Laser-Induced Breakdown Spectroscopy for 24/7 Automatic Liquid Slag Analysis at a Steel Works

Abstract

Laser-induced breakdown spectroscopy (LIBS) is applied for the inline analysis of liquid slag at a steel works. The slag in the ladle of a slag transporter is measured at a distance of several meters during a short stop of the transporter. The slag surface with temperatures from ≈600 to ≈1400 °C consists of liquid slag and solidified slag parts. Automatic measurements at varying filling levels of the ladle are realized, and the duration amounts to 2 min including data transmission to the host computer. Analytical results of the major components such as CaO, Fe, SiO2, MgO, Mn, and Al2O3 are compared with reference values from the steel works laboratory for solid pressed slag samples as well as for samples from the liquid slag. Stable 24/7 operation during the first three-month test run was achieved.

On-line Analysis of Cr₂O₃ Content of the Slag in Pilot Scale EAF by Measuring Optical Emission Spectrum of Electric Arc

“…Some of these methods measure slag composition directly by electrochemical sensor 3,4) or by laser-induced breakdown spectroscopy (LIBS), [5][6][7] while others measure the slag composition indirectly by monitoring off-gas composition 8) or electrical parameters. 9) Both of these types have their advantages and limitations.…”

LIBS analyses for industrial applications – an overview of developments from 2014 to 2018

“…2 Even greater working distances in the range of up to 4 m are required for inline analysis tasks of hot objects such as liquid metals or liquid slag [3][4][5] or up to 1 m for objects moving fast on transport lines.…”

“…With a scanner optics, a laser beam is then scanned to selected electronic components to measure a chemical information with LIBS. 35 The measuring volume has the dimensions 500 Â 500 Â 60 mm 3 . A 2D-and a 3D-camera detect high resolution colour images and the 3D-proles of measuring objects placed inside this volume.…”

Applications of laser-induced breakdown spectroscopy in the aluminum electrolysis industry

“…The first reported experiment using LIBS on molten metal was performed by Runge et al in 1966 [10]. As lasers and other optoelectronic devices have become more advanced, LIBS attracted further interest as a tool for melt measurements in the late 1980s [11][12][13][14]. Carlhoff and Kirchhoff [15] first reported the application of LIBS on molten steel in a converter.…”