Low-Frequency Acoustic-Assisted flotation of a Gold-Bearing mixed copper Sulfide-Oxide Ore: Laboratory and Pilot-Scale Demonstration

Improving flotation recovery without sacrificing concentrate grade remains a key challenge in the beneficiation of complex copper ores, prompting the exploration of novel process intensification strategies. The flotation behavior of a gold-bearing mixed copper sulfide-oxide ore was systematically investigated using low-frequency acoustic sound at laboratory scale and pilot scale. Laboratory-scale tests conducted in a 2.5 L mechanical flotation cell under the preferred reagent and operating conditions showed that the application of acoustic sound, generated by a 10 W loudspeaker at a fixed frequency of 375 Hz, increased copper and gold recoveries by 7.1 and 15.4 percentage points, respectively. These improvements were achieved without any loss in copper grade, while the gold grade increased by 3.2 percentage points. To evaluate consistency across scales, pilot-scale tests were performed in a 20 L mechanical flotation cell equipped with four 10 W loudspeakers operating at the same frequency. The acoustic assistance increased copper and gold recoveries by 7.7 and 10.8 percentage points, respectively, with no deterioration in concentrate grades. The consistent improvements observed at both scales demonstrate the robustness of low-frequency acoustic-assisted flotation, indicating strong potential for industrial application in copper ore beneficiation.