Abstract: The kinetics of extraction of cobalt with P5709 was studied in a Lewis cell. In the extraction system the aqueous phase was the solution of CoSO_4 (8.8×10~(-4)—3.4×10~(-2)M) and Na_2SO_4 (0.63M.) at pH 5.5; the organic phase was 15% (v/v) P5709 in kerosene (saturated with hydrogen).In order to determine the control regime of extraction of cobalt, the stirring speed, the interracial area between the two phases and the operating temperature were varied in the experiments. Experimental results showed that the extraction process of cobalt was predominantly governed by the diffusion process, and the overall mass transfer coefficients were found to be as follows:_((a)): (2-5)×10~(-3)cm/s, _((o)): (0.3-1)×10~(-3)cm/s.The results of the experiments and calculations indicated that K did not remain constant during the extraction process, Reasons for the variations in K were discussed.

摘要： The kinetics of extraction of cobalt with P5709 was studied in a Lewis cell. In the extraction system the aqueous phase was the solution of CoSO_4 (8.8×10~(-4)—3.4×10~(-2)M) and Na_2SO_4 (0.63M.) at pH 5.5; the organic phase was 15% (v/v) P5709 in kerosene (saturated with hydrogen).In order to determine the control regime of extraction of cobalt, the stirring speed, the interracial area between the two phases and the operating temperature were varied in the experiments. Experimental results showed that the extraction process of cobalt was predominantly governed by the diffusion process, and the overall mass transfer coefficients were found to be as follows:_((a)): (2-5)×10~(-3)cm/s, _((o)): (0.3-1)×10~(-3)cm/s.The results of the experiments and calculations indicated that K did not remain constant during the extraction process, Reasons for the variations in K were discussed.