With the furnace originally commissioned in 2000, the SSAB blast furnace was in need of a reline and repair. To ensure another successful campaign and to reinstate the furnace back to its original condition, SSAB turned to Primetals Technologies because it had originally designed, installed, and commissioned the furnace.
Challenge
With only one blast furnace on the site, the challenge was to reline the furnace and modify the hot blast system within a strict timescale on a turnkey basis, with no lost-time accidents.
SSAB Lulea Blast Furnace No.3
Solution
The cooling system was upgraded with the bend-resistant copper stave technology from Primetals Technologies. Another notable innovation in the construction techniques employed was the pre-fabrication of large sections of the hot blast main, including pre-installed refractories, to allow modular construction.
During the plant shutdown, Primetals Technologies was responsible for the construction and worked closely with SSAB and other contractors active on the site.
Scope of supply
Furnace equipment:
- Minor shell repairs
- New carbon hearth
- New copper staves with patented anti-bending solution
- New cast iron staves
- New above-burden probes
- Furnace refractory
Hot blast system equipment:
- New ceramic burner
- New hot blast main fabrication
- New mixing chamber fabrication
- New hot blast system expansion joints
- New hot blast system refractory throughout
- Cold blast control and isolation valve
This turnkey project was completed with no lost-time accidents – supporting the approach to zero harm.
The furnace reline and hot blast system replacement were completed on time, and taking-over certificates were issued.
The furnace, which had been running successfully since 2000, retained the original profile that had been developed by Primetals Technologies in 1998.
SSAB Lulea Blast Furnace No.3
Results
The shutdown works proceeded to plan through the demolition and construction phases and were completed on schedule. The rebuild of the blast furnace has restored its availability and reliability for the future campaign. The plant has shown excellent operating characteristics since returning to operation. The furnace performance acceptance certificates were issued very quickly.
Furnace Design Parameters
- Average production: 6,700 t/d
- Peak production: 7,000 t/d
- Furnace hearth diameter: 11.4 m
- Furnace working volume: 2,540 m³
- Furnace inner volume: 3,003 m³
- Top gas operating pressure: 1.50 bar g
- Blast pressure at furnace: 3.50 bar g
- Normal productivity on inner volume: 2.08 tHM/d/m³
- Normal productivity per hearth area: 65.7 tHM/d/m²
- Number of tuyeres: 32 off
- Number of tapholes: 2 off
SSAB Lulea Blast Furnace No.3
Benefits
- Furnace successfully retained the original profile.
- Zero lost-time accidents.
- Project completed within the short timescales outlined.
- Fixed plant shutdown duration of 75 days realized.
Conclusion
- A successful rebuild of a well-designed and high-performing blast furnace, ensuring SSAB was able to maximize production and run another successful campaign.
