657 4. CONCLUSIONS AND IMPLICATIONS This study employed a 1 m3 conventional flotation cell to investigate the effect of replacing the stator with baffles across varying air rates, focusing on the critical impeller speed for just suspension (Njs), and the power draw and interface oscillations at Njs. Statistical regression models were developed to assess the significance of the studied variables. The results revealed clear differences between the two baffling configurations. Baffles significantly improved suspension efficiency, reducing Njs. Baffles also lowered power consumption, with the largest reductions observed at high airflow rate, highlighting their potential for improving energy efficiency in large-scale flotation cells. Conversely, the stator more effectively dampened interface oscillations under aerated conditions. These findings have direct implications for coarse particle flotation performance. Operation with baffles reduced the impeller speed and overall power input, indicating lower turbulence levels. This reduction in turbulence is expected to minimise bubble-particle detachment, which is particularly beneficial for coarse particles. In contrast, the stator’s ability to suppress interface oscillations translates into a more stable pulpfroth interface, which can decrease the loss of coarse particles through drop-back, thereby improving froth recovery. Overall, the results highlight a trade-off between two mechanisms that are critical to coarse particle flotation: (i) reduced bubble-particle detachment when operating with baffles, and (ii) enhanced froth recovery due to improved interface stability when operating with a stator. A potential mitigation strategy for excessive oscillations when operating with baffles is the use of a froth mesh, which could act as a physical barrier protecting the interface from turbulence originating in the pulp. Tests with a froth mesh have also been conducted and the results will be presented in a subsequent publication. Future work will investigate whether improvements in particle suspension and reductions in interface oscillations translate into enhanced coarse particle flotation recovery. Improved recovery of coarse particles can reduce grinding requirements, resulting in substantial energy savings. Furthermore, coarse particle flotation facilitates water recovery and tailings management, delivering both economic and environmental benefits to the mining industry. ACKNOWLEDGEMENTS The authors acknowledge the sponsors of the Collaborative Consortium for Coarse Particle Processing Research (Aeris Resources, Anglo American, Eriez Flotation Division, Glencore Copper, Hudbay, Newmont and Rio Tinto) and the University of Queensland for the financial support to conduct this research. Funding was also provided by the Australian Research Council for the ARC Centre of Excellence for Enabling Eco-Efficient Beneficiation of Minerals, grant number CE200100009. Participation in this conference was made possible through funding from the SMI Bill Whiten Memorial Award. The authors also express their gratitude to Tailing Technology, a flotation equipment supplier based in South Africa, who generously designed the 1 m3 flotation cell, and built and shipped a standard and an oversized mechanism with their associated stators to the SMI-JKMRC for incorporation into the test cell. The authors also greatly thank Michael Kilmartin for manufacturing the flotation rig and assisting in its commissioning, and Mitchell Alexander for his support in implementing design modifications throughout the experimental program. Special thanks to Emeritus Professor Tim Napier-Munn for his valuable assistance with experimental design and statistical regression modelling. REFERENCES Arbiter, N., Harris, C., & Yap, R. (1969). Hydrodynamics of flotation cells. SME Transactions, 244, 134148. Arbiter, N., Harris, C., & Yap, R. (1976). The air flow number in flotation machine scale-up. International Journal of Mineral Processing, 3(3), 257-280. https://doi.org/10.1016/0301-7516(76)90005-3
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