Influence of pore saturation on compressive strength of green iron ore pellets

A simple and robust method has been developed to measure accurately the porosity of wet green pellets and the saturation degree of the pores, i.e. the percentage of the pore volume that is filled with water. The influence of the saturation degree on the compressive strength of the pellets is of practical importance. Although this is acknowledged in most papers dealing with the subject, it is not quantitatively treated. In laboratory trials it was found that a 5% decrease in the saturation degree, a change that is not unthinkable in industrial scale balling, causes a decrease of 2 N in the compressive strength. This is equivalent to the effect of lowering the surface area of the feed material from 3000 to 2000 cm(2) g(-1).