Regular Article

Effect of slag composition on desulfurization during recycling rejected electrolytic manganese metal by electroslag remelting

¹ The State Key Laboratory of Refractories and Metallurgy, Wuhan University of Science and Technology, Wuhan 430081, PR China
² Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education, Wuhan University of Science and Technology, Wuhan 430081, PR China
³ Hubei Provincial Key Laboratory for New Processes of Ironmaking and Steelmaking, Wuhan University of Science and Technology, Wuhan 430081, PR China

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

Received: 27 November 2020
Accepted: 19 February 2021

Abstract

To reduce the Mn vaporization during recycling rejected electrolytic manganese metal by electroslag remelting, it is proposed to reduce the temperature of molten slag pool, but which leads to the degradation of slag desulfurization. The desulfurization by interaction between CaF₂–CaO–Al₂O₃–Na₂O slag and rejected electrolytic manganese metal scrap was studied from the view of thermodynamics in this study. The results show that sulfur distribution ratio decreases with increase of CaF₂ content, and increases with the increase of Na₂O content and temperature. Na₂O increases sulfur distribution ratio of slag by increasing CaO activity. Na₂O addition in CaF₂–CaO–Al₂O₃–Na₂O slag can enhance desulfurization ability of slag due to the larger sulfur distribution ratio and lower viscosity. Thus, sulfur content in test of slag T3 bearing 45.8 wt% CaF₂-23.2 wt% CaO-22.7 wt% Al₂O₃-8.3 wt% Na₂O is much lower than that of slag without Na₂O, implying that 45.8 wt% CaF₂-23.2 wt% CaO-22.7 wt% Al₂O₃-8.3 wt%Na₂O slag is the promising slag for recycling rejected electrolytic manganese metal by ESR.