EXPERIMENTAL INVESTIGATION OF THE EFFECT OF THE POWDER AND THE SUSPENSION RHEOLOGY ON GRINDABILITY

The grindability of raw materials is a key parameter of mineral processing. It is also very important for some kinds of secondary raw materials, such as demolition and construction wastes. The rheological behavior of the ground slurry or suspension evidently affects grinding because of the well-known viscous dampening effect. However, the grindability of materials as a function of the moisture content and rheology has not been studied online. Therefore, the grindability of a soft adhesive (limestone) and a hard non-adhesive (quartz) material was examined in the Universal Hardgrove Mill during room temperature dry and wet (in tap water) grinding. The powder flow behavior of the dry ground samples was measured in an FT4 powder rheometer, while the rheological properties of the wet ground suspensions were measured in a rotational rheometer.