Abstract: In order to improve the quality and broaden application fields of semi-coke, taking semi-coke prepared by Shanbei jet coal with solid heat carrier technol ogy as raw material, on the basis of intensive analysis on proximate, ultimate and grading analysis, surface topography and N2 adsorption, species and dissemination p roperties of minerals, semi-coke flotation experiments were investigated. The flotation effect of conventional collecting agent and foaming agent and adjusting slurryp H value on yield and ash of clean coal were studied. Meanwhile, the comparison test was carried out by DOP and kerosene. The results showed that moisture and volatile of semi-coke after low temperature pyrolysis were separated out, fixed carbon become more enrichment, surface pore structure and large specific surface area become larger. It would have negative effects on flotation processing. With routine agents, when slurry p H value was 6.2, Zeta potential was-1.44 m V, the clean semi-coke's yi eld was 53.79%, ash content was 5. 66%. Under the best conditions of the single factor experiment, when DOP dosage of 800 g/t, the clean semi-coke's yield was 58.6 2%，ash content from 9.57% decreased to 5.07%. The FITR results showed that physical and chemical adsorption happened on surface of semi-coke between DOP and organic matter, and produced kinds of hydrophobic functional groups, including benzene rings, alkyl groups and aromatic nucleus, which could improve flotation effect.