Optimized flotation of smithsonite and hemimorphite using mixed PAX–Armac C collectors: synergistic effects and desliming strategies

The progressive depletion of zinc sulfide ores and growing environmental constraints have shifted attention toward the beneficiation of zinc oxide ores, which are inherently more challenging due to their complex mineralogy and poor floatability. This study investigates the flotation behavior of a low-grade zinc oxide ore from the Barmalek deposit in Iran, with a focus on the synergistic effects of mixed collectors. The ore, composed predominantly of smithsonite and hemimorphite with significant calcite and magnesite gangue, was characterized using XRD and liberation analysis. Three collector regimes, potassium amyl xanthate (PAX), cocoalkyl amine acetate (Armac C), and their mixture, were tested under different process parameters using Taguchi orthogonal designs. Results showed that the mixed collector system significantly improved zinc recovery and selectivity compared to single collectors. Notably, desliming (removal of <۲۰ µm particles) enhanced flotation performance, increasing zinc recovery from ~۶۳% (without desliming) to over ۸۰% under optimal conditions, while also reducing gangue entrainment. The optimal reagent scheme, determined via statistical modelling and ANOVA, provided a favorable balance between zinc grade and calcium rejection. Validation experiments confirmed the model’s reliability, albeit with some zinc loss attributed to desliming. The findings demonstrate the efficacy of synergistic collector systems and tailored reagent schemes in overcoming the metallurgical challenges of oxidized zinc ores. This approach contributes to the sustainable processing of alternative zinc resources, offering insights into reagent design, process optimization, and slime management for industrial applications.

کلیدواژه ها:

Flotation ، Mixed collectors ، Smithsonite ، Hemimorphite ، Sulfidization