某难选金矿选厂浮选时间和放大系数的优化研究

浮选时间是选厂设计的重要参数之一，而浮选时间的确定与实验室小型试验的浮选时间和放大系数有关。针对难选金矿浮选时间的选定问题，在某选厂原设计（1 500 t/d）的基础上，重新进行了选厂设计以及实际浮选时间和放大系数的计算，验证选厂浮选时间的放大系数。随着矿石性质的变化，在该选厂开展了浮选工艺优化试验，将试验成果应用于选厂生产中，并在磨矿细度和浮选条件相同的情况下，开展了不同矿石处理量工业试验，确定了选厂最佳矿石处理量，计算了优化后的浮选时间和放大系数。结果表明：小型试验浮选时间为21 min，选厂实际浮选时间为84.08 min，实际放大系数为4.00；相比优化前，在原矿金品位降低0.47 g/t的情况下，选厂矿石处理量增加了204 t/d，金精矿富集比降低了0.11，金回收率提高了3.22%。研究结果可为同类型矿石性质选厂的浮选工艺设计提供参考。

Study on Optimization of Flotation Time and Magnification Coefficient of a Refractory Gold Ore Concentrator

Flotation time is one of the important parameters in the design of concentrator.The length of flotation time has great influence on the recovery and utilization of mineral resources and the operation effect of the concentrator.The determination of flotation time is related to the flotation time and magnification factor of small laboratory tests.In view of the selection of flotation time for refractory gold ores and the verification of the amplification factor of the flotation time of the concentrator，the concentrator was designed on the basis of the design of a 1 500 t/d concentrator，and the actual flotation time and amplification factor were calculated.The flotation time of the pilot scale test was 31 min.The designed flotation time is 54 min，and the average amplification coefficient is 1.74（roughing K value is 1.5，cleaning K value is 2.50 to 2.67）.The actual flotation time of the concentrator is 68.99 min，and the actual amplification coefficient is 2.23（the actual rough scavenging K value is 1.86 to 2.41，and the actual cleaning K value is 1.88 to 3.45）.With the change of ore properties，the pilot scale test of flotation process optimization was carried out for the gold mine according to the change of ore properties.Compared with the flotation test in the design，the flotation concentration is increased from 25% to 28%，the -74 μm content of grinding classification product is reduced from 75% to 71%，and the collector butyl xanthate was replaced with iso-amyl xanthate.The amount of sodium carbonate in rough scavenging process increases by 500 g/t，the amount of copper sulfate decreases by 200 g/t，no more copper sulfate and sodium carbonate was added in scavenging，and the flotation time is reduced from 31 min to 21 min.On this basis，the mineral processing tests with the same grinding fineness，flotation concentration and system conditions were conducted in the mill.The best ore dressing plant capacity of 1 704 t/d was determined.Combined with the survey of flotation process，according to the laboratory flotation test，the time of flotation，the flotation machine volume of each activity and the concentration of flotation were determined.The flotation time and K value of each flotation operation in the concentrator were calculated.The total flotation time of the concentrator reaches 84.08 min，and the K value of the flotation time is 4.00.The K value of rough sweep selection is 3.96 to 4.21 with an average of 4.10，and the K value of clean selection is 3.66 to 4.00 with an average of 3.81.After optimization，ore processing capacity increase by 204 t/d，gold concentrate concentration ratio decrease by 0.11 and gold recovery rate increase by 3.22% when the gold grade of raw ore decrease by 0.47 g/t.The research provides reference for the design of concentrator of the same type ore.