Stone coal power generation selenium extraction comprehensive utilization system and method

Disclosed are a stone coal power generation selenium extraction comprehensive utilization system and method. The system comprises a fluidized bed boiler, a superheater, an economizer, high-temperature dust removing equipment and low-temperature dust removing equipment. The superheater and the economizer are sequentially arranged in a tail flue of the fluidized bed boiler, the high-temperature dust removing equipment and the low-temperature dust removing equipment are sequentially arranged on different temperature area segments of an outlet of the tail flue of the boiler, and the fluidized bed boiler comprises a combustion chamber, a separator communicated with the top of the combustion chamber and a circulating dust discharging controller communicated with the separator and the combustion chamber. A controller dust inlet pipe on the top of the circulating dust discharging controller and a material returning device stand pipe at the bottom of the separator are used in common, or one branch is led out of the material returning device stand pipe. A material returning inclined pipe and a low-temperature dust discharging pipe are arranged on an outlet of the circulating dust discharging controller, the material returning inclined pipe is communicated with a combustion chamber dense-phase area, an outlet of the low-temperature dust discharging pipe is divided into two paths, one path is connected with a circulating dust conveying system, and the other path performs direct discharging. The stone coal power generation selenium extraction comprehensive utilization method of the system is provided. The method and system have the advantages of being low in energy consumption, high in selenium extraction efficiency, simple in system, small in selenium extraction investment scale, low in selenium escape rate, low in equipment investment and the like.