To address the challenge of separating scheelite and calcite due to their similar physicochemical properties, this study employed sulfonated phenolic resin (SPR) as a depressant and evaluated its impacts on the flotation behavior of scheelite and calcite in the system with sodium oleate (NaOL) as a collector. The mechanism of SPR on scheelite and calcite surfaces was investigated by contact angle measurements, Zeta potential analysis, infrared spectroscopy, X-ray photoelectron spectroscopy and density functional theory simulations. The results demonstrated that scheelite and calcite could be effectively separated with a significant recovery difference of 51.33 % under conditions of 60.0 mg/L SPR at pH 9.5. Mechanism studies revealed SPR was adsorbed on the mineral surface through the interaction between the oxygen atoms in the sulfonic acid group and calcium ions. Moreover, SPR was more strongly adsorbed on calcite, with an adsorption energy of −81.05 kJ/mol on calcite, while the adsorption energy on scheelite was −57.89 kJ/mol. Consequently, SPR occupied more calcium adsorption sites on the calcite surface, significantly hindering the subsequent adsorption of NaOL on calcite, while causing minimal interference with NaOL adsorption on scheelite. This differential adsorption behavior enhanced the floatability contrast between the two minerals, thereby achieving the selective flotation separation of scheelite from calcite.

中文翻译：

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使用磺化酚醛树脂作为新型抑制剂从方解石中浮选白钨矿的机理

为了解决白钨矿和方解石因其相似的物理化学性质而分离的挑战，本研究采用磺化酚醛树脂 （SPR） 作为抑制剂，并评估其对白钨矿和方解石在以油酸钠 （NaOL） 作为捕收剂的体系中浮选行为的影响。通过接触角测量、Zeta 电位分析、红外光谱、X 射线光电子能谱和密度泛函理论模拟，研究了白钨矿和方解石表面 SPR 的机理。结果表明，在 pH 9.5 为 60.0 mg/L SPR 的条件下，白钨矿和方解石可以有效分离，回收率差异为 51.33 %。机理研究表明，SPR 通过磺酸基团中的氧原子与钙离子之间的相互作用吸附在矿物表面。此外，SPR 在方解石上的吸附强度更高，在方解石上的吸附能为 −81.05 kJ/mol，而对白钨石的吸附能为 −57.89 kJ/mol。因此，SPR 在方解石表面占据了更多的钙吸附位点，显著阻碍了 NaOL 在方解石上的后续吸附，同时对 NaOL 在白解石上的吸附造成的干扰最小。这种不同的吸附行为增强了两种矿物之间的可浮性对比，从而实现了白钨矿与方解石的选择性浮选分离。