Abstract:A gold ore in Yunnan contains 3.39g/t of gold and 1.19% of sulfur. The gold has a very fine grain size, which is less than 10μm, and is mainly filled in arsenopyrite and pyrite. The flotation experiment was carried out with isobutyl xanthate and GYM as the combined collector. The flotation process parameters were: grinding fineness -0.074mm, 98%, collector amount, 300g/t, adjusting agent,sodium carbonate. The dosage of 1250g / t, the inhibitor water glass dosage 2000g / t, the activator copper sulfate dosage 120g / t, after a rough selection, four selections and two sweeps of closed-circuit flotation process, obtained gold concentrate gold grade 56.61 g/t, gold recovery rate of 81.49% of the selection indicators. The tailings analysis showed that some of the monomer gold was not fully dissociated,resulting in a higher tailing gold grade.