关键词: 金矿石, 浮选尾矿 , 回收率, 多硫化钠, 正交试验

Abstract: The flotation tailings of a gold mine in Jiangxi province belongs to low-grade refractory gold-bearing sulfide ores. Due to the long-term storage of the tailings， the surface oxidation degree of some sulfide ores is high. Ores dressing experiments was conducted to determined the utilization and development processing of the tailings. The results of process mineralogy showed that Au grade of the ore is 0.70 g/t， which is the main recovered element. According to the characteristics of the ore， the flotation process using sodium polysulfide as vulcanizing agent was carried to treat the ore. The condition test results showed that the optimal dosage of sodium polysulfide in roughing is 80 g/t and the optimal pH value is 8. On the basis of the conditional tests， the orthogonal test of the dosage of copper sulfate， ammonium butyric black drug， butyl xanthine and sodium polysulfide was conducted， and the test results were verified. Finally， the optimal level combinations were determined as copper sulfate of 50 g/t， butyl xanthine of 150 g/t， ammonium butyric black drug of 50 g/t and sodium polysulfide of 80 g/t. In the roughing condition of grinding fineness of -0.074 mm accounting for 90%， slurry pH value of 8， kerosene dosage of 100 g/t， sodium polysulphide dosage of 80 g/t， butyl xanthate with butyl ammonium black drug dosage of （150+50） g/t， copper sulfate dosage of 50 g/t， sodium silicate of 200 g/t and 2# oil dosage of 40 g/t， gold concentrate of Au grade of 13.25 g/t and Au recovery rate of 57.16% could be obtained by"one roughing two cleaning two scavenging" closed-circuit process. The concentrate indexes was good compared with no adding sodium polysulphide flotation process， which provides references for the recovery and utilization of tailings resources in the mine and similar mines.

Key words: Gold ore, Flotation tailings, Recovery rate, Sodium polysulfide, Orthogonal experiments