Applying a novel collector ML-8 to achieve efficient flotation separation of marmatite from pyrrhotite

Owing to the poor selectivity of xanthates, the selective separation of marmatite from pyrrhotite remains challenging, which limits the efficient utilization of zinc resources. Herein, micro-flotation tests confirmed that pyrrhotite was more easily activated by Cu²⁺ in the butyl xanthate (BX) system and exhibited low floatability when using ML-8 as a novel collector, indicating that ML-8 was more suitable for marmatite separation. Adsorption behavior analysis demonstrated that Cu²⁺ was not only adsorbed by marmatite but also possessed a certain affinity for pyrrhotite. After Cu²⁺ pre-treatment, the adsorption of BX was enhanced on both marmatite and pyrrhotite surfaces. Conversely, Cu²⁺- treatment only promoted the affinity of ML-8 on marmatite surfaces, whereas the promotion of ML-8 adsorption on pyrrhotite surfaces was negligible; thus, pyrrhotite showed stronger wettability in the ML-8 system. X-ray photoelectron spectroscopy revealed that the anchored Cu sites on the pyrrhotite surface exhibited lower chemical activity than those on marmatite surface and could not readily form complexes with ML-8. Finally, the effective flotation separation of marmatite from pyrrhotite using actual ore samples was achieved by substituting BX with ML-8, and the grade of the Zn concentrate was significantly improved from 5.87 % to 23.84 %.