7TH EUROPEAN COKE AND IRONMAKING CONGRESS - ECIC 2016

Oxidizing pelletization of imported high combined water bearing manganese ore fines was conducted by simulating grate-kiln process in electric tube furnace, and its consolidation mechanism was revealed by the determination of the mineralogy of fired pellet. The raw manganese ore fines were finely ground by HPRG for preparing pellet feed with specific surface areas of 2563 cm2/g and bentonite was used as binder. The good quality green balls were made under the conditions of 2.0% bentonite, 16% moisture and balling in disc pelletizer for 7 min, and drop numbers of 23.1 times from 0.5 m height, compressive strength of 10.20 N/pellet being achieved, respectively. The green balls were then prehea ted at 1050°C for 10 minutes and fired at 1340°C for 15 minutes, the mechanical strength of fired pellets reaches 2711 N/pellet. The consolidation mechanism of fired manganese ore pellets is the interlinkage of recrystallized hausmannite and black manganese grains by solid diffusion. In the meantime, some manganate liquid phases are formed with multicomponents, mainly consists of K2O•2.4Al2O3•1.7MnO•13.8SiO2, which form bonding phases between coarse particles of hausmannite and black manganese. Both the solid hardening and liquid phases bonding maintain the high mechanical strength of fired manganese ore pellets.