Influence of comminution products on abrasive wear during high pressure crushing

A novel high pressure shear cell (HPSC) has been used to study comminution and wear behaviour at surface stresses commonly experienced in ore crushers. In this work, quartz and Ni-hard 4 were chosen as representative ore and wear surface materials. Surface normal loads of more than 300 MPa were used, together with tangential loads sufficient to initiate and maintain slip at the wear surface. Comminution was studied in terms of overall particle size distribution and size distribution in the crushing zone. Worn surfaces were studied using optical, confocal and scanning electron microscopy, and contact profilometry. There is a strong coupling between comminution outcomes and wear. When crushed ore is subjected to a shear stress at the wear surface, this shear stress increases the principal stress so that a layer of fine powder is produced against the wear surface. By appropriate control of the normal/shear stress cycle, this can lead to a protective layer of fine material against the wear surface which inhibits larger particles from becoming embedded in the surface, thus reducing both ploughing and cutting wear mechanisms. This can lead to reduced wear by ploughing and cutting at higher surface normal loads compared to the case of lower normal surface loads.