Application of Composite Materials Based on Various Extractants for Isolation of Lanthanide(III) Nitrates from Multicomponent Aqueous Solutions

Extraction of lanthanide(III) nitrates of ceric subgroup was studied by pure tributylphosphate, 50% solution of trialkylmethylammonium nitrate in toluene and composite materials based on porous Teflon and mentioned extractans in the presence of 1–5 mol/dm3 of sodium nitrate in aqueous phase. Effect of additions of sodium sulfate and chloride to nitrate solutions on distribution parameters of lanthanides(III) was determined. The extraction process can be described with taking into account the formation of [Ln(NO3)3(S)j] (j = 3, 4) in organic phase. The extraction constants were estimated. It was established, that accounting tributylphosphate concentration in the phase of composite, extraction constants and isotherm shape for systems based on tributylphosphate are identical within the error of determination. In the case of trialkylmethylammonium nitrate those for composite are little greater then for liquid extractant.