Iron Ore Pelletization: Part I. Fundamentals

The behavior of iron ore pellet binders is complex. Any pellet binder is subject to a handful of practical requirements: that it be readily dispersed through a pellet, that it effectively controls the movement of water within the pellet, and that it contributes to the inter-particle bonding within the pellet. Meeting these requirements leads to the formation of strong pellets by efficiently controlling the growth of pellets as they are pelletized. How the pellets grow is ultimately the determining factor for the quality of the pellets, and this review aims to provide the overview of how the many approaches to pellet binders can be simplified down to these requirements. The contributions of binders such as bentonite, starch, cements, dispersants, fluxes, and other additives which have been used in pellets are discussed with particular emphasis on how these effects paint a coherent picture of the pelletization process as whole. A framework which describes how these binders interact not just with the pellet feed but also with each other is developed. This part describes the history, goals of pelletization, and provides a framework so that the chemical factors leading into an effective pelletizing process can be understood. The general overview of binders is covered to provide an outline of what binding mechanisms are present, but details regarding specific binders will be explicated further in later parts. Part 2 will focus on how inorganic materials impact pellet binding, while Part 3 will focus on organic binders in pelletization.