The hydraulic performance of the H2O-30% trialkyl phosphine oxide (TRPO)-ke
rosene system and the mass transfer properties of HNO3 and Nd3+ were studie
d in a single-stage miniature centrifugal contactor with 10 mm diameter. A
cascade cold test for partitioning Nd3+ from the simulated high-level liqui
d waste (HLLW) using the TRPO process was conducted on the miniature contac
tors. Based on results from the cold tests, a hot test for partitioning Am3
+ from the genuine HLLW using the TRPO process was conducted on miniature c
ontactors. The results showed that approximately 200 mL waste feed will all
ow the partitioning process with 24-stage miniature contactors; of 10 mm di
ameter to reach steady state. The test results also showed that the miniatu
re centrifugal contactors have good hydraulic performance and high stage ef
ficiency. The cascade cold and hot test results agreed well with calculatio
ns from extraction models.