Liquid-liquid extraction in a novel rotor-stator spinning disc extractor

This work describes a novel rotor-stator spinning disc extractor (RSSDE), which shows high efficiency of liquid-liquid mass transfer and rapid separation of mixed phases in comparison to conventional extractors. Extraction of phosphoric acid from an aqueous phase to an organic phase was selected as the experiment system. The influence of rotational disc speed (R), volumetric flow rate (Q), and rotor-stator distance (H) on extraction efficiency (η) and volumetric mass transfer coefficient (KLa) are investigated in an RSSDE with a spiral-grooved rotor disc or smooth rotor disc. The results show that the maximum value of η is 98.8% under optimized conditions. η increases with increasing R and decreases with increasing both Q and H. KLa increases as both the increase of R and Q and decreases as the increase of H. The maximum value of KLa is nearly 10 times higher than for a rotating disc column. The mass transfer performance of the spiral-grooved rotor disc is superior to the smooth rotor disc. Correlations of the main parameters such as angular velocity (ω), Q, and H on η and KLa for an RSSDE with both the spiral-grooved rotor disc and the smooth rotor disc are presented. The calculation result shows good coincidence with experimental data.