Process Improvements for Direct Reduced Iron Melting in the Electric Arc Furnace with Emphasis on Slag Operation
Abstract
:1. Introduction
2. Process Characteristics of DRI/HBI Melting and Refining in the EAF
3. Increased Mass and Energy Efficiency by Controlled EAF Slag Operation
3.1. Slag Analysis as Helpful Tool to Monitor, Control and Improve EAF Operation
3.2. Slag Characteristics of DRI-EAF Heats
3.3. Slag Operation of DRI Heats at Lower Total Slag Mass
4. EAF Process Modeling and Results.
4.1. Consistent Mass and Energy Balance Model for EAF Process
4.2. Results–Implications on Energy Balance, Savings and Productivity
5. Discussion
Author Contributions
Funding
Conflicts of Interest
References
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Prod. Site | C | Femet | MgO | CaO | SiO2 | Al2O3 | Metallization 1 |
---|---|---|---|---|---|---|---|
A | 2.0 | 88.4 | 2.0 | 0.7 | 3.7 | 0.5 | 81.5 |
B | 1.8 | 91.4 | 0.3 | 0.4 | 2.4 | 0.9 | 95.1 |
C | 1.7 | 80.5 | 1.5 | n.a. | 3.1 | 0.2 | 91.4 |
D [21] | 2.5 | 88.9 | 0.3 | 1.0 | 1.5 | 0.4 | 94.4 |
E [17] | 4.3 | 87.3 2 | 3.8 | 96.0 | |||
F [17] | 4.0 | 83.0 2 | 6.2 | 94.0 |
Charges Based on | 100% Scrap | 80–95% DRI | |
---|---|---|---|
Share of DRI/HBI | (%) | 0–5 (HBI) | 60–95 (DRI) |
Electric energy demand | (kWh/t) | 340–390 | 530–680 |
Natural gas | (m3/t) | 5–10 | 0–2 |
Oxygen | (m3/t) | 25–37 | 20–35 |
Coal and carbon fines | (kg/t) | 2–9 | 8–17 |
Slag former (lime, doloma, etc.) | (kg/t) | 23–35 | 27–60 |
Tap temperature | (°C) | 1600–1635 | 1600–1635 |
Tap-to-tap time | (min) | 50–60 | 60–100 |
Metal yield | (%) | 90–94 | 87–92 |
Scrap | # | CaO | SiO2 | FeO | MgO | Al2O3 | MnO | Cr2O3 | Total 1 | σ FeO | Basicity | |
---|---|---|---|---|---|---|---|---|---|---|---|---|
EAF 1 1 | 422 | 26.1 | 16.7 | 29.5 | 10.5 | 8.4 | 5.6 | 1.6 | 99.6 | 4.1 | 1.6 4 | 1.5 5 |
EAF 2 1 | 359 | 31.1 | 11.6 | 28.1 | 10.6 | 5.4 | 5.0 | 1.1 | 94.4 | 4.6 | 2.7 4 | 2.5 5 |
EAF 3 1 | 1216 | 25.6 | 13.5 | 34.5 | 11.3 | 6.0 | 6.4 | 2.5 | 100.7 | 5.3 | 1.9 4 | 1.9 5 |
EAF 4 1 | 472 | 25.6 | 12.1 | 29.7 | 9.4 | 14.5 | 4.6 | 2.1 | 97.9 | 4.9 | 2.1 4 | 1.3 5 |
EAF 5 2 | 149 | 27.3 | 8.8 | 40.2 | 8.3 | 3.5 | 7.0 | 3.2 | 99.4 | 5.2 | 3.1 4 | 2.9 5 |
EAF 6 1 | 424 | 28.4 | 12.6 | 36.2 | 3.8 | 8.7 | 9.6 | n.a. | 99.8 | 3.9 | 2.3 4 | 1.5 5 |
EAF 7 1 | 202 | 30.0 | 14.5 | 34.5 | 10.8 | 4.5 | 1.9 | 0.6 | 98.3 | 4.5 | 2.1 4 | 2.1 5 |
EAF 8 1 | 858 | 36.1 | 15.7 | 25.0 | 9.3 | 10.3 | 0.7 | n.a. | 97.5 | 4.0 | 2.3 4 | 1.7 5 |
DRI | CaO | SiO2 | FeO | MgO | Al2O3 | MnO | TiO2 | Total 2 | σ FeO | Basicity | ||
EAF 9 1 | 132 | 27.0 | 16.0 | 31.1 | 14.9 | 6.0 | 1.9 | 1.2 | 98.0 | 8.3 | 1.7 4 | 1.9 5 |
EAF 10 1 | 29 | 39.2 | 16.6 | 31.8 | 5.4 | 5.9 | 1.4 | n.a. | 100.3 | 6.9 | 2.4 4 | 2.0 5 |
EAF 11 1 | 325 | 28.5 | 19.4 | 33.9 | 9.7 | 3.2 | 0.2 | 3.7 | 99.3 | 4.9 | 1.5 4 | 1.7 5 |
EAF 12 1 | 203 | 36.9 | 17.4 | 30.1 | 7.7 | 5.1 | 0.9 | n.a. | 95.5 | 5.5 | 2.1 4 | 2.0 5 |
EAF 13 3 | 519 | 32.4 | 18.7 | 28.5 | 10.4 | 8.7 | 1.2 | n.a. | 99.8 | 4.7 | 1.7 4 | 1.6 5 |
EAF 14 1 | 19 | 40.5 | 17.7 | 21.7 | 9.4 | 6.7 | 1.9 | 0.8 | 99.2 | 9.6 | 2.3 4 | 2.0 5 |
EAF 15 1 | 918 | 30.5 | 21.0 | 26.3 | 11.3 | 5.2 | 1.2 | n.a. | 95.9 | 4.5 | 1.4 4 | 1.6 5 |
EAF 16 1 | 123 | 38.9 | 18.2 | 31.5 | 4.3 | 5.6 | 2.0 | n.a. | 100.4 | 6.2 | 2.1 4 | 1.8 5 |
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Kirschen, M.; Hay, T.; Echterhof, T. Process Improvements for Direct Reduced Iron Melting in the Electric Arc Furnace with Emphasis on Slag Operation. Processes 2021, 9, 402. https://doi.org/10.3390/pr9020402
Kirschen M, Hay T, Echterhof T. Process Improvements for Direct Reduced Iron Melting in the Electric Arc Furnace with Emphasis on Slag Operation. Processes. 2021; 9(2):402. https://doi.org/10.3390/pr9020402
Chicago/Turabian StyleKirschen, Marcus, Thomas Hay, and Thomas Echterhof. 2021. "Process Improvements for Direct Reduced Iron Melting in the Electric Arc Furnace with Emphasis on Slag Operation" Processes 9, no. 2: 402. https://doi.org/10.3390/pr9020402