Abstract: To address the industry challenges of low solid waste utilization and significant loss of combustible coal resources caused by stockpiled flotation tailings in coal preparation plants, as well as the poor separation efficiency of conventional re-flotation due to high-ash fine slime interference, this study aims to break through the technical limitations of existing tailings re-separation processes, which only involve coarse-grain grinding without the pretreatment of fine-grained high-ash clay minerals. The ultimate goal is to achieve the highly efficient recovery and utilization of coking clean coal resources from flotation tailings. A combined separation process consisting of pre-desliming with a small-diameter hydrocyclone and fine grinding-liberation with a stirred mill was adopted. Using the flotation tailings from the Lvjiatuo Coal Mine of Kailuan Group as the experimental raw material, a series of experiments were sequentially conducted, including raw material particle size and mineral composition analysis, hydrocyclone desliming condition tests, stirred milling tests, and comparative flotation washability tests. The research results indicate that under the optimal operating conditions of a ϕ75 mm hydrocyclone—with a feed pressure of 0.25 MPa and a feed slurry mass concentration of 15%—the underflow and overflow yields are 36.16% and 63.84%, respectively. The ash content difference between the underflow and overflow products reaches up to 17.25 percentage point, demonstrating that the high-ash fine slime components are heavily enriched and effectively removed in the overflow. After grinding the hydrocyclone underflow material in the stirred mill for 4 min, the volume mean particle size of the material decreases to 75.16 μm, which is a reduction of 47.42 μm compared to the original flotation tailings, significantly enhancing the degree of liberation between coal and gangue minerals such as quartz and kaolinite. Under the target product specification limiting the clean coal ash content to 12.50%, the flotation clean coal yield of the deslimed and ground underflow can reach 40%, representing a 35 percentage point increase compared to the clean coal yield obtained from the direct flotation of the original tailings. Front-end desliming using a hydrocyclone can pre-remove kaolinite-type high-ash fine slime impurities, thereby eliminating the negative coating effects of fine slime on the flotation system. Meanwhile, the subsequent milling operation effectively liberates interlocked middlings (composite particles). The combination of these two processes can dramatically improve the mineral composition and particle size characteristics of the flotation feed, substantially enhancing the recovery efficiency of coking clean coal from flotation tailings. This study opens up a novel process path for the resource-oriented recovery of stockpiled flotation tailings.