With the continuous consumption of high-grade nickel ore resources, the utilization of low-grade nickel ore and nickel-bearing tailings is gradually receiving attention. In this study, a fine-grained copper-nickel tailings (Panzhihua, Sichuan Province) with 0.13%~0.14% nickel content was upgraded to obtain a concentrate product having Ni grade higher than 1%. The heterogeneous agglomeration between the nickel-bearing mineral and gangue minerals (magnesium silicate minerals) was the main bottleneck restricting the improvement of flotation enrichment. In addition, most of the nickel element was embedded in fine-grained particles, which is harmful for the flotation separation selectivity. Thus, the pulp precondition treatment and the optimizations of floatation reagents were employed to address the above problems. In the rougher stage, activators, inhibitors, and physical conditioning methods (such as mechanical friction and high-tensity agitation) were used to enhance the dispersion of the slurry and improve the Ni flotation recovery from the raw ore. In the cleaner stage, the nickel grade was gradually increased through multi-stage flotation separation circuit with the adjustment of the amounts of slime dispersants and inhibitors. Finally, a nickel content of 1.003% in the final concentrate product was obtained by 1-stage rougher and 5-stage cleaner circuit coupled with high-tensity agitation and a combination of NaCO₃, (NaPO₃)₆, H₂SO₄, CuSO₄, high efficiency collector ZL-2, carboxymethyl cellulose, and terpineol.

copper-nickel tailings,flotation,slime coating,pre-conditioning treatment,flotation reagent