Fine coal slime recovering device

The invention relates to a fine coal slime recovering device and belongs to the technical field of coal washing equipment. The fine coal slime recovering device is used for recovering coal slime in a coal washing process. The invention adopts the technical scheme that an overflow port and an underflow port of a primary grading cyclone and a secondary grading cyclone are inserted into an overflow groove and an underflow groove correspondingly; a floatation pipeline interface is formed in the bottom of the overflow groove and connected with a floatation and filter pressing operation process; an opening is formed in the bottom of the underflow groove and is opposite to a dehydrating sieve; a minus sieve chute is positioned below the dehydrating sieve; a water pipe is arranged at the bottom of the minus sieve chute and connected with a water inlet of a water return pump; a water outlet of the water return pump is connected with a minus sieve water pipeline; the upper end of the minus sieve water pipeline is conne