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，使用 Fe²⁺/NaClO 系统进行调节降低了 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。