Does the Zeta Potential of an Iron Ore Concentrate Affect the Strength and Dustiness of Unfired and Fired Pellets?

Role of Flocculation and Dispersion in Pelletization of Iron Ore

“…The role of electrostatic repulsion has essentially never been considered prior, but according to Rumpf's equation should only serve to decrease the strength of a pellet overall. Instead, exactly the opposite phenomena occurs -pellets made with dispersants, that is to say pellets formed with strong repulsive forces, are much stronger than pellets made with flocculants (Halt and Kawatra, 2017).…”

“…The strength of iron ore pellets has been a critical parameter of interest essentially since pelletization was developed. There is much literature discussing the theoretical and practical aspects of controlling iron ore pellet strength (Rumpf, 1962;Capes, 1972;Meyer, 1980;Seville et al, 1997Seville et al, , 2000Iveson et al, 2001;Bika et al, 2001; Ripke and Kawatra, 2003;Eisele and Kawatra, 2003;Casey, 2016;Halt and Kawatra, 2017). The most heavily cited model of pellet strength is Rumpf's (1962) equation, which provided significant insight into many of the parameters involved in making strong pellets.…”

“…Dispersion and flocculation are phenomena associated with the surface charge of particles in liquid solution (Halt and Kawatra, 2017;Zhang et al, 2019). Essentially no model of pelletization takes this surface charge into account, but the experimental work of Halt and Kawatra (2017) shows that it has a drastic effect on the final pellet strength.…”

“…Dispersion and flocculation are phenomena associated with the surface charge of particles in liquid solution (Halt and Kawatra, 2017;Zhang et al, 2019). Essentially no model of pelletization takes this surface charge into account, but the experimental work of Halt and Kawatra (2017) shows that it has a drastic effect on the final pellet strength. It had previously been considered that electrostatic interactions were of little interest to pellet strength (Seville et al, 1997(Seville et al, , 2000, but these considerations were primarily based on potential electrostatic attractions within the pellet.…”

“…Existing models of pellet strength have no treatment of dispersion or flocculation, and completely fail to explain why the introduction of a repulsive force during pelletization leads to the formation of stronger pellets in the end. The magnitude of the effect is also quite large, with the strongest pellets Halt and Kawatra (2017) reported being over twice as strong as the weakest using otherwise the same materials and binders, differing only by the nature of the dispersing or flocculating additive used.…”