Effect of TiO_2 on Thermophysical Properties and Structure of P-Bearing Steelmaking Slags

摘要

In this study, the viscous flow and crystallization behavior of CaO-SiO_2-MgO-Al_2O_3-Fe_tO-P_2O_5-TiO_2 steelmaking slags have been investigated over a wide range of temperatures. The results indicated that the viscosity of the slags slightly decreased with increasing TiO_2 content. The constructed non-isothermal continuous cooling transformation (CCT) diagrams revealed that the addition of TiO_2 lowered the crystallization temperatures. This can mainly be ascribed that the addition of TiO_2 promotes the formation of [TiO_6]-octahedra units, thereby MgFe_2O_4-Mg_2TiO_4 solid solution is formed. Moreover, the decreasing viscosity has a significant effect on the diffusion of ion units, such as Ca~(2+) and [TiO_4]-tetrahedra, from bulk melts to crystal-melt interface. The crystallization of CaTiO_3 and CaSiTiO_5 was therefore accelerated, which can improve the phosphorus content in P-enriched phase.