关键词: 氧化煤, 浮选, 表面性质, 疏水化, 预处理

Abstract: Oxidation results in an increase in the amount of oxygen-containing functional groups on the surface of coal particles, a decrease in hydrophobicity, and a decrease in the recovery effect of flotation. But oxidized coal reserves are huge, the study on its separation and utilization has important significance. The oxidation layer obstructs the effective contact of collector molecules and bubbles with the hydrophobic part of coal slime, which is the main reason for the decrease of floatability of fine oxidized coal. The hydrophobic pretreatment of fine oxidized coal surface before flotation has become one of the main methods and the research focus to improve the floatability of fine oxidized coal. In this paper, the identification and quantitative characterization techniques and methods of oxygen-containing functional groups on the surface of oxidized coal were summarized, and the methods of surface hydrophobic pretreatment were reviewed. The analysis results show that, some materials surface analysis techniques, such as infrared spectrum, Raman spectrum, and X-ray electron spectroscopy effectively supply the information about the functional groups properties at different levels of fine oxidized coal, and have been used widely by researchers. Suitable pretreatment, such as grinding, high strength and high concentration conditioning, and ultrasonic treatment can achieve the surface hydrophobic modification of fine oxidized coal. However, different measurement and pretreatment methods have their own limitations, so researchers and engineers need to choose and comprehensively apply them according to the properties of materials, research purposes, feasibility and other aspects. This paper provides some references for improving the floatability of fine oxidized coal.