Modelling of Pipeline for Disposal of Highly Concentrated Fly-Bottom Ash Slurry for Backfill Using CFD

Abstract

Mine backfilling is a technique in which the backfill material is hydraulically conveyed through the pipeline to fill the underground deep evacuated mine. To study and design the pipeline for filling purpose there are some parameters to be associated with transportation like pressure drop, critical velocity, flow regimes, pipe diameter, concentration of slurry etc. In the present study, an attempt has been made to design the slurry pipeline for the backfilling of coal mine. The mixture of bottom ash and fly ash are chosen as a backfill material. The sample of bottom and fly ash collected from Deenbandhu Chhotu Ram thermal power plant, Yamuna nagar. The physical, chemical properties like particle size distribution, X-ray diffraction, Scanning electron microscopy, pH, settling, specific gravity, bulk density, water holding capacity, porosity, plasticity and TGA/DTA analysis has been studied by using different bench scale test. The fly ash particles are finer and spherical in shape where as bottom ash particles are in irregular in shape. The elemental composition of bottom ash and fly ash consist of SiO2, Al2O3, CO2. Mixture of bottom and fly ash behave as Newtonian in nature up to 50% by weight beyond this mixture behaves as non-Newtonian fluid.