Sintering behaviours of chromite fines and the consolidation mechanism

A study on sintering of imported chromite fines using sinter pot (diameter 150 mm, depth 600 mm) was conducted. The effect of sintering parameters including coke breeze size and dosage, sinter mix moisture, bed depth, ignition duration and suction, and sintering suction on the sintering performance of chromite fines was investigated. It is shown that normal sintering process is suitable for agglomeration of chromite fines. And the sintering of chromite fines is characterized by wider combustion zone (75.00 mm), higher sintering temperature (1450 °C–1500 °C) and longer cooling time when compared with iron ores. Furthermore, the consolidation mechanism of chromite sinter was determined by using Leica DMRXP microscope equipped with Leica Qwin image processing and analysis application, scanning electron microscope (SEM) and energy dispersive spectrometer (EDS). It is revealed that the consolidation of chromite sinter mainly depended on about 20% liquid phase of olivine along with solid-state reactions and recrystallization of Cr2O3 contributing to sinter strength to some extent, which is quite different from the sintering of iron ores with about 35%–40% liquid phase.