Continuous closed-circuit experiment flotation machine

The utility model discloses a continuous closed-loop experiment flotation machine which comprises a raw ore stirring unit and a tailing unit which are sequentially connected through a pipeline along the circulation path of raw ore, and further comprises a feeding pump for lifting ore pulp to a concentrate unit and a vertically-arranged lower washing pipe, and the discharging end of the lower washing pipe extends into the concentrate unit. A concentrate discharging part is arranged at the upper end of the concentrate unit; the tailing unit is positioned below the concentrate unit; a pneumatic valve is arranged at the ore pulp discharging position of the concentrate unit; the pneumatic valve is communicated with the lower washing pipe; the lower washing pipe is provided with an air inlet; the concentrate discharging part and the tailing unit are respectively communicated with the raw ore stirring unit through pipelines; according to the utility model, a small amount of ore samples circulate in the equipment, an