Abstract: A copper-lead-zinc mine in Sichuan belongs to the multi-metal sulfide with the feature of easy to concentration but difficult to separation. Silver associated with the minerals are mainly enriched into lead concentrate in dressing process to realize a comprehensive recovery. Due to a large number of pyrite existing in minerals, it is easily floated with the activation of copper ions generated by secondary copper sulfide, which makes lead-zinc-sulfur difficult to separate. For these problems in production, a series of lab tests, small closed-circuit tests and industrial tests are contrasted starting from choosing inorganic inhibitors. The combination of inorganic inhibitors——ZnSO₄ YD was ultimately found out with a better suppression on pyrite, and its flotation mechanism was analyzed as well.

Key words: Inorganic inhibitors, Low alkalinity, Cu-Pb-Zn mine, Flotation