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–CaO–Al2O3–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 N m−1, the Tend decreases from 1683 to 1648 K, and the activation energy decreases gradually. When the CaO/Al2O3 increases from 0.9 to 1.8, both the surface tension and Tonset show a minimum value, the surface tension is 2.286 N m−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 Ti4+ for Al3+ in the [AlO4]5− structure to form the Ti2O64− structure, which leads to depolymerization of the Q2 and Q3 polymerization degree and thus the slag system structure, while CaO/Al2O3 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. In this article, it is aimed to study the effect of TiO2 and CaO/Al2O3 on the surface tension, melting characteristics, and structure of a low‐fluoride slag system, which has a low surface tension and melting temperature at a CaO/Al2O3 of 1.2 and a TiO2 of 16%. It is of great significance in electroslag‐remelting process and environmental protection.