Effect of addition of fly ash and drag reducing on the rheological properties of bottom ash

Abstract

Disposal of bottom ash is a major concern for thermal power plant operations. The objective of the present study was to investigate the possibility of disposal of bottom ash at higher solid concentrations. As rheology of the slurry plays a major role in flow, the rheological behavior of the bottom ash in the concentration range of 10-50% (by weight) has been studied with and without the addition of fly ash and an additive (sodium bi-carbonate) to facilitate conveying bottom ash slurry at higher concentrations. Fly ash was added in five different proportions of the total ash concentration whereas the additive was added in four different concentrations for each concentration of bottom ash slurry. The behaviour of all the slurries was observed as Newtonian. Based on the experimental data, a correlation was developed to predict the relative viscosity of ash slurries as a function of total solids fly ash in the range of 10-40% (by weight) and, additive concentrations in the range of 2-8% (by weight).