| The thesis is written in two parts. The first part discusses the effect of grinding media composition, mineral type and slurry environment on the wear rate of various grinding media. The wear rate was determined using marked ball tests in 8-inch diameter porcelain laboratory mills in which different environments, i.e., O(,2), N(,2) and air were used. The mode of wear was established qualitatively using scanning electron microscopy examination of the ball surfaces and correlated with the wear data from which the influence of corrosive and abrasive wear mechanisms was postulated. The second part discusses the effect of impact on the wear of grinding balls and mill liners in large diameter (8.2 m) semi-autogenous grinding (SAG) mills. Fatigue failures and spalling were found to be responsible for the wear of mill liners and grinding balls under these latter conditions. |
