Peculiarities of extraction of carbonate complexes of trivalent transplutonium elements by alkylpyrocatechins

Extraction of trivalent americium, curium, californium and europium by technical mixture of mono- and didecylpyrocatechin (TAP) in various diluents from carbonate solutions is investigated. Effect of many factors (pH, K2CO3 concentration, TAP, metal; the time of phase contact) on the completeness of element isolation and separation is clarified. It is ascertained that the elements listed are quantitatively extracted by TAP solution in toluene and cyclohexane in the range of K2CO3 concentrations from 0.25 to 1.5 mol/l. The difference in americium and curium distribution coefficient during their extraction by TAP from 0.25 mol/l of K2CO3 solution is detected. Separation coefficients of the pair increase with the increase of carbonate solution pH. The separation can be improved at the stage of element reextraction by the mixture of K2CO3 and DTPA or EDTA from alkylpyrocatechin, sunce rate constants of americium and curium reextraction differ greatly. Using 13C NMR the composition of compounds in organic phase on the basis of 4-(α, α-dioctylethyl)pyrocatechin is investigated