Page 430 - Advanced Mine Ventilation

24
Mine Sealing and Recovery

Chapter Outline

24.1 Mine Sealing 400
24.1.1 Surface Sealing 400
24.1.2 In-Mine Seals 400
24.1.2.1 Temporary Stoppings 400
24.1.2.2 Permanent Stoppings/Seals 401
24.1.2.3 Explosion-Proof Stoppings 401
24.2 Inertization of the Sealed Area 402
24.2.1 Flooding With Water 402
24.2.2 Inertization With Nonreactive Gas 403
24.3 Sampling the Sealed Mine Atmosphere and Interpretation of Data 403
24.3.1 Indices Used to Predict the Status of Fire Behind Seals 404
24.3.2 Sampling and Gas Analysis Procedure 404
24.3.3 Interpretation of Air Analysis Data 405
24.3.3.1 Litton Ratio (R) 405
24.3.3.2 Hydrocarbon Ratio (HR) 407
24.4 Recovery of the Sealed Mine 408
24.4.1 Reventilation 409
24.4.2 Air Locking 410
Problem 410
References 410

In the last three chapters, various methods of mine design, equipment design, and other
preventative techniques to prevent a mine fire have been discussed. In summary they
are as follows:
1. Design a mine to minimize spontaneous combustion,
2. Prevent frictional ignitions and use only permissible equipment in the working face,
3. Degas the coal seam, premining, and postmining to minimize methane ignitions,
4. Make coal dust noncombustible with adequate rock dusting,
5. Use stone dust barriers, where required,
6. Better housekeeping and keeping some firefighting equipment handy. These include dry
powder fire extinguishers, water hydrants, and equipment to create high-expansion foam.
Detailed descriptions of these items are available in the literature [1]. They are also often
required by the Federal and State regulations [2].
In spite of all efforts, there are occasions when a mine must be sealed. The rule of
thumb is that if the fire is not “controlled” within a few hours, planning for sealing
must start [1]. “Controlled” does not mean extinguished: it means the fire has been

Advanced Mine Ventilation. https://doi.org/10.1016/B978-0-08-100457-9.00024-9
Copyright © 2019 Elsevier Ltd. All rights reserved.