This document summarizes the results of injecting lime into electric arc furnaces rather than charging it via buckets at two ArcelorMittal steel plants in Brazil. Key findings include: - Injecting lime led to improvements in metallic charge yield, power on time, electric consumption, refractory wear, flux consumption, and phosphorus removal compared to bucket charging. - Other benefits included improved safety by eliminating contact with lime, reduced manpower, and a cleaner workshop environment. - The conclusions were that lime injection provided an easier process control tool for operators, significantly impacted production costs, productivity and steel quality, and removed many unsafe operations involving people and machinery.

1. Formulated Lime (Flucal® Jet) co-injected or not
with oxygen into Electric Arc Furnace fed with
solid and liquid pig iron in Arcelormittal Cariacica
and 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 Cariacica
2ArcelorMittal Juiz de Fora
3Belocal Lhoist do brazil, Sao José de lapa,
4Lhoist SA (belgium)
* speaker

2. Content
Steel shop presentation
System description
Process parameter
Experimental results
Conclusion
2

3. 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

4. 4
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

5. 5
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

6. lime 100% bucket charged lime 100% injected
6
Motivations :
Cost reduction, Productivity, Improved safety, Process improvement
AM Cariacica AM Juiz de Fora
Project presentation :
lime 100 % from bucket charged to 100% injected through the EAF wall

7. 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.
7
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

8. Injection pattern description
AM Cariacica
8
AM Juiz de Fora
Injection flow pattern Injection flow pattern
Dolime pattern
Lime pattern
Scrap
basket
Scrap
basket
Hot
metal
First
basket
Second
basket
Scrap
basket
Scrap
basket
Hot
metal

9. Experimental results (1/4)
9
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
30
32
34
36
38
Bucket Inject Bucket Inject
Power on time (min)
AM Cariacica AM Juiz de Fora
+2%
-2,5%-1%
407 403
265 252
200
250
300
350
400
450
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%

10. 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)

11. Experimental results (2/3)
11
3,67 3,29
4,1
2,7
2
3
4
5
6
7
Bucket Inject Bucket Inject
Refractory wear (kg/t)
AM Cariacica AM Juiz de Fora
-34%
39,8 39,1
39,5 52
20
30
40
50
60
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 25,5
28,8
24,8
20
23
26
29
32
35
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
0,5
0,7
0,9
1,1
1,3
1,5
Bucket Inject Bucket Inject
Electrode cons. (kg/t)
AM Cariacica AM Juiz de Fora
-7%
-4,5%

12. Experimental results (3/3)
12
87
97
86
98
70
80
90
100
110
Bucket Inject Bucket Inject
CaO Yield (%)
AM Cariacica AM Juiz de Fora
0,53
0,67
0,45 0,72
0,2
0,4
0,6
0,8
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%

13. 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
13

14. Explanations
Improvement 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
*

15. 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
15