Utilization of Fly Ash in Mine Stowing : An investigation to assess the suitability of fly ash and pond ash for stowing in underground coal mines

In recent years, fly ash is a subject of worldwide concern due to considerable environmental importance. It has been recognised that use of fly ash in stowing or backfilling of mines is an attractive solution to its disposal problems. Characteristics of fly ash and its response to imposed load must be studied beforehand for its effective utilization in stowing. This research work presents the physico-chemical characterization of fly ash of two thermal power stations located in the eastern part of India utilizing Talcher coal as fuel for power generation to assess their suitability for stowing in underground coal mines. An effort has been made to enhance the settling of fly ash particles and water drainage from the hydraulically stowed pond ash using polymeric flocculant. Besides, the geotechnical properties, viz. the compaction and consolidation properties of the fly ash are studied in this research. Lastly, the competency of stowed pond ash in taking load of the overlying strata has also been predicted. This research will be useful for the mining professionals, researchers, and students as a guide to assess the suitability of fly ash for stowing and help in its bulk utilization.