Raising domestic coal output is consistent with Beijing's broader effort to indigenise supplies of critical energy sources, raw materials and technology.
Production has been growing faster than coal-fired electricity generation as the government tries to increase fuel stocks and cut reliance on imports.
Imports of coal and lignite have also fallen to 168 million tonnes in the first eight months of 2022, from 198 million tonnes in 2022 and 220 million tonnes in 2019.
Coal imports include both high-grade coking coal for blast furnaces as well as lower-grade coal for use in power plants.
Low levels of hydro generation forced China to rely more heavily on coal-fired units and draw more heavily on coal supplies since the start of July.