Characterization of the Bonding Effect of Nano-CaCO3 Modified CMC on Magnetite Concentrate Pellets

The organic binder CMC (carboxymethyl cellulose) was modified with nano-CaCO3 and then used to improve the compressive strength of preheated and fired pellets. SEM (scanning electron microscope) data on modified CMC (CCMC) showed that the nano-CaCO3 compactly coated the CMC surface. Studies of preheated and fired pellets’ compressive strength revealed that the CCMC has excellent bonding properties for pellets and could increase the pellet compressive strength beyond that afforded by CMC. SEM studies of pellets showed that CCMC improves the strength of preheated pellets by compacting particles and reducing pores; the increase in fired pellet strength was attributed to CCMC facilitating the bridging, bonding and recrystallization of the magnetite and hematite during pelletization.