Effects of Dolomite on Mineral Compositions and Metallurgical Properties of Chromium-Bearing Vanadium–Titanium Magnetite Sinter

Weijun Zhang,Mi Zhou,Weidong Tang,Xiangxin Xue,Songtao Yang,Tao Jiang

doi:10.3390/min7110210

Abstract

Chengde chromium-bearing vanadium–titanium magnetite (CCVTM) has been used as an important mineral resource in sinter making. The MgO content of this sinter can be enhanced by adding dolomite, which improved operation of the blast furnace. The effects of MgO in the form of dolomite on metallurgical properties, microstructure and mineral compositions of CCVTM sinter were studied by a sinter pot test, X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), and mineral phase microanalysis. The results were as follows: The flame front speed and sinter coefficient decreased with an increase in MgO content from 2.66 to 3.86% by adding dolomite. With an increase in MgO content from 2.66 to 3.86%, the flame front speed, sintering utilization factor, and the value of RI decreased, while RDI and the softening–melting properties improved. In addition, the value of sinter strength (TI) reached a maximum value at MgO = 3.56%. In addition, an increase in the abundance of magnetite, magnesium ferrite, and silicate phase, as well as a decrease in hematite, was found with an increase in MgO content. We concluded that the most appropriate MgO content in the sinter is 3.56%.

Highlights

The development of mineral separation techniques has allowed the utilization of Chengde chromium-bearing vanadium–titanium magnetite (CCVTM)
This was reflected in the positive influence that the MgO content had on the liquidity, the stability, and the desulfurization ability of the slag and the metallurgical properties of sinter
The liquidity, desulfurization, and dealkalization capacities of the slag could be improved by using a high MgO content of sinter in the blast furnace (BF)

Summary

Introduction

The development of mineral separation techniques has allowed the utilization of Chengde chromium-bearing vanadium–titanium magnetite (CCVTM). The viscosity and the TiO2 content of the slag are high in the blast furnace (BF) iron-making process, due to the high TiO2 content in the CCVTM. The slag experiences a decreased ability for desulfurization, and it is difficult to separate the slag from the iron [8,9,10,11,12,13]. MgO has a substantial influence on the BF iron-making process. This was reflected in the positive influence that the MgO content had on the liquidity, the stability, and the desulfurization ability of the slag and the metallurgical properties of sinter. The liquidity, desulfurization, and dealkalization capacities of the slag could be improved by using a high MgO content of sinter in the BF

Methods

Discussion

Conclusion