有色金属(选矿部分)

云南某氧化铅浮选尾矿为典型低品位难选氧化锌矿，其锌品位仅为2.01%，锌氧化率高达95.52%，锌矿物主要以硅锌矿（3.78%）和菱锌矿（1.24%）形式存在，伴生白云石（55.26%）、方解石（23.28%）、云母（6.15%）等大量脉石矿物，且矿石易泥化、矿浆体系复杂，显著增加了锌资源回收难度。为实现该低品位氧化锌矿的高效利用，在系统开展工艺矿物学分析（化学多元素分析、锌物相分析及矿物组成鉴定）的基础上，针对性设计摇床重选与反浮选两种回收方案，并通过条件试验与闭路试验优化工艺参数。摇床重选试验结果显示，随着磨矿细度提升，锌精矿品位逐步升高但回收率持续下降，当磨矿细度为-0.074 mm占80%时，仅获得Zn品位36.15%、回收率23.81%的选别指标，难以满足工业回收需求。反浮选工艺经多因素优化后确定最优参数：磨矿细度-0.074 mm占70%、调整剂硫化钠用量5 000 g/t、捕收剂P33用量60 g/t，采用“一粗两精两扫”闭路流程进行试验，最终获得Zn品位26.87%、回收率73.41%的高质量锌精矿。对比分析表明，反浮选工艺在回收率方面较摇床重选提升近50个百分点，且药剂制度简单、操作稳定性强，有效解决了传统工艺处理该类矿石时存在的矿泥干扰大、回收效率低等问题。本研究通过工艺优化实现了低品位难选氧化锌矿的高效回收，不仅为该矿区浮选尾矿的资源化利用提供了切实可行的技术方案，也为国内同类型低品位、高氧化率氧化锌矿的综合回收提供了重要的理论依据与工程参考。

A lead oxide flotation tailing in Yunnan was a typical low-grade refractory zinc oxide ore,with a zinc grade of only 2. 01% and a zinc oxidation rate as high as 95. 52%. Zinc minerals mainly existed in the forms of willemite(3. 78%) and smithsonite(1. 24%),accompanied by a large amount of gangue minerals such as dolomite(55. 26%),calcite(23. 28%),and mica(6. 15%). Additionally,the ore was prone to slime formation and the pulp system was complex,which significantly increased the difficulty of zinc resource recovery. To achieve the efficient utilization of this low-grade zinc oxide ore,on the basis of systematic process mineralogy analysis(chemical multielement analysis,zinc phase analysis,and mineral composition identification),two recovery schemes— shaker gravity separation and reverse flotation— were designed targetedly,and process parameters were optimized through condition tests and closed-circuit tests. The results of the shaker gravity separation test showed that with the increase of grinding fineness,the grade of zinc concentrate gradually increased while the recovery rate continued to decrease. When the grinding fineness of-0. 074 mm accounted for 80%,only a separation index of Zn grade 36. 15% and recovery 23. 81% was obtained,which was difficult to meet the industrial recovery requirements. After multi-factor optimization,the optimal parameters for the reverse flotation process were determined as follows:grinding fineness of-0. 074 mm accounting for 70%,regulator sodium sulfide dosage of 5 000 g/t,and collector P33 dosage of 60 g/t. A closed-circuit process of “one roughing,two cleanings,and two scavengings” was adopted for the test,and finally a high-quality zinc concentrate with Zn grade 26. 87% and recovery 73. 41% was obtained. Comparative analysis indicated that the recovery of the reverse flotation process was nearly 50 percentage points higher than that of shaker gravity separation. Moreover,the reagent system was simple and the operation stability was strong,which effectively solved the problems of severe slime interference and low recovery efficiency existing in the treatment of such ores by traditional processes. This study realized the efficient recovery of low-grade refractory zinc oxide ore through process optimization,which not only provided a practical technical scheme for the resource utilization of flotation tailings in this mining area,but also offered important theoretical basis and engineering reference for the comprehensive recovery of domestic similar low-grade and high oxidation rate zinc oxide ores.