Abstract: There is 4.09 g/t gold in a gold ore in Gansu，contents of Cu，Pb，Zn，Fe and Sb are too low to have value.Main metallic minerals are pyrite，arsenopyrite，stibnite and limonite.To recovery valuable element Au，flotation-flotation tailings sodium thiosulfate leaching tests were conducted．Results show that gold concentrate of 56.78 g/t Au and recovery of 71.27% were got through one roughing，two cleaning and two scavenging closed-circuit flotation process under grinding fineness of -0.074 mm is 90%，Na₂CO₃ as pH regulator，isoamyl xanthate + butylamine aerofloat as collector and 2# oil as foaming agent.Substances，such as FeS₂，FeAsS，Sb₂S₃，that affect gold leaching were enriched in concentrate.Flotation tailings treated with liquid-solid ratio of 4，Na₂S₂O₃·5H₂O dosage of 0.20 mol/L，CuSO₄ dosage of 0.018 75 mol/L，(NH₄)₂SO₄ dosage of 0.05 mol/L，and NH₃·H₂O dosage of 1.0 mol/L，pulp pH of 9.5，stirring speed of 450 r/min and leaching for 3 h，gold leaching rate of 67.05%，total gold recovery rate of 90.52% was obtained.Experiment results can provide technical basis for comprehensive utilization of the gold ore.

Key words: Gold ore, Flotation, Sodium thiosulfate, Leaching