Original Article

Investigation on surface tension of CaF₂–CaO–SiO₂ (–MgO–Al₂O₃) melts

¹ School of Metallurgy Engineering, Jiangsu University of Science and Technology, Zhangjiagang, Jiangsu 215600, PR China
² The State Key Laboratory of Refractories and Metallurgy, Wuhan University of Science and Technology, Wuhan, Hubei 430081, PR China
³ Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education, Wuhan University of Science and Technology, Wuhan, Hubei 430081, PR China

^* e-mail: gaoyunming@wust.edu.cn
^** e-mail: liguangqiang@wust.edu.cn

Received: 7 July 2024
Accepted: 24 August 2024

Abstract

In this work, the surface tension of CaF₂–CaO–SiO₂ melt with high CaF₂ contents was measured by pulling cylinder method at 1773 K. The effects of CaF₂ content, basicity, and the addition of MgO and Al₂O₃ on the surface tension were also investigated by considering the change in the melt structure. It was observed that as the CaF₂ content increased from 30 to 80 mass%, there was no further depolymerizing effect on the silicate structure of the melt, maintaining a constant basicity of 1. However, the surface tension of the melts decreased from 397 to 325 mN/m due to the surface-active effect of CaF₂. With the increase of basicity from 0.5 to 3, the surface tension of the melt initially increased from 342 mN/m to a maximum value of 390 mN/m, then decreased to 368 mN/m. The maximum value occurred at a basicity of 2. Furthermore, at constant basicity, the addition of MgO from 0 to 10 mass% led to a decrease in the surface tension of the melt decreased from 358 to 326 mN/m. Similarly, with the basicity ranging from 1 to 3, the addition of 10 mass% Al₂O₃ resulted in a decrease in the surface tension of the melt.