Correlation of wear and work in dual pivoted jaw crusher tests

A laboratory sized jaw crusher with uniform movement of the jaws, the Dual Pivoted Jaw Crusher (DPJC), was used to determine the relationship between wear and work. Wear was concentrated on the jaw plates opposing each other and was measured as mass loss of the specimens. Work was measured directly from the force and the displacement of the instrumented jaw, which allowed work to accumulate only from the actual crushing events. The tests were conducted with several jaw geometries and with two motional settings, where the relation of compressive and sliding motion between the jaws was varied. The comminution of rock is presumed to be irreversible, meaning that the energy used for crack formation in the rock particles eventually results in the fracture of the particles. Therefore, the amount of energy needed to comminute rock particles should be roughly constant and not dependent on the loading conditions, if the speed of the loading contact is not changed. The DPJC test method allows the separation of work components into comminution specific work and sliding specific work. The results can be used to compare the crushability of minerals without the influence of the used test geometry or the selected jaw plate materials. The sliding work can be used for the comparison of the wear of the jaw plate material