The Solvent Extraction of Heptavalent Technetium by Tributyl Phosphate

Solvent extraction studies with some fission product elements from nitric acid media employing tri-iso-amyl phosphate and tri-n-butyl phosphate as extractants

“…The extracted nitric acid reduces the free extractant concentration, thereby reducing the D Tc . Similar extraction behaviour has been observed by EL-Kot and Pruett for Tc by TBP as the maximum is found at 0.5 M HNO 3 [29,30]. Similar to Zr(IV) and RuNO(III), the D Tc values by TiAP are marginally lower than that of TBP over wide range of acidities.…”

Density and activity of pertechnetic acid aqueous solutions at T = 298.15 K

“…As a matter of fact, our result is consistent with Neck's [22] and Lemire's [23] values (respectively 47.1 and 48.1 cm 3 Á mol À1 ), taking into account the sensible values of the fitted coefficients. It is also close to the limiting partial molar volume of HReO 4 [12,21,24], which is often used as a non-radioactive model for technetium to simulate its behaviour [2,15,25].…”

1,10-Phenantroline complex of iron(II) nitrate: the challenging salt for the technetium precipitation from nitric acid solutions

“…The Ferroin nitrate solution provides recovery of Tc from the nitric acid solutions as TcO 4 -. Certain control of the precipitation conditions, such as temperature of the solution and amount of the added precipitant, allows attaining maximum possible amount of precipitated technetium of 93 ± 5 %.…”

“…It is known that pertechnetate-ion is well precipitated with single charged metal cations such as Cs?, Ag?, Tl?, forming slightly soluble salts in neutral and slightly acidic solutions [7]. Also the reductive precipitation of TcO 4 -with hydrazine hydrate is possible [8], in this case TcO 4 -, is reduced to TcO 2 . The precipitation with formic acid during the denitration can also be performed [9].…”

“…processes technetium, partly distributes along the streams of U, Pu, Np, Zr [1][2][3][4][5]. The presence of technetium in the streams of actinides affects their purity and thus the extra refining stages are required.…”