LAUSR

Abstract The hydraulic characteristics of the 30% TRPO (trialkylphosphine oxide)/kerosene―1.0 M HNO3 and 0.025 M iPr-C [4]C-6 (25,27-bis(isopropoxy) calix [4]-26,28-crown-6)/n-octanol―1.3 M HNO3 systems were systematically investigated in a φ20 ACE (annular centrifugal extractor) to find the cause of the hydraulic performance problem of the CECE (calixcrown ether extraction) process operated in ACEs. The results show that the operating and structure parameters have different influences on the F (A/O) (phase ratio (A/O)) and V (liquid hold-up volume). Moreover, the Vr (V of the rotor) of the 30%TRPO/kerosene―HNO3 and iPr-C [4]C-6/n-octanol―HNO3 systems are almost same, while the Vm (V of the mixing zone) and Vt (total V of the ACE) for the former are slightly higher than those for the latter under the same experimental conditions. Meanwhile, both the Fm (A/O) (F (A/O) of the mixing zone) and Fs(A/O) (F (A/O) of the separating zone) for the 30%TRPO/kerosene―HNO3 system are also higher than those for the iPr-C [4]C-6/n-octanol―HNO3 system under the same experimental conditions. Moreover, the Fs(A/O) of the iPr-C [4]C-6/n-octanol―HNO3 system is less than 1.5 under most of the present experimental conditions, which shows organic phase entrainment may easily occur in the outlet aqueous phase. This may be the cause of the hydraulic performance problem of the CECE process operated in ACEs.