Best Practice Guidance for Effective Methane Drainage and Use in Coal Mines (Second Edition)
Today coal supplies around 30 per cent of global primary energy and 40 per cent of global electricity. Coal extraction has become increasingly challenging as shallow reserves are exhausted and deeper seams, with significant content of methane, are mined. Societies are demanding and expecting safer mine working conditions, and greater environmental stewardship from the coal industry. The global coal industry, national governments, trade unions, and worker safety advocates are concerned that the frequency and severity of methane explosions, especially in emerging economies, are unacceptably high. Coal mine methane (CMM) only becomes flammable and creates an explosion hazard when allowed to mix with air. Methane-rich gases, generally containing 80 per cent to 95 per cent methane at underground mining depths, occur naturally in coal seams and are released as CMM when coal seams are disturbed by mining activities. Methane is an explosive gas in the range of 5 per cent to 15 per cent methane in air. The application of best practices for methane drainage and use is critical to reduce methane-related accidents and explosions that all too often accompany coal mining, while also contributing to environmental protection through reduction of greenhouse gas (GHG) emissions. Good mining practices need to be transferred to all countries to ensure that risks are managed professionally and effectively. No mine, even in the most developed countries, is free from safety risks. Regardless of location or mining conditions, it is possible to significantly reduce the risk of methane related incidents and explosions. Good safety practice in coal mines is to reduce explosion risk by preventing the occurrence of explosive mixtures and, where practical, by monitoring and rapidly diluting explosive mixtures to safe concentrations.
