Tributyl Phosphate In Kerosene Research Articles

Treatment of a Nigerian covellite ore. Part II: extraction and purification of copper by tri-butyl-phosphate and enhanced β-diketones in kerosene

ABSTRACT Research was carried out to investigate the use of tributylphosphate (TBP) and enhanced β-diketones for extracting copper from covellite ore leach liquor. The effect of some parameters such as contact time, temperature, phase ratio, equilibrium pH, and extractant concentration on the extent of copper extraction was examined. For the following conditions: temperature 27 ± 2°C, phase ratio 1:1, extraction efficiency of 95.30% total copper was achieved using a mixture of 0.25 mol/L enhanced β-diketones + 0.10 mol/L TBP in kerosene within 15 minutes at pH of 7.8. Furthermore, the stripping of approximately 97.3% of pure copper from the loaded organic phase was successfully attained at optimal conditions. The hydrometallurgical flow chart summarizing the analytical operations for the extraction and recovery process was provided.

The Design and Verification of a TBP/OK Pyrolysis Incineration Stable System

This project designed and created a large-scale pyrolysis incineration system that decomposes waste tributyl phosphate/kerosene (TBP/OK) solvent from the plutonium/uranium process (PU-REX) in the nuclear industry. This system consists of a suspension preparation system (SPS), a pyrolysis and ash discharge system (PADS), and a combustion furnace and gas treatment system (CGS). The preparation of a waste TBP/OK emulsified suspension in the SPS, continuous operation experiments of the PADS and CGS, and pyrolysis incineration experiments were conducted. The results show that the SPS achieved the automatic preparation and feeding of emulsified suspensions at 30 kg/h. The PADS decomposed 99.99% of the TBP/OK emulsified suspensions and fixed more than 99% of phosphorus. The CGS burned the pyrolysis gas without diesel oil and purified more than 99.995% of the radioactive nuclides. This system showed great feasibility, stability, continuity, and safety, proving the compatibility between multiple systems of this new design. This paper marks a significant step in pyrolysis incineration technology for the nuclear industry.

Cerium sulfate preparation from Egyptian monazite's rare earth cake for its application as corrosion inhibitor of aluminum alloy AA6061

Pure cerium sulfate was prepared from economic natural resources using Egyptian monazite rare earth cake. About 90% of the former was extracted by tri-butyl phosphate in kerosene at the optimum conditions: 15% solvent concentration, equilibrium pH of 1.7, equilibrium time 7 min and O/A ratio of 1/1. The aim of the present work was studying the corrosion inhibition properties of cerium sulfate towards aluminum alloy AA6061 in two solutions; 1.0 M disodium hydrogen orthophosphate and 3.5 % sodium chloride (simulation of sea water). The corrosion inhibition was evaluated using electrochemical techniques under different experimental conditions. The results showed that, in the presence of cerium sulfate, the AA6061 surface is well protected due to formation of passive film composed of Ce2O3/Ce(OH)3 which precipitated on the electrode surface.

Airborne Release Fractions from Surrogate Nuclear Waste Fires Containing Lanthanide Nitrates and Depleted Uranium Nitrate in 30% Tributyl Phosphate in Kerosene

Airborne contaminants from fires containing nuclear waste represent significant health hazards and shape the design and operation of nuclear facilities. Much of the data used to formulate DOE-HDBK-3010-94, “Airborne Release Fractions/Rates and Respirable Fractions for Nonreactor Nuclear Facilities,” from the U.S. Department of Energy, were taken over 40 years ago. The objectives of this study were to reproduce experiments from Pacific Northwest Laboratories conducted in June 1973 employing current aerosol measurement methods and instrumentation, develop an enhanced understanding of particulate formation and transport from fires containing nuclear waste, and provide modeling and experimental capabilities for updating current standards and practices in nuclear facilities. A special chamber was designed to conduct small fires containing 25 mL of flammable waste containing lutetium nitrate, ytterbium nitrate, or depleted uranium nitrate. Carbon soot aerosols showed aggregates of primary particles ranging from 20 to 60 nm in diameter. In scanning electron microscopy, ~200-nm spheroidal particles were also observed dispersed among the fractal aggregates. The 200-nm spherical particles were composed of metal phosphates. Airborne release fractions (ARFs) were characterized by leaching filter deposits and quantifying metal concentrations with mass spectrometry. The average mass-based ARF for 238U experiments was 1.0 × 10−3 with a standard deviation of 7.5 × 10−4. For the original experiments, DOE-HDBK-3010-94 states, “Uranium ARFs range from 2 × 10−4 to 3 × 10−3, an uncertainty of approximately an order of magnitude.” Thus, current measurements were consistent with DOE-HDBK-3010-94 values. ARF values for lutetium and ytterbium were approximately one to two orders of magnitude lower than 238U. Metal nitrate solubility may have varied with elemental composition and temperature, thereby affecting ARF values for uranium surrogates (Yb and Lu). In addition to ARF data, solution boiling temperatures and evaporation rates can also be deduced from experimental data.

Ion-Exchange Methods of Scandium Recovery from the Ores of the Tomtor Deposit

Abstract—The extraction of scandium from a nitric acid solution after pressure leaching of the hydrate cake that forms upon processing the ore of the Tomtor deposit is studied. The main technological laws of scandium sorption and extraction using various absorbers under static and dynamic conditions are investigated. To extract scandium, we recommend using phosphorus-containing cation exchanger Purolite D5041 and a mixture of extraction agents 7.5% Cyanex 923 + 15% tributyl phosphate in kerosene. The developed technologies make it possible to extract scandium and radioactive elements almost completely with the formation of a collective concentrate containing 2–3% Sc, 7–10% Th, and 0.3% U. Our data can be used to develop a technology of industrial scandium recovery after the extraction of thorium and uranium by the well-known methods.

Batch adsorption study of uranium on various ion exchange resins as an alternative method to solvent extraction

The project is aimed at recovering uranium from scrap material containing useful amounts of Low Enriched Uranium. The common method of recovering uranium is by using acidic or alkaline medium for dissolution, followed by solvent extraction using tributyl phosphate in kerosene. However the normal challenge with solvent extraction is the generation of enormous liquid waste which is slightly radioactive. Therefore in this project we studied the adsorption of uranium on various ion exchange resins in order to use it as an alternative method to solvent extraction. Uranium solution from the scrap materials was used, and different ion exchange resins such as Amberjet 1600 H, PPC100H, Purolite S940 and S950 chelation resin, and Purolite A500 were tested under various conditions for the adsorption of uranium. The strong acid cation resins show no selectivity between the uranium and aluminium species, both species were fully adsorbed irrespective of the pH. The strong base anion resins had good uranium adsorption attaining 100%, they also show a pH effect for the aluminium adsorption. The use of ion exchange resins, especially with anion resins showed promising results and potential for use as an alternative to solvent extraction.

Uranium recovery and purification from simulated waste streams containing high uranium concentrations with dispersion liquid membranes

The suitability of dispersion liquid membranes (DLMs) to recover and purify uranium from simulated waste streams containing nitric acid, high uranium concentrations and radionuclide contaminants with tributyl phosphate (TBP) and ammonium carbonate ((NH4)2CO3) as stripping solution was investigated. The radionuclide surrogates were not extracted and complete uranium recovery was obtained from 15 g U L−1 solutions using a 1:4 ratio of 30% TBP in kerosene and 0.75 M (NH4)2CO3 dispersion. In addition, all the uranium in the stripping solution was precipitated. Consequently, DLM proved to be a promising solvent extraction contacting method for uranium recovery and purification.

Coextraction and successive selective stripping of cerium(IV) and thorium from monazite leach solutions with tributyl phosphate (TBP)

Solvent extraction of Ce(IV) and Th(IV) from 8 M HNO3 with TBP in kerosene was studied. The dependence of the extraction on the TBP concentration, kind of diluent, O/A phase ratio, and contact time was examined. The extraction efficiency reaches 99.3 and 97.7% for Ce and Th, respectively, at 5% TBP in kerosene, 1/1 O/A phase ratio, and 5 min contact time. Successive selective stripping of Ce(III) and Th(IV) from the loaded organic phase was reached at 1.1 M H2O2 concentration, 10 min contact time, 3/1 O/A phase ratio, and room temperature (25 ± 2°C). After stripping of cerium, the remaining organic was contacted with H2O for thorium stripping at 5 min contact time, 2/1 O/A phase ratio, and room temperature (25 ± 2°C).

Separation of Cu, Sn, Pb from photovoltaic ribbon by hydrochloric acid leaching with stannic ion followed by solvent extraction

A recycling process consisting of HCl leaching with Sn4+ followed by solvent extraction is proposed to recover Cu, Sn and Pb from photovoltaic (PV) ribbon. During HCl leaching with Sn4+, Sn and Pb were removed from PV ribbon whereas Cu remained as plate. The leaching efficiency of Sn increased with increasing temperature, initial Sn4+ concentration or decreasing pulp density. In the case of leaching test performed in the 1M HCl solution at 400rpm and 70°C with 5% pulp density and 5000mg/L Sn4+, the leaching efficiency of Sn increased to >99% within 60min, whereas 71.9% of Pb was recovered as PbCl2 powder after settling the leach solution for 24h at room temperature. A solvent extraction with tri-butyl phosphate (TBP) was performed to extract selectively Sn from leach solution. The extraction efficiency of Sn increased with increasing the contents of TBP in kerosene, and <1% of Pb was extracted. Therefore, the separation of Sn, Cu, Pb was achieved successfully by the recycling process.

Extraction of Uranium Nitrate with 30% (v/v) Tributyl Phosphate in Kerosene in a Pilot Annular Pulsed Disc-and-Doughnut Column—Part II: Axial Mixing and Mass Transfer Performance

ABSTRACTMass transfer experiments were carried out in an annular pulsed disc-and-doughnut column (APDDC) using 30% (v/v) TBP-kerosene + uranium nitrate + nitric acid + water system (uranium nitrate system) for both extraction and stripping processes. Parameters in the axial dispersion model (ADM) and plug-flow model (PFM), namely, the axial dispersion coefficient of the continuous phase and the number of mass transfer units, were regressed by correlating the respective model with the experimental concentration profile. The mass transfer coefficient is calculated, and new correlations are developed to predict the axial mixing coefficient of the continuous phase and the volumetric mass transfer coefficient. The height of a transfer unit is also calculated. The influence of axial mixing on mass transfer performance for the uranium nitrate system is discussed.

Hydrometallurgical methods of recovery of scandium from the wastes of various technologies

The recovery of scandium from the wastes of the production of uranium, titanium, iron–vanadium, and alumina is studied. The applied acid schemes of scandium transfer to a solution followed by ion-exchange recovery and extraction concentration of scandium ensure the precipitation of crude scandium oxides containing up to 5% Sc2O3. Scandium oxides of 99.96–99.99% purity are formed after additional refining of these crude oxides according to an extraction technology using a mixture 15% multiradical phosphine oxide or Cyanex-925 + 15% tributyl phosphate in kerosene.

Extraction of Uranium Nitrate with 30% (v/v) Tributyl Phosphate in Kerosene in an Pilot Annular Pulsed Disc-and-Doughnut Column—Part I: Hydraulic Performance

ABSTRACTThe annular pulsed disc-and-doughnut column (APDDC) is an important extraction contactor used in the PUREX process. In this work, hydraulic investigation was carried out in a stainless-steel APDDC, with 30% (v/v) tributyl phosphate (TBP)-kerosene + uranium nitrate + nitric acid + water as the test system. Two operation modes with aqueous phase and organic phase as the continuous fluid were performed separately. The equations, which were previously developed for 30% TBP-kerosene + nitric acid + water system in aqueous phase continuous operation mode, were presently used to predict the holdup, the Sauter drop diameter, the flooding holdup, the flooding throughput, and the operating regimes in both operation modes. Good agreement with the experimental data was observed because the wettability of the dispersed phase on the internals in both the operation modes was similar with that in the aqueous phase continuous operation mode in the previous work. An exception is the flooding properties of the organic continuous operation mode because of a different flooding mechanism. And so new equations were proposed to calculate the flooding properties for the organic continuous operation mode.

Processing of Phosphorus Slag with Recovery of Rare Earth Metals and Obtaining Silicon Containing Cake

The present research is devoted to the processing of slag generating during the yellow phosphorus production. In this paper are presented studies on leaching of phosphorus production slag by nitric acid with recovery of rare earth metals (REMs) into solution. REMs recovery into the solution achieved 98 % during the leaching process with using 7.5 mol/L of HNO3, liquid-to-solid ratio is 2.6:1, temperature is 60°C, process duration is 1 hour and stirrer speed is 500 rpm. Behaviour during the leaching of associated components such as calcium, aluminium, and iron was studied. After the leaching cake contains ∼⃒75-85 % of SiO2 and it might be useful for obtaining of precipitated silicon dioxide. With the purpose of separation from the impurities, recovery and concentrating of REMs, the obtained solution after leaching was subjected to extraction processing methods. The influence of ratio of organic and aqueous phases (O: A) on the extraction of rare earth metals by tributyl phosphate (TBP) with concentrations from 20 up to 100 % was studied. The REMs extraction with increasing TBP concentration under changes O:A ratio from 1:20 down to 1:1 into the organic phase from the solutions after nitric acid leaching increased from 22.2 up to 99.3%. The duration effect of REMs extraction process was studied by tributyl phosphate. It is revealed that with increasing of duration of the extraction process from 10 to 30 minutes REMs recovery into the organic phase almost did not changed. The behaviour of iron in the extraction process by TBP was studied. It was found that such accompanying components as calcium and aluminium by tributyl phosphate didn't extracted. To construct isotherm of REMs extraction of by tributyl phosphate was used variable volume method. It was calculated three-step extraction is needed for REMs recovery from the solutions after nitric acid leaching of phosphorus production slag. The process of the three-steps counter current extraction of rare earth metals was modelled from the solutions after slag leaching with using 50 % of TBP in kerosene at the ratios O:A = 1:6 and 1:20. So, REMs recovery into the extract achieved 97.0 and 76.5 %, respectively. It was offered flowsheet of processing of phosphorus slag production with extraction of rare earth metals and obtaining silicon containing cake.

Extraction equilibria of lithium with N,N-bis(2-ethylhexyl)-3-oxobutanamide and tributyl phosphate in kerosene and FeCl3

The application of the β-carbonyl amide N,N-bis(2-ethylhexyl)-3-oxobutanamide for the extraction of lithium ions from saturated MgCl2 solutions was investigated using tributyl phosphate (TBP) as the second component in a mixed extractant and FeCl3 as the co-extractant. The effects of the extractant concentrations, H+ solution concentrations, phase ratios, Fe/Li molar ratios, and other factors on the extraction were fully investigated. Our results demonstrate that compared to conventional extraction systems, a higher Li-to-Mg separation factor of 450–700 can be obtained, and the formation of phase interface objects can be effectively avoided under low solution acidity without emulsification. The mechanism suggests that (LiFeCl4·2TBP·NB2EHOTA)·4TBP·NB2EHOTA is formed at lower (10%) TBP/NB2EHOTA mixed concentrations. This paper reports the application of β-carbonyl amide extractants for Li separation from salt lake brine with high Mg-to-Li ratios.

Lithium Extraction with a Synergistic System of Dioctyl Phthalate and Tributyl Phosphate in Kerosene and FeCl3

Innovative applications of dioctyl phthalate (DOP) as a synergist for the extraction of lithium chloride from saturated MgCl2 solutions were investigated using tributyl phosphate (TBP) as the extractant and FeCl3 as the co-extractant. The effects of solvent concentration, HCl concentration, phase ratio, Fe/Li molar ratio, and other factors on Li extraction were analyzed. The preliminary results demonstrated that a single-stage Li extraction efficiency of >90% was obtained with a low TBP concentration of 40% (V/V) and 20% (V/V) DOP without phase separation problems. A Li extraction efficiency of 99.5% was obtained via a three-stage simulation of countercurrent extraction. A study on the mechanism revealed that TBP and DOP molecules associated with the Fe-Li complex through hydrogen bonding. Compared with the traditional TBP–kerosene system, the proposed system prevented the formation of the third phase and significantly reduced the TBP concentration, resulting in less severe causticity to the equipment and reduced aqueous loss of TBP during the extraction process.

SYNERGISTIC SOLVENT EXTRACTION OF Co(II) AND Li(I) FROM AQUEOUS CHLORIDE SOLUTIONS WITH MIXTURE OF CYANEX 272 AND TBP

In this work, separation of cobalt(II) over lithium(I) ions from aqueous chloride solutions by synergistic solvent extraction (SX) has been studied. A synergistic mixture of commercial extractants such as bis(2,4,4-trimethylpentyl)phosphinic acid (Cyanex 272) and tributyl phosphate (TBP) in kerosene was used as a selective extractant. The investigations were first performed to select optimal conditions for the effective separation including pH of the aqueous phase as well as concentration of synergistic mixture. High selective solvent extraction of cobalt(II) over lithium(I) from chloride solution has been achieved by the mixture of 0.1 M Cyanex 272 and 0.05 M TBP in kerosene while efficient Co(II) stripping has been performed by 0.5 M sulphuric acid.

Extraction of uranium(VI) from sulfate leach liquor after iron removal using manganese oxide coated zeolite

The present work deals with purification of uranium(VI) solutions derived from leaching processes of as bearing silicate rocks at Gattar V (GV) area, eastern desert, Egypt. Manganese oxide coated zeolite (MOCZ) was used to minimize the iron content and most of impurities present in the leach liquor by adsorption process. In this concern, different parameters involving adsorption such as pH, MOCZ amount, iron concentration, stirring time and temperature were investigated. Uranium was extracted from treated sulfate leach liquor by solvent extraction using tributyl phosphate (TBP) at Org./Aq. (2:1) of 1.5M TBP in kerosene for 10min at room temperature. Under the optimum conditions 85.8% of uranium was extracted. The purified organic phase extract was then subjected to uranium stripping process using 7M sulfuric acid.

Mini Liquid‐Liquid Extractor without Moving Parts Based on the Coanda Effect

AbstractA mini liquid‐liquid extractor was designed based on a feedback fluidic oscillator. According to the Coanda effect, the designed oscillator with two feedback channels enables good mixing of the aqueous and organic phases. Co‐current liquid‐liquid extraction was performed in the mini extractor, and it was visually observed that the aqueous phase was dispersed into small droplets because of fluidic oscillation and vortex formation. The aqueous phase was more effectively dispersed at the stage near the outlet and with increasing flow. Several tests were performed for evaluating the extraction performance of the extractor using 30 % tributyl phosphate‐kerosene and 3 M HNO3 solutions as the organic and aqueous phases, respectively. The obtained extraction efficiency was close to the equilibrium efficiency, indicating that this extractor has the potential for liquid‐liquid extraction of hazardous liquids.

Passive Microextractor with Internal Fluid Recirculation for Two Immiscible Liquids

Abstract A microextractor comprising an inlet channel, a mixing chamber, two feedback channels, and an outlet channel and having no moving parts was designed for immiscible liquid–liquid extraction. Two liquids were mixed passively without any external energy input, and the extraction was completed in the microextractor. The extractor performance with or without a splitter was investigated by visualization and mass transfer experiments. Two mixing mechanisms were observed: (i) molecular diffusion at lower Reynolds number and (ii) chaotic advection at higher Reynolds number. The transition point between the two mechanisms was at Reynolds numbers 375.2 and 179.9 for the aqueous phase (3 mol/L HNO3 solution) and the organic phase (30% tributyl phosphate (TBP)–kerosene solution), respectively. In the chaotic advection mode, two vortexes rotating in opposite directions were formed on both sides of the main flow, which enhanced the mass transfer between the two liquids. Mass transfer between the 3 mol/L HNO3 and 30% TBP–kerosene solutions was achieved with an efficiency of 92.8% at the extractor exit when the extractor operated in the chaotic advection mode.

Extraction Equilibria of Lithium with Tributyl Phosphate, Diisobutyl Ketone, Acetophenone, Methyl Isobutyl Ketone, and 2-Heptanone in Kerosene and FeCl3

The extraction equilibrium behavior of Li by tributyl phosphate (TBP), diisobutyl ketone, acetophenone, methyl isobutyl ketone, and 2-heptanone in kerosene were investigated. The partition coefficient of Li with TBP in kerosene decreased significantly when the volume concentration of TBP was greater than 60%. The values derived for the partition coefficients of four selected ketones in kerosene were smaller than that of TBP in kerosene. The stoichiometric coefficients between TBP and Li, the stoichiometric coefficients between the four selected ketones and Li, and the apparent equilibrium constant for the extraction reaction equation for TBP and the four ketones in kerosene were obtained. The tendency in extraction with the TBP and four selected ketones in kerosene can be predicted from these parameters. The polar solvents used as diluents for TBP can yield higher Li partition coefficients, strong dilution effects for TBP, and strong polarity and low density of the extracting solvents formed with both pol...