Hydrophobicity of coal surface is determined by its physical property and chemical composition. Once coal was oxidized or spontaneously ignited under natural conditions, the surface properties would change greatly, which inevitably affect the hydrophobicity of coal surface. To reveal the changing regulations of coal surface’s hydrophobicity after oxidation and pyrolysis treatment, in this paper, two conditions (pyrolysis and oxidation) of heating treatment were used to produce a series of coal surfaces, and then characterizing their physical and chemical properties through SEM and XPS. Meanwhile, induction time and flotation tests were performed to measure the hydrophobicity of coal. Results showed that the pores and cracks were well developed on the coal surface after both oxidation and pyrolysis processes. But they contributed to opposite aspects later in the flotation test. Additionally, the content of oxygen-containing functional groups on the surface decreased after pyrolysis, whereas having a sharp increase after the oxidation process, which predicted that the hydrophobicity of coal surface under two heating conditions would be completely different. Coal after pyrolysis owned a very short induction time, and its flotation recovery was high. For oxidation process, the coal surface became more hydrophilic and their induction time could reach at about 4000 ms, very hard to float.

煤表面的疏水性取决于其物理性质和化学组成。一旦煤炭在自然条件下被氧化或自燃，其表面性质将发生巨大变化，这不可避免地影响了煤炭表面的疏水性。为了揭示氧化和热解处理后煤表面疏水性的变化规律，本文采用加热处理的两个条件（热解和氧化）来生产一系列煤表面，然后通过SEM和SEM表征它们的理化性质。 XPS。同时，进行诱导时间和浮选试验以测量煤的疏水性。结果表明，经过氧化和热解处理后，煤表面的孔隙和裂纹均发育良好。但是，它们后来在浮选试验中为相反的方面做出了贡献。另外，热解后表面含氧官能团的含量降低，而氧化过程后急剧增加，这表明在两种加热条件下煤表面的疏水性将完全不同。热解后的煤具有很短的诱导时间，浮选回收率高。对于氧化过程，煤表面变得更亲水，并且它们的诱导时间可以达到约4000 ms，非常难以漂浮。预测在两种加热条件下煤表面的疏水性将完全不同。热解后的煤具有很短的诱导时间，浮选回收率高。对于氧化过程，煤表面变得更亲水，并且它们的诱导时间可以达到约4000 ms，非常难以漂浮。预测在两种加热条件下煤表面的疏水性将完全不同。热解后的煤具有很短的诱导时间，浮选回收率高。对于氧化过程，煤表面变得更亲水，并且它们的诱导时间可以达到约4000 ms，非常难以漂浮。