Abstract Xanthates are widely used for the flotation of most sulphide minerals. As well as xanthates, various reagents (e.g. sodium hydrosulphide, NaHS) are used in sulphide mineral flotation to improve selectivity. Both xanthates and NaHS target the solid–liquid interface and modify the surface to achieve sufficient difference in wettability between the gangue and target mineral. This study examines the role of potassium amyl xanthate (PAX) and NaHS at the air–liquid interface in the presence of a frother, methyl isobutyl carbinol (MIBC). The separate and joint effects of these reagents on the stability of bubbles were studied by measuring bubble size in a batch flotation cell and the lifetime of bubble pairs using a bubble coalescence apparatus. The results of the bubble coalescence experiment with the PAX/MIBC mixture showed that the presence of PAX in a concentration as low as 1 ppm significantly increased the bubble lifetime compared to the MIBC only solution. The lifetime of the bubbles was longer in the NaHS/MIBC mixture, although this might be due to the gain in the liquid viscosity in the presence of high NaHS concentrations. Depending on the concentration of PAX in the solution, the bubbles showed unstable, metastable and ultra-stable behaviors. The influence of PAX and NaHS on the Sauter mean diameter of bubbles was studied and both had a notable effect on inhibiting bubble coalescence, reducing the bubble size by 26%, while in the PAX/MIBC mixture, the size of the bubbles was largely dominated by the concentration of MIBC. Overall, the results strongly suggested that the role of PAX and the synergistic effect of PAX, NaHS and MIBC in modifying the air–liquid interface should be considered when using these reagent combinations.

中文翻译：

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非发泡试剂对气泡大小和气泡稳定性的影响

摘要 黄药被广泛用于大多数硫化物矿物的浮选。除了黄药，在硫化物矿物浮选中还使用了各种试剂（例如硫氢化钠、NaHS）以提高选择性。黄原酸盐和 NaHS 都针对固液界面并修饰表面，以在脉石和目标矿物之间实现足够的润湿性差异。本研究检验了戊基黄原酸钾 (PAX) 和 NaHS 在存在起泡剂甲基异丁基甲醇 (MIBC) 的情况下在气液界面上的作用。通过测量间歇浮选池中的气泡大小和使用气泡聚结装置的气泡对的寿命，研究了这些试剂对气泡稳定性的单独和共同影响。使用 PAX/MIBC 混合物进行气泡聚结实验的结果表明，与仅使用 MIBC 的溶液相比，存在浓度低至 1 ppm 的 PAX 显着增加了气泡寿命。NaHS/MIBC 混合物中气泡的寿命更长，尽管这可能是由于在高 NaHS 浓度下液体粘度增加。根据溶液中 PAX 的浓度，气泡表现出不稳定、亚稳态和超稳定的行为。研究了PAX和NaHS对气泡Sauter平均直径的影响，两者均对抑制气泡聚结有显着影响，使气泡尺寸减小26%，而在PAX/MIBC混合物中，气泡尺寸占主导地位通过 MIBC 的浓度。全面的，