#### AMIT 135: Lesson 7 Ball Mills Circuits – Mining Mill ...

The percent of mill volume occupied by grinding media, ... density and composition of the ore. Ball wear is directly proportional to surface area per unit mass and thus inversely proportional to ball diameter. Other factors include: Speed of mill rotation; Mill diameter; Mineral density; Work Index. Bond estimated the amount of wear in terms of kilograms per kWh based on the abrasion .