【作者】 张红涛；

【导师】 宋翔宇；

【作者基本信息】 郑州大学 ， 材料与化工（专业学位）， 2023， 硕士

【摘要】 斑岩型铜钼矿提供了全球约75%的铜和50%的钼,其中铜矿物主要为黄铜矿,钼矿物主要为辉钼矿,在自然界中这两种矿物密切共生,可浮性相似,难以有效分离。目前,大多数选矿厂主要使用硫化钠来抑制黄铜矿以实现铜钼分离,但硫化钠用量很大、且有毒易污染环境,在环保与安全要求越来越严格的今天,受到了越来越多的限制。本文研究利用臭氧氧化预处理的方法来实现铜钼矿的浮选分离,目的是避免或减少抑制剂的使用,开发绿色铜钼分离新工艺。本文以黄铜矿和辉钼矿单矿物与实际铜钼混合精矿为研究对象,探讨臭氧氧化预处理对单矿物可浮性的影响及对铜钼混合精矿浮选分离指标的影响,并通过接触角、Zeta电位、XPS、SEM及热力学等检测分析手段,研究了臭氧氧化预处理实现铜钼分离的机理。主要结论如下:（1）臭氧氧化预处理可以明显降低黄铜矿的可浮性,但基本不影响辉钼矿的可浮性。研究表明,在臭氧氧化预处理时间为2 min时,黄铜矿的浮选回收率由未处理时的57.7%迅速下降至16.7%,辉钼矿的浮选回收率依然保持在90%以上。与硫化钠抑铜浮钼工艺对比,臭氧氧化预处理工艺同样能够实现不同铜钼比例的人工混合矿的选择性浮选分离,且可以获得较好的浮选分离指标。（2）针对某矿山生产的铜钼混合精矿进行了臭氧氧化预处理浮选分离研究。该混合精矿中钼含量为22.03%,铜含量为1.21%。在臭氧氧化预处理时间为3 min的条件下,经“一粗三精”全流程闭路试验,可获得钼品位和回收率分别为47.46%和94.96%的钼精矿,钼精矿中铜品位和回收率分别为0.10%和3.52%。臭氧氧化预处理实现了对该铜钼混合精矿的高效选择性浮选分离。（3）接触角与Zeta电位测试结果表明,臭氧氧化预处理可选择性地使黄铜矿表面亲水,辉钼矿表面仍然保持疏水性。对铜钼矿物表面臭氧氧化产物进行了XPS和SEM分析,结果表明,黄铜矿表面生成了Cu O、Cu（OH）₂、Fe OOH和Fe₂（SO₄）₃等亲水性氧化产物,降低了黄铜矿的可浮性;而辉钼矿表面基本没有氧化产物,可浮性变化不大,原因是氧化产物以Mo O₄^2-和SO₄^2-的形式溶于水中。由热力学可知,臭氧与黄铜矿和辉钼矿的反应都可以自发进行。更多还原

【Abstract】 Porphyry copper-molybdenum ores provide about 75%of the world’s copper and50%of the world’s molybdenum,of which copper minerals are mainly chalcopyrite and molybdenum minerals are mainly molybdenite,in nature these two minerals are closely symbiotic,similar floatability,and difficult to effectively separate.At present,most mineral processing plants mainly use sodium sulfide to suppress chalcopyrite to achieve copper-molybdenum separation,which is very large,toxic,and easy to pollute the environment,and is increasingly restricted in today’s increasingly strict environmental and safety requirements.This paper investigates the use of O₃oxidation pretreatment to achieve flotation separation of copper-molybdenum ore,to avoid or reduce the use of depressants and develop a new green copper and molybdenum separation process.In this paper,the effect of O₃ oxidation pretreatment on the floatability of single minerals and the flotation separation index of copper-molybdenum bulk concentrates was investigated by using chalcopyrite and molybdenite single minerals and actual copper-molybdenum bulk concentrates,and the mechanism of O₃ oxidation pretreatment to achieve copper-molybdenum separation was studied using contact angle,Zeta potential,XPS,SEM and thermodynamics and other detection and analysis.The main conclusions are as follows:（1）O₃ oxidation pretreatment can significantly reduce the floatability of chalcopyrite but does not affect the floatability of molybdenite.The study showed that the flotation recovery of chalcopyrite rapidly decreased from 57.7%to 16.7%without treatment at 2 min of O₃ oxidation pretreatment time,and the flotation recovery of molybdenite remained above 90%.In contrast to the sodium sulfide copper flotation and molybdenum flotation process,the O₃ oxidation process can also achieve selective flotation separation of artificially mixed ores with different copper-molybdenum ratios and can obtain better flotation separation indexes.（2）O₃ oxidation pretreatment flotation separation study was carried out for copper-molybdenum bulk concentrates produced by a mine.The molybdenum content of this mixed concentrate was 22.03%and the copper content was 1.21%.Under the condition of O₃ oxidation pretreatment time of 3 min,the molybdenum concentrate with 47.46%molybdenum grade and 94.96%copper recovery,and the molybdenum concentrate with 0.10%copper grade and 3.52%copper recovery were obtained by the closed circuit test of"one coarse and three fine".The O₃ oxidation pretreatment achieved an efficient selective flotation separation of this copper-molybdenum mixed concentrate.（3）The contact angle and Zeta potential test results showed that the O₃ oxidation pretreatment could selectively make the surface of chalcopyrite hydrophilic,while the surface of molybdenite remained hydrophobic.XPS and SEM analysis of O₃oxidation products on the surface of copper and molybdenum minerals showed that hydrophilic oxidation products such as Cu O,Cu（OH）₂,Fe OOH,and Fe₂（SO₄）₃ were generated on the surface of chalcopyrite,which reduced the floatability of chalcopyrite;while there are basically no oxidation products on the surface of molybdenite,the floatability does not change much.The reason is that the oxidation products are dissolved in water in the form of Mo O₄^2-and SO₄^2-.According to thermodynamics,O₃ reacts spontaneously with chalcopyrite and molybdenite.更多还原