Formulated Lime (Flucal® Jet) co-injected or not with oxygen into Electric Arc Furnace fed with solid and liquid pig iron in Arcelormittal Cariacicaand Juiz de Fora (Brazil)

M. Ventura 1, M. Arcanjo* 1, T. Furtado2, B. Pinheira*2

M.A. de Menibus3, P. Bartolomeo3, P. Nicacio3,Perrin Eric4

1ArcelorMittal Cariacica2ArcelorMittal Juiz de Fora

3Belocal Lhoist do brazil, Sao José de lapa, 4Lhoist SA (belgium)

* speaker

Content

� Steel shop presentation

� System description

� Process parameter

� Experimental results

� Conclusion

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3

AM JUIZ DE FORA�Capacity : 1.000.000 t�Products Type : Longs Manufacturing Process : BF/EAF

Plant Profile of AM Juiz de Fora�BFs (2 unid)• Capacity 360.000 t • Iron ore/Coal

�EAF(1 unit)•Tap Weight = 110t •Manufacturer – Paul Wurth

�LF (1 unit)•Capacity = 110t•Manufacturer – ASEA

�CCM•Manufacturer-Concast/Danieli

•5 strands •Radius 6m•Square Section 130 x 130

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AM CARIACICA�Capacity : 600.000 t�Products Type : Longs Manufacturing Process : EAF

�EAF(1 unit)•Tap Weight = 75t •Manufacturer – Demag

�LF (1 unit)•Capacity = 75t

�CCM (1 unit)�100x100; �120x120; �130x130;�150x150 and�160x160mm

Plant Profile of AM Cariacica

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Production flow

�Continuous Casting Machine

�Pig Iron �Scrap

�Scrap

�Shear

�Dedusting

�Ladle Furnace �Electric Arc Furnace

�Continuous Casting Machine

�Blast Furnace�Gusa Líquido

�Pig Iron �Scrap

�Scrap

�Shear

�Dedusting

�Ladle Furnace �Electric Arc Furnace

AM Juiz de Fora : 30% Hot metal

AM Cariacica : 30 % pig iron

� lime 100% bucket charged � lime 100% injected

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Motivations :Cost reduction, Productivity, Improved safety, Proc ess improvement

AM Cariacica AM Juiz de Fora

Project presentation : lime 100 % from bucket charged to 100% injected through the EAF wall

Technology presentation

Cariacica layout Process Technology International (PTI) injector

� Two silos of 240 t each.� Pneumatic system for lime transport to reach

200 kg/min.� Jetbox® and a QuadJet® (PTI) with burner

and lime injection in the centre.

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Juiz de Fora layout Lumar injector � Two silos of 200 t each.� Pneumatic system for lime transport in 120

kg/min from PTI.� Air-shrouded lime injector in the wall

Formulated lime (Flucal® Jet)� lime or dolime (0 to 10 mm)� Controlled granulometry

Injection pattern description

� AM Cariacica

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� AM Juiz de Fora

�Injection flow pattern �Injection flow pattern

Dolime pattern

Lime pattern

Scrap

basketScrap

basket

Hot metal

First basket

Second basket

Scrap

basketScrap

basket

Hot metal

Experimental results (1/4)

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89,9 90

88,9

90,7

88

89

90

91

Bucket Inject Bucket Inject

Metallic charge yield (%)

AM Cariacica AM Juiz de Fora

33,8 33 36,7 36,4

3032343638

Bucket Inject Bucket Inject

Power on time (min)

AM Cariacica AM Juiz de Fora

+2%

-2,5%-1%

407 403265 252

200250300350400450

Bucket Inject Bucket Inject

Electric cons. (kwh/t)

AM Cariacica AM Juiz de Fora

-5%

-1%

before Lime Bucked charge

after Lime injected

559 549 442 433

300

400

500

600

Bucket Inject Bucket Inject

Total energy (kwh/t)

AM Cariacica AM Juiz de Fora

-2%-1.8%

� Process improvement whatever the hot metal ratio

10

20

25

30

35

40

45

30000 35000 40000 45000 50000 55000

Hot Metal (kg/heat)

Power On (min)

Big Bag Flucal Linear (Big Bag) Linear (Flucal)

Experimental results : (2/4)Lime Injection Impact on Power On and on Electric consumption

150

250

350

30000 35000 40000 45000 50000 55000

Hot Metal (kg/heat)

Electric cons. Kwh/ton

Big Bag Flucal Linear (Big Bag) Linear (Flucal)

Experimental results (2/3)

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3,67 3,294,1

2,7

234567

Bucket Inject Bucket Inject

Refractory wear (kg/t)

AM Cariacica AM Juiz de Fora

-34%

39,8 39,1

39,5 52

2030405060

Bucket Inject Bucket Inject

Total fluxe specific cons. (kg/t)

AM Cariacica AM Juiz de Fora

+33%-2%

before Lime Bucked charge

after Lime injected

27,5 25,528,8

24,8

202326293235

Bucket Inject Bucket Inject

Fetot in EAF slag (%)

AM Cariacica AM Juiz de Fora

-14%-7%

-10%1,3 1,24 0,84 0,78

0,50,70,91,11,31,5

Bucket Inject Bucket Inject

Electrode cons. (kg/t)

AM Cariacica AM Juiz de Fora

-7%-4,5%

Experimental results (3/3)

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8797

8698

708090

100110

Bucket Inject Bucket Inject

CaO Yield (%)

AM Cariacica AM Juiz de Fora

0,530,67

0,45 0,72

0,20,40,60,8

Bucket Inject Bucket Inject

Phophorus removal (kg/t)

AM Cariacica AM Juiz de Fora

+14%+60%+24%

before Lime Bucked charge

after Lime injected

+11%

Other operational impacts

� Safety : elimination of contact with lime

� Manpower reduction

� Time reduction to prepare the scrap bucket

� Workshop cleanliness : reduction of lime dust

� Much lower stock of big bags. More free areas

� No more losses of big bas stock due to the rain

� Refractory ladle life time increase

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ExplanationsImprovement on the control and management of slag formation

� Better foaming slag formation : � More efficient thermal barrier :� Improved heat transfer to the melt

� Faster slag formation� CaO and dolime dissolution increase� Phosphorus Removal raise� Higher refractory protection

� Better EAF process stability – smooth noise.

� Electrode profile and consumption.

� Easy tool and more flexible to adjust the slag during the process

14*Takao Nakagiri & al, NSSMC presentation to scanmet conference may 2012 in stoklhom

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Conclusions

� Safety : remove many unsafely operations involving man and machine

� Process technology : easy tool for operators

� Implementation : real change in term of process control

� Results : significant impacts on :� Production cost, productivity, steel quality (P removal)

� Next step� Operation consistency and fluxes consumption optimization

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