Monitoring of less-common residual elements in scrap feeds for EAF steelmaking.

Abstract

The steel scrap quality is classified according to the amount of residual elements. However, there is a limited analysis of some of the less common residual elements such as antimony (Sb), tungsten (W), cobalt (Co), nickel (Ni) and molybdenum (Mo) mixed with steel scrap received by steel plants. This paper reports a historical analysis of these elements in the steel compositions from two steel plants, located in different regions, during 2011 to 2018, analysing around 21000 heats. The concentration of W and Sb dropped by 0.002%, due to the increasing recovery of non-ferrous metals from mixed scrap. It was found that the calibration and maintenance of the spectrometer used to analysis had a direct impact on the results. The presence of Sb, W and Co in the steel indicates contamination from other materials, since 80% of the use of these elements is in applications associated with non-ferrous materials. This is the first analysis of these elements in steel scrap reported the literature and the conclusion of the study is that more attention should be paid to monitor less common residuals elements, because analysis of these elements can provide information about the quality of the metal scrap.