Laser-induced breakdown spectroscopy for 24/7 automatic liquid slag analysis at a steel works

Area of Science:

• Materials Science
• Analytical Chemistry
• Process Engineering

Background:

• Steel production generates liquid slag at high temperatures (600-1400 °C).
• Accurate, real-time analysis of slag composition is crucial for process optimization and quality control.
• Traditional sampling methods can be time-consuming and may not represent the dynamic slag conditions.

Purpose of the Study:

• To implement and evaluate Laser-Induced Breakdown Spectroscopy (LIBS) for inline analysis of liquid steel slag.
• To assess the feasibility of remote, automated slag analysis in a steelworks environment.
• To compare LIBS results with established laboratory reference values.

Main Methods:

• Utilized Laser-Induced Breakdown Spectroscopy (LIBS) for remote, non-contact analysis of slag in a transporter ladle.
• Automated measurement process accommodating varying ladle fill levels.
• Data acquisition and transmission to a host computer within a 2-minute timeframe.
• Analysis of major components including CaO, Fe, SiO2, MgO, Mn, and Al2O3.

Main Results:

• Successful remote analysis of liquid slag surfaces from several meters.
• Accurate determination of major slag components (CaO, Fe, SiO2, MgO, Mn, Al2O3).
• LIBS results showed good agreement with reference values from the steelworks laboratory.
• Achieved stable 24/7 operation during a three-month trial period.

Conclusions:

• LIBS is a viable technology for inline, real-time analysis of liquid steel slag.
• The developed system offers automated, rapid, and accurate monitoring capabilities.
• Continuous operation demonstrates the robustness and practical applicability of LIBS in industrial steelmaking settings.