Mineral processing techniques to enhance gold-telluride flotation: development from laboratory to industrial scale for Åkulla Kankberg Ore, Sweden

• Combination of collectors improves gold, silver, and tellurium recoveries. • Mineral characterisation supported the optimisation of recovery and selectivity. • Multivariate analysis correlates collector effect and flotation performance. • Results obtained at laboratory scale were proved at industrial scale. The Åkulla Kankberg deposit, in operation since 2012 at the Boliden Area Plant in northern Sweden, hosts gold-telluride (Au-Te) mineralisation within quartz-andalusite and topaz alteration zones, with minor sulphide mineralisation. Gold occurs predominantly as native gold and gold-tellurides, with occasional associations with pyrite. This study presents an industrial case study that integrates mineral processing techniques from laboratory to industrial scale, aimed at optimising the flotation performance of Au-Te ore. Comprehensive mineralogical characterisation of plant samples, coupled with advanced statistical analyses such as Principal Component Analysis (PCA) and Partial Least Squares (PLS) regression, was conducted to evaluate the efficacy of Aerophine compared to xanthate as a collector in flotation tests. Results demonstrate that the Aerophine–xanthate combination significantly improved gold, silver, and tellurium recoveries at industrial scale, increasing gold recovery from 68.64 ± 0.88 % to 71.89 ± 1.63 %. This synergistic effect also reduced pyrite entrainment while maintaining high recovery of target metals. In plant practice, the most effective reagent addition strategy was to introduce approximately 60 % of the Aerophine dosage into the rougher feed and the remaining 40 % into the scavenger feed. Xanthate was added to the scavenger concentrate launders, which recirculate to the rougher feed. Laboratory findings were successfully scaled up to industrial conditions. Prolonged exposure to pyrite-rich mineralisation has led to preferential pyrite recovery with xanthate, adversely affecting gold recovery. By applying multivariate analysis, this work established key correlations between collector chemistry and flotation performance, providing a framework for improving metallurgical outcomes. The study underscores the value of integrating mineralogical diagnostics with statistical modelling to develop efficient and sustainable flotation strategies, offering actionable insights for industrial practice.