The weak collection ability of conventional benzohydroxamic acid (BHA) impedes its widespread application in the direct flotation of copper oxide minerals. Conversely, octyl hydroxamic acid (OHA) with enhanced hydrophobicity demonstrated superior collecting ability while exhibiting weak selectivity in malachite flotation. In order to achieve a balance between collecting ability and selectivity, we synthesized a novel N-cyclohexyl-N-hydroxyacetamide collector (ECHA) that featured similar structure of hydroxamate compounds and improved selectivity for the direct flotation of malachite. The bench-scale flotation results demonstrated that ECHA exhibited stronger collecting ability and excellent selectivity, 14.66% and 15.17% of copper recoveries increased than sodium butyl xanthate (SBX) and BHA, respectively. Contact angle tests, Zeta potential tests and solution chemistry analysis revealed that the interaction intensity of ECHA with malachite was significantly stronger than that of calcite and quartz. FTIR and XPS analysis showed that the reaction sites of ECHA were primarily located on the [–N(OH)CO–] group, suggesting possible chemisorption on the malachite surface. Additionally, DFT calculations indicated that the ECHA anion could potentially form a five-membered structure chelate complex with a Cu atom on the malachite surface through its [–N(OH)CO–] functional group. ECHA proved to be promising as an attractive collector in the direct flotation of malachite.

中文翻译：

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使用新型 N 取代异羟肟酸直接浮选回收孔雀石：吸附机理和 DFT 计算


常规苯并羟肟酸 （BHA） 的弱收集能力阻碍了其在氧化铜矿物直接浮选中的广泛应用。相反，具有增强疏水性的辛基异羟肟酸 （OHA） 表现出优异的收集能力，同时在孔雀石浮选中表现出较弱的选择性。为了实现收集能力和选择性之间的平衡，我们合成了一种新型 N-环己基-N-羟基乙酰胺捕收剂 （ECHA），其结构与异羟肟酸盐化合物相似，并且对孔雀石的直接浮选具有更高的选择性。小规模浮选结果表明，ECHA 表现出更强的收集能力和优异的选择性，铜回收率分别比丁基黄原酸钠 （SBX） 和 BHA 高 14.66% 和 15.17%。接触角测试、Zeta 电位测试和溶液化学分析表明，ECHA 与孔雀石的相互作用强度显著强于方解石和石英。FTIR 和 XPS 分析表明，ECHA 的反应位点主要位于 [–N（OH）CO–] 基团上，表明孔雀石表面可能存在化学吸附。此外，DFT 计算表明，ECHA 阴离子可能通过其 [–N（OH）CO–] 官能团在孔雀石表面与 Cu 原子形成五元结构螯合物。事实证明，ECHA 在孔雀石直接浮选中是一个有吸引力的收集器。