There is no gas disaster and no measured data of methane emission in open-pit coal mine. The mining depth of this kind of coal mine is small, and the gas content of coal seam is also low. When utilizing this data set for Life Cycle Assessment (LCA), users should take into account that the estimated methane emission coefficients are specifically tailored for open-pit coal mines with low gas content and no gas disasters. The coefficient is set at half the rate of methane emissions from low gas mines in state-owned key coal mines. Adjustments may be needed for mines with different gas emission profiles. Output flow is primarily methane (CH4).