2000 Volume 26 Issue 4 Pages 542-547
New types of lipophilic phthalocyanine derivatives, that is, hexadeca (2, 2, 2-trifluoroethoxy) phthalocyanine and hexadeca (2, 2, 3, 3, 3-pentafluoro-propoxy) phthalocyanine (abbreviated as H2Pc (TFE) 16 and H2Pc (PFP) 16, respectively), were prepared for selective extraction of lithium.
The extraction equilibria of alkali metals with H2Pc (TFE) 16 and H2Pc (PFP) 16 (H2R) were measured at 303 K. Both the extractants showed the selectivity for lithium extraction in a high pH region. The dependency on pH of the extractability of the alkali metals differed for each metal. The extracted complex of sodium is estimated to be H2RNa+Cl-, and those of lithium are estimated to be Li2R andLiHR for H2Pc (TFE) 16 and Li2R for H2Pc (PFP) 16, respectively. The extracted species of potassium is estimated to be K2Pc (TFE) 16. Each extraction equilibrium constant for alkali metals with the extractants was calculated.
The extraction rate of lithium with K2Pc (TFE) 16 was measured by using a stirred transfer cell. The extraction process is considered to be limited by the diffusion of the extractant.