Exposing the froth phase of a flotation system to low-frequency acoustic sound was reported to improve the process efficiency, which was thought to be due to the improvement in the froth stability. However, no direct evidence of the stabilization effect of sound on froths or foams is available to date. The present work aims to resolve this issue by experimentally studying the effect of low-frequency acoustic sound on the stability of a foam, the two-phase counterpart of flotation froth, across a wide range of experimental conditions. Three different setups consisting of a flotation column or a bottom-driven mechanical flotation cell, with the foam being exposed to sound from above or below, were tested. The equilibrium height of the foam with a given flow rate of air supply was measured at steady state using the Bikerman’s method. The equilibrium foam height was found to increase within certain ranges of sound frequencies and amplitudes, and at various surfactant concentrations (3–50 ppm) and superficial gas velocities (0.3–2.0 cm·s⁻¹). An increase in sound amplitude or superficial gas velocities was also found to broaden the range of sound frequency that led to the stabilization effect. These findings were largely common for the three different setups tested, suggesting that this is a versatile method for improving the stability of foams. A strong correlation was also found between the stabilization of foam demonstrated in the present work and the stabilization of froth reported in a previous study, implying that the stabilization mechanisms could be similar.

据报道，将浮选系统的泡沫相暴露于低频声波中可以提高工艺效率，这被认为是由于泡沫稳定性的提高。然而，迄今为止，还没有直接证据表明声音对泡沫或泡沫的稳定作用。目前的工作旨在通过实验研究低频声学对泡沫（浮选泡沫的两相对应物）在各种实验条件下的稳定性的影响来解决这个问题。测试了由浮选柱或底部驱动的机械浮选池组成的三种不同设置，泡沫暴露在上方或下方的声音中。使用 Bikerman 方法在稳定状态下测量具有给定空气供应流量的泡沫的平衡高度。^-1 )。还发现声音幅度或表面气体速度的增加会扩大导致稳定效果的声音频率范围。这些发现在测试的三种不同设置中基本相同，表明这是一种提高泡沫稳定性的通用方法。在目前的工作中证明的泡沫稳定性与先前研究中报道的泡沫稳定性之间也发现了很强的相关性，这意味着稳定机制可能是相似的。