Melting Features and Viscosity of TiO2-Containing Primary Slag in a Blast Furnace

Abstract

The performance of the primary slag in the cohesive zone of blast furnace is critical for smooth operation of blast furnace ironmaking process. In the present work, the CaO–SiO2–MgO–TiO2–Al2O3–FeO slag system was studied to identify the influence of the FeO and the TiO2 on the melting features and viscosity. The temperatures of melting features are found to decrease with increasing FeO from 5 wt% to 20 wt% and increase with increasing TiO2 from 5 wt% to 15 wt%. The viscosities of the slag change with TiO2 can be divided into four periods, which are slow period, rapid period, slow down period and dramatically rise period. The introduction of TiO2 into silicate network performs as network modifier at high temperature and network former at a relative low temperature. FeO can decrease the effect of Ti2O64– chain units and decrease the precipitation temperature of the solid phase.

Keywords

• blast furnace
• primary slag
• melting features
• viscosity
• tio2