氯化镁和碳/氧自由基捕获剂协同阻化煤自燃的实验研究

Study on the synergistic inhibition of coal spontaneous combustion by MgCl_(2) and carbon/oxygen radical scavengers

为了考察碳/氧自由基捕获剂(N,N-二苄基羟胺DBHA/2,6-二叔丁基-4-甲基苯酚BHT)和氯化镁结合形成的2种复合阻化剂对煤自燃抑制的行为,利用热分析(TG-DSC)、阻化性能测定和红外光谱实验对阻化处理前后的煤样自燃特性进行研究。结果表明:经复合阻化剂处理后的煤样CO释放量减少,交叉温度点和抑制率显著增高;复合阻化剂可降低反应体系中羟基、羰基和脂肪族—C—H等活性组分含量。在80℃之前,氯化镁发挥主要物理阻化作用,BHT和DBHA与水分子形成缔合氢键发挥协同阻化作用;在80~120℃,BHT与煤中含氧活性自由基结合,抑制煤与氧气吸附和含C O类化合物的生成,其协同抑制效果优于DBHA复合阻化剂;在120℃之后,DBHA复合阻化剂处理煤样的抑制率均在70%以上,比BHT对煤中自由基的捕获能力更强,抑制稳定性更高。

In order to investigate the inhibition behavior of the two composite inhibitors formed by the combination of carbon/oxygen radical scavenger(DBHA/BHT)and MgCl_(2) on coal spontaneous combustion,thermal analysis(TG-DSC),inhibition performance test and Fourier infrared analysis(FTIR)experiments were used to study spontaneous combustion characteristic of coal samples before and after inhibition treatment.The results show that the release amount of CO from coal samples treated by the composite inhibitor decreases,and the CPT and the inhibition rate increase significantly;the composite inhibitor can reduce the content of active components such as hydroxyl,carbonyl and aliphatic—C—H content.Before 80℃,MgCl_(2) play a major role in physical inhibition,and BHT and DBHA form associated hydrogen bonds with water molecules to play a cooperative role in inhibition;from 80℃to 120℃,BHT combines with oxygen-containing active radicals in coal to inhibit the adsorption of coal and oxygen and the formation of CO compounds,the synergistic inhibition effect is superior to DBHA composite inhibitor;after 120℃,the inhibition rate of coal samples treated with DBHA composite inhibitors is above 70%,the ability to capture free radicals is stronger and its stability is higher than BHT.