Original Article

Effect of ludwigite on sintering and metallurgical properties

¹ School of Metallurgy, Northeastern University, Shenyang, PR China
² Liaoning Low-carbon Steelmaking Technology Engineering Research Center, Shenyang, PR China
³ Engineering Research Center of Frontier Technologies for Low-carbon Steelmaking (Ministry of Education), Shenyang, PR China
⁴ State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang, PR China

^* e-mail: chums@smm.neu.edu.cn

Received: 5 August 2023
Accepted: 23 October 2023

Abstract

Ludwigite is a multi-element coexisting iron ore. Through the sinter pot experiment, the effect of ludwigite on the metallurgical properties of the sinter is studied, and its action mechanism is revealed combined with X-ray diffraction (XRD) analysis. The appropriate amount of ludwigite is obtained on the evaluation mechanism of softening and melting properties of the sinter, which provides theoretical guidance for practical production. The results show that with the increase of the amount of ludwigite, the yield, vertical sintering speed, and drum index in the metallurgical properties of the sinter show a gradual downward trend, and the low-temperature reduction pulverization index RDI_+3.15 shows a gradual upward trend. The addition of ludwigite is conducive to the formation of calcium ferrite and promotes the activity of MgO. The addition of excessive ludwigite will lead to the formation of Mg₂B₂O₅ and Ca₃B₂O₆, Slag phase is formed. With the increase of the proportion of ludwigite, the melting range of the sinter is slightly widened, and the permeability is improved first and then reduced. Under this ore blending condition, ludwigite resources can be added and used in sintering batching, and the proportion shall not exceed 6%.