Abstract: In order to ascertain the feasibility of using rock powder to prevent spontaneous combustion of residual coal, the methods of theoretical analysis and experimentation were used to study the spontaneous combustion process of residual coal mixed with rock powder. First, according to theoretical analysis, the rock powder mixed with the residual coal will prevent spontaneous combustion of the residual coal. The experiment included three groups. The heating processes of coal samples were observed. The experimental results show that both the quantity and the particle size of the rock powder have a great influence on the spontaneous combustion process of the residual coal,that rock powder can prevent spontaneous combustion of residual coal when its quantity is greater than the criticality quantity, that spontaneous combustion of residual coal will not occur when the mixing ratio of rock powder to coal is 1∶1 and above,that when the particle size of rock powder is larger than the criticality particle size and near to the peak particle size, the efficiency with which the rock powder prevents spontaneous combustion of the residual coal is the greatest,and that it is feasible theoretically that using rock powder to prevent spontaneous combustion of the residual coal when the quantity and the particle size are determined reasonably.

Key words: spontaneous combustion of residual coal, experimental study, criticality quantity of mixing rock flour, criticality particle size of mixing rock flour, peak particle size of mixing rock flour