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

The influence of TiO 2 and CaO/Al 2 O 3 on the surface tension of CaF 2 –CaO–Al 2 O 3 –SiO 2 –MgO–TiO 2 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 TiO 2 from 7% to 16%, the surface tension decreases from 2.97 to 0.71 N m −1 , the T end decreases from 1683 to 1648 K, and the activation energy decreases gradually. When the CaO/Al 2 O 3 increases from 0.9 to 1.8, both the surface tension and T onset show a minimum value, the surface tension is 2.286 N m −1 , the T onset is 1498 K, and the crystallization phase is formed during the melting process. The main reason TiO 2 affects the structure is the substitution of Ti 4+ for Al 3+ in the [AlO 4 ] 5− structure to form the Ti 2 O 6 4− structure, which leads to depolymerization of the Q 2 and Q 3 polymerization degree and thus the slag system structure, while CaO/Al 2 O 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.