Study on Spontaneous Combustion Features of Broken Coal Around Coal Drift and Fire Prevention Plan

According to the potential spontaneous combustion problem of the broken coal left around the coal drift in fully-mechanized top coal caving face, taking t he air returning gateway of No.18-5 fully-mechanized top coal caving face in Nanshan Mine as a study object, a numerical simulation was conducted on the oxygen an d temperature distribution features of the broken coal around the coal drift with the only condition of ventilation leakage source. A theoretical prediction was conducted on the fire prevention effect of nitrogen injection and gateway sealing. The results showed that seepage would occur when the oxygen with fresh air ventilation flowed fr om the coal drift entry to the broken coal around. The seepage scope along the strike would be in a reduced tendency with the ventilation air leakage pressure lost.The high temperature area was in the middle of the coal pillar with a certain distance to the air leakage boundary and would be steadily upward moved to a location around t he top coal. The gateway sealing and nitrogen injection in the gateway would have different restricted functions to the spontaneous combustions. The coordinated appli cation of sealing and nitrogen injection locally could have good fire prevention effects. The numerical simulation results and the site monitored and measured results wo uld be well ftted.