New binary extractants and prospects of their application

Abstract

The distribution of chlorides and nitrates of lanthanides from aqueous solutions has been investigated in the absence of a salting out agent using a new binary extractant, methyl trioctyl ammonium dialkyl phosphinate compared with methyl trioctyl ammonium dialkyl phosphate. Isotherms of the extraction of lanthanides have ben obtained. The extraction stoichiometry of these metals in systems with binary extractants is determined. It has been found that, in the case of the extraction of nitrates of lanthanides by methyl trioctyl ammonium dialkyl phosphate and dialkyl phosphinate, extractable compounds of varying composition are formed. The extraction and separation of lanthanide chlorides by the conventional counter-current scheme and by the scheme based on the technology of free supported liquid membranes (FSLMs) have been experimentally and computationally investigated. It has been found that, when using the FSLM scheme, an increase in the degree of extraction and separation of lanthanides is observed.