Properties of MnO on high Al₂O₃ slag and its mechanism used for flushing blast furnace (BF)

Abstract

Flushing blast furnace by manganese ore was one of the important methods to recover the hearth inactivity caused by hearth accumulation. In this work, the properties and mechanism of the slag with different MnO content were researched, including the viscosity and critical temperature measured by rotating cylinder method, the mineral phase and microstructure confirmed by X-ray diffraction (XRD), scanning electronic microscopy (SEM) and fourier transform infrared spectrometer (FTIR). The experiment results showed that during the process of flushing blast furnace, the appropriate and optimal MnO in the slag was 1,5 to 2,0 mas .%, the mechanism of flushing by MnO was that the tephroite whose melting point is low forms, the depolymerization of [SiO4]-tetrahedral structure caused by MnO addition also plays an important role in reducing the viscosity of the slag.

Keywords

• blast furnace
• high Al₂O₃ slag
• MnO
• property
• structure