On the detection of silicon in pig iron by LIBS

The on-site detection of Si in pig iron is a crucial issue for the assessment of the quality of steel in its industrial production process. Laser Induced Breakdown Spectroscopy (LIBS) has the potentiality for such an application. In this work, it is proposed a LIBS methodology for the measurement of Si content, which is robust with respect to variable measurement conditions in an industrial environment, and capable of measuring readily Si percentages as low as 0.1%. The technique is based on a delayed detection that cleans the Si LIBS signal from overlapping Fe II lines, and on the proper choice of a reference Fe I emission feature that keeps track of the changing experimental conditions.