Magnesium reducing slag sorting device and comprehensive treatment device and treatment method thereof

The magnesium reducing slag sorting device comprises a reducing slag large material tank used for storing materials in a classified mode, a reducing slag coarse powder tank and a reducing slag fine powder tank, a discharging channel is arranged above the reducing slag large material tank, and a discharging opening of the discharging channel faces downwards and directly faces a feeding part of the reducing slag large material tank; a cyclone type powder concentrator is arranged on one side of the discharging port, an air blowing mechanism used for blowing coarse powder and fine powder into the cyclone type powder concentrator is arranged on the other side of the discharging port, a discharging port of the cyclone type powder concentrator is communicated with the reducing slag coarse powder tank, an air outlet of the cyclone type powder concentrator is communicated with a negative pressure powder collector, a discharging port of the negative pressure powder collector is communicated with the reducing slag fine