The effect of microwave’s location in a comminution circuit on improving grindability of a porphyry copper deposit

Abstract

ABSTRACTThe present work initially studies the impact of a laboratory microwave (MW)’s location (before and after a jaw crusher) on grindability of a copper ore. Additionally, the role of MW’s radiation time (15–150 sec) and grinding time (13, 15 and 17 min) on the produced particle size distribution (PSD), mineral liberation degree (LD) and energy consumption are investigated. relative work index (RWI), standard Bond work index (Wi), and grindability index (GI) together with the breakage and selection functions were utilized to assess the grinding efficiency and its kinetics of the untreated and MW-pretreated (at a constant power of 0.9 kW) samples. Bond work indices were obtained 13.70, 13.04 and 10.86 kWh/t for the untreated, MW-treated uncrushed and MW-treated crushed samples, respectively. Besides, the results confirmed that the microwave pretreatment was comparatively effective at the shortest grinding time (13 min). Furthermore, locating the microwave after the crushing stage indicated substantial improvements in the sample’s grindability and its kinetics rate. The product size (P80) of the MW-treated crushed sample (13 min, 0.9 kW, 150 sec) showed enhancements of 27% and 17% in comparison with the un-microwaved and MW-treated uncrushed samples. Finally, the comparative GIs acquired in the entire spectrum of the particle range were reasonably higher if the microwave was located after the jaw crusher, particularly for the coarse fraction sizes.