Effects of particle size on the flotation behavior of coal slime

In order to investigate the influence of particle size on the flotation behavior of coal slime, industrial analysis, elementary analysis, and particle size composition analysis were carried out on coal slime. The coal slime is divided into three sizes: −0.5 + 0.25, −0.25 + 0.074, and −0.074 mm, and full −0.5 mm particle sizes. Through contact angle measurement, wetting heat measurement, and step-by-step release test to investigate the hydrophobicity of each particle size; in addition, the flotation kinetics test of different particle sizes coal slime was also carried out. The results show that the particle size has a significant effect on the flotation behavior of fine coal slime. The medium particle size −0.25 + 0.074 mm has the best hydrophobicity, followed by −0.5 + 0.25 mm, again −0.5 mm, and finally −0.074 mm particle sizes. Use Origin software to fit six kinetic models to the test data of coal slime flotation kinetics, and analyze the maximum combustible recovery r ∞ , flotation rate constant (k), and correlation coefficient ( R 2 ) of each particle size, The results show that the first-order model with rectangular distribution of floatabilities can better describe the flotation of coal slime of each particle size.