Secondary magnetic separator

The utility model relates to a two-stage magnetic separator which comprises a shell, a feeding hole, a permanent magnet roller assembly and a discharging area, the feeding hole is formed in the top of the shell and is communicated with a waste residue pipe of the primary magnetic separation device; the permanent magnet roller assembly comprises a rotating roller, a transmission mechanism and a magnet yoke mechanism, the transmission mechanism comprises a transmission shaft and a speed reducer, the magnet yoke mechanism comprises a magnet yoke shaft and a permanent magnet, the permanent magnet is arranged along the circumferential part of the outer ring of the magnet yoke shaft, the discharging area is arranged at the bottom of the shell and comprises a waste residue opening and a steel grit opening, and the waste residue opening is communicated with the steel grit opening. The waste residue opening is formed below one side of the magnetic yoke shaft, and the steel grit opening is formed below one side of the