Induration mechanisms of oxidised pellets prepared from mixed magnetite–haematite concentrates

Abstract

AbstractThe crystallisation behaviour of Fe2O3 during preheating and roasting of pellets made from mixed magnetite–haematite (M–H) concentrates has been studied. The results indicate that the strength of pellets is mainly provided by the crystalline connections between Fe2O3 particles during preheating. This occurs because the activity of Fe2O3 from secondary haematite (SH) (oxidised from magnetite concentrate, SH) is higher than from original haematite (OH). In the roasting process, when temperature is lower than 1250°C, the strength is mainly provided by the development, connection and growth of Fe2O3 crystalline grains from SH. Only if the temperature exceeds 1280°C does Fe2O3 recrystallisation in OH grains develop well with the iron ore particles in the pellets fully connected, so increasing pellet strength.Keywords: MAGNETITEHAEMATITEOXIDISED PELLETINDURATION MECHANISM