(Theme session) Forefront of metal resource circulation science and technology developments by next-generation leaders in industry, academia, and government

[2401-09-06] Development of Sustainable Flotation Process in Kyushu University

○Gde Pandhe Wisnu Suyantara¹, Hajime Miki¹, Hirajima Tsuyoshi¹ (1. Department of Earth Resources Engineering, Kyushu University)

司会：髙谷 雄太郎（東京大学）

Keywords:Sustainable Flotation, Green depressants, Selective flotation of sulfide minerals

In response to growing global demand for low-impact mineral processing technologies, our research at Kyushu University focuses on developing sustainable flotation strategies by integrating environmentally benign reagents and selective surface modification techniques. Recent studies have demonstrated the efficacy of oxalic acid as a green depressant for selectively suppressing copper-activated pyrite in chalcopyrite flotation, as well as for enhancing the separation of galena from lead-activated sphalerite without relying on traditional toxic reagents. We have also explored oxidation treatments using hydrogen peroxide (H₂O₂) to control surface hydrophobicity and improve separation efficiency in copper–molybdenum (Cu–Mo) flotation. This approach enables partial oxidation of chalcopyrite, enhancing molybdenite selectivity under controlled conditions. Furthermore, in seawater-based flotation—a more sustainable alternative to freshwater use—we have investigated the use of sodium metabisulfite (Na₂S₂O₅) as alternative of conventional toxic copper depressant to selectively depress copper in selective Cu-Mo flotation at mildly acidic and neutral condition. These findings contribute to the advancement of eco-friendly flotation processes by minimizing environmental impact, reducing reliance on conventional toxic reagents, and adapting flotation chemistry to non-traditional water sources. The research paves the way for future applications in complex ore systems and supports Japan’s broader goals in promoting sustainable mineral resource development.