High-Temperature Reduction and Melting Mechanism of Sinter with Different MgO Content

Abstract

Adding MgO to sinter is considered to be a popular counter measure to cope with the use of high Al2O3 ores. The purpose of this paper is to investigate the effect of the MgO content on the reduction melting behavior in order to clarify the main mechanism of melting and dripping under simulated blast furnace (BF) conditions. It was found that reduction behavior was inhibited with an increased MgO content; the reduction mechanism was further investigated by means of XRD, SEM, and kinetic analysis. The influence of MgO on the melting mechanism of high basicity sinter was also studied. The softening start temperature and softening temperature increased, and the softening zone increased as a whole with the increased MgO contents from 1.3 to 2.0 wt%. The melting temperature was similar, because the MgO remained in an unslagged state and existed in wustite as FeO-MgO solid solution. The dripping temperature was increased; the main reason for this was that high melting-point slags appeared, and that it was more difficult for carburization to occur with increased MgO content. The most appropriate MgO content in the sinter was 1.3 wt% according to principal component analysis (PCA).

Influences of Al2O3 and TiO2Content on Viscosity and Structure of CaO–8%MgO–Al2O3–SiO2–TiO2–5%FeO Blast Furnace Primary Slag

“…The Ti-bearing primary slag assigned to CaO-MgO-Al 2 O 3 -SiO 2 -TiO 2 -FeO system with high basicity and a significant amount of FeO has different viscous behaviour to the slag in hearth. Recently, the usage of low-cost and high-alumina iron ore is gradually increased because of continuous consumption of the ores rich in iron [7,8]. Al 2 O 3 content in the slag may reach a certain level [9] and the relative amount of TiO 2 changes.…”

The Effects of MgO and Al2O3 Content in Sinter on the Softening–Melting Properties of Mixed Ferrous Burden

“…The effect of MgO or Al 2 O 3 content on the SM properties of sinter and pellets has been reported in many studies in the literature. The works of Guo et al [19,20] demonstrated that the softening temperatures and the maximum pressure drop increased, and the melting temperature interval became wide with the increasing MgO content in sinter, because the MgO existed as a wüstite solid solution when sinter softened, and then on melting it brought a high-melting point slag. Li et al [21] conducted a study of the effect of MgO content on the SM performance of high-gangue sinter and partially supported Guo's viewpoint.…”

Revealing the Softening-Melting Behaviors and Slag Characteristics of Vanadium-Titanium Magnetite Burden with Various MgO Addition

“…Higuchi et al [24] highlighted that when the sinter had low Al 2 O 3 , high MgO, and 1.0-1.5 basicity, the T S and T D is the best. Guo et al [25] considered that the reduction behavior was inhibited by the increase in MgO content through the study on the high-temperature reduction and melting mechanism of sinters with various MgO content.…”