Investigating Effects of Temperature on Fly Ash Encapsulation Paste

摘要

The power industry is investigating means to achieve robust and future-proof Zero Liquid Discharge (ZLD) management of wastewater at electric power plants. Concentrated wastewater brines produced by volume reduction technologies, like membranes or evaporators, can be combined with fly ash and additives to create pumpable, grout-like, cementitious pastes in a process sometime referred to as encapsulation or solidification and stabilization. We envision these paste mixtures being engineered for safe and cost-effective transport and disposal. A wide array of properties are strongly influenced by temperature, including pumpability and set time. Because temperature can have both beneficial or detrimental effects on pastes in transport and during curing, and implementation of fly ash encapsulation will span a range of weather and operating conditions, understanding the impact of ambient and material temperatures is important to engineering paste performance. Using data collected from benchtop rheometry and calorimetry, the authors present observations about the impact of temperature on bench-scale paste testing and methodologies to best evaluate the effects temperature has on encapsulation paste viability.