The flotation separation of galena (PbS) and chalcopyrite (CuFeS2) is not yet fully resolved due to the lack of efficient depressants. This study proposed a new depressant, i.e. an Fe2+/NaClO system, as an efficient PbS depressant. The inhibition effect of the Fe2+/NaClO system is attributed to the oxidation effect of •OH radicals from the reaction between HClO and Fe2+. The recovery of PbS is only 9.48 % and that of CuFeS2 is 82.33 % under the following conditions: pH 3.5, 4 min reaction time, 10:1 Fe2+:NaClO molar ratio and 1 × 10−2 mol/L NaClO concentration. Contact angle test results suggested that the hydrophobicity of PbS was decreased by conditioning with the Fe2+/NaClO system. X-ray photoelectron spectroscopy results showed that the S2− species on the PbS surface was oxidised into SO42−, and thus, PbSO4 occurred on the PbS surface. Furthermore, SO42− concentration reached 61.67 % of the total S species. Oxidative production coated the PbS surface well, depressing PbS flotation. However, the Fe2+/NaClO system barely changed the components of the CuFeS2 surface. The CuFeS2 surface still exhibits a high hydrophobic level. Therefore, PbS can be efficiently separated from CuFeS2 by using the Fe2+/NaClO system.

中文翻译：

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使用来自 Fe2+/NaClO 系统的羟基自由基作为抑制剂，浮选分离方铅矿和黄铜矿


由于缺乏有效的抑制剂，方铅矿 （PbS） 和黄铜矿 （CuFeS2） 的浮选分离尚未完全解决。本研究提出了一种新的抑制剂，即 Fe2+/NaClO 系统，作为一种有效的 PbS 抑制剂。Fe2+/NaClO 系统的抑制作用归因于 HClO 和 Fe2+ 反应中 •OH 自由基的氧化作用。在以下条件下，PbS 的回收率仅为 9.48 %，CuFeS2 的回收率为 82.33 %：pH 3.5、4 分钟反应时间、10：1 Fe2+：NaClO 摩尔比和 1 × 10−2 mol/L NaClO 浓度。接触角测试结果表明，用 Fe2+/NaClO 系统调节降低了 PbS 的疏水性。X 射线光电子能谱结果表明，PbS 表面的 S2− 物质被氧化成 SO42−，因此，PbS 表面出现 PbSO4。此外，SO42− 浓度达到 S 总种类的 61.67%。氧化生成很好地覆盖了 PbS 表面，抑制了 PbS 浮选。然而，Fe2+/NaClO 系统几乎没有改变 CuFeS2 表面的成分。CuFeS2 表面仍然表现出高疏水性。因此，通过使用 Fe2+/NaClO 系统，可以有效地将 PbS 与 CuFeS2 分离。