鸳鸯湖矿区延安组煤岩煤质特征及成煤环境研究

Study on lithology and coal quality features and coal forming environment of Yan'an Formation in Yuanyanghu Mining Area

为了揭示不同煤岩煤质的形成条件,采用煤岩学和地球化学等方法,基于煤岩、工业分析和灰成分数据分析,探讨了鸳鸯湖矿区延安组主采煤层的煤岩煤质特征及成煤环境。研究结果表明:延安组煤以半暗煤为主,富惰质组,以低灰、低硫、低磷、特低氯为主,煤灰成分以Si O2、Al2O3为主。垂向上,由下至上镜质组含量先增后减,惰质组含量先减后增,成煤环境表现为氧化型—弱氧化型~还原型—氧化型。下段和上段煤层惰质组含量高,灰分高,主要受古河道影响;中段镜质组与惰质组相当,聚煤程度具有周期性变化的特点。平面上,北部靠近物源区,灰分、硫分高,发育河道和三角洲平原环境;中部为区域沉降中心,富镜质组,灰分、硫分较低,表明由三角洲平原向三角洲前缘、湖泊环境过渡;南部的灰分、硫分最低,富惰质组,碎屑物质减少,发育三角洲平原环境。

In order to reveal the formation conditions of different lithology and coal quality,based on the coal and rock,industrial analysis and ash content data analysis,the lithology and geochemical and other methods were applied to discuss the lithology and coal quality features and the coal formation environment of the mining seam in Yan＇an Formation of Yuanyanghu Mining Area. The results showed that the coal in Yan＇an Formation was a semi durain coal mainly. The rich inertinite group was mainly the low ash,low sulfur,low phosphor and ultra low chlorine. The ash content was mainly Si O2 and Al2 O3. Vertically,from the bottom to the up,the content of the vitrinite was firstly increased and then decreased. The content of the inertinite was firstly decreased and then increased. The coal forming environment was an oxidation type-weak oxidation type or reduction type-oxidation type. The content of the inertinite in the low section and top section of the seam was high and the ash composition was high. Mainly the influences affected by paleochannel,the vitrinite and inertinite in the middle section was the same and the coal accumulation had periodical varied features. On a plane,the north part was closed to the provenance,the ash content and the sulfur content was high and the environment was the developed river and delta plain. The middle part was the regional subsidence center,the inertinite was rich,the ash content and sulfur content was low and thus the delta plain was transited to the delta leading edge and the lake environment. In the south part,the ash content and sulfur content were low,the inertinite was rich,the detrital material was reduced and the environment was a developed delta plain.