Effect of adding moisture and wettability on granulation of iron ore

As the fundamental study for determining the optimum moisture content for granulated particle, the contact angle between iron oxide and water was measured by the sessile drop method using reagent hematite samples that have different porosity and five kinds of iron ores. The granulation experiment was conducted by using five kinds of iron ores and the effects of adding moisture and wettability on the granulation property were investigated. The contact angle of reagent hematite sample and iron ore became large as the surface roughens becomes large. Therefore, the wettability between iron oxide and water greatly influenced the surface roughness of iron oxide. When iron ore with high wettability was used for nuclei particles, it can be granulated under all conditions in this study. On the other hand, when iron ore with low wettability was used for the nuclei particles, it was remained some fine iron ore particles without granulating. Therefore, when iron ore with low wettability was used for the nuclei particles, it was necessary to increase the adding moisture in order to improve the granulation property of fine particles. The fracture strength increased with decreasing the contact angle without regard to the kind of iron ore using for nuclei particles. Consequently, It was necessary to increase the adding moisture in order to improve the fracture strength.