Slime　contamination　is　an　urgent　problem　that　should　be　solved　in　coal　flotation.　The　adverse　effects　of　slime　contamination,　by　which　low-ash　clean　coal　is　covered　by　high-ash　fine　slime　and　hence　cannot　be　separated　through　the　direct　flotation　process,　have　been　recognized　for　the　past　decades.　In　this　investigation,　to　reduce　slime　contamination,　the　reverse-and-direct　flotation　process　was　proposed.　Flotation　results　indicated　that,　based　on　the　similar　ash　content,　the　concentrate　yield　increased　by　7.36%　using　the　reserve-and-direct　flotation　process　compared　with　the　two-steps　direct　flotation　process.　XPS　(X-ray　Photoelectron　Spectroscopy)　and　SEM　(Scanning　Electron　Microscopy)　results　verified　that　the　reduction　of　fine　clay　minerals　coating　on　the　surface　of　clean　coal　was　achieved　and　hence　the　flotation　performance　was　improved　with　the　reverse-and　direct　flotation　process.　Therefore,　it　can　be　arrived　that　the　reverse-and-direct　flotation　process　is　a　potential　and　effective　separation　method　to　upgrade　the　flotation　performance　of　fine　coking　coal.　©　2019　Elsevier　B.V.