Elemental monitoring of steel scrap loading an electrical arc furnace

The use of laser-induced breakdown spectroscopy (LIBS) for scrap analysis has been evaluated for elemental monitoring of steel scrap loading an electrical arc furnace (EAF). A LIBS prototype was developed and installed during a field test above a pendulum conveying trough between the scrap charging area and the EAF, approx. 25 m from the EAF. The width and depth of the conveying trough filled with the scrap are approx. 2 m and 1 m, respectively. The average scrap velocity is adjusted to the EAF loading requirements within a range of 0.3 to 5.5 m/min, resulting in a scrap throughput of 100 tons per hour, typically. At the installation site, primarily, the detection of a high content of silicon in the low-alloy steel scrap is of interest for an improved control of the EAF. The on-line LIBS measurement showed the capability of detecting high silicon scrap in an industrial environment, although the developed prototype detected only a fraction of the scrap load surface due to the restricted measuring volume of 600 ? 600 ? 180 mm3. Increasing the measuring volume should further improve the performance in order to exploit it for charging/process control and management.