泡沫稳定性是影响浮选过程效率的重要参数之一。为了探究柴油对浮选泡沫稳定性的影响，借助泡沫扫描分析仪(FOAMSCAN)研究了气液两相体系下不同浓度的柴油与体积分数20×10^-6的甲基异丁基甲醇(MIBC)混合溶液的起泡能力与泡沫稳定性，采用动态液膜分析装置分析了泡沫间液膜的最终状态，进一步明晰了柴油对泡沫稳定性的影响机制，并通过细粒煤浮选及气液固三相泡沫稳定性试验探讨了柴油对实际浮选体系泡沫性质及浮选效果的影响。气液两相体系泡沫稳定性试验表明，随着柴油浓度的增加，溶液起泡能力和泡沫稳定性逐渐降低。泡沫间液膜测试结果说明，柴油浓度加大使得泡沫间液膜由最终的平衡状态转为破裂状态，液膜稳定性变差，气泡更容易兼并甚至破裂，该结论与气液两相泡沫稳定性试验结果保持一致。浮选结果表明，柴油用量较低时，随着柴油浓度增加，最大泡沫层高度和半衰期逐渐增大，浮选精煤产率也随之增大，这主要是由于柴油改善煤样表面疏水性以及细粒煤的稳泡作用所致;但当柴油用量增加到一定浓度后，最大泡沫层高度和泡沫半衰期减小，浮选精煤产率减小，一方面，柴油油滴进入泡沫间液膜中，在范德华力等力的驱使下，泡沫间的液膜逐渐薄化直至形成经典的油滴架桥现象，最终导致气泡兼并甚至破裂，另一方面，柴油油滴竞争吸附起泡剂分子，使得气液界面的起泡剂浓度降低，从而导致泡沫稳定性降低，柴油具有一定的消泡作用。

Foam stability is an important parameter affecting the flotation efficiency. To investigate the effect of diesel on foam stability,the foaming ability and foam stability of mixed solution of different diesel concentrations with 20 × 10-6 methyl isobutyl carbinol ( MIBC) solution were explored by foam scanning analyzer ( FOAMSCAN). The final status of liquid film between foams was analyzed by dynamic liquid film apparatus,and the effect of diesel on foam sta- bility was further clarified. Moreover,the effect of diesel on foam characteristics and flotation performance were dis- cussed through fine coal flotation tests and gas-liquid-solid three-phase foam stability tests. The foam stability tests of gas-liquid two-phase system showed that the foaming ability and foam stability gradually decreased with the increase of diesel concentration. The results of liquid film tests showed that the final liquid film changed from the equilibrium state to the rupture state,and became more and more unstable with the increase of diesel concentration,which eventually made the bubble more likely to coalesce or even rupture. This conclusion was consistent with the results of gas-liquid two-phase foam stability tests. In addition,the flotation results showed that the maximum froth height and half-life in- creased with the increase of diesel concentration when the concentration was lower,and the flotation clean coal yield increased as well,which was mainly due to the improvement of hydrophobicity on the coal surface and the effect of sta- bilizing foam of fine coal. However,the maximum froth height and half-life gradually decreased,and the flotation clean coal yield also decreased when the concentration exceeded a certain concentration. This is because,on the one hand, diesel invaded into the interfoam film and the film thinned driven by van der Waals force and other forces until the for- mation of classic oil droplet bridging phenomenon,eventually leading to the bubbles rupture. On the other hand,the diesel oil droplets competitively adsorbed frother molecules,so that the concentration of frother at the gas-liquid inter- face decreased,making foams less stable. Therefore,diesel has a certain defoaming effect on foam stability in flotation.