Memorie scientifiche - Acciai Inossidabili
Laser OES - How an efficient melt shop monitoring tool tackles increasing energy and raw material costs A. Schlemminger
Winter 2021-2022. The steel industry faces one of the most significant increases in energy prices in a short period. On the other hand, the shortage of alloying elements makes completely new process designs economically attractive. In this environment, dynamic process control is becoming increasingly important. But the availability of in-situ measurement data from the process is crucial for successful dynamic process control. Until now, the composition of the slag was missing from this approach. Due to the time-consuming sample homogenization before analysis, the chemical composition of the slag was available post-mortem. But this has changed now, and the extremely fast Laser Optical Emission Spectroscopy (Laser OES) solves that issue. The measurement rate in the kHz range generates such large amounts of data that homogenization of data instead of physical samples is possible from now on. With early-stage deviation detection, the precise adjustment of slag parameters in small steps can tolerate more considerable variations in input materials.
KEYWORDS: LASER OES, LIBS, SLAG ANALYSIS, SAMPLE PREP. FREE ANALYSIS, MELT SHOP MANAGEMENT, LADLE FURNACE OPTIMIZATION, IN SITU PROCESS CONTROL, STEELMAKING EFFICIENCY; TODAYS ANALYSIS OF HETEROGENOUS MATERIALS The simplest and fastest method to analyze heterogeneous materials such as slags, dust, minerals, alloying materials, or others was the measurement with a (handheld) XRF device. After 2-4 repeated measures, an average analysis value was generated. Due to the few measurements, outliers resulting from sample heterogeneity can strongly influence the analysis result. Hence, this approach is considered somewhat unreliable for process control. Nevertheless, handheld XRF instruments are prevalent due to their usability and low investment.
Alexander Schlemminger QuantoLux Innovation GmbH, Germany
alexander.schlemminger@quantolux.de
Until now, the most common way to analyze heterogeneous samples quickly and accurately at the same time relied on X-ray-based technologies in combination with prior sample homogenization. This approach requires a solidified sample, undergoing plenty of preparation steps. The samples are first broken in a crusher within a few seconds and then magnetically demetallized. The subsequent grinding step takes approximately 2-5 minutes before the
La Metallurgia Italiana - Luglio-Agosto 2022
pagina 38
