Efficient separation of naturally hydrophobic gangue, such as talc and carbonaceous materials, from sulphide minerals in flotation is becoming a significant challenge in many processing plants due to the need to process lower grade and more complex ores. Considering the hydrophobic nature of these gangue minerals, prefloating them at the beginning of the flotation circuit in the absence of collectors and rejecting the concentrate is a common practice to remove these gangue minerals. However, sulphide minerals, such as chalcopyrite, can become naturally floatable due to surface oxidation and therefore may float together with naturally hydrophobic gangue. In this study, a new approach was developed to maximize the prefloat of hydrophobic gangue while minimizing the loss of sulphide minerals. The new approach introduced a prefloat cleaner stage where sulphide minerals recovered to the prefloat concentrate was depressed and separated from other hydrophobic gangue minerals at a low pulp potential with the prefloat cleaner tailing fed back to the main sulphide flotation circuit. Flotation tests were conducted using chalcopyrite and organic carbon. The results show that the proposed approach can significantly reduce the loss of valuable minerals in the prefloat flotation without affecting the reject of naturally hydrophobic gangue. Applying pulp potential control at the prefloat cleaner flotation stage also reduces the consumption of reducing agents while minimizing the effect of reducing agents on downstream rougher flotation.

中文翻译：

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贱金属硫化矿物浮选中选择性剔除天然疏水脉石的新方法

由于需要处理低品位和更复杂的矿石，因此在浮选中将天然疏水脉石（例如滑石和含碳材料）与硫化物矿物的有效分离正成为许多加工厂面临的重大挑战。考虑到这些脉石矿物的疏水性，在没有捕收剂的情况下，在浮选回路开始时对它们进行预浮选并剔除精矿是去除这些脉石矿物的常见做法。然而，硫化物矿物，例如黄铜矿，由于表面氧化而变得可自然漂浮，因此可能与天然疏水脉石一起漂浮。在这项研究中，开发了一种新方法来最大限度地提高疏水脉石的预浮力，同时最大限度地减少硫化矿物的损失。新方法引入了预浮选清洁阶段，其中回收到预浮选精矿中的硫化物矿物在低矿浆潜力下被压低并与其他疏水性脉石矿物分离，预浮选清洁尾矿返回主硫化物浮选回路。使用黄铜矿和有机碳进行浮选试验。结果表明，所提出的方法可以显着减少浮选过程中有价值矿物的损失，同时不影响天然疏水脉石的剔除。在预浮选清洁浮选阶段应用矿浆电位控制还可以减少还原剂的消耗，同时最大限度地减少还原剂对下游粗浮选的影响。