Effects of TiO2 and CaO/Al2O3 on Melting Characteristics, Surface Tension, and Structure Electroslag-Remelting-Type Low-Fluorine Slag

The influence of TiO2 and CaO/Al2O3 on the surface tension of CaF2-CaOAl2O3-SiO2-MgO-TiO2 low-fluorine slag system is determined by pulling method, and the melting characteristics of the slag system are determined by differential scanning calorimetry. It is found that the surface tension decreases with the increase of temperature. With the increase of TiO2 from 7% to 16%, the surface tension decreases from 2.97 to 0.71 Nm(-1), the Tend decreases from 1683 to 1648 K, and the activation energy decreases gradually. When the CaO/Al2O(3) increases from 0.9 to 1.8, both the surface tension and Tonset show a minimum value, the surface tension is 2.286 Nm(-1), the Tonset is 1498 K, and the crystallization phase is formed during the melting process. The main reason TiO2 affects the structure is the substitution of Ti4thorn for Al3thorn in the [AlO4]5- structure to form the Ti2O64 structure, which leads to depolymerization of the Q(2) and Q(3) polymerization degree and thus the slag system structure, while CaO/Al2O(3) affects the slag polymerization degree by influencing the amount of bridging oxygen. Finally, the surface tension is characterized using each structure to derive a relationship between structure and surface tension.