在高温沉降炉上,进行了高氯高碱准东煤、低氯低碱准东煤和由低氯准东煤处理制得的调质准东煤在含不同浓度HCl的模拟空气中的燃烧实验。利用DLPI进行了颗粒物的分级收集,对其质量粒径分布和矿物元素分布特性进行了讨论分析。结果表明,高氯高碱准东煤的超细模态颗粒物生成量和峰值粒径均明显大于其他两种煤,其主要成分为Na和Cl。Ca的迁移特性与其形态密切相关,原煤中的Ca主要以无机矿物形式存在,主要迁移进入粗颗粒物而对超细颗粒物生成贡献较小。气氛中加入不同浓度HCl气体后,低钠煤和调质煤产生细颗粒物中Cl含量均升高,但生成量无显著变化。表明HCl并未显著促进矿物的气化,但会促进NaCl形式矿物蒸气的形成,进而促进成核形成超细颗粒物。
In the present study, three Zhundong coals with different contents of chlorine and AAEMs(alkali and alkali earth metals) were burned in a high temperature drop tube furnace. The derived particulate matter(PM) was collected with DLPI(Dekati Low Pressure Impactor) sampling system and discussions were performed based on the PM yield and composition. The coal with high contents of chlorine and AAEMs produced ultrafine PM with high contents of Na and Cl, which was of both higher mass yields and larger peak sizes than that of the other coal. The partitioning of Ca into PM was related to its mode of occurrence in coal. Ca in the two untreated coal was mainly migrated into coarse PM and contributed little to the formation of ultrafine PM as it was mostly in inorganic minerals in coal. The extra added HCl had no significant effects on the yield of ultrafine PM while resulted in much higher contents of Na and Cl. The results showed that increasing HCl would not significantly promote the mineral vaporization while it accelerated the formation of chlorides, which nucleated more easily and formed ultrafine PM.