Study on Retarding of Organic Phosphorus Flame Retardant on Coal Spontaneous Combustion

Coal spontaneous combustion accident is an important cause of the current coal mine accidents. In order to reduce the occurrence of such accidents, it’s necessary to carry out resistance processing of coal. This research selects the coal samples from Donghuantuo Mine as raw material for resistance experiments of adding organic phosphorus flame retardant, and uses temperature programmed gas chromatography hyphenated technique to analyze the resistance effect. The results showed that the flame retardant effect is the best when the phenyl phosphinic acid, 2-carboxethyl phenyl phosphinic acid, as well as the dimethyl methylphosphonate concentration is 30 wt.%, 8 wt.% and 15 vol.% respectively. Through the parameters analysis （CO index gas, inhibition rate, O₂ concentration and ethylene index gas） of the samples with the optimum resistive effect, it is considered that the best inhibition effect of the Donghuantuo coal is phenyl phosphinic acid with the concentration of 30 wt.%.