The Behaviour of Titania in Metallurgical Slags

The paper describes and discusses the results of thermodynamic studies carried out in the authors' laboratory on slags containing TiO2. The activities of FeO and MnO, measured by gas-slag equilibration techniques in the overall system FeO-MnO-CaO-SiO2-TiO2, are represented as isoactivity curves on various ternary and pseudo-ternary diagrams. Good agreement is obtained with those calculated using a model which assumes that O2− ions are the only anions present.Measurements of viscosity and electrical conductivity in melts containing TiO2 under both oxidising and reducing conditions are reviewed. The structural behaviour of TiO2 deduced from these studies is clearly different from that of SiO2 and is consistent with the indications from the phase diagrams and solution thermodynamics. The reduction behaviour of TiO2 is also very different from that of SiO2. The reasons for these differences and the possible industrial significance of these results are briefly discussed.