Effect of pellet size on pellet sintering process of manganese ore fines at natural basicity

The permeability of the sintering process can be significantly improved by the pellet sintering, but the excessive permeability will impact the heat accumulation of the sinter bed. Thus, it is very essential to clarify the influence of the pellet particle size on the heat transfer process of sintering. Therefore, pilot-scale sinter pot tests of pellet sintering with manganese ore fines of different particle sizes were conducted, and traditional sintering was compared to reveal the heat transfer process of sintering and its impact on the microstructure of sintered ore. The results indicate that under suitable pellet sizes (8–12 mm), the heat transfer efficiency and the heat accumulation effect between the layers of sinter bed are strengthened by the pellet sintering, as well as the highest temperature in the combustion zone and the duration of high-temperature zone. This also leads to the further growth of ferrotephroite or hausmannite in liquid phase and its more reasonable crystal distribution. Ultimately, compared with the traditional sintering process, the total solid fuel consumption can be reduced by 20%–30%, and the productivity can be increased by 11.71%–16.21%.