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

•The Electric Pulse Fragmentation (EPF) was tested at pilot scale on a schist ore.•Two approaches for the EPF step were investigated: pre-concentration and crushing.•Comparison with the use of conventional crushers was performed.•The treatment with the EPF led to a reduction in the Bond rod mill work index.•Use of EPF led to a lower recovery of the concentrate but its Sn grade was higher. Two approaches for the use of the Electric Pulse Fragmentation (EPF) in the beneficiation of a low-grade cassiterite schist ore were investigated through pilot-scale tests performed on samples of about 270 kg. The first approach used EPF treatment for pre-concentration while in the second approach the EPF technology was mostly used for crushing. Comparison with the use of conventional crushers was performed. Results showed that the EPF pre-treatment led to a decrease of the Bond rod mill work index while the Bond ball mill work index remained unchanged. This means that the decrease in the energy consumption requested to grind the material down to 1.18 mm (closing screen of the Bond rod mill work index) is no longer noticeable with additional grinding stage to reach a size down to 106 µm (closing screen of the Bond ball mill work index). This may be due to the fracture network generated during EPF being consumed immediately in the subsequent comminution step. Alternatively, it may be that the Bond ball mill work index is not appropriate for exhibiting the weakening effect of the EPF technology when the mineral liberation size is coarser than the closing screen size used for the test. Concentration tests performed on the sample treated with the first approach for EPF showed no marked change in separation performance. However, a higher concentrate grade was obtained when using this EPF pre-treatment, indicating a probable potential for improvement.