Desulphurisation ability of blast furnace slag containing high Al₂O₃ and 5 mass% TiO₂ at 1773 K

Abstract

The sulphide capacities (C_S) of CaO–SiO₂–Al₂O₃–MgO–TiO₂ blast furnace slags were experimentally measured at 1773 K, and the percentages of free oxygen ions (O²⁻) and bridge oxygen (O⁰) of molten slag were calculated using molecular dynamics at 1773 K. The measured and calculated results were closely correlated with the change in CaO/SiO₂, MgO, and Al₂O₃ contents in the slag. The results show that C_S increases with increasing CaO/SiO₂ and MgO contents in the slag, but decreases with increasing Al₂O₃ content. The effects of O²⁻ and O⁰ on C_S were analysed using multiple linear regression, and results show that sulphide increases with the increase in the mass percentage of free oxygen and decreases with the increase in the mass percentage of bridge oxygen.

Keywords:

• Sulphide capacity
• Sulphur distribution ratio
• Molecular dynamics
• Free oxygen
• Alumina

Acknowledgements

This work is supported by the Fok Ying Tung Education Foundation (No. 131048), the Fundamental Research Funds for the Central Universities (Grant No. CDJRC10130009), and Chongqing Iron and Steel Co., Ltd.