Fine Particle Control to Improve Mineral Handling

New challenges in mineral processing arise as high-grade ores become less available and the mining industry is forced to exploit lower grade ores. One of the challenges in beneficiating lower grade ores is the liberation of mineral particles while maintaining control over material management. Lower grade ores need fine grinding to free valuable minerals, but finely divided particles can cause severe problems, such as dustiness and flowability, in subsequent stages of material management. There are at least two approaches that can be taken to resolve this dilemma, both of which relate to particle size enlargement. First, the application of a dust suppressant can be used to control that aspect of material management. The optimal choice of dust suppressant agent depends on effectiveness and cost, both of which can be strongly influenced by the selection of application method. Second, agglomeration combining small particles into larger units-can reduce dust and improve the flow characteristics of the material at the same time. There are several mechanisms that can be employed to agglomerate mineral materials. Although agglomeration adds a new processing step, it is often cost effective. This paper describes these two approaches and their respective challenges, as they relate to a mined ore. We report on modified or newly developed procedures for characterizing mineral ores with respect to material management. On the same material, we use agglomeration processing to capture fines within larger particles and show how dustiness and other aspects of material handling are affected. We conclude by discussing their specific application in accordance with the mineral properties and processing needs.