Challenges
The blast furnace is the heart of any steelmaking operation and has a huge impact on competitiveness. Steelmakers face a number of blast furnace related challenges:
- Maximizing production from existing assets. Steel producers are attempting to extend blast furnace campaign life to minimize capital costs and production losses associated with relines.
- Project selection and implementation. Available funds for capital investment are dwindling and selecting the correct projects and ensuring they are implemented on schedule and under budget is critical.
- Operational performance to minimize hot metal costs. Successful steel producers are remaining competitive by driving hot metal costs down.
- Training new workers and upgrading engineers and technicians’ knowledge and understanding.
- Minimizing disruption to existing production with limited planned and unplanned shut downs.
- Maintaining performance within the ever-changing environmental requirements.
Solutions
Abrasion Resistant Staves and Remedial Cooling Products
Abrasion is one leading cause of stave wear and requires interim and major shutdowns to fix or rebuild. Hatch’s wear-resistant staves provide an integrated hard surface that resists abrasion and is many orders of magnitude harder than a typical copper, cast iron, or refractory hot face on a typical stave.
Extending stave service life is one strategy employed to extended campaign life. Water leaks from worn staves can be very problematic for furnace production. Hatch’s finger coolers can be installed to lower stave temperatures and reduce wear rate. The finger coolers provide superior cooling compared to cigar coolers due to the conductive metal-to-metal contact rather than relying on a grouted connection.
Water Leak Detection
Early detection of possible water leaks is critical to ensure stable blast furnace operation and safety of plan personnel. Hatch has developed two separate technologies: a pressure leak detection system (PLDS) and a soft sensor system. The PLDS uses supply/return valves and pressure meters installed on individual circuits to identify leaks. The system is automated to rapidly test circuits (~1 minute tests) and store historical data. Hatch’s soft sensor uses installed flowmeters in tandem with statistical methods to calculated deviations in differential flow. Both leak detection methods result in much faster and more predictable leak detection.
Non-Destructive Testing (Hearth)
Comprehensive inspection and monitoring techniques are needed to extend the campaign life of many blast furnaces. Hatch’s patented Acousto Ultrasonic-Echo (AU-E) technique measures the thickness and condition of refractory linings in the blast furnace hearth. AU-E can detect refractory thickness and deterioration-build-up thickness, metal impregnation, metal penetration, and refractory hydration and oxidation.
PyroLIBS (real-time chemical analysis)
Laser-induced breakdown spectroscopy (LIBS) provides direct real-time measurements of molten material composition (any elements of interest) without having to sample and test the material. The real-time data would provide feedback control to improve the process. While LIBS for solid materials is readily available (multiple companies), LIBS for molten material is a new frontier. Hatch is working with the National Research Council (NRC) of Canada to commercialize this technology for high-temperature, molten metal applications.
Plasma Hot Blast Superheating
Hatch is investigating the use of plasma torches to augment the hot blast temperature with green energy. This system would replace the conventional cold mixer control system currently used to control hot blast temperature. This technology can provide users with a variety of benefits including increase hot blast temperature, reduced blast furnace coke consumption and CO2 emissions, reduced stove enrichment requirements, improved production during stove rebuilds or ability to reduce stove temperature and reduce tendency for stress corrosion cracking.