含钠磷酸盐对煤自燃抑制性能研究

Study on inhibition performance of coal spontaneous combustion by sodium phosphate

为了探究含钠磷酸盐阻化剂对煤自燃氧化反应的抑制作用,以气煤作为实验煤样,选取磷酸二氢钠NaH_(2)PO_(4)和磷酸钠Na_(3)PO_(4)2种含钠磷酸盐化合物制备阻化剂。采用同步热分析实验和程序升温氧化实验分析含钠磷酸盐对煤自燃过程中热失重、热释放,以及气相特性的影响。结果表明:当煤自燃达到热解温度后,Na_(3)PO_(4)不再具有阻化作用;NaH_(2)PO_(4)可显著提高煤自燃的临界温度、干裂温度、着火温度等,此外,NaH_(2)PO_(4)有效提高了煤自燃初始放热温度和最大释热温度,且降低了煤自燃最大释热功率和放热量;NaH_(2)PO_(4)能够提高煤自燃过程中CO、CO_(2)及各烃类气体的初始生成温度,削弱其释放强度,其阻化率可达65.4%;相比于Na_(3)PO_(4)阻化剂,NaH_(2)PO_(4)阻化剂具有更好的阻化效果,且在煤自燃氧化全过程中均发挥了抑制作用。

In order to explore the inhibiting effect of sodium phosphate inhibitors on spontaneous combustion oxidation of coal,taking gas coal as the experimental coal sample,two types of sodium phosphate(NaH_(2)PO_(4)and Na_(3)PO_(4))were selected to prepare inhibitors.By synchronous thermal analysis experiment and programmed temperature-rise oxidation experiment,the effects of sodium phosphate on the characteristics of thermal weight loss,thermal release and gas phase during coal spontaneous combustion were analyzed.The results show that Na_(3)PO_(4)no longer has resistance when the spontaneous combustion of coal reaches the pyrolysis temperature;NaH_(2)PO_(4)significantly improves the critical temperature,dry crack temperature and ignition temperature of coal spontaneous combustion,in addition,NaH_(2)PO_(4)not only effectively increases the initial exothermic temperature and maximum exothermic temperature,but also reduces the maximum exothermic power and heat release of coal spontaneous combustion;NaH_(2)PO_(4)improves the initial generation temperature of CO,CO_(2)and hydrocarbon gases during coal spontaneous combustion and weakens its release intensity,its resistance rate reaches 65.4%;compared with Na_(3)PO_(4)inhibitor,NaH_(2)PO_(4)inhibitor has better inhibiting effect and plays an inhibitory role in the whole process of coal spontaneous combustion.