Effects of liquid infiltration characteristics of iron ores with a high proportion of limonite on sinter strength

Since the strength of unmelted nuclei ores and the bonding phase are constant under the same conditions of sintering parameters and ore-proportioning structure, sinter strength is largely determined by the bonding degree between unmelted nuclei ores and the bonding phase. The bonding degree is mainly dependent on the infiltration behavior of sintering liquid on nuclei ores. Infiltration tests were carried out using micro-sinter equipment in order to clarify the liquid infiltration characteristics of mixed ores with a high proportion of limonite. The effects of the infiltration area index of the original liquid (IAO), infiltration volume index of the secondary liquid (IVS) and sinter body bonding strength (SBS) on the tumbler index of the sinter (T ) are discussed using a laboratory sinter pot test. The results showed that T increased first and then decreased with an increasing IAO and IVS, but increased linearly with increasing SBS. In order to improve the sinter strength with a high proportion of limonite, the IAO and IVS should be controlled within 2.02–2.38 and 0.19–0.21, respectively. Meanwhile, sintering schemes with a high SBS should be chosen during ore-proportioning optimization.