STUDIES ON THE BEHAVIOR OF SIEVE PLATE EXTRACTION COLUMN WITH TRAPEZOIDAL PULSE

The trapezoidal pulsed column is operated in dispersion-coalescence mode.Repeated coalescence and redispersion of two phases enhance the rate of surfacerenewal and obvious coalesing layers during the pulse stop serve to overcome thebackmixing. The drop size is fairly well-distributed throughout the cartridges.The flooding velocities of the column achieve about 1.8 cm/s, and only a half ofpulse intensity is required as compared with sinusoidal pulsed column. Extractionefficiency of the trapezoidal pulsed column increases more than 30% than that ofthe sinusoidal one. Simulating Np (IV) With Th(IV) in an artificial high activitywaste nitrate solution, mass transfer experiments have been performed in anextraction column of 50 mm i. d. and 1.1 m effective height with trapezoidalpulse. The recovery of Th is larger than 98% and an equivalent theoretical stagenumber of 4.9 is obtained.