High Performance Longwall Mining in Deep and Methane-rich Coal Deposits in Germany Taking into Account Methods and Technologies for Controlling the Calculated Gas Liberation

摘要

In German underground hard coal mining,extraction has had to be moved to ever-greater depths,using the multi-seammining method.On the one hand this requires high quality longwall entries,which are normally used twice.On the other handsuccessful control of gas emissions is a decisive factor if longwall mining is to be productive.Despite extremely difficult geologicalconditions with winning depths of more than 1,100m,rock temperatures of over 60°C and releasable gas contents in the workingseams up to 9 m3/t coal and in the surrounding strata (for 1 ton saleable coal) up to 40 m3/t,it has been possible to implementhigh-performance longwall mining operations.Several factors are important for this success today and in the future: a program foradvance calculation of gas emissions developed on the basis of practical experience,modem gas drainage and monitoring technology,supporting and sealing off the seam edge areas using innovative construction material machinery-and last but not least,a carefullytrained and experienced mining team.