Corrosive-Erosive Wear of Grinding Ball Metals at High Jet Velocities

Erosive/corrosive wear of two types of grinding ball metal alloys was studied using an electrochemically instrumented jet slurry apparatus. Quartz particles of –100 to + 200 mesh and less than 200 mesh were used in the jet slurries under varying pH conditions, jet velocity, and temperature under either oxygen or nitrogen aeration. At low jetting velocities, protective films were not completely removed and increasing pH resulted in lower corrosion rates; however, at high jetting velocities, the protective films were removed and increasing pH resulted in increased corrosion. The larger quartz particles were found to increase corrosion rates as compared to the smaller particles. Synergistic effects between corrosion and erosion were found to occur with the major effect occurring for larger particles and higher jet velocities. At the highest jet velocities, the erosive and corrosive actions of the slurries were found to be major factors in weight loss with pH, temperature, and aeration playing minor roles.