Preliminary-tailing-discarding coal slime pre-grading sorting device

The utility model belongs to a coal mine production device, and particularly relates to a preliminary-tailing-discarding coal slime pre-grading sorting device, which is characterized in that a hydrocyclone group A (4) is arranged above a first section underflow buffer pool (13), a feeding inlet of each small taper-angle hydrocyclone in parallel connection in the hydrocyclone group A (4) is connected with the left end of a feeding pressure stabilizing pipe A (3), the right end of the feeding pressure stabilizing pipe A (3) is closed, the side wall of the feeding pressure stabilizing pipe A (3) is provided with a pressure gauge (3-1), an overflow pipe (1) is respectively arranged above each small taper-angle hydrocyclone in the hydrocyclone group A (4), an overflow pipe (5) is respectively arranged above each small taper-angle hydrocyclone in a hydrocyclone group B (6), the bottom end of a second section underflow buffer pool (10) is connected to a feeding end of a second section slurry pump (9) through a pipel