Separation Of Rare Earth Metal Ions Research Articles

Solvent Extraction of Lanthanides(III) in the Presence of the Acetate Ion Acting as a Complexing Agent Using Mixtures of Cyanex 272 and Caprylic Acid in Hexane

A new extraction system containing a mixture of Cyanex 272 and caprylic acid is proposed for the extraction and separation of lanthanides(III). It was shown that this system possesses a high level of extraction ability and capacity. The extraction of lanthanides(III) from chloride-acetate and nitrate-acetate media was investigated on an example of La(III). The composition of the extracted species was confirmed, based on the analysis of lanthanum(III) extraction isotherms. In the case of acetic-acetate aqueous solutions, a decrease in lanthanum(III) extraction efficiency was observed, due to the decreasing equilibrium pH of the aqueous phase in accordance with the cation-exchange mechanism. The composition of the synergistic mixture of Cyanex 272-caprylic acid established demonstrates highly efficient separation of rare-earth metal ions.

Selective separation of rare-earth metal ions from aqueous solutions on the example of slightly soluble cerium and lanthanum compounds using electroflotation method in a flow-through plant

The prospects of the electroflotation method for selective separation of rare-earth metal ions (Ce4+ and La3+) from aqueous solutions in a flow-type plant are described. The separation process proceeds most effectively in sodium sulfate and sodium nitrate solutions at pH value of 5.0. The separation factor of metals is higher than 18. Separation efficiency drops sharply in the presence of cationic surfactant DDAC. The separation does not take place and a mixture of two metals is extracted at pH 10.