Thermodynamics of Phosphorus and Sulphur Removal during Basic Oxygen Steelmaking

The removal of impurity elements, particularly phosphorus and sulfur, from hot metal is crucial for the production of quality steel in basic oxygen steelmaking. This study aims to investigate the thermodynamic behavior of phosphorus and sulfur during the steelmaking process, addressing the differences in the distribution of these elements compared to earlier research. A comprehensive examination of the oxidation of phosphorus, along with the lesser-discussed removal of sulfur, was undertaken. The methodology involved analyzing the reaction kinetics and the chemical forms of sulfur in steelmaking slag under varying conditions. Results indicate a significant discovery that in addition to the commonly accepted sulfide form, sulfur can also be present as sulfate in oxidizing conditions, highlighting an important aspect of sulfur management during the process. This research emphasizes the criticality of precisely controlling impurity levels to meet the stringent requirements of modern steel applications, especially in thin sheets and pipelines, thereby contributing to the overall efficiency and effectiveness of steel production methodologies.