Distribution and Prevention of CO in a Goaf of a Working Face with Y-Type Ventilation

In recent years, the mining technology of ″roof cutting and pressure releasing″ has appeared in China. It is called China's third mining revolution. The technology of ″roof cutting and pressure releasing″ has changed the traditional working face ventilation system and the boundary conditions of a goaf. The law of air leakage in the goaf has changed, resulting in changes in the distributions of CO and other disaster gases. In order to ensure the promotion of this advanced mining technology safely, research on the distributions of CO and other disaster gases is very necessary. By installing CO sensors in the air intake lanes, gob-side entry retaining, and goaf, the distribution of CO in the goaf during the advancement of the working face under the ″roof cutting and pressure releasing″ mining method is studied. The concentration of CO in the upper corners of the working face under the traditional mining method and the ″roof cutting and pressure releasing″ mining method was compared and analyzed. The results show that the CO in the experimental working face mainly comes from the oxidation of the residual coal; after analysis, the CO concentration in the goaf is divided into three areas: the slowly increasing area, sharply increasing area, and attenuation area; the CO concentration in the upper corner of the working face of Y-shaped ventilation with ″roof cutting and pressure releasing″ mining is much lower than that in the upper corner of the working face of U-shaped ventilation in the traditional mining; In order to prevent the oxidation and heating of the residual coal in the goaf to produce CO, comprehensive prevention measures for CO escape in the goaf have been adopted. After actual production verification, the prevention and control measures show good effects to ensure the safe and effective production of the working face.