Study of mass transfer and emphasis on pulsed and non-pulsed conditions for implementing cobalt extraction in the pilot plant column with disc and doughnut configuration

Choosing equipment that has a higher rate of transferring mass and consumes less energy is essential for effectively extracting and separating cobalt ions in liquid-liquid extraction operations. The influence of liquid/ liquid mass transfer on the reaction of cobalt ions with D2EHPA extractant in a pilot plant pulsed column was investigated in this study. The extraction rate of cobalt into the organic phase was studied in the steady-state condition with inlet phase velocities between 0.11 and 0.23 cm/s and at different pulsation velocity (2.6-4.3 cm/s). The results suggested that the non-pulsed condition followed a slow reaction regime with low mass transfer rates, but the pulsation intensity seemed to control the overall process for better efficiency in cobalt transfer and the higher mass transfer coefficients. According to the mass transfer, the increment in the holdup and the decrement in the drop sizes should be obtained to increase the interfacial area for reaction. At the conditions studied in this column, the mass transfer coefficient of the continuous phase (Kocx a) was found to be in the range 0.00684-0.01164 1/s. The predictions of the new correlations for mass transfer coefficients are in excellent agreement with experimental results.