| Coal gangue is the solid castoff of coal mining and machining process, which usually accounts for the 10%-15% of the total coal product. At present, their whole amount adds up to 5.0 x109 t and occupies the area of 2 .0x10 8 m2, constructing hundreds of coal gangue hills, moreover, one third of them are still burning.The spontaneous combustion of coal gangue is an extremely complex physicochemical course, which often changes from the static state under normal temperature to state of combustion. Its oxidation process is not only restricted by its intrinsic physicochemical properties, but also has close relationship to its lithofacies composition, water content, specific surface area, porosity and entironment.To analyze the comprehensive internal causes of spontaneous combustion and develop a theoretical system on spontaneous combustion of coal gangue. A series of advanced testing and analyzing methods were applied. The theories on the flow pattern of the air inside gangue hills and lacunaris medium dynamics was used to deduce a mathematical model which is sufficient to describe the dynamic process of sufficient and necessary conditions for spontaneous combustion of coal gangue. Based on this mathematical model as its theoretical foundation, the study on the control to it and chemical reactivity preventing reagent were done both in theoretic and practical way to offer useful supervising scheme and function in real project. The main achievements are as follows:In terms of the mechanism of spontaneous combustion of coal gangue, the concerned research achievements are synthetically analyzed, compared, and drawed a conclusion. Systematical and developed qualitative analysis combined with various of coal gangue and quantitative analysis about kinds of S-content were made scientifically. In addition, to supply necessary and reliable data and scientific principles for the mechanism of spontaneous combustion of coal gangue, water content, and radiation amount and changing regulations of all kinds of forms of S were analyzed, which promoted to form a more well-developed and systematical elementary theoretical framework. To make a good theoretical gist for the spontaneous combustion of coal gangue, the process of spontaneously firing on gangue was simulated and the oxygenating and heating speed of samples were analyzed through advanced testing and analyzing methods, then their O2-consuming amount and regulation of CO, CO2 as well as various of hydrocarbon coming out in this procedure were investigated. Based on the series of experiments, through introduceing the adsorption theory, free radical reactivity theory and FeS2 oxidation theory, together with all kinds of results, the foundation of a more well-developed and systematical elementary theoretical framework were completed by comparison and conclusion.To deduce out the mathematical model of spontaneous combustion of coal gangue, the air flowing state of coal gangue, combined with Darcy law, infiltrative equation, and conservation of mass, and makes use of macroscopical continuous medium were explored.A systematical and all-around constructing schedule and technical measure aimed to the prevention and management of spontaneous combustion were developed by investigation on the mathematical model.As to the management of it, according to the cause of combustion, an effective reagent and a scientific ,systematic blueprint and means which can be widely applied in real project was developed through theoretical analysis and tentative study on chemical reactivity preventing reagent.The practice indicated that the pouring slurry measure is security, effectivity, feasible, it is liable to introduce to the application.
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