Abrasion Characteristics of Ores

Effects of time and size on t₁₀, the abrasion parameter (fineness indicator) using a calibration model for a given ore type is presented. A model for predicting t₁₀ from a small diameter core material for any ore type is also presented. The ores studied are: Ok Tedi 1, Ok Tedi 2, Red Dome, Alcoa, and Broken Hill. Shape factor of the particles that varies with both the particle size and the ore type affects the abrasion characteristics. Abrasion process in a tumbling mill is described by two mechanisms namely (1) chipping, and (2) abrasion, occurring at different rates. The chipping phenomenon depends on the ore and the shape factor. The abrasion phenomenon is independent of t₁₀° (t₁₀° is the ore-specific t₁₀ at 7 × 10^?4 kWh/t tumbling test energy) and the shape factor. Abrasion process occurs at a much slower rate compared to the chipping process. Transition between chipping and abrasion occurs approximately after 2 min of tumbling. The long-term rate is controlled by the abrasion or attrition rather than by the chipping mechanism.