The graded warning method of coal spontaneous combustion in Tangjiahui Mine

摘要

The accurate prediction of the degree of coal spontaneous combustion is critical for the prevention and control of spontaneous combustion in coal mines. However, the qualitative three-stage classification method is difficult to meet the demand for accurate early warning of coal spontaneous combustion. Therefore, with long-flame coal in the Tangjiahui Mine as the study object, this paper conducted the temperature-programed coal spontaneous combustion experiment and the coal spontaneous combustion experiment. The parameters that were measured were O-2 concentration and gas generation volume during the process of coal spontaneous combustion under different oxygen supply conditions. Furthermore, this study analyzed the characteristics of gas and gas ratio variation with coal temperature, screened out the characteristic gas indexes of coal spontaneous combustion in Tangjiahui Mine, and defined six characteristic temperatures and their threshold values. Accordingly, the coal spontaneous combustion process was divided into seven stages, including the latent stage, recombination stage, self-heating stage, activation stage, thermal decomposition stage, fission stage, and combustion stage. We provide the early warning criteria and the threshold values of characteristic gas parameters at each stage and define the names of graded warnings, such as gray, blue, yellow, orange, red, and black. With this warning method, we successfully forecasted the degree of coal spontaneous combustion in the gob of the 61,102 working face, guaranteeing the successful withdrawal of this working face.