Sorting process for high-ash and difficult-separation coal slime

Disclosed is sorting process for high-ash and difficult-separation coal slime. Floatation coal slime is fed into a stirring barrel to be prepared into ore pulp with percentage concentration of 80g/L-120g/L, the ore pulp automatically flows to roughing and floatation equipment to be sorted, roughing tail coal enters a cyclone to be concentrated in a classified manner, concentrated bottom flow products enter a high-frequency screen to be dewatered, dewatered substances on the high-frequency screen return to roughing pulp mixing operation to be sorted again after being finely ground via a ball mill, floatation rough and fine ores are fed to a precipitation perforated basket centrifuge to be dewatered, after being dewatered via the precipitation perforated basket centrifuge, fine ore filter liquor is fed into concentration flotation equipment to be concentrated, and concentration tail coal and overflow of the ball mill return to roughing pulp mixing operation together via a pipeline to besorted again. Accordingly, low-ash and high-recovery-rate flotation clean coal is obtained. The sorting process not only avoids influence of high-ash content and fine particle slime and integrated ore to a floatation process, but also avoids contradiction between the quality and the recovery rate of a high-ash difficult-separation coal slime sorted product.