Yang Xiaoxia, Mu Yufan, Liu Shiqi
School of Mechanical Engineering, Taiyuan University of Science and Technology, Taiyuan 030024, China.
The University of Queensland, Brisbane, QLD 4072, Australia.
Molecules. 2024 May 27;29(11):2517. doi: 10.3390/molecules29112517.
Despite being a major cyanide species in the process water, it is unclear how iron cyanide influences pyritic gold ore flotation as well as how lead ions influence pyritic gold ore flotation in the presence of iron cyanide. This study aims at revealing the interaction of Fe(CN) and lead ions in pyrite flotation to investigate the strong depressing effect of Fe(CN) on pyritic gold ore flotation and the significant activating effect of lead ions on pyritic gold ore flotation in the presence of Fe(CN) using flotation, zeta potential measurement and surface analysis methods. The flotation results showed that upon 5 × 10 mol/L Fe(CN) addition, pyrite recovery drastically decreased from about 51.3% to 8.6%, while the subsequent addition of 9.5 × 10 mol/L lead ions significantly activated pyrite with the recovery increasing from 8.6% to 91%, which demonstrated that Fe(CN) strongly depressed pyrite flotation, while lead ions completely activated pyrite in the presence of Fe(CN). Zeta potential measurement, surface analysis using Cryogenic X-ray photoelectron spectroscopy (Cryo-XPS) and electrochemical impedance spectroscopy (EIS) revealed that Fe(CN) depression was attributed to the chemical adsorption of Fe(CN) on iron sites of pyrite as Prussian Blue (Fe[Fe(CN)]); however, this hydrophilic layer could be covered totally by lead ions which adsorbed on as lead hydroxide/oxide through electrostatic interactions, which resulted in the significant activation effect of lead ions. The results from this study will lead to improved flotation of gold associated with pyrite in gold flotation plants.
尽管亚铁氰化物是工艺用水中的主要氰化物物种，但尚不清楚亚铁氰化物如何影响黄铁矿型金矿的浮选，以及在存在亚铁氰化物的情况下铅离子如何影响黄铁矿型金矿的浮选。本研究旨在揭示亚铁氰化物和铅离子在黄铁矿浮选中的相互作用，以利用浮选、ζ电位测量和表面分析方法，研究亚铁氰化物对黄铁矿型金矿浮选的强烈抑制作用以及在存在亚铁氰化物的情况下铅离子对黄铁矿型金矿浮选的显著活化作用。浮选结果表明，添加5×10⁻⁴mol/L的亚铁氰化物后，黄铁矿回收率从约51.3%急剧下降至8.6%，而随后添加9.5×10⁻⁴mol/L的铅离子显著活化了黄铁矿，回收率从8.6%提高至91%，这表明亚铁氰化物强烈抑制黄铁矿浮选，而在存在亚铁氰化物的情况下铅离子完全活化了黄铁矿。ζ电位测量、使用低温X射线光电子能谱（Cryo-XPS）和电化学阻抗谱（EIS）的表面分析表明，亚铁氰化物的抑制作用归因于亚铁氰化物以普鲁士蓝（Fe[Fe(CN)₆]）的形式化学吸附在黄铁矿的铁位点上；然而，这种亲水层可以被通过静电相互作用吸附为氢氧化铅/氧化铅的铅离子完全覆盖，这导致了铅离子的显著活化作用。本研究结果将有助于提高金浮选厂中与黄铁矿相关的金的浮选效果。
