Mud-sand separator for concrete mixing plant

The utility model discloses a mud and sand separator for a concrete mixing plant. Screening device, the screening device comprises a classification box; discharge ports are formed in the side surfacesof the classification boxes; a fluid feeding hole is formed in the top end of the classification box; a filter pipe is fixedly mounted at the top end of the classification box; an opening in the bottom end of the filter pipe is positioned right above the fluid feeding hole; openings are respectively formed in two sides of the filter pipe; the heights of the openings in the two sides are inconsistent; conveying plates are welded to the openings in the two sides of the filter pipe correspondingly, a first screen and a second screen are obliquely installed at the openings in the filter pipe correspondingly, the first screen is located above the second screen, the mesh number of the second screen is smaller than that of the first screen, and a feeding device is fixedly installed on one side of the top end of the clas