对新型煤堆阻燃覆盖剂进行防自燃试验,分析了新型阻燃覆盖剂的阻火性能.结果表明:煤样粗糙的表面被具有极低孔隙度和渗透率的阻燃覆盖剂均匀覆盖后会变得光滑,多孔结构消失,在煤样表面形成致密的密封覆盖层,从而阻止氧气进入煤堆内部,达到防止自燃的作用;阻隔空气渗入可降低煤样升温速率,使其温度保持在100℃左右,从而降低了煤样自燃趋势;覆盖阻燃剂的煤样升温到110℃后,其温升速率明显低于参比样品,在2.2×104 s时温度为150℃,阻燃覆盖剂可有效地抑制样品的自燃;覆盖改进的新型煤堆阻燃覆盖剂煤样的温升速率低于原覆盖剂,2.2×104 s时,两者温差仍约12℃,改进型阻燃覆盖剂的阻燃效果更优.
The autoignition preventing experiment was carried out for a novel flame retardant covering agent in coal heap,and the fire resistance performance of the novel flame retardant covering agent was analyzed. The results show that,after covered evenly by the flame retardant agent with low porosity and permeabili-ty,the rough coal surface became smooth,the porous structure disappeared and a dense sealing cover formed on the pulverized coal surface,which can prevent the oxygen going into the pile inside,thus to pre-vent the spontaneous combustion.Preventing the air flowing into the pile inside can control the tempera-ture rise rate of coals,and the coal temperature can be kept at about 100 ℃,thus the spontaneous combus-tion tendency of coals can be reduced.When the temperature increased to above 110 ℃,the temperature rise rate of the coals covered by the flame retardant cover agent was dramatically lower than that of the ref-erence sample,at the time of 2.2×1064 s,the detected coal temperature was 150 ℃,indicating the spontane-ous combustion of the coals was effectively inhibited.For the improved covering agents,the coals'tempera-ture rise rate was lower than that of the original one,at time of 2.4×10^4 s,the temperature difference be-tween the coals covered by the two agents was still about 1 2 ℃,implying the improved flame retardant covering agent has more excellent flame retardant effect.