Herein, benzohydroxamic acid/dodecylamine (BHA/DDA, optimal molar ratio of 6:1) demonstrated the excellent separation in the flotation of spodumene (ca. 88% recovery) from feldspar (ca. 24% recovery) at pH 8–9. To detect the underlying mechanism, in-situ attenuated-total-reflectance Fourier-transform infrared (ATR-FTIR) spectroscopy with two-dimensional correlation spectroscopy (2D-COS), zeta potential measurements, in-situ microcalorimetry, and X-ray photoelectron spectroscopy (XPS) were performed. In-situ microcalorimetry results indicated that the mixed collector released more heat than the individual collectors for both minerals. Moreover, The order of the difference in the adsorption reaction heat between this two minerals is as follows: |ΔQ| (13.948 J·g) ˃ |ΔQ| (3.116 J·g) ˃ |ΔQ| (1.110 J·g), confirming the excellent separating ability of mixed collector. In-situ attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy and two-dimensional correlation spectroscopy (2D-COS) sequences results showed that the sorption process and configuration of BHA/DDA (0.4 mM, molar ratio = 6:1) on spodumene and feldspar surfaces were different at pH of 4–5 and 8–9, mainly due to the different BHA structure and the formation of hydrogen bond between BHA and DDA at different pH range. Zeta-potential and X-ray photoelectron spectroscopy (XPS) also suggested that their prominent separation is not simply due to the higher adsorption density for a single collector in the presence of mixed collector. Lastly, recommended adsorption models for the adsorption of the complex on the surfaces of spodumene and feldspar were proposed. This work provided powerful in-situ detection technologies to reveal the reagent-solid interaction in selective separation processes.

中文翻译：

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锂辉石-长石浮选体系中混合捕收剂BHA/DDA的原位吸附


在此，苯并异羟肟酸/十二烷胺（BHA/DDA，最佳摩尔比为 6:1）在 pH 8-9 时证明了锂辉石（回收率约 88%）与长石（回收率约 24%）的出色分离。为了检测潜在的机制，采用了原位衰减全反射傅立叶变换红外 (ATR-FTIR) 光谱与二维相关光谱 (2D-COS)、zeta 电位测量、原位微量热法和 X 射线光电子学进行了光谱分析（XPS）。原位微量热法结果表明，对于两种矿物来说，混合捕收剂比单独捕收剂释放更多的热量。而且，这两种矿物之间的吸附反应热差异的顺序如下：|ΔQ| (13.948 J·g) ˃ |ΔQ| (3.116 J·g) ˃ |ΔQ| (1.110 J·g)，证实了混合捕收剂具有优异的分离能力。原位衰减全反射傅里叶变换红外（ATR-FTIR）光谱和二维相关光谱（2D-COS）序列结果表明BHA/DDA（0.4 mM，摩尔比=6:1）的吸附过程和构型pH值4-5和8-9时锂辉石和长石表面的氢键不同，这主要是由于BHA结构不同以及不同pH范围BHA和DDA之间氢键的形成所致。 Zeta 电位和 X 射线光电子能谱 (XPS) 还表明，它们的显着分离不仅仅是由于混合捕收剂存在下单一捕收剂具有更高的吸附密度。最后，提出了配合物在锂辉石和长石表面吸附的推荐吸附模型。这项工作提供了强大的原位检测技术来揭示选择性分离过程中试剂与固体的相互作用。