Study On The Inhibition Mechanism Of Phosphorus Compounds For Coal Spontaneous Combustion

Coal spontaneous combustion is one of the main disasters in mine.It is an effective means to prevent coal spontaneous combustion by inhibitors.Phosphorous compounds have the advantages of high efficiency,low cost and non-polluting,but the inhibition mechanism of it for coal spontaneous combustion is not clear.It is of great significance for the safety production of coal mine and the improvement of fire prevention and control technology to deeply explore the inhibition mechanism.Using STA-FTIR technology,the oxidation characteristics and changing rules of three kinds of coal with different metamorphic degrees were studied from the characteristic temperature points,heat release,escaping gas and activation energy.The inhibition effect of four kinds of phosphorous compounds was compared and analyzed.The characteristics of functional groups in coal were studied by in-situ FTIR technology.The elementary reactions of hydroxyl radicals and the pyrolysis products of phosphorous compounds with active functional groups in coal were determined by quantum chemical calculation.By comparing the microcosmic change rules of raw coal and inhibitor treated coal samples in the whole process of temperature-rising and combining with the macroscopic inhibition characteristics,the inhibition mechanism of organic and inorganic phosphorus compounds for coal spontaneous combustion and heat release were expounded respectively.The results are as follows: Hydroxyl radicals can spontaneously react with aliphatic hydrocarbons or oxygen-containing functional groups at room temperature.Four kinds of phosphorous compounds show different retarding effects on coal spontaneous combustion.Compared with other inhibitors,DMMP and Na H2PO2 inhibitors have better inhibition effect on coal spontaneous combustion.The organic and inorganic phosphorus compounds can improve the activation energy of the oxidation reaction of coal spontaneous combustion,but the chemical inhibition mechanism has essential difference: the pyrolysis products of organic phosphorus compounds can react with hydroxyl radicals and active functional groups in coal to block the chain reaction of coal spontaneous combustion,however,the inorganic phosphorus compounds can retard coal spontaneous combustion by inhibiting the formation of hydroxyl radicals and promoting the formation of stable saturated ether bonds.Figure 25;Table 16;Reference 63...