淮北金石矿岩浆顺层侵入煤层对瓦斯赋存规律的影响

Affecting regularity of magmatic intrusion into the coal seam along with the coal-gas excavation in Huaibei Jinshi Mine

以淮北金石矿132采区3煤层为对象,通过实验室试验、现场观察、理论分析研究岩浆顺层侵入煤层对瓦斯赋存规律的影响。通过淮北金石矿地勘数据分析岩浆侵入范围及特征,结合煤体瓦斯基本参数,查明影响瓦斯分布规律的主要因素。结果表明：测定范围内大部分瓦斯含量较小,在0.19～6.69 m3/t,部分点存在以游离状态为主的瓦斯积聚现象;煤层瓦斯压力在0.11～0.25 MPa,没有明显规律,瓦斯仍处于瓦斯风化带或向甲烷带的过渡带;f在0.3～2.04,煤体普遍较硬,Δp在133.3～999.8 Pa,瓦斯放散初速度较慢;灰分、挥发分较大,随埋深有上升趋势,二者是影响该区域瓦斯分布规律的主要因素,煤的变质程度变化较大,部分变为天然焦,但大部分区域为煤焦互层。

The paper is to be engaged in a study of the influential regularity of the magmatic intrusion into the coal seam along with the coal-gas excavation in Jinshi Coal Mine,Huaibei. In this paper,we would like to take No. 3 coal seam of No. 132 mining area as the object of the research,the impact of the magmatic intrusion along with the coal seam on the gas outburst rules and make a deep-going discussion with the methods including the experiments that we have done in the gas lab based on the field observation and the theoretical analysis. First of all,we have analyzed the scope and characteristics of the magmatic intrusion along with coal seam according to the geological data of Huaibei Jinshi Mine so as to reveal the gas distribution regularity and its influential factors concerned. In so doing,we have chosen 14 gas-seam exemplary contents and gas pressures,11 coal handiness coefficients fand the initial speed of methane diffusion Δp and 5 absorption constants a and b in hoping to determine the lab experimental and analysis results gained in the study process. The research results show that the data of the gas content concentration account for between 0. 19 m3/ t and 6. 69 m3/ t,with the general trend increasing with the deepening of the mining activities going on,though not very remarkable. However,the gas pressure tends to increase from 0. 11 MPa to 0. 25 MPa,though not obvious with the increase of the depth. As to the gas composition,we have found that it consists of methane,nitrogen and carbon dioxide,with 1. 73%-75. 88%,12. 22%- 88. 00% and 0. 85%- 46. 34% being distributed,respectively. According to the above calculation results,No. 132 mining area should be classified into the gas weathering zone or transitional zone. From the point of view of drilling and cutting,it can be said that the coal of the mine is hard with magma rocks of the destructive type of Ⅰ- Ⅴ. The coal handiness coefficients range from 0. 3 to 2. 04 with the coal initial speed of diffusion being slowed down and the Δp going on between 133. 3Pa and 999. 8 Pa. Therefore,the coal seam under discussion can be said endowed with the strong impact of the magmatic intrusion along the coal seam,the enormous variation of volatile matter from 4. 97% to 40. 27%,that is to say,the gap of the coal classifications is quite great. Some of the coal can be transformed into natural coke,while most of the coal can be turned into the coal tar alternating layers. With the ash being totally high,its value of utility is merely over 35%. And,in turn,both of the aforementioned features can be taken as the main factors of effect on the gas distribution of the said coal seam.