• TJ-215, a novel composite thionocarbamate collector, demonstrates superior selectivity for chalcocite over pyrite at pH>8 compared to Z-200, enabling effective flotation separation in low-alkaline conditions.
• The enhanced performance of TJ-215 is attributed to the synergistic coordination of NH—C=S and C=N—OH groups, which form stronger Cu-S, Cu-N, and Cu-O bonds with chalcocite surfaces, as confirmed by zeta potential analysis.
• TJ-215 offers a cost-effective alternative to Z-200 due to its low-cost raw materials and short synthetic route, potentially reducing reagent costs and environmental impact in industrial copper-sulfur separation.
• The findings provide practical guidance for replacing Z-200 with TJ-215 in the flotation of secondary copper ores, improving separation efficiency and economic viability under weak alkaline conditions.