Sodium Peroxide Research Articles

A novel process for high efficiency recovery of rare earth metals from waste phosphors using a sodium peroxide system

Download options Please wait... Supplementary files Supplementary information PDF (1947K) Article information DOI https://doi.org/10.1039/C3RA46381H Article type Communication Submitted 04 Nov 2013 Accepted 10 Jan 2014 First published 14 Jan 2014 Download Citation RSC Adv., 2014,4, 7927-7932 BibTex EndNote MEDLINE ProCite ReferenceManager RefWorks RIS Permissions Request permissions A novel process for high efficiency recovery of rare earth metals from waste phosphors using a sodium peroxide system Y. Wu, B. Wang, Q. Zhang, R. Li and J. Yu, RSC Adv., 2014, 4, 7927 DOI: 10.1039/C3RA46381H To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page. If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given. If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page. Read more about how to correctly acknowledge RSC content. Social activity Tweet Share Search articles by author Yufeng Wu Baolei Wang Qijun Zhang Ruiqing Li Jiamei Yu

Mössbauer study of oxo derivatives of iron in the Fe2O3-Na2O2 system

Various compositions of oxo derivatives of iron reacting with sodium peroxide have been studied by Mossbauer spectroscopy. We have examined several mathematical models of the measured spectra. The results obtained are inconsistent with hypotheses made previously that such conditions may lead to the formation of compounds of iron in oxidation states above (6+). We demonstrate that a large excess of an alkali peroxide leads, most likely, to the formation of at least two iron(V) derivatives in tetrahedral coordination. In their Mossbauer spectra, they have isomer shifts of −0.45 and −0.51 mm/s and unusually large quadrupole splittings: 1.32 and 1.94 mm/s (at room temperature).

Corrosion-electrochemical behavior of nickel in an alkali metal carbonate melt under a chlorine-containing atmosphere

The corrosion-electrochemical behavior of a nickel electrode is studied in the melt of lithium, sodium, and potassium (40: 30: 30 mol %) carbonates in the temperature range 500–600°C under an oxidizing atmosphere CO2 + 0.5O2 (2: 1), which is partly replaced by gaseous chlorine (30, 50, 70%) in some experiments. In other experiments, up to 5 wt % chloride of sodium peroxide is introduced in a salt melt. A change in the gas-phase composition is shown to affect the mechanism of nickel corrosion.

Features of radiation-induced changes in the diffuse reflectance spectra of modified titanium-dioxide powders

Changes in the diffuse reflectance spectra of titanium-dioxide micropowders (initial, modified by nanoparticles, treated with oxidants such as potassium peroxoborate and sodium peroxide, or ultraviolet irradiated in an oxygen atmosphere) in the range 0.3–2.1 μm after irradiation with ultraviolet light, electrons, or protons are analyzed. The general and distinctive features of changes in the spectra in the visible and near infrared regions are revealed and an explanation of the obtained data is proposed.

Resistance and Growth of Fusarium species in Contact Lens Disinfectant Solutions

To compare the biocidal efficacy of contact lens care solutions against clinical isolates and the American Type Culture Collection (ATCC) 36031 reference strain of Fusarium species and to determine the ability of the organism to survive and grow in such systems. The ISO 14729 reference method to assess biocidal efficacy was applied to the purified conidial form of 10 strains of Fusarium species. Six multipurpose disinfectant solutions (MPDSs), a one-step hydrogen peroxide (Per-1) system, a hydrogen peroxide-sodium chlorite (Per-2) system, and a one-step povidone iodine (PI) system were compared. Challenge organism viability was determined at various intervals, including the manufacturers' recommended disinfection time for the products (4 to 6 hours) and thereafter to 21 days. All MPDSs achieved a 3- to 4-log10 reduction in viability of ATCC 36031 within the recommended disinfection time of 6 hours. For the clinical strains, MPDS-1 (PQ-1 + alexidine) and MPDS-2 (PQ-1 + PHMB) produced 3 to 5 log₁₀ kill after 6 hours. Multipurpose disinfectant solution 3 (PQ-1 + Aldox 0.0006%), MPDS-4 (PQ-1 + Aldox 0.0005% + C-9 ED3A), and MPDS-5 (PQ-1 + Aldox 0.0005%) showed reduced efficacy for the same two strains, with 0.6 to 1.7 log₁₀ kill. Multipurpose disinfectant solution 6 (PHMB) gave 1.6 log₁₀ for one strain and 3 to 4 log₁₀ for the remainder. Growth in all the MPDS was not detected up to 21 days incubation. Per-1 showed less than 1 log₁₀ kill at 6 hours for six of 10 strains, including ATCC 36031, and growth (1.2 to 2.7 log₁₀) occurred with three of 10 strains by 7 days. Per-2 gave less than or equal to 0.5 log₁₀ kill after 6- or 24-hour exposure without growth. The PI system showed 4 to 5 log₁₀ kill for all strains tested by the first time point of 4 hours. However, with the exception of ATCC 36031, growth (1.7 to 4.0 log₁₀) occurred with all strains by 7 days in PI. All MPDSs were effective against the ATCC 36031 reference strain of Fusarium solani. However, reduced efficacy was found for some MPDSs against the clinical isolates. Unlike MPDSs, peroxide- and povidone iodine-based systems have no continued antimicrobial presence once neutralized, and this can allow growth of surviving Fusarium in the solution. Accordingly, lenses should be subject to fresh disinfection if stored in such solutions for extended periods.

AB Initio calculations of thermodynamic parameters of lithium, sodium and potassium peroxides

UDC 544.971: 544.03 Using a linear combination of atomic orbitals within the CRYSTAL09 software code, the oscillation frequencies of the atoms of lithium, sodium, and potassium peroxides are calculated. In a quasiharmonic approximation of the Debye model, the thermodynamic potentials, entropy, thermal capacity, and the coefficient of thermal expansion are calculated, and their dependence on pressure and temperature is investigated. Using sodium peroxide as an example, the critical point for the sublimation process is found.

Synthesis, Structure of Zwitterionic 2‐Amino‐N′‐(imidazolidin‐2‐ylidene)benzohydrazides, and Their Transformation into 3‐(Imidazolidin‐2‐ylideneamino)quinazolin‐4(1H)‐one Derivatives

The reaction of 2‐chloro‐4,5‐dihydroimidazole (5) with 2‐aminobenzohydrazides 6a–e led to the formation of 2‐amino‐N′‐(imidazolidin‐2‐ylidene)benzohydrazides as zwitterions 7a–e, which on treatment with carbon disulfide in the presence of triethylamine afforded 3‐(imidazolidin‐2‐ylideneamino)‐2‐thioxo‐2,3‐dihydroquinazolin‐4(1H)‐ones 8a–e. Compounds 8a–d were further converted into the corresponding 3‐(imidazolidin‐2‐ylideneamino)quinazoline‐2,4(1H,3H)‐diones 9a–d using hydrogen peroxide–sodium hydroxide solution. The structures of the compounds prepared were established by elemental analyses, IR and NMR spectra as well as X‐ray crystallographic analyses of 7e and 9a.

Thermal Hazards Evaluation on the Manufacturing of LPO by DSC for Environment Protection in Material Engineering and its Application

Lauroyl chloride is synthesized by the reaction of phosphorus trichloride and lauroyl acid. It is, in turn, oxidized by a toluene solution of hydrogen peroxide and sodium peroxide to manufacture lauroyl peroxide (LPO). As a retrospective case, a cleaning drum exploded during transfer of the toluene layer including LPO to the filter after separation of the aqueous phase. It is speculated that plant managers did not fully apprehend the hazardous decomposition of LPO, or could not make operators understand it. This study investigated the reaction hazards in the manufacturing process to forestall explosion in the manufacturing of LPO by differential scanning calorimetry (DSC) and TSS model simulations.

Ab initio investigation of the effect of pressure on the structure and electronic properties of alkali metal oxides and peroxides

Within the framework of a gradient approximation of the all-electron density functional theory (DFT), using a linear combination of atomic orbitals of the CRYSTAL09 software package, the structural and electronic properties of lithium, sodium, and potassium oxides and peroxides are investigated under hydrostatic conditions in the range of pressures from −3 to 15 GPa. The crystal structure parameters are determined, the band structure, densities of state (DOSs), atomic charges, and overlap populations are calculated, and their dependence on pressure is established. The energy band gap is shown to increase with pressure.

Determination of vitamin C in drugs using of an optimized novel TCPO–Amplex red–gold/silver alloy nanoparticles–H2O2 chemiluminescence method by the Box–Behnken design

Response surface methodology (RSM), based on a Box–Behnken design (BBD) was used to optimize three of the most important operating variables (concentrations of TCPO, Amplex red and pH effect) at peroxyoxalate-chemiluminescence (PO-CL) system. For the first time Amplex red (AR) was introduced as a new fluorescent emitter for predicting the reaction mechanism of PO-CL by means of the fluorescence property of its oxidation product. In optimum conditions, it was found that Au/Ag alloy nanoparticles (NPs) could enhance the CL intensity and the method sensitivity toward the evaluation of trace amount of vitamin C. Based on the antioxidant property of vitamin C noticeably the CL signal of the bis-(2,4,6-trichlorophenyl)oxalate–AR–NPs–hydrogen peroxide–sodium salicylate system was quenched in a low basic medium. A simple, rapid and sensitive CL method for the determination of vitamin C has been developed. The results showed a linear relationship between vitamin C concentration and PO-CL intensity in the range of 0.082–82.7μg/mL. Detection limit of 0.012μg/mL and the relative standard deviation (RSD)<4% was obtained.

Preparation of Magnetite Nanoparticles by Partial Oxidation of Fe2+ Using Aqueous Na2O2

In this article, Fe3O4 nanoparticles (2.2 -12.1 nm) were prepared by partial oxidation of Fe2+ ion using sodium peroxide as oxidizing agent in the presence of ammonium hydroxide and ammonium oleate as precipitating reagent and capping agent, respectively. The synthesized products were characterized by XRD, LLS, EDX, TEM, FTIR and chemical analysis. The main effective factors on the formation of smaller average particle size of Fe3O4 nanoparticles were optimized using the L8 Taguchi experimental design. The magnetic behavior of Fe3O4 nanoparticles was determined using vibrating sample magnetometer (VSM) at 300 K.

Structure and electronic properties of the surface of alkali metal peroxides

The CRYSTAL09 program with the implemented B3PW hybrid density functional in a localized basis of atomic orbitals is used to determine the atomic and electronic structure of the surface of lithium, sodium, and potassium peroxides. Geometric parameters, surface energies, partial densities of states, electron density distributions, overlap populations, and atomic charges are calculated. It is found that the geometry relaxation has a characteristic depth up to ∼10 A, while the surface states are located in the upper layers at a depth up to ∼2.5 A. Structural displacements of atoms do not exceed ∼ 0.2 A; the charge of the upper surface layers is positive, whereas the energy state shifts relative to the bulk ones can reach ∼1 eV. The surface energy of peroxides decreases with an increase in the atomic number of the cation.

K2NaOsO5.5 and K3NaOs2O9: The first osmium perovskites containing alkali cations at the “A” site

K2NaOsO5.5 and K3NaOs2O9 were obtained from solid-state reactions of potassium superoxide, sodium peroxide and osmium metal at elevated oxygen pressures. K2NaOsO5.5 crystallizes as an oxygen-deficient cubic double perovskite in space group Fm3¯m with a=8.4184(5)Å and contains isolated OsO6 octahedra. K3NaOs2O9 crystallizes hexagonally in P63/mmc with a=5.9998(4)Å and c=14.3053(14)Å. K3NaOs2O9 consists of face sharing Os2O9 pairs of octahedra. According to magnetic measurements K2NaOsO5.5 is diamagnetic, whereas K3NaOs2O9 displays strong antiferromagnetic coupling (TN=140K), indicating enhanced magnetic interactions within the octahedral pair.

Determination of rare earth elements in Indian kimberlite using inductively coupled plasma mass spectrometer (ICP-MS)

A method has been developed for the analysis of rare earth elements (REEs) in kimberlite samples using inductively coupled plasma mass spectrometer (ICP-MS). The samples were dissolved using sodium peroxide fusion and after appropriate dilutions the solutions were analyzed using ICP-MS. The paper presents the concentration of rare-earth elements as determined by ICP-MS in eight kimberlite samples from Central India. The method was validated using certified reference materials STSD-1 and STSD-2 from Canadian Certified Reference Material Project. The method detection limit of various REEs varies from 0.12 to 1.54 mg kg−1. The total REE concentrations range from 418 to 726 mg kg−1 and fall within the interval of those reported in the literature for kimberlites. Despite the marked difference in the REE contents, all the analyzed samples show similar REE patterns that resemble those for kimberlites. In order to compare ICP-MS results, the samples were analyzed using instrumental neutron activation analysis which is a reference method for determination of REEs in geological samples.

Abstracts of the 17th International Symposium on Bioluminescence and Chemiluminescence ‐ (ISBC 2012)

WARNING : The light-emitting molecular structures responsible for the chemiluminescence and fluorescence phenomena are not necessarily the same!

Corrosion behavior of a Kh30N45YuT alloy and 20Kh23N18 steel in a lithium and potassium carbonate melt during anode polarization

The effect of temperature, the gas phase composition, and the addition of sodium peroxide on the corrosion behavior of a Kh30N45YuT alloy and 20Kh23N18 steel in a eutectic Li2CO3-K2CO3 melt is studied by measuring the corrosion potential and during steplike anode polarization.

Reactions of Sodium Peroxide with Components of Legacy Plutonium Materials

Plutonium oxide (PuO2) calcined at >900 °C resists dissolution in nitric acid (HNO3)-potassium fluoride (KF) solutions commonly used for their dissolution. The Savannah River National Laboratory (SRNL) has developed an alternate method for large samples of PuO2-bearing materials using sodium peroxide (Na2O2) fusion as a pretreatment. The products of the reaction between Na2O2 and PuO2 have been reported in the literature. As part of the SRNL development effort, additional data about the reaction between Na2O2 and PuO2 were required. Also needed were data concerning the reaction of Na2O2 with other components that may be present in the feed materials. Sodium peroxide was reacted with aluminum metal (Al), beryllium metal (Be), graphite, potassium chloride (KCl), magnesium chloride (MgCl2), and calcium chloride (CaCl2). The paper reports and discusses the reaction products of these and related compounds with Na2O2.

Determination of uranium, thorium and rare-earth elements in zircon samples using ICP-MS

Zircon is an accessory mineral, which occurs at low concentrations in a wide variety of rocks and is a host for hafnium, rare-earth elements (REE) and radio active elements like uranium and thorium. The presence of uranium in zircon has led to its increased use in the age determination of rocks. Zirconium is also considered as a strategic, hi-tech element because of its various applications, especially in the manufacturing, nuclear and aerospace industries. Analysis of zircon constitutes one of the tough tasks in analytical chemistry as it is a highly resistant mineral and it is extremely difficult to achieve its complete decomposition. In the present work, inductively coupled plasma mass spectrometry has been applied to the determination of hafnium, REE, uranium and thorium in zircon samples using two different sample dissolution procedures, one employing sodium peroxide fusion and another using a fusion mixture of KHF2 and NaF in 3:1 ratio. Some selected zircon samples originating from different places on the eastern coast of India have been analysed by both the methods and values obtained by both methods were found to be in good agreement with each other. Though a number of international zircon reference materials are available, certified or even proposed values are available only for a very few elements in them. Two zircon reference materials have also been analysed by both methods and usable values have been proposed in this paper. The values obtained by both methods were found to compare well with each other and as well with those reported in literature. The % RSD for all the estimated elements varied from 1.0 to 12.0% at different concentration levels.

Modeling of quasi-steady sodium droplet combustion in convective environment

In the event of accidental leakage of sodium from the systems of a Liquid Metal Fast Breeder Reactor (LMFBR), a spray of liquid sodium droplets may be formed which will burn by reacting with the surrounding atmospheric oxygen. In order to understand the burning characteristics of the complete spray, combustion of an individual sodium droplet forms the basis and this has been investigated in the present study. A comprehensive numerical model has been developed to analyze the isolated sodium droplet combustion in a mixed convective environment. The governing equations for mass, momentum, species and energy conservation have been solved in axisymmetric cylindrical coordinates using the Finite Volume Method (FVM). Finite rate kinetic mechanisms have been incorporated to simulate droplet burning, using available kinetics data for basic sodium oxidation reactions. Salient features of the numerical model include a global single-step reaction for sodium oxidation in air and the incorporation of property variations with temperature and concentration. An equilibrium mixture of sodium peroxide, sodium monoxide and sodium vapor is considered as the final reaction product, taking into account the effects of dissociation reactions. The numerical model has been validated with experimental results available in literature. Results for the fuel mass burning rates and flame shapes are presented for different sizes of droplets burning under different free-stream conditions. The model predicts the occurrence of envelope flame around a sodium droplet even at fairly high free-stream velocities.

Hydrogen peroxide–sodium hydrosulfite chemiluminescence system combined with high-performance liquid chromatography for determination of 1-hydroxypyrene in airborne particulates

In this research, a highly sensitive chemiluminescence method based on a sodium hydrosulfite (NaHSO3)–hydrogen peroxide (H2O2) reaction for the determination of 1-hydroxypyrene (1-OHP) was developed. The response of this system was linear in the range from 0.5 to 50pmol (R2=0.9983). The limit of detection for 1-OHP was 100fmol (S/N=3). 1-OHP in airborne particulates was well separated from interfering compounds using an ODS column with 75% methanol as the mobile phase in isocratic mode. The proposed method was successfully applied to determine the 1-OHP in airborne particulates collected in Kanazawa, Japan. The average concentration of 1-OHP in the atmosphere was 2.0pg/m3 (9.2fmol/m3).