Study on Spontaneous Combustion “Three Zones” of the Distribution Law and Integrated Fire Prevention Technology in Mined-Out Area of Lingquan Mine

Table 1

Spontaneous combustion “three zones” division.

Index	Basis	Heat dissipation zone	Oxidation zone	Suffocation zone
O2 content	O2 concentration in the goaf (%)	＞19	9–19	＜9
Speed of air leakage	Speed of air leak in the goaf (m/s)	＞0.0045	0.0016–0.0045	＜0.0016
Temperature	Temperature in the goaf (°C/d)	Take the 1°C/d increasing gradient as the boundary condition between oxidation zone and heat dissipation zone (for reference only)