Numerical Investigation of Coal Self-heating in Longwall Goaf Considering Airflow Leakage from Mining Induced Crack

•Majority of the airflow leakage into goaf sources from mining induced edge cracks.•High level oxygen (8 %∼13 %) is retained in start-off zone due to airflow leakage.•Heating evolution in the start-off zone may cause a problem due to continual airflow leakage.•Investigation of various inertisation plans to control the potential fire hazard in the start-off zone.