Analysis of Methane Emission for the Bigger Mining-Length and Fully Mechanized Top-Coal Caving Face in Yangquan Ⅲ Mine

Abstract：Methane emission rate per unit time is high in the big mining-length and fully mechanized top-coal caving face where the raised mechanization is used, and the concentration of methane exceeding limit in return airflow corner and return airflow roadway usually takes place.The feature of methane emission can be found by analysing methane headstream.The methane emission laws of the K8206 top-coal caving face are investigated during the initial mining stage and normal mining stage.The reason of large fluctuating is that methane swarms constantly and periodically from the goaf, and the abrupt roof caving and crannies occurring will also arose the unexpected methane effusing from the adjacent stratum.The problem of methane effusing from the adjacent stratum during normal mining stage could be resolved only by the suction pressure of the high-position alley.At the same time, methane effusing from the coal seam being worked increases, and the emphases of methane control could be put on the methane effusing from coal seam being worked.

Keyword：bigger mining-length and fully mechanized top-coal caving face;methane emission;methane resource;methane extraction;