(538e) Entrainment of Aqueous Hazes in Liquid-Liquid Extraction Equipment and Their Effect on Fission Product Carry-over in Fuel Processing Operations

Aqueous haze formation and behavior was studied in the liquid-liquid system tri-n-butyl phosphate in odorless kerosene and 3M nitric acid with uranyl nitrate cesium nitrate to represent the primary solute and a fission product, respectively. A pulsed column, mixer-settler and centrifugal contactor were chosen to investigate the effect of different turbulence characteristics on the manifestation of haze since these contactors exhibit distinct mixing phenomena. The dispersive processes of drop coalescence and breakage, and water precipitation in the organic phase were observed to lead to the formation of haze drops of ~1 µm in diameter. The interaction between the haze and primary drops of the dispersion was critical to the performance of the liquid-liquid extraction equipment. Conditions of high power input and spatially homogeneous mixing enabled the haze drops to become rapidly assimilated within the dispersion to maximize the scrub performance and separation efficiency of the equipment.