Assessing the energy efficiency of a jaw crusher

• Energy efficiency is defined as function of area increment for comminution processes.
• Simulation procedure comparison for crushing and grinding processes is given.
• An optimization scheme can be based on evolutionary algorithms (EA).
• Comminution modelling with discrete element calibration and simulations were studied.
• Experimental setup for energy efficiency measurements based on area increment.

It is well known and taken for granted that the efficiency of energy use by comminution (i.e. breaking, crushing, grinding) equipment is very low, typically less than 10%. Most of the process input power is dissipated as heat and noise and ineffective deformation of the material to be processed and the device itself. Here, a study is reported that analyses the reasons for this low efficiency and tries to give recommendations for improvement. With a lab-scale jaw crusher as a test case, an optimisation was made on how to operate it most energy-efficiently by using an evolutionary algorithm numerical method. For a selected optimised case an attempt was made to simulate the jaw crusher using a commercial software for discrete element modelling (DEM), after first simulating single particle breakage using this software. Also, some experimental results on the crushing of several ∼600 g pieces of rock while measuring electric power during the process are reported.