Chemical mining technology for deep coal resources

GE Shirong

Abstract：To explore new methods for underground coal mining technology revolution,the concept of chemical mining was proposed.Three chemical mining methods were summarized,namely underground coal gasification,underground coal pyrolysis and underground coal biological dissolution.In this paper,the technical framework,process system and key techniques to be tackled were put forward for the first time,which include 1) underground shield-gasification collaborative process and equipment system,approaches of applying synthetic gas into integrated gasification combined cycle power generation and CO2 burial,methods of underground gasification pollutants inhibition and stable gas yield control;2) underground in-situ destructive distillation technology based on concentrated solar energy heating and hot dry rock heating,underground pyrolysis technology based on electromagnetic induction heating and microwave radiation heating;3) underground biological mining based on bio-solubilization of coal.Studies at home and abroad indicate that,compared with the traditional underground mining and power generation system,the investment into underground coal gasification is decreased by 60％,the cost of production is lowered by 70％,the recovery ratio of coal resources is improved by 95％,the cost of land second ploughing is reduced by 80％,the thermal efficiency of electricity generation is increased by 50％,and the generating cost is around 0.15 yuan/(kW · h).It is predicted that chemical mining will become a new direction of coal exploration technology revolution characterized by high recovery,low damage,ultra-low emission and zero death.