低阶煤是我国煤炭供应的重要组成部分。 低阶煤浮选问题严重制约细粒低阶煤的清洁高 效利用，是煤炭行业迫切需要解决的重大技术难题。 针对低阶煤的浮选难题，改进了现有的油泡浮 选装置。 通过在常规浮选载体表面包覆油膜的方式，增强它对低阶煤颗粒的捕获能力，从而达到强 化低阶煤浮选矿化过程的目的。 并选用合适的表面活性剂进行油泡的表界面活性强化，从热力学 层面探讨表面活性剂类型和用量对油泡浮选性能的影响，通过诱导时间测试和油泡浮选实验全面 评价活性油泡浮选技术的可行性，探讨了活性油泡强化低阶煤浮选的机理。 结果表明，煤样表面含 氧官能团含量高达 29.21%，其可浮性极差，在捕收剂用量高达 60 kg/ t 时才可获得 82.06%的可燃 体回收率。 所提出的油泡浮选方法实现了低阶煤的高效分选，捕收剂用量为 7 kg / t 时，油泡浮选获 得了可燃体回收率 76.82%和精煤灰分 7.21%的良好指标，优于常规浮选捕收剂用量 40 kg/ t 时的 浮选指标，相当于把捕收剂用量降低了 82.50%。 表面活性剂 2-乙基己醇和 DDAB 均可降低柴油 的表面张力。 同时，2 者对柴油的粘度也有一定程度的影响，其中 2-乙基己醇对改性柴油的粘度 影响很小，而 DDAB 则能够大幅增大改性柴油的粘度。 润湿热力学研究表明，表面活性剂可以在 一定程度上促进柴油分子在煤粒表面的吸附与铺展，提高捕收剂的热力学性能，并且改性柴油对煤 样的润湿能力并不完全是随表面张力的减小而增大，还与粘度这一参数密切相关。 诱导时间和浮 选实验结果证实了两种表面活性剂可进一步增强油泡的表界面活性，改善煤样浮选效果。 但是，表 面活性剂的使用量存在一个最佳临界值，煤样浮选效果对 DDAB 用量更为敏感，需根据煤样性质 严格控制表面活性剂的用量。

Low⁃rank coal accounts for a large proportion in China’s coal supply.The flotation problem of low⁃rank coal severely restricts the clean and efficient utilization of fine low⁃rank coal particles，and it is a major technical prob⁃ lem that urgently needs to be solved by the coal industry.Aiming at the problem of low⁃rank coal flotation，the existing oily bubble flotation method in which the air bubbles were covered by a thin oily⁃collector layer to enhance its ability for capturing low⁃rank coal particles was improved in this paper so as to achieve the purpose of strengthening the min⁃ eralization process of low⁃rank coal.Additionally，the suitable surfactants were used to improve the surface / interface ac⁃ tivity of oily bubbles，and the effect of surfactant type and dosage on the performance of oily⁃bubble flotation was dis⁃ cussed from the perspective of thermodynamics.The feasibility of the reactive oily⁃bubble flotation technology was com⁃ prehensively evaluated through the induction time measurement and the oily bubble flotation experiment，and the strengthening mechanism of reactive oily⁃bubbles to the low⁃rank coal flotation was discussed. The results indicated that there existed as high as 29.21% of oxygen⁃containing functional groups on the coal surface，which resul⁃ ted in the extremely poor floatability of the coal sample.Correspondingly，a collector dosage of 60 kg / t was required for obtaining a combustible matter recovery of 82. 06%. The oily⁃bubble flotation method proposed in this paper realized the high⁃efficiency recovery of low⁃rank coal.A good flotation efficiency with a combustible matter recovery of 76.82% and a concentrated ash content of 7.21% was attained when the collector dosage for the oily⁃bubble flotation was7 kg/t，which is better than that of the conventional flotation at a collector dosage of 40 kg/t.In other words，the collector consumption was reduced by 82.50% using the oily⁃bubble flotation technology.The surfactants 2⁃ ethylhexanol and DDAB can reduce the surface tension of diesel oil.At the same time，2⁃ethylhexanol has a very limit⁃ ed effect on the viscosity of diesel oil，while DDAB can greatly increase the viscosity of diesel oil.Wetting thermody⁃ namic studies indicated that the two surfactants can promote the adsorption and spread of diesel molecules on the low⁃ rank coal surface to a certain extent，improving the thermodynamic properties of the collector.Moreover，the wetting a⁃ bility of modified diesel oil for the coal sample does not entirely increase with the decreasing surface tension，and the liquid viscosity is also a very relevant factor.The results of induction time measurement and flotation experiments con⁃ firmed that the two surfactants can further enhance the surface / interface activity of oily bubbles and improve the flota⁃ tion effect of the coal sample.However，there is an optimal critical amount for the surfactants，and the flotation effect of the coal sample is more sensitive to the DDAB dosage.Consequently，the dosage of surfactant needs to be strict⁃ ly controlled according to the properties of the coal sample.