EXTRACTION OF NICKEL WITH CAPRIC ACID

Bis(caprato)-tetrakis(capric acid)-nickel(II)(NiR2HR) and dimeric bis(caprato)-bis(capric acid)-nickel(II)(NiR22HR)2) are found responsibel for the extraction of nickel(II) with capric acid dissolved in benzene (HR: capric acid). Constants for the following extraction equilibrium have been determined: {A figure is presented}KMjx = [(MR2xHR)j]0[H+] 2j [M2+]j[(HR)2] 0j(1+ x 2) as log K14Ni = 11·34 ± 0·05 and log K22Ni = 19·15 ± 0.·05. Monomer-dimer equilibria of nickel species in benzene can be written as: {A figure is presented} with the value of log KdimNi = 3·5 ± 0·2. Electronic spectrumm of the extracted species suggests the octahedral structure for the dimer. The results are compared with those obtained in the extraction of cobalt caprate. © 1969.