陕北三叠纪煤田子长矿区瓦窑堡组特高焦油产率煤富集规律分析

Study on Wayaobu Formation Extra-high Tar Yield Coal Enrichment Pattern in Zichang Mining Area,Northern Shaanxi Triassic Coalfield

特高焦油产率煤的富集受煤变质程度、成煤环境等因素的制约。子长矿区瓦窑堡组可采煤层为5号煤层和3号煤层,通过对煤岩样品进行低温干馏试验,得到瓦窑堡组焦油产率平均为13.4%,其中5号煤焦油产率为12.55%,3号煤焦油产率为13.7%,属于特高焦油产率煤层。在空间分布上,高油煤占比达到77%,富油煤占比为23%,零星发育含油煤。研究表明,煤层焦油产率高的原因有3个,一是以低—中等变质程度的气煤为主,高挥发分、高含氢、高含氧;二是显微煤岩组成中有机含量、活性组分平均含量高;三是本区成煤环境以陆相沼泽、湖泊沉积为主,还原程度高。

The enrichment of extra-high tar yield coal has been restricted by factors of coal metamorphism degree,coal-forming environment etc.The Wayaobu Formation mineable coal seams in the Zichang mining area have coal Nos.5 and 3.Through low temperature carbonization experiment obtained average coal tar yield is 13.4%,in which,coal No.512.55%,coal No.313.7%,all belong to extra-high tar yield coal seam.Spatially,high tar yield coal proportion is 77%,rich tar yield coal 23%,sporadically developed oil-bearing coal.The study has shown that there are three causes of high coal tar yield:the first is coal belongs to high volatile matter,high hydrogen and high oxygen gas coal;the second is high mean contents of organic matter and active constituent in macerals;the third is coal-forming environment in the area is mainly limnic bogs and lacustrine deposits with high reductibility.