Steelmaking research saves energy, reduces costs with fiber optics
About 70% of steel production in the United States uses the electric arc furnace (EAF) process to melt scrap and virgin iron to create steel in a much more energy-efficient process than smelting from ore. But EAF steelmaking efficiency is dependent on many factors, and researchers at Missouri University of Science and Technology are working to save energy and costs related to EAF steel production by using fiber optic sensors.
“These are high-productivity units that can produce 170 tons of steel in 30 to 40 minutes,” says Dr. Ronald O’Malley, the F. Kenneth Iverson Chair Professor in Steelmaking Technologies at Missouri S&T and principal investigator for the research project. “That takes very high energy input, and you have to protect the furnace from damage under these conditions.”
O’Malley, director of the Kent D. Peaslee Steel Manufacturing Research Center (PSMRC) at Missouri S&T, says one method of EAF protection is to use slag in the furnace to generate a slag foam that can cover the electric arc and shield the furnace side walls and roof from arc radiation. In this research project, fiber-optic sensors are used to detect hot spots in the furnace as they develop, and the sensor outputs can be used to activate a flexible injection system that directs chemical energy from carbon and oxygen and generates slag foaming as needed. The integrated dynamic control system would also be used to adapt to differences in incoming scrap metal and virgin iron to save energy, reduce operating costs and increase production yields.
Two steel companies, Big River Steel and Commercial Metals Co., will host the demonstration testing, O’Malley says.
“What’s exciting about this work is that these fiber optic systems traditionally have not been used in this kind of environment,” says O’Malley. “We’re actually tailoring several types of fiber optic technologies for specific applications in different parts of the EAF.”
O’Malley has been researching fiber optic sensors for other applications in steelmaking, and he says that the industry is excited about the application fiber optics. Researchers are tailoring different fiber technologies to get different measurement lengths and resolutions, resulting in higher area coverage versus higher resolution coverage, depending on the need, O’Malley says.
Missouri S&T is partnering in the research project with Arizona State University and Continuous Improvements Experts (CIX), which provides EAF training and optimization services for the steel industry. In addition to Big River Steel and Commercial Metals Co., steel producers Gerdau and Nucor and industrial gas and technology provider Linde are also partnering in the research.
Gerdau and Nucor are members of S&T's PSMRC, which is a consortium of steel companies, foundries, suppliers and university researchers working together to address steelmaking issues. The center offers industry-driven research to educate and train metallurgical engineering students at Missouri S&T to keep the steel industry strong into the future.