Slag-foaming phenomenon originating from reaction of titanium-bearing blast furnace slag: effects of TiO2 content and basicity

The foaming behaviour originating from the reduction of iron oxide in molten CaO-SiO2-MgO-Al2O3-TiO2 slag was studied at 1500 degrees C with the aid of a real-time foaming process monitoring system. The effect of TiO2 content and binary basicity on the slag foaming were investigated. It was found that the TiO2 content has a significant influence on the foaming degree, while the basicity of the slag has a smaller influence. The foam-generation time, foam duration, and foam-elimination time greatly increased with increasing TiO2 content, while they slightly increased with increasing basicity. Furthermore, the source of gas and the effect of physical properties of the slag on the foaming behaviour were also discussed. This study can provide a guideline for the utilisation of high-ratio titanium-bearing magnetite ore in the blast-furnace iron-making process, which is seriously affected by the slag-foaming problem.