Characteristics of Coal Spontaneous Combustion Induced by Air Leakage in the Goaf of Shallow Buried Close-Distance Coalbed

Abstract

ABSTRACT This study investigates the air leakage patterns and coal spontaneous combustion prevention in shallow-buried close-distance coalbed goafs during opposite mining, using the 2201 and 2206 working faces of Shaozhai coal mine as a case study. Through theoretical analysis, in-situ testing, and numerical simulation, we examine air leakage relationships in opposite working face goafs of shallow-buried close-distance coalbeds. We identify coal spontaneous combustion risk areas in single and composite goafs with a 100 m reverse spacing. Our results indicate that the mining method significantly affects air leakage patterns in the 2201 and 2206 working faces under opposite close-distance arrangement, with increased air leakage in composite goafs elevating coal oxidation risk. As working faces advance, air leakage channels in coal pillars increase, leading to mutual influence between the composite goafs of the 2201 and 2206 working faces. We delineate specific spontaneous combustion risk areas for both working faces and observe intensified air leakage in coal pillars between composite goafs within 100 m of opposite mining spacing. Based on these findings, we propose comprehensive prevention and control measures, including bundle tube monitoring, air leakage plugging, and inerting techniques. This study provides valuable insights for preventing and controlling coal spontaneous combustion in composite goafs of shallow-buried close-distance coalbeds.