Abstract

Flotation performance of fine-grained Pb-Zn sulfide ores is fundamentally controlled by the coupling between mineral textures, particle size distribution, and liberation behaviour. However, the role of microtextural features in governing metal recovery and selectivity remains insufficiently constrained. In this study, we investigate the texture-size-liberation relationships in a representative fine-grained Pb-Zn ore from the Maoping deposit (Yunnan, China) using automated mineralogy (MLA) combined with bulk geochemical analysis. The results show that two microtextural features exert dominant controls on flotation performance: (i) ~5μm veinlet or dendritic galena intergrown with pyrite or sphalerite, which leads to Pb misplacement, and (ii) Submicrometer pyrite inclusions within sphalerite, which limit the achievable Zn concentrate grade. These findings demonstrate that flotation selectivity is fundamentally constrained by microtextural scale rather than bulk liberation alone. The results provide a mineralogical basis for understanding performance limitations in fine-grained Pb-Zn systems and have broader implications for similar deposits characterized by complex intergrowths.

Keywords:Pb-Zn Sulfide ore; Process mineralogy; Automated Mineralogy (MLA); Microtextural control; Liberation-texture coupling; Fine-grained intergrowths