Comparative Laboratory Studies of Conventional and Electrodynamic Fragmentation of an Industrial Mineral

Abstract

Abstract:In order to address comminution efficiency, which could be defined as the increase in mass specific surface against net specific energy input, the energy consumption of an industrial mineral with and without preweakening by high voltage pulses covering the same size range were compared. The three tested comminution sequences consisted of a laboratory jaw crusher or pilot scale high voltage pulse machine at two different circulating loads, a laboratory crusher and two tumbling mills of differing grinding media; all being operated following the principles of energy optimized comminution according to the OCS-method. The first results indicate that possible energy reduction by electrodynamic pre-weakening is available in the immediately subsequent, but not in further conventional comminution stages for the tested industrial mineral. Keywords

Pilot-scale investigation of two Electric Pulse Fragmentation (EPF) approaches for the mineral processing of a low-grade cassiterite schist ore

“…This improvement of the grindability with the EPF treatment is no longer noticeable however when performing the Bond ball mill work index ( Table 3 ). This corresponds with Tschugg et al (2017) , which showed that EPF treatment can result in energy savings in the comminution step directly after EPF, however did not observe additional energy savings subsequently in the comminution flow sheet, most likely due to the fracture network generated during EPF being consumed immediately in the next comminution step. Another explanation for these results is material specific, in that the Bond ball mill work index is not appropriate for exhibiting the weakening effect of the EPF technology when the major gangue mineral liberation size is coarser than the closing screen size used for the Bond ball mill test (usually around 100 µ m).…”

“…However, when comparing not the whole particle size range but only particles smaller than 1 mm ( Fig. 9), it can be observed that conventional crushing led to the production of a higher amount of fine particles compared to the EPF technology, as already observed by Tschugg and al. (2017).…”