Read Books Online and Download eBooks, EPub, PDF, Mobi, Kindle, Text Full Free.
The Dissolution Of Uranium Dioxide As An Electron Transfer Reaction
Download The Dissolution Of Uranium Dioxide As An Electron Transfer Reaction full books in PDF, epub, and Kindle. Read online The Dissolution Of Uranium Dioxide As An Electron Transfer Reaction ebook anywhere anytime directly on your device. Fast Download speed and no annoying ads. We cannot guarantee that every ebooks is available!
Book Synopsis The Dissolution of Uranium Dioxide as an Electron Transfer Reaction by :
Download or read book The Dissolution of Uranium Dioxide as an Electron Transfer Reaction written by and published by . This book was released on 1971 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In the course of a study of the fundamental aspects of the dissolution of UO2 in acid solutions containing Fe(3+), the strong similarity was observed between factors affecting the dissolution of UO2 and factors affecting many electron transfer reactions occurring in solution - particularly the Fe(3+) - Fe(2+) exchange. For instance, in a perchlorate medium both the Fe(3+) - Fe(2+) exchange and the dissolution of UO2 by Fe(3+) are strongly catalyzed by the presence of small concentrations of sulphate, while both reactions are also affected in a similar manner by the concentration of H+ in solution. Both these effects of SO4(2-) and H+ are attributed to the formation of certain Fe(3+) ionic species, whose concentrations appear to be rate determining in both reactions. From a comparison of the results previously reported in studies of relevant homogenous reactions and the results obtained in the present study of the dissolution of UO2 the type of reaction occurring and the mechanism of reaction at the UO2 surface is discussed.
Book Synopsis The Dissolution of UO2 as an Electron-transfer Reaction by :
Download or read book The Dissolution of UO2 as an Electron-transfer Reaction written by and published by . This book was released on 1970 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: The factors affecting the dissolution of single crystals in acid solutions containing ferric ion were studied. Single crystals of high-purity uranium dioxide were mounted in briquettes, which were then placed in an enclosed reaction vessel to which solutions were added at a constant temperature of 35 degrees C. The effect of the following on the dissolution of uranium was studied: chloride, nitrate, and sulphate additions; perchlorate media at different pH values; the concentration of ferric and ferrous ions. It is concluded that the dissolution of uranium dioxide by ferric ions is a redox reaction similar to many other related electron-transfer reactions. Activation energies of between 15.5 and 16.1 kcal/mol were obtained.
Book Synopsis The Anodic Dissolution of Uranium Dioxide. 1. In Perchlorate Solutions by :
Download or read book The Anodic Dissolution of Uranium Dioxide. 1. In Perchlorate Solutions written by and published by . This book was released on 1975 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The anodic dissolution of uranium dioxide in perchlorate solution has been studied. Steady-state potentiostatic and cyclic voltammetric measurements have been shown to be consistent with a mechanism that involves successive electron-transfer reactions. The presence of insulating uranium (VI) films on the surface at high anodic potentials has been confirmed by measurements with ring-disc electrodes. A comparative study of the behaviour of several samples of differing stoichiometry, crystallinity and porosity has revealed the existence of considerable solid-state effects, the origin of which is not clear.
Book Synopsis The Anodic Dissolution of Uranium Dioxide. 2. In Carbonate Solutions by :
Download or read book The Anodic Dissolution of Uranium Dioxide. 2. In Carbonate Solutions written by and published by . This book was released on 1977 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The anodic dissolution of uranium dioxide in alkaline carbonate solutions has been studied. Steady-state potentiostatic and cyclic voltammetric measurements have been shown to be consistent with a mechanism that involves a rate-determining two-electron transfer reaction. The presence of insulating uranium(VI) films on the surface at high anodic potentials has been confirmed by the use of ring-disc electrode measurements and characterized by X-ray-diffraction analyses. The dissolution behaviour of the films has been characterized and compared with that of samples of synthetic uranium trioxide and uranyl carbonate.
Book Synopsis Kinetics of the Dissolution of Uranium Dioxide in Carbonate-bicarbonate Solutions by : W. E. Schortmann
Download or read book Kinetics of the Dissolution of Uranium Dioxide in Carbonate-bicarbonate Solutions written by W. E. Schortmann and published by . This book was released on 1958 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Reduction of Uranium Trioxide to Uranium Dioxide with Hydrogen by : Carl. W. Kuhlman (Jr.)
Download or read book Reduction of Uranium Trioxide to Uranium Dioxide with Hydrogen written by Carl. W. Kuhlman (Jr.) and published by . This book was released on 1948 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1976-02 with total page 722 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Chemical Hydrometallurgy: Theory And Principles by : A R Burkin
Download or read book Chemical Hydrometallurgy: Theory And Principles written by A R Burkin and published by World Scientific. This book was released on 2001-07-11 with total page 426 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hydrometallurgy is a field of chemical technology concerned with the production of metals from their ores and secondary sources. Modern hydrometallurgy began with the need to obtain uranium in the 1940s and extended into new areas with the development of pressure hydrometallurgy in the mid-1950s and acceptance of solvent extraction as an industrial scale process for copper production in the late 1960s to early 1970s. With the introduction of new processes for many metals, the present stage of development of hydrometallurgy has come to maturity and a survey of the current state of the field is timely.This book is derived from the lectures on the principles on which hydrometallurgical processes are based, given as part of the undergraudate and MSc courses in hydrometallurgy which Professor A R Burkin gave from 1961 until he retired in 1988.Professor Burkin's earlier book, The Chemistry of Hydrometallurgical Processes, was regarded as the major work in the field. This is his long awaited new textbook./a
Book Synopsis Comparison of Uranium Dissolution Rates from Spent Fuel and Uranium Dioxide by :
Download or read book Comparison of Uranium Dissolution Rates from Spent Fuel and Uranium Dioxide written by and published by . This book was released on 1994 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: Two similar sets of dissolution experiments, resulting from a statistical experimental design were performed in order to examine systematically the effects of temperature (25--75°C), dissolved oxygen (0.002-0.2 atm overpressure), pH (8--10) and carbonate concentrations (2--200 x 10−4 molar) on aqueous dissolution of UO2 and spent fuel. The average dissolution rate was 8.6 mg/m2·day for UO2 and 3.1 mg/m2·day for spent fuel. This is considered to be an insignificant difference; thus, unirradiated UO2 and irradiated spent fuel dissolved at about the same rate. Moreover, regression analyses indicated that the dissolution rates of UO2 and spent fuel responded similarly to changes in pH, temperature, and carbonate concentration. However, the two materials responded very differently to dissolved oxygen concentration. Approximately half-order reaction rates with respect to oxygen concentration were found for UO2 at all conditions tested. At room temperature, spent fuel dissolution (reaction) rates were nearly independent of oxygen concentration. At 75°C, reaction orders of 0.35 and 0.73 were observed for spent fuel, and there was some indication that the reaction order with respect to oxygen concentration might be dependent on pH and/or carbonate concentration as well as on temperature.
Book Synopsis Dissolution of Uranium Dioxide Microspheres in Carbonate and Hydrogen Peroxide Solutions by : Timothy G. Adams
Download or read book Dissolution of Uranium Dioxide Microspheres in Carbonate and Hydrogen Peroxide Solutions written by Timothy G. Adams and published by . This book was released on 2013 with total page 77 pages. Available in PDF, EPUB and Kindle. Book excerpt: Uranium dioxide has been used in industry both as a fuel for power reactors and as a target for the production of radioisotopes. One of the most important radioisotopes produced using these targets is molybdenum-99 (Mo-99, 65.94hr half-life), which is the parent isotope to technetium-99m (Tc-99m, 6.01hr half-life), a radioisotope used in 70% of diagnostic medical isotope procedures performed in the United States of America. [1] [2] Molybdenum-99, produced by either the thermal neutron fission of uranium-235 in nuclear reactors or by neutron activation of molybdenum-98, is purified, packaged, and shipped to hospitals worldwide. The maximal activity of Tc-99m is reached in 22.9hrs, so it can be milked from the parent Mo-99 repeatedly. Mo-99 is one of many fission products generated during the thermal neutron fission of uranium-235. For production of Mo-99, irradiation targets based on metallic uranium, uranium alloys, or uranium dioxide are produced. After neutron irradiation in a reactor, the uranium target must first be dissolved in a suitable medium. This has traditionally been done using boiling nitric acid solutions. In literature and in industry, the use of alkaline solutions, specifically carbonate salt solutions combined with hydrogen peroxide, are being explored as an alternative to the nitric acid based dissolution process. The carbonate-peroxide dissolution scheme has several advantages over traditional nitric acid dissolutions including less damage to equipment during operation and smaller volumes of waste produced during process. This thesis research work explores the initial dissolution rates of uranium dioxide in carbonate medium containing hydrogen peroxide. Effect of three different counter cations- ammonium, sodium, and potassium - on the dissolution behavior of uranium was investigated. The kinetic factors of dissolution, activation energy, frequency factor, and reaction order with respect to both the carbonate salt and hydrogen peroxide were found for each of these systems. Information in this thesis is organized into six chapters and list of cited literature sources.
Book Synopsis Studies of the Electron-transfer Reactions of Uranium (III) in Perchlorate Media by : Ashley Brooks McLaren
Download or read book Studies of the Electron-transfer Reactions of Uranium (III) in Perchlorate Media written by Ashley Brooks McLaren and published by . This book was released on 1977 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis A Potentiostatic Study of the Anodic Dissolution of Uranium Dioxide in Aqueous Solutions by : MJ. Nicol
Download or read book A Potentiostatic Study of the Anodic Dissolution of Uranium Dioxide in Aqueous Solutions written by MJ. Nicol and published by . This book was released on 1972 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: The anodic dissolution of uranium dioxide is shown to occur as a two-electron process with a current efficiency of 100 per cent in both acidic perchlorate and alkaline carbonate solutions. The effects, on the anodic dissolution process, of pH, temperature, and the various anions known to be present in commercial leaching solutions, were studied by the use of stationery potentiostatic measurements. The effects observed are interpreted in terms of the nature and properties of both the uranium dioxide surface and the primary products of oxidation.
Book Synopsis Chemical Dissolution of Metal Oxides by : Miguel A Blesa
Download or read book Chemical Dissolution of Metal Oxides written by Miguel A Blesa and published by CRC Press. This book was released on 2018-02-06 with total page 434 pages. Available in PDF, EPUB and Kindle. Book excerpt: The dissolution behaviour of metal oxides has applications in many scientific fields, each with its own jargon and methodological approach. Any scientist interested in this subject should understand the literature from these various areas. This book describe different specialized treatments to surface-controlled metal oxide dissolution reactions and translates them into a unified picture based on surface complexion
Book Synopsis Coupling of the Biogeochemical Cycles of Uranium and Manganese by : Zimeng Wang
Download or read book Coupling of the Biogeochemical Cycles of Uranium and Manganese written by Zimeng Wang and published by . This book was released on 2013 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: Organic electron donor stimulated microbial reduction of U(VI) to U(IV) has been proposed as a strategy for the in situ immobilization of uranium contamination in the subsurface. The success of the bioremediation of uranium relies on the stability of the reduced U(IV) species (e.g., UO2) with respect to reoxidation and/or remobilization under groundwater conditions. Manganese is present at appreciable concentrations at several uranium-contaminated sites, and the redox cycling of manganese may significantly impact uranium's fate and transport. The biogeochemical coupling of uranium and manganese involves multiple interaction pathways that occur in the aqueous phase as well as at solid-water interfaces. A mechanistic and quantitative understanding of these processes is needed to establish input parameters for reactive transport models and to enable decision-making for remediation strategies. Coupling of the biogeochemical cycles of uranium and manganese involves various interfacial reactions that occur between UO2 and Mn species of various oxidation states (+IV, +III and +II). This study investigated the physical and chemical factors controlling the interactions between uraninite (UO2) and manganese oxide (MnO2), which are both poorly soluble minerals. A multi-chamber reactor with a permeable membrane was used to simulate a barrier for direct contact of the two solids. The results suggested that an effective redox reaction between UO2 and MnO2 requires physical contact. Continuously-stirred tank reactors (CSTRs) were used to evaluate the dissolution rates of UO2. MnO2 dramatically promoted UO2 dissolution, but the degree of promotion leveled off once the MnO2:UO2 ratio exceeded a critical value. The fate of uranium and manganese after the reaction was investigated by chemical extraction and X-ray absorption spectroscopy (XAS). Substantial amounts of U(VI) and Mn(II) were retained on MnO2 surfaces, and the fate of Mn products may involve Mn(III) phases. A conceptual model was proposed to describe the oxidation of UO2 by MnO2, which is potentially applicable to other environmental redox processes involving two poorly soluble minerals. Although MnO2 can oxidize UO2, the U(VI) produced may not be readily released into the aqueous phase due to its strong adsorption to MnO2. This study integrated batch experiments of U(VI) adsorption to synthetic and biogenic MnO2, surface complexation modeling (SCM), and molecular-scale characterization of adsorbed U(VI) with extended X-ray absorption fine structure (EXAFS) spectroscopy. The surface complexation model incorporated the surface complexes that are consistent with EXAFS analysis, and it could successfully simulate adsorption results over a broad range of pH and dissolved inorganic carbon concentrations. The description of bidentate surface complexes, which are widely observed for contaminant adsorption to metal oxides including the U(VI)-MnO2 system, is a subject with considerable confusion in the literature. Consequently, a critical review was prepared that discussed the theoretical and practical aspects of mass action expressions for bidentate surface complexation reactions. Suggestions were provided for handling bidentate reactions and publishing results without ambiguity or confusion. The effects of soluble Mn species (+III and +II oxidation states) on UO2 dissolution were also investigated. Soluble Mn(III) species were recently identified as important intermediates in Mn biogeochemical cycling. This study evaluated the kinetics of oxidative UO2 dissolution by soluble Mn(III) stabilized by pyrophosphate (PP) and desferrioxamine B (DFOB). The Mn(III)-PP complex was a potent oxidant that induced rapid UO2 dissolution at a rate higher than by a comparable concentration of dissolved O2. However, the Mn(III)-DFOB complex was not able to induce oxidative dissolution of UO2. The potency of Mn(III) with respect to oxidizing UO2 was governed by the identity of the ligand and water chemistry parameters that affect the speciation of the Mn(III). The effect of soluble Mn(II) was more complicated than that of non-redox-active divalent cations (e.g., Ca and Zn). Under anoxic conditions, Mn(II) inhibited UO2 dissolution, which may be attributed to both Mn(II) adsorption to the UO2 surface and precipitation of MnCO3, both of which could decrease the exposure of U(IV) surface sites. In contrast to the anoxic conditions, Mn(II) promoted UO2 dissolution under oxidizing condition. The promotional effect was likely due to Mn redox cycling in which oxidized forms of Mn species were (re)generated as oxidants of UO2 that were more potent than O2. The observed effects of soluble Mn(II, III) species on UO2 dissolution highlighted the need to consider Mn redox intermediates in facilitating electron transfer processes in subsurface biogeochemical cycles.
Download or read book Nuclear Fuel Cycle written by B. S. Tomar and published by Springer Nature. This book was released on 2023-06-26 with total page 457 pages. Available in PDF, EPUB and Kindle. Book excerpt: The present book describes the various processes involved in different stages of the entire nuclear fuel cycle, which include exploration of uranium, thorium, and other nuclear materials, mining and milling of ores, conversion of the separated nuclear material into nuclear grade, fabrication of different types of nuclear fuels and their physical as well as chemical quality control, thermodynamics of the interaction among fuel and fission products during reactor operation, post irradiation examination, spent fuel reprocessing, radioactive waste management, accounting and control of nuclear materials, and safety aspects involved in handling and transportation of nuclear materials. The book provides the fundamental knowledge to the practicing nuclear scientists and engineers, young researchers, and postgraduate students interested in pursuing a career in nuclear industry in general and those engaged in human resource development in the field of nuclear science and technology in particular. It can also be prescribed as a textbook for a course on nuclear fuel cycle at postgraduate level.
Book Synopsis Environmental Degradation of Advanced and Traditional Engineering Materials by : Lloyd H. Hihara
Download or read book Environmental Degradation of Advanced and Traditional Engineering Materials written by Lloyd H. Hihara and published by CRC Press. This book was released on 2013-10-23 with total page 722 pages. Available in PDF, EPUB and Kindle. Book excerpt: One of the main, ongoing challenges for any engineering enterprise is that systems are built of materials subject to environmental degradation. Whether working with an airframe, integrated circuit, bridge, prosthetic device, or implantable drug-delivery system, understanding the chemical stability of materials remains a key element in determining their useful life. Environmental Degradation of Advanced and Traditional Engineering Materials is a monumental work for the field, providing comprehensive coverage of the environmental impacts on the full breadth of materials used for engineering infrastructure, buildings, machines, and components. The book discusses fundamental degradation processes and presents examples of degradation under various environmental conditions. Each chapter presents the basic properties of the class of material, followed by detailed characteristics of degradation, guidelines on how to protect against corrosion, and a description of testing procedures. A complete, self-contained industrial reference guide, this valuable resource is designed for students and professionals interested in the development of deterioration-resistant technological systems constructed with metallurgical, polymeric, ceramic, and natural materials.
Book Synopsis External and Internal Surfaces in Metal Oxides by : Louis-Claude Dufour
Download or read book External and Internal Surfaces in Metal Oxides written by Louis-Claude Dufour and published by . This book was released on 1988 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt: Materials Science Forum Vol. 29.
