Dephosphorization mechanism and phase change in the reduction of converter slag

Abstract

In the steelmaking process, the remained converter slag with P-containing materials is harmful to the molten steel in the next furnace. By the slag-splashing process with air blowing, P in the molten slag can be reduced and separated from the slag in the form of gas. In this paper, the reduction experiments of converter slag were carried out by flowing N2 at high temperatures, and the P-containing gas formed in this process was cooled and collected in water. It is found that the P gas was mainly composed of P2, which matched well with the results predicted by the FactSage7.2 calculation. The reaction mechanism of gasification dephosphorization in molten slag was analyzed, which was mainly proceeded on the surface of the slag. SEM-EDS and XRD were used to detect and characterize the samples. The ore phase of the converter slag and the gasification dephosphorization slag was determined, and the phase change was analyzed and compared.

Keywords

• steelmaking
• converter slag
• gasification dephosphorization
• ore phase