Influence of dispersants on the rheological and colloidal properties of iron ore ultrafine particles and their effect on the pelletizing process—A review

The use of binders for iron ore pelletizing is required to: (a) increase the pellet strength before heating – green strength; (b) prevent the collapse of the pellets during firing, when the gases generated by water vaporization could cause cracks. Bentonite is the main binder used in industry, and its binding mechanism in iron ore pellets has been widely studied and understood. Efforts to solve the problems of using bentonite in iron ore pelletizing have focused on the employment of organic binders the composition of which presents dispersant properties. This review critically evaluates the current understanding of the influence of dispersants on the quality of iron ore pellets, by means of their action on the colloidal and rheological properties of iron ore ultrafine particles. Emphasis is given to obtaining parameters for practical application of this action in the pelletizing process in bench and pilot scales.