Research And Application On Predicting Method Of The Hazard Of Coal Spontaneous Combustion In Goaf Based On SEM

The coal production industry in China is still of a high-risk with the serious hidden dangers of safety production and high frequency on safety production accident,consequently the disaster of coal spontaneous combustion restricts the development of coal industry in China.The damage degree of coal mine fire could be reduced,and the impact range of which was controlled after the accident through predetermining the main factors affecting the spontaneous combustion of coal in gob,grasping the danger degree of coal spontaneous combustion accident,and taking targeted preventive measuresBased on the mechanism of coal spontaneous combustion accident and the main influencing factors of spontaneous combustion of coal in gob,the main factors that cause serious damage to coal spontaneous combustion in gob were determined in this paper:the tendency of coal spontaneous combustion,the geological structure of coal seam,the design of mining process,the technical measures for fire prevention.The interaction mode of each influencing factor on the risk of coal spontaneous combustion and the relationship among various influencing factors were analyzed.So that,22 hypotheses was proposed based on the relationships between various influencing factors,and the conceptual model of the prediction index system of coal spontaneous combustion hazard in gob was established.Combining researches on questionnaire survey and established survey questionnaire on the influencing factors of coal spontaneous combustion risk in gob,the 43 research item was determined and applied in Ningxia mine.The recycling questionnaire selection of factor analysis and principal component analysis were analyzed in the reliability and validity through the practical field investigation.The analysis results showed that the reliability and validity of the survey data satisfied the standards,and the conceptual model could be fitted and tested.Based on theoretical analysis and investigation data of factors affecting gob coal spontaneous combustion risk,the conceptual model was explained in detail,and the initial prediction index system model of gob coal spontaneous combustion risk was constructed.The SEM(structural equation model)was introduced to test the established initial prediction model of coal spontaneous combustion risk in gob,and the maximum likelihood method was selected to fit and evaluate the established initial model.The index system model of influencing factors on coal spontaneous combustion risk in gob was determined to close the reality through correction.Based on the results of the model revision,the functional way and functional degree of each index were determined for coal spontaneous combustion risk in gob,and the weight of all indicator was handled for integration.According to the survey questionnaire scores of each index,and comprehensive evaluation of the risk of coal spontaneous combustion of a gob in Ningxia coal mine,the results conformed to the coal mine actual situation on site.This study provides a new way for predicting the risk of coal spontaneous combustion in gob,and the results of this study have a good guiding significance for reducing the risk of coal spontaneous combustion accidents on coal production industry in China.