Si. El-dessouky et al., Mechanism of the synergistic extraction of octahedral Co(II) from nitrate medium by 8-hydroxyquinoline-Db18C6 chloroform mixture, RADIOCH ACT, 85(1-2), 1999, pp. 79-82
The kinetics of extraction of radioactive octahedral Co(II) by a chloroform
mixture of 8-hydroxyquinoline (HOX) and dibenzo-18-crown-6 (Db18C6) from n
itrate medium was investigated using a stirred Lewis cell. The effects of t
he stirring speed, temperature, specific interfacial area and interfacial t
ension on the extraction rate showed that the extraction process is control
led by a chemical reaction in the bulk aqueous phase rather than at the int
erface. The results of the effect of [HOX], [Db18C6] and [H+] on the extrac
tion rate indicated that the synergistic extraction of octahedral Co(II) is
first-order dependent on HOX concentration, of fractional negative order w
ith respect to H+ while it is nearly independent of the crown ether concent
ration. The extraction process is expressed by a reaction mechanism in whic
h the formation of the 1:1 cobalt species in the aqueous phase is the rate-
controlling step.