Synergistic impact of a natural extract and bottom ash on the rheology of high-concentration fly ash water slurry

Hydraulic transportation of fly ash is indeed challenging, particularly at higher solid concentrations, due to its poor flow properties. This study aimed to modify the flow characteristics of high-concentration fly ash slurry by incorporating varying proportions of the natural extract, Trigonella foenum-graecum, commonly referred to as fenugreek. We examined the surface activity of fenugreek extract, which showed a critical micellar concentration of 0.028 g/mL. Besides fenugreek, different amounts of bottom ash (10–30%) and the amount of time used to mix the slurry (10–190 minutes) can also change the flow ability property of the slurry. The other parameters, such as fly ash concentration, pH, static stability, and temperature (298-313K), on the apparent viscosity of slurry have been extensively studied and reported. The slurry demonstrated non-Newtonian pseudo-plastic characteristics within the fly ash weight concentration range of 45–65%. The combination of natural extract and bottom significantly enhances rheological properties by reducing viscosity, a key parameter for increasing ash content and minimizing water usage in hydraulic transportation.