Characteristics on hydrated temperature field of cementing flling body and affected to coal spontaneous combustion features

In order to prevent the spontaneous combustion risk of adjacent coal bodies during soldification process of flling body in cemented backfill mining, a sit e measurement of the temperature field as well as the index gas test of the coal spontaneous combustion were individually conducted. There were 16 measuring points set in different locations, as the 1 386 m3 backfilled mass of the branch gateway in the aeolian sand paste-like backfill continuous mining face, the interfaces connected with the external and the neighboring seam. A 50 days monitoring and measurement was conducted on the hydrated temperature filed of the backfill mass. The results s howed that the temperature variation could be divided into three stages, including“a rapid rising", “quick declining' "and "gently declining" . After 94 ~ 98 h, the internal te mperature would reach the peak value of 63.5~ 64. 4 °C. The hydrated temperature lasted time would be about 30 days. The depth of the neighbor seam affected by th e hydration heat was about 0.5 m. The lab test of the spontaneous combustion index gas ( CO, C2H4 and C3Hg) showed that, affected by the hydrated heat of the backf ill mass, the initial temperature generated from the index gas of the coal samples would be lower than the conventional coal samples. Under the same temperature, the index gas concentration of the coal sample affected by the hydrated heat would be higher than the conventional coal samples, and this indicates that the coal sample af fected the hydrated heat would be easy to be spontaneously combusted. The research showed that, the spontaneous combustion risk of the coal in the cemented backfi II goaf could not be ignored.