Research On Spontaneous Combustion Tendency Of Typical Power Coal

Coal is an organic macromolecules made by a variety of functional groups and chemical bonds. All kinds of coal have self-heating properties, when the accumulation of heat exceeded that emited, the coal become spontaneous combustion. Spontaneous combustion of coal is a complicated process, including changes of several active groups, followed different reaction mechanism in different stages.This paper selected 3 kinds of typical power coal as the major object of study. The following aspects have been studied for its features of spontaneous combustion.(1) Infrared spectrum technology is used to research coal reactivity in different oxidation temperature. Analysis each functional groups'changes during the process of coal spontaneous combustion, The order of reactivity of functional groups is discovered:Amino> Methyl, Aromatic methylene> Acid, Lipid, Vinyl> Ether. Differential spectrum analysis is used to 3 kind of coal, the spontaneous combustion tendency is discovered:Heishan>Shenfu>Fuling.(2) The spontaneous combustion tendency is identified by oxygen absorption method.Get the conclusion is Heishan coal:0.68ml/g dry coal; Shenfu coal:0.65ml/g dry coal; Fuling coal:0.50 ml/g dry coal.The spontaneous combustion tendency is: Heishan>Shenfu>Fuling.(3) Coal warm-up procedure is studied by TG analysis. Choose 6 characteristic temperatures, study on different granularity and metamorphism. A certain variation is found.(4) Prepared Shenfu coal sample cotains different moisture, using DSC analysis. The critical moisture of coal spontaneous combustion is between 12%-16%.(5) Adopt activated energy as the index parameters of spontaneous combustion. The thermal reaction of coal divides into three stages:The initial weight loss stage; weight gain stage;after the fire stage. Regression fit with 38 mechanical functions, choose a certain mechanical functions. Coats-Redfern method is used to calculate activated energy. Get the same result with step 1 and step 2.