[en] An original way for TBP synthesis was developed by combining two classical reactions. This process consists in esterifying butanol with o-phosphoric acid in presence of small amounts of promoting agent. The reaction occurs without solvent and under pressure. The promoter seems to play an enhancing role and presents a synergetic effect. Its action is obvious only for optimal conditions when TBP yield can reach 60%mol after 5 to 10 hours. This process is interesting by the fact that the process is accelerated by comparison to the classical esterification which is known to be very slow and that the process uses hydrated phosphoric acid which is a very low cost reagent and non-corrosive material. According to the operating conditions, one can favour selectively the formation of mono-, di- or triester and this process can be applied in manufacturing other phosphoric extraction agents

[en] The processes of sorption decontamination of aqueous solutions from TBP on the polymeric sorbent Polysorb-1, as well as of a 70% solution of TBP in dodecane from butylphosphoric acids using layered double oxides and Mg-Al hydroxides were studied. It has been established that the use of the polymeric sorbent Polysorb-1 makes it possible to decontaminate aqueous solutions from TBP in static and dynamic modes, and the use of the LDH-Mg-Al-CD-OH sorbent allows the decontamination of TBP solutions in dodecane from acid products of decomposition and hydrolysis of TBP.

[en] The possibility of using the polymeric sorbent Polysorb-1 for the decontamination of nitric acid solutions from organophosphorus compounds, including tributyl phosphate (TBP), and hexachlorobutadiene (HCBD) was studied. It has been shown that the purification of nitric acid solutions containing organophosphorus compounds, HCBD, U(VI), and Pu(IV) with the Polysorb-1 sorbent under dynamic conditions makes it possible to reduce the phosphorus content to ~2 mg/dm³ and less and the HCBD content to 0.05 mg/dm³ or less. In this case, the sorption of U(VI) and Pu(IV) on this sorbent does not occur. Schemes for the regeneration of the Polysorb-1 sorbent to remove TBP and HCBD by vacuum distillation and live steam stripping are considered. The optimal temperature of the process was chosen equal to 170°C.

[en] The polarographic behavior of tri-n-butylphosphate (TBP) in nitric acid media in general and its influence on the height of the polarographic wave of uranium in particular are discussed. After the presentation of a short review of the literature concerning this subject, results of own investigations in this field are presented. Trials undertaken with the aim of indirect polarographic determinations of TBP by means of its diminishing effect on the polarographic wave of uranium were without success, which, in view of known facts, is not surprising. (orig.)

[en] The dynamics of the Ce distribution in a nonequilibrium extraction process are investigated. Results are presented for the extraction of Ce by tributylphosphate in organic diluents from an aqueous solution in which a Belousov-Zhabotinskii oscillating reaction is occurring. The time dependences of [Ce] in the organic phase of the oscillatory extraction system that are synchronous with the redox-potential dependences are obtained for the first time. The effect of the initial concentrations of Ce, oxidant, and organic substrate on the principal parameters of the oscillatory extraction, such as the frequency, amplitude, etc., is found. A conclusion is made about the ability to control an oscillatory extraction process

[en] Results of centrifugal contactor rig trials of the flowsheet of the first solvent extraction cycle in protective glove boxes using simulated solutions of spent nuclear fuel and 30 and 45% TBP in isoparaffin as a solvent are compared. It was shown that an increase in the TBP concentration to 45% resulted in deterioration of the quality of the products obtained by the same flowsheets with 30% TBP in Isopar L as a solvent. Comparison of experimental and computer simulated profiles of component distribution across the stages of extraction units demonstrated satisfactory agreement in nitric acid and uranium concentrations. At the same time, it was found that simulation model of zirconium, technetium, and neptunium extraction requires improvement considering interaction of these elements with complexing agents.

[en] Tributyl phosphate-based solvent extraction processes have been used at Savannah River for more than 30 years to separate and purify thorium, uranium, neptunium, plutonium, americium, and curium isotopes. This report summarizes the advancement of solvent extraction technology at Savannah River during the 1980's. Topics that are discussed include equipment improvements, solvent treatment, waste reduction, and an improved understanding of the various chemistries in the process streams entering, within, and leaving the solvent extraction processes

[en] The extraction equilibrium for a hypothetical standard, designated as 1 M aqueous solution of Ln(III) nitrate and the state of the pure components in organic phase with a mole fraction of 1 have been determined assuming formation of tri- and tetrasolvates of the metal(III) nitrates in organic phase. The excessive thermodynamic functions of mixing tri-n-butyl phosphate with solutions of Ln(III) nitrate trisolvates are presented

[en] In this work gas chromatographic technique was used for the measurement of H2 and CH4 yields in gamma irradiated 30% TBP-Kerosene-3 M HNO3 solutions. Possible mechanisms for the formation of H2 and CH4 were discussed. The radiation chemical yields of H2 and CH4 (G-values) in irradiated solutions were calculated

[en] There was a significant research progress achieved with the aim to modify conventional PUREX process by stripping of plutonium from the tri-n-butyl phosphate (TBP) extraction product in the form of non-extractable complexes upon addition of back-hold complexation agents. The present paper reports effects of such salt-free complexant, acetohydroxamic acid (HAHA), on distribution ratio of Pu(IV) under wide concentration of nitric acid and additional nitrate. General formula of plutonium species present in the organic phase can be described as Pu(OH)_x(AHA)_y(NO3)_4-x-y x 2TBP x wHNO₃. (author)