7. Challenges and innovations in iron ore pelletizing

The properties of iron ore depend much on its genesis. Different ores have distinct characteristics and varying performances in the mining and in the metallurgical processes. Ore particle shape, size, texture and capability of water retention, capillarity and cohesive strength among different particles determine the velocity of pellet growth during balling and pellet porosity. Ore characteristics also influence on the required amount of binder to produce pellets with satisfactorily quality. The use of iron ores with smaller crystal size and less dense structure usually results in pellets with better reducibility, impacting the performance of ironmaking reactors. Therefore, different iron ores should be valued in function of the benefit from their use [3].

The influence of ore characteristics on beneficiation, concentration, and pelletizing are important for process optimization, improving product quality, and consequently, more efficient use of natural resources and energy. Hence, as described by Moraes and Ribeiro [31], the growing importance of this topic that is referred to as geometallurgy is evident.

Mining companies work toward obtaining pellets with customized properties for each type of ironmaking process and also to meet specific requirements of different iron- and steelmaking companies. Hence, the amount and quality of supplied iron ore products are important but also to provide a diversity of types of pellets.

Therefore, the reasons why new investments in pelletizing capacity are likely to occur are the following [29]:

