Forecast methane content in coal seams from -250 m to -400 m of Mong Duong coal mine

Abstract

Methane is considered to be the most dangerous gas in underground mining coal mines, and is particularl especially dangerous for mines ranked high in methane such as Mao Khe, Quang Hanh, Khe Cham, Mong Duong.... Mong Duong coal mine is tending to exploit down to -400 m and will zone mining areas in 2022, which means that the methane content in the coal seams also tends to increase with the mining depth, especially for the level below -250 m of Mong Duong coal mine, where has relatively complicated geological conditions and very limited methane exploration works. In order to have effective preventive measures to avoid methane gas explosions, the paper has made predictions for the methane storage capacity of Mong Duong coal mine at different depths. The paper has built the prediction chart of methane concentration when exploiting deeply based on the least squares method of Excel software. From there, the forecast data of methane content in coal seams from the current mining depth to -400 m level of Mong Duong coal mine. The forecast results of the methane content in coal seams at -400 level of Mong Duong coal mine are markedly increased compared to the current exploitation level, especially at I12 with increased methane content in the coal seam, maximum reached 4.5828m3/T.kc. The methane content in reservoir I-12 is shown by the equation y = 0.0132x-0.6983. The results of the prediction of methane content make it easier to proactively plan to eliminate methane incidents and ensure safety in underground coal mining.