Abstract: The mine ventilation system is one of the traditional eight major systems in underground mines,undertaking the important tasks of dust,toxic and harmful gas,and moisture removal,as well as providing oxygen and heat exchange for underground operations. The exhaust air discharged from the return air shaft contains dust,toxic and harmful gases,and fog,which has a certain impact on the surface environment. In response to these issues,relevant scholars have conducted exploratory research on the treatment technologies for pollution factors in the return air shaft and built related engineering demonstrations. However,there is a lack of in-depth summaries of the current research and application status. Based on this,the components of the pollution factors discharged from the return air shaft of typical mines were detected and their causes were analyzed. Moreover,the typical technologies and cases for treating pollution factors in the return air shaft in recent years were sorted out. The research results show that the concentrations of the known pollution factors are affected by underground operation processes and exhibit a time-periodic distribution characteristic. There are unknown irritating pollution gases. Inertial method,high-voltage electrostatic method,wet resonance grid method and adsorption method can effectively reduce the concentrations of pollution factors. Based on the above analysis,the current research status of pollution factor treatment technologies in the return air shaft was analyzed,and the existing deficiencies were pointed out. The main research directions for the future were proposed,including exploring the mechanism of defogging and dust reduction in return air wells,improving the synergistic technology of waste heat recovery and defogging in return air wells,developing rapid adsorption technology for low concentration harmful gases,and constructing a coordinated control system for dust condensation mist harmful gases. 

Key words: mine ventilation,return air shaft,pollution treatment,fog and dust removal,electrostatic fog removing,collaborative governance