Work

Influence of slag composition on desulfurization and cleanliness of silicon steel

Year: 2025

Type: article

Abstract: To clarify the effect of CaO saturated slag on desulfurization mechanism and steel cleanliness during the secondary refining process of non-oriented silicon steel, slag-steel reaction experiments at 1873K were conducted to systematically analyze the variations in the sulfur partition ratio, the average size of MnS-containing inclusions, and the sulfur distribution in the slag. The results show that the CaO–Al 2 O 3 –CaF 2 –MgO slag containing saturated CaO can effectively reduce the sulfur content in steel to below 15 ppm. An increase in both the initial addition amount of CaF 2 and the CaO/Al 2 O 3 ratio in the liquid slag significantly increases the sulfur partition ratio. When the CaO/Al 2 O 3 ratio in the liquid slag is maintained at around 2.1, the growth time of MnS inclusions is effectively shortened, and the cleanliness of the steel is notably improved. A clear threshold effect of slag liquid fraction on desulfurization was observed. Optimal sulfur partition ratio was achieved when the liquid fraction was maintained at approximately 60 %. Below this value, the main phase of the slag changed from 12CaO·7Al 2 O 3 ·CaF 2 (CaS) to CaO·Al 2 O 3 ·CaF 2 (CaS), while the decrease in liquid phase fraction increased viscosity, causing sulfur distribution in the liquid slag to shift from homogeneous to discrete point-like dispersion.

Source: Journal of Materials Research and Technology

DOI: 10.1016/j.jmrt.2025.09.019

Authors: Jianzhen Zhai, Junjie Huang, Yijiang Zhao, Haojie Wang, Qiang Wang, Guangqiang Li

Institution: Wuhan University of Science and Technology

Language: English

Topic: Metallurgical Processes and Thermodynamics

Subfield: Mechanical Engineering

Field: Engineering

Domain: Physical Sciences

SDG: Responsible consumption and production

Open Access status: gold

Estimated APC paid: $1,640