Regular Article

Factors influencing melt fluidity of iron ore

School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing (USTB), 30 Xueyuan Road, Haidian District, Beijing 100083, PR China

^* e-mail: xiaobo_zhai@sina.com

Received: 31 July 2017
Accepted: 28 February 2018

Abstract

The melt fluidity (MF) of iron ore, which reflects the flow and bonding abilities of the melt, plays a significant role during sintering. In this study, the MF of iron ore was measured by the micro-sintering method, and the formation and flow of the melt were analyzed using Factsage 7.0. Additionally, chemical reagent simulation tests were conducted to determine the effects of chemical components and gangue mineral types on MF, and the effect of MF on sinter strength was studied by sinter pot tests. The results show that the sintering melt includes some non-miscible liquids and solids. The liquid phases of hematite and limonite ores include silico-ferrites of calcium and aluminum system (predominant) and silico-ferrites of calcium system, and those of the magnetite ores are CaO-FeO-Fe₂O₃-SiO₂ systems. The MF of iron ore depends mainly on liquid amount and viscosity, which play opposite roles in increasing the MF. Moreover, SiO₂ increases the MF, whereas Al₂O₃ and loss on ignition decrease the MF. Increasing the substitution proportion of quartz and gibbsite by kaolinite enhances the MF. The effect of MF of the ore blends on the shatter index of the sinter shows a trend of inverted “V”.