The Effects of Slag Compositions on the Coal Gasification Reaction in Molten Blast Furnace Slag

Abstract

The char-CO₂ gasification reactions in molten blast furnace slag were studied kinetically by the isothermal thermogravimetry using STA409PC thermal analyzer. The effects of slag compositions (SiO₂, MgO, CaO, and Al₂O₃) on gasification reaction were investigated. The results showed that CaO has certain catalytic effects on gasification reaction; however, when the gasification reaction temperature reached a certain value, the catalytic effect of CaO on gasification could be neglected. MgO also played a catalytic role in the gasification reaction. In this experiment, the gasification reaction rate increased with increasing the MgO content from 8 to 10 mass%, whereas it decreased with increasing the MgO content from 10 to 12 mass%. SiO₂ had no catalytic effect on gasification reaction.

Keywords:

• blast furnace
• coal gasification
• economic and environmental evaluation
• high temperature
• molten slag
• waste heat recovery