伊宁凹陷侏罗系主要煤层煤岩煤质特征

Coal Petrology and Coal Quality Characteristics of Early-Middle Jurassic, Yining Hollow

伊宁凹陷煤系地层主要分布于侏罗系中下统水西沟群(J1-2sh)八道湾组(21-23煤、27-29煤)、西山窑组(6-7煤、10煤),煤层厚度大,分布稳定,结构简单。研究结果表明:伊宁凹陷4套主要煤层显微组分以惰性组为主,镜质组次之,壳质组极少,自下而上惰性组含量逐渐增高,镜质组含量逐渐减少;煤质属低-中灰、低硫、中高-高挥发分、高-特高发热量不粘煤;煤的挥发分与灰分呈弱负相关关系,与全硫含量、发热量分别弱正相关。究其原因,传统的煤变质指标挥发分对于低变质长烟煤、不粘煤适用性较差。

The coal-bearing strata of Yining hollow distribute in Badaowan Formation and Xishanyao Formation of Shuixigou Group. The main coal-seams of Badaowan Formation are 21-23 and 27-29 while Xishanyao Formation is 6-7and 10. The coal seams are thick, steady and simple. According to the research, we got the following concludes：the coal macerals content of four main coal seams of Yining Hollow are Inertinite, Vitrinite, and Exinite, from high to low. The coal quality belongs to non-caking coal of low-middle ash, low sulfur, high volatiles and high calorific value. The coal content of volatiles has a low-negative correlation with ash, while sulfur and calorific is low-positive correlation. The reason for low-correlation is that the traditional coal metamorphic indicators of volatiles has a poor suitability for coal of non-caking coal and long flame coal in lower metamorphic.