Study and application on early prediction index of coal spontaneous combustion

In order to obtain a practical and more reliable early prediction method of the site coal spontaneous combustion, the typical coal samples were selected from Yuanyang Lake Mining Area. With the coal spontaneous combustion experiment, the production law and feature parameters of the main index gases were obtained from the coal spontaneous combustion process, CO and C,H, were determined as the main early prediction indexes. In combination with the main sources of CO and the factors that interference gas concentration in the coal mining face,a theoretical model of CO concentration in the top corner was provided and the limit index value of volume fraction 0.04% from the calculation was applied to predict the oxidation degree of the coal left in the goaf. Based on the observed data of CO concentration in the top corner during the mining period of the typical coal mining face in Yuanyang Lake Mining Area, the main causes of CO concentra-tion dynamic fluctuation in the top corner were analyzed, including the relevance with grouting, nitrogen injection, improved advancing ate and other prevention and control measures. Meanwhile, the established limit predicted index system was confirmed could meet the early waming requirements of coal spontaneous combustion.