Trace impurities would partially remain from the initial uranium ore and be introduced to the uranium matrix through the above processing processes as well. The trace impurities in the final uranium product sample could reflect the provenances of the original materials, the characteristic physicochemical properties and the nature of the …
Recycled uranium can be refined using physical or chemical properties of fission products or transuranic elements at the fluorination step of the uranium conversion process. Some impurities, which ...
The high content of impurities in productive solution indicated a low selectivity of sulfuric acid leaching method and required the using of additional stages of uranium purification, such as extraction or ion exchange.
The paper discusses a method developed for the determination of uranium in uranyl nitrate raffinate (UNR) generated through sodium di-uranate (SDU) process using inductively coupled plasma atomic emission spectrometer (ICP-AES). High concentration of Na in UNR limits the direct determination of uranium in ICP-AES. Therefore, selective …
The excitation of uranium in the plasma generates a complex optical spectrum forming thousands of emission lines that interfere with the lines of the trace impurities to be detected. The solution to this problem was found by removing the uranium matrix.5
In the given paper after uranium concen trate dissolution in nitric acid and solution clarification by means of centrifuging and/or filtering highly con centrated nitrate uranium solutions are sent to extrac tion refining from soluble impurities using tributyl phosphate as an extractant (TBP).
This study was carried-out to leach uranium from rock phosphate using sulphuric acid in the presence of potassium chlorate as an oxidant and to investigate the relative purity of different forms of yellow cakes produced with ammonia, magnesia and sodium hydroxide as precipitants, as well as purification of the products with TBP and …
A new processing scheme was developed using an anion exchange column run in a cycling mode with HNO 3 media as the primary uranium purification process. This was followed with a uranyl peroxide precipitation step to purify and solidify the uranium before conversion to U 3 O 8.
The Mining Solutions unit of BASF (formerly Cognis) has been intimately involved in uranium processing technology since 1957. That was when we introduced Alamine® 336 to the mining industry as the first commercially available tertiary amine solvent extraction (SX) reagent for the recovery and concentration of uranium.
Measurement methods for the analysis of trace impurities in uranium materials, essential in nuclear fuel production and nuclear forensics, are continuously improving. Analytical methods were developed with the goal of lowering uncertainties of next generation certified uranium oxide reference materials for trace impurity …
Turgis et al. (2014) investigated the uranium recovery with an amino-phosphonate substituent from phosphoric acid, which is obtained using sulfuric acid from phosphate rocks [66]. This research was focused in the preparation and testing of compounds for the selective extraction of U (VI) from phosphoric acid solutions.
Solid solution, high density (low porosity) samples greater than 95% TD were processed by cold pressing at 150 MPa and sintering above 2600 K for times longer than 90 min. Some impurity oxide phases were noted in some samples attributed to residual gases in the furnace during processing.
Processing of the ore to a concentrate occurs at or near the mines. Most of the uranium ore deposits at present supporting today's mines have average grades in excess of 0.10% of uranium. In the ...
Based on density functional theory (DFT) calculations, we perform an extensive investigation of intrinsic point defects and Xe impurities in uranium monocarbide
The study of uranium processing is an ongoing effort due to the inherent issues present in nuclear reactors used for electricity production; nuclear weapon production and dismantlement; the treatment, recycling, and storage of nuclear waste; and the cleanup of Cold War nuclear material production sites.
In either case, the uranium compound is removed from the original solution, leaving many impurities behind. By repeating the ion exchange or solvent extraction process, it is possible to obtain a very pure uranium product.
The pre- and post-treatment of phosphoric acid were also highlighted together with a history of different extractant systems employed for uranium recovery. Recent developments in evaluating the new extractant molecules for effective separation of uranium from phosphoric acid solution have also been elaborated.
This review discusses the technical conditions and mechanisms of U (VI) treatment as key points for optimizing the performance of the technologies, thus providing a useful guide for environmental engineering researchers. The insights presented could help guide the way in the research field. 2. Ecotoxicity of uranium.
solvent, thus separating the uranium from the radioactive fission products. The uranium is stripped from the solvent by a weak nitric acid solution and, to purify it further, it is prOcessed with another organic solvent in two more extraction stages. The product of the third extraction cycle is a uranyl nitrate solution from which practically all fission …
This chapter outlines the basic steps involved in mining, processing, and reclamation that might be suitable for uranium ore deposits in the Commonwealth of ia. For uranium ore deposits, the choice of mining methods and processing options is very deposit-specific and dependent on many variables such as the quality and …
The study of uranium processing is an ongoing effort due to the inherent issues present in nuclear reactors used for electricity production; nuclear weapon production and dismantlement; the …
The processes of uranium stripping from 30% tri- n -butyl phosphate (TBP) in "odorless" kerosene by H 2 O 2 solutions both with and without NH 4 OH added were investigated in the temperature range of 20–50 °C and with a volumetric ratio of 1 between the organic and aqueous phases. The uranium was selectively precipitated in the form …
Measurement methods for the analysis of trace impurities in uranium materials, essential in nuclear fuel production and nuclear forensics, are continuously improving.
The Mining Solutions unit of BASF (formerly Cognis) has been intimately involved in uranium processing technology since 1957. That was when we introduced Alamine® 336 to the mining industry as the first commercially available tertiary amine solvent extraction (SX) reagent for the recovery and concentration of uranium.
The acid leaching operating conditions allow us to obtain a recovery uranium rate of 93%. The uranium concentration of the pregnant solution is approximately of 1.2 g/l. This value justifies the ...
Non-disperse solvent extraction is an effective technique for the extraction of metal ions from aqueous solution. In this study, uranium extraction using n-dodecane solvent containing ...
An important stage of the SE scheme for the processing of U/Pu-containing carbonate solutions in the CARBEX process is the precipitative re-extraction(stripping) of uranium and plutonium in the form of crystalline carbonate compounds mixture.
CCD overflow containing uranium or the pregnant leach solution will be pumped to the evaporation pond to remove excess water. The leach solution will be recovered from the evaporation pond and sent to the …
Oxygen Isotope and Fluorine Impurity Signatures during the Conversion of Uranium Ore Concentrates to Nuclear Fuel ... understanding of how oxygen isotopes are influencedduring uranium processing. This study explores oxygen isotope exchange and fractionation between magnesium diuranate (MDU), ammonium ... and concentrate the uranium in …
The leach solution obtained by heap leaching contains slightly lower amounts of impurities such as Fe, Al, Mn, Mg, Ca than those obtained by the two other methods while uranium concentration of these solutions are relatively similar.
The chemical composition of the impurity may vary widely depending on the type and source of the natural graphite. The concentration of some impurity elements is extremely low because of successful removal by thermal purification, producing invisible or very thin bars in Fig. 4 (a) and (c).
line environment, employing either a resin-in-solution or resin-in-pulp process. The resin of choice will have a high capacity for uranium, while at the same time exhibiting good selectivity for uranium over other impurities in the leach liquor. Additionally, a strong, durable resin is required, especially when contacted directly with pulps. At the same …
(2) This process allows initial purification of the leach solution in the first step. (3) The selectivity factor for molybdenum versus uranium is greater than 3. (4) When this electrodialysis process is used for the treatment of uranium leaching solution it provides a diluate solution suitable for use in the process of uranium extraction.
Their study first used selective precipitation to separate impurities; then, the solution was treated with a magnetic resin to separate uranium from rare earth elements.
At extraction processing of uranium concentrated solutions containing molybdenum, iron, silicon, and other impurities molybdenum causes the greatest diffi culties that is defined by its rather high coefficient of di stribution in tributyl phosphate [4].
5.1 This test method is applicable to uranium metal, ura-nium oxides and compounds soluble in nitric or sulfuric acid, and uranium solutions which can be converted to uranium oxide (U3O 8) in a muffle furnace. It may be used to determine the impurities in uranium compounds as listed in Specifications C 753, C 776, C 788, and C 967.
Samples of materials involved in the conversion of uranium into nuclear-grade products are collected to support the verification of States' declarations and to look for indications of possible undeclared materials and activities. Samples are analysed by several laboratories to determine concentrations of about sixty impurities; the data consistency …
