Abstract The presence of Pb2+ can activate cassiterite flotation, however, its biotoxicity may lead to environmental issues. Therefore, the feasibility of using Zn2+ instead of Pb2+ in cassiterite flotation was investigated in this study. The effects and mechanism of Zn2+ on the floatability of cassiterite were analyzed using benzohydroxamic acid (BHA) as the collector. The results indicated there was a higher recovery of cassiterite in the presence of Zn2+ than in the presence of Pb2+. The maximum recovery of cassiterite in the presence of Zn2+ was 90.54%. This was attributed to an increase in the adsorption quantity of BHA on the cassiterite surface with Zn2+. The maximum growth range was 4.47 × 10-6 mol/g. Further chemistry analysis of the solution indicated that BHA and Zn2+ were mainly present in the form of BHA molecules and Zn(OH)+ at pH 7.5–8.0. X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) confirmed that Zn(OH)+ reacted with OH– on the cassiterite surface to form a Zn-O bond. Then, this metallic bonding combined with BHA molecules to generate a new type of chelate ring (-Sn-O-Zn-BHA). This structure made BHA attach more firmly on the cassiterite surface, causing a rise in the recovery of cassiterite.

中文翻译：

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以苯异羟肟酸为捕收剂的锡石浮选中锌离子的活化机理

摘要 Pb2+ 的存在可以激活锡石浮选，但其生物毒性可能会导致环境问题。因此，本研究考察了在锡石浮选中使用 Zn2+ 代替 Pb2+ 的可行性。以苯异羟肟酸（BHA）为捕收剂，分析了Zn2+对锡石可浮性的影响及机理。结果表明，在 Zn2+ 存在下锡石的回收率高于在 Pb2+ 存在下。在 Zn2+ 存在下锡石的最大回收率为 90.54%。这归因于 Zn2+ 在锡石表面上 BHA 的吸附量增加。最大生长范围为 4.47 × 10-6 mol/g。溶液的进一步化学分析表明，BHA 和 Zn2+ 在 pH 值为 7 时主要以 BHA 分子和 Zn(OH)+ 的形式存在。5–8.0。X 射线光电子能谱 (XPS) 和傅立叶变换红外光谱 (FTIR) 证实 Zn(OH)+ 与锡石表面上的 OH- 反应形成 Zn-O 键。然后，这种金属键与 BHA 分子结合生成一种新型螯合环（-Sn-O-Zn-BHA）。这种结构使 BHA 更牢固地附着在锡石表面，导致锡石的回收率上升。