction degree

of sinter● Carbon consumption ratio of ferro-coke

Base Homogeneouslymixed

Upperlayer

Lower layer



Concept of Mathematical Blast Furnace Model

Fe2O3,Fe3O4, FeO,Ganuge

FeO, Fe,Gangue

Fe2O3→Fe3O4→FeO→Fe

FeO(l), Fe(l),Gangue(l)

CO

CO2 CO

Ore Coke

COCO COCO22

C, Fe, Gangue

CC↓↓, Fe, Gangue

CC→→00, Fe, Gangue

Fe(l), Gangue(l)

Ferro-coke

This mathematical blast furnace model can estimate inner furnacereactions when Ferro-coke is charged into blast furnaces.

This mathematical blast furnace model can estimate inner furnacereactions when Ferro-coke is charged into blast furnaces.

Gasification model of Ferro-coke is required to evaluate the effect of Ferro-coke on blast furnace operation.Gasification model of Ferro-coke is required to evaluate the effect of Ferro-coke on blast furnace operation.



Measurement of gasification rate of Ferro-coke

)('2

2 Kppkk CO

CO

Ferro coke Sample ( diameter: 11mm )

(11)(1)

(2)

(3)

(6)

(7)

(10)

(12)

(1)

(2)

(8)(9)

(4)(5)

(11)(1)

(2)

(3)

(6)

(7)

(10)

(12)

(1)

(2)

(8)(9)

(4)(5)

(1) Cooling water Inlet (2) Cooling water outlet(3) Purge gas inlet(4) Strain gauge(5) Copper tube(6) Stainless steel wire(7) Reaction gas outlet(8) Sample(9) Reaction tube(10) Electric Furnace(11) Reaction gas inlet(12) Thermo-couples

Apparent reaction rate constant k’

Reaction rate constant k

)56.174790,170exp(RT

TK

Equilibrium constant

0 600 1200 1800 2400 3000 3600

0

0.1

0.2

0.3

0.4

0.5

1000℃

Frac

tiona

l gas

ifica

tion(

-)

Time(sec)An example of fractional gasification curve.

Gradient of fractional gasification curve


Modeling of gasification rate of Ferro-coke

)RT.exp(.kE f

37 107181102082

・

)RT.exp(.kE f

37 101169100011

・

)RT.exp(.kE f

36 102158108284

・

Ore 0%

Ore 10%

Ore 30%

Where,

Raten = ( C CO2

b - C CO2

e )・s

Bulk ConcentrationEquilibrium Concentration

Volume fraction

ka

f

p

fa kd

kEk 611

Mass transfer coefficient

Over-all reaction rate constant

Particle diameter

Effective reaction rate constant

Gasification model of Ferro-coke was combined into the mathematical blast furnace model

Effective reaction rate constant

Kyushu Univ. NSSMC

Gasification model of Ferro-coke made by Kyushu University was combined into the mathematical blast furnace model developed by NSSMC. The effect of Ferro-coke on blast furnace operation can be evaluated by the model.

Gasification model of Ferro-coke made by Kyushu University was combined into the mathematical blast furnace model developed by NSSMC. The effect of Ferro-coke on blast furnace operation can be evaluated by the model.

Coke D (Ore 30%)Coke E (Ore 30%)Coke F (Normal Coke)

0.6 0.7 0.8 0.9-3

-2

-1

0

1

2

3

1000/T (1/K)

lnE f

・k

(-)

T.Nakamura et.al.: Camp ISIJ, 25(2012),222.



Effect of Ferro-coke on temperature distribution, gas concentration in blast furnace

Volume fraction of Ferro-coke [%] CO concentration [vol frac.]Solid temperature [℃]

Base 100kg/t Base 100kg/t Base 100kg/t

800

1000

1200

14001600

800

1000

12001400

1600

0.25

0.30

0.35

0.25

0.30

0.35

Variation of inner-furnace state due to the charge of Ferro-coke was estimated.Variation of inner-furnace state due to the charge of Ferro-coke was estimated.

17%

15%

12%10%

JIS-RI=64.1%CRI=30.0%

JIS-RI=64.1%CRI=30.0%



21ｍFerro-coke

54ｍ

Photo ③

Photo ①

Photo ① Photo ②

Photo ③

Photo ②

Stock yard of FerroStock yard of Ferro--coke for blast furnace testcoke for blast furnace test



SurgeHopper

Charging BC

Direct charge bin

Ore binNut coke

Stock yard of ferro-coke

Ferro-coke of 2100 ton was transported by truck to the direct charge bin.

Five days charging test was carried out in March 2013.

Feeder gatecontrol

Charging of FerroCharging of Ferro--coke to Chiba No.6 blast furnacecoke to Chiba No.6 blast furnace



Concluding Remarks

The innovative inromaking process development was the final year of four years project in FY2012.

1) Optimization of production conditions of an innovative binder from Hyper coal process and evaluation at the pilot plant.

2) Successive operation of briquetting and carbonization was carried in the end of FY2011 and continuous production trials and charging tests to a blast furnace has successfully completed in FY 2012 to findprocess feasibility of the production process and technical subjects of blast furnace charging.

3) Development of charging condition for the optimum layer structure has been established at laboratory scale experiments.

4) Evaluation of blast furnace operation with the Ferro-coke at No.6 blast furnace in Chiba Works.


development of ferro-coke process for mitigating co2 ... and steel 2 secured... · kanji takeda...

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