Paste Backfilling in Underground Coal Mines

Surface disposal of coal ash is a challenging task due to adverse socio-environmental impacts. A possible alternate solution is to use the coal ash as a paste backfill material for underground coal mines. Development of Paste backfill technology and its application in the few coal mines of the world marked the dawn of new era in backfill technology for coal mines. This has sparked an urge to develop this technology into Indian mining scenario.

Conventional hydraulic filling requires additional work elements as well as man power for its application in underground coal mines. For instance, it requires sophisticated underground porous retaining barricade structures, re-handling of surplus water and there is a risk associated in form of failure and flow of backfilled material. However, paste backfill technology is an improved and effective option as compared to conventional mine stowing.

Less water requirement, improvement in coal pillar recovery percentage, enhances stability, minimizes surface and subsurface subsidence, capable of increasing in underground coal production.