Virgin rock temperature

The incendivity of the environment can also be boosted by the increase of Virgin Rock Temperature (VRT). Theoretically, it has been supported by the frictional ignition predicting model developed by Blickensderfer, in which higher temperatures of the sliding bodies boost the frictional heating up... 

In summary, the presence of incendive ignition source rehes on presence of threshold shding distance and shding speed for the incendive rocks the incendivity of the environment can be boosted by the presence of hquid carbon hydrogen, the increase of virgin rock temperature, and the presence of the gas product of the thermal decomposition prod-... 

Temperatures in tunneis are not usuaiiy of concern uniess the tunnei is more than 170 m beiow the surface. When rock is exposed by excavation, the amount of heat liberated depends on the virgin rock temperature, VRT the thermai properties of the rock the length of time of exposure the area, size and shape of exposed rock the wetness of rock the air flow rate the dry buib temperature and humidity of the air. 

The temperature of the rocks influences the temperature of any water they may contain. Fissure water that flows into workings acts as an efficient carrier of heat. This may be bcaiiy more significant than the heat conducted through the rocks themselves. For example, for every litre of water that enters the workings at a virgin rock temperature of 40°C, if the water cools to 25°C before it reaches the pumps, then the heat added to the ventilating air stream will be 62.8 kW. 

Rock wool, frequently referred to as mineral fiber, is made from non virgin siUceous materials and is formed in a similar manner to that of fiber glass. Refractory fibers (qv), also formed in a similar manner, are available for high temperature appHcations. 

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