Top PDF Method for treating rare earth-transition metal scrap

Method for treating rare earth transition metal scrap

Method for treating rare earth-transition metal scrap

Rare earth-transition metal (e.g., iron) scrap (e.g., Nd-Fe-B scrap) is flux (slag) remelted to reduce tramp non- metallic impurities, such as oxygen and nitrogen, and metallic impurities, such as Li, Na, Al, etc., picked up by the scrap from previous fabrication operations. The tramp impurities are reduced to concentrations acceptable for reuse of the treated alloy in the manufacture of end-use articles, such as permanent magnets. The scrap is electroslag or inductoslag melted using a prefused, rare earth fluoride-bearing flux of CaF.sub.2, CaCl.sub.2 or mixtures thereof or the slag resulting from practice of the thermite reduction process to make a rare earth-iron alloy.
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Potentiometric study of transition metal and rare earth metal complexes with
Isoniazid drug in 20 % (V/V) ethanol water mixture

Potentiometric study of transition metal and rare earth metal complexes with Isoniazid drug in 20 % (V/V) ethanol water mixture

Proton ligand stability constant (pK) of Isoniazid drug was determined by point wise calculation method as suggested by Irving & Rossotti. Metal- ligand stability constant (logk) of transition metal ions and rare earth metal ions with Isoniazid drug were calculated by point wise and half integral method as suggested by Irving & Rossotti [20] . For the present investigation we have studied the stability constants of divalent transition metal ions except Fe which is in trivalent state. Since we got n - A between 0.2 to 0.8 and 1.2 to 1.8 indicating 1:1 and 1:2 Complex formation .It will be interesting to study the solid state formation of such complex and to study its biological activity ,which is included in our future plan.
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Production method for making rare earth compounds

Production method for making rare earth compounds

A method of making a rare earth compound, such as a earth-transition metal permanent magnet compound, without the need for producing rare earth metal as a process step, comprises carbothermically reacting a rare earth oxide to form a rare earth carbide and heating the rare earth carbide, a compound-forming reactant (e.g. a transition metal and optional boron), and a carbide-forming element (e.g. a refractory metal) that forms a carbide that is more thermodynamically favorable than the rare earth carbide whereby the rare earth compound (e.g. Nd.sub.2 Fe.sub.14 B or LaNi.sub.5) and a carbide of the carbide-forming element are formed.
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Temperature dependent magnetocrystalline anisotropy of rare earth/transition metal permanent magnets from first principles : the light RCo5 (R = Y, La Gd) intermetallics

Temperature dependent magnetocrystalline anisotropy of rare earth/transition metal permanent magnets from first principles : the light RCo5 (R = Y, La Gd) intermetallics

ent and intercept. Equation 3 and the ST method strictly apply to ferromagnets, but the same technical procedure can be applied to RE-TM ferrimagnets too [27]. How- ever, the fact that the external field can induce a canting between the RE and TM moments means that the ex- tracted anisotropy constants for the ferrimagnet are ef- fective ones, which measure both the anisotropy of the individual sublattices and the strength of the exchange interaction keeping the spin moments antialigned [27, 46]. The experimental data in Fig. 2 demonstrates the di- versity in κ among RECo 5 . The behavior of YCo 5 and
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Recent Advances in the Measurement of Rare-Earth Metal Transition Probabilities Using Laser-Induced Plasmas

Recent Advances in the Measurement of Rare-Earth Metal Transition Probabilities Using Laser-Induced Plasmas

In Chapter 2 I discuss laser-induced breakdown spectroscopy theory to provide a better understanding of how atomic measurements may be made on a laser- induced plasma. I will also describe several relevant effects that it is necessary to understand when using a laser-induced plasma for such atomic measurements. In Chapter 3 I discuss the experimental setup and the new components I designed and implemented to improve light collection. In Chapter 4 I discuss experimental parameter optimization to increase observed emission from specific species in the plasma, which results in an improved measurement of emission lines and the observation of previously unobservable emission lines. In Chapter 5 I discuss the data and error analysis of the spectroscopic data for measurement of transition probabilities. In Chapter 6 I report and discuss transition probability measurements made on our laser-induced plasmas. In Chapter 7 I introduce and discuss a new method, laser-induced breakdown spectroscopy – laser-induced fluorescence (LIBS- LIF), for atomic measurements to minimize and alleviate certain problems associated with atomic measurements on laser-induced plasmas. In Chapter 8 I summarize the work presented in this thesis and discuss future work. In Appendix A I list programs used for automated data analysis.
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Rare earth/transition metal magnetic interactions in pristine and (Ni,Fe) doped YCo5 and GdCo5

Rare earth/transition metal magnetic interactions in pristine and (Ni,Fe) doped YCo5 and GdCo5

spherical harmonics up to a maximum angular momen- tum quantum number of l = 3. Although the KKR- CPA is an all-electron method, there is still a partition- ing of electrons into core and valence which determines their treatment within multiple-scattering theory; here the 4p (5p) states were treated as valence for Y (Gd). A 20×20×20 Brillouin zone sampling was used and a fixed electronic temperature of 400 K in calculating the elec- tronic occupations in the self-consistent calculation.

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Rare earth transition metal magnets at finite temperature : self interaction corrected relativistic density functional theory in the disordered local moment picture

Rare earth transition metal magnets at finite temperature : self interaction corrected relativistic density functional theory in the disordered local moment picture

A. Relativistic DFT-DLM calculations The large atomic number of the REs necessitates the use of relativistic (R) DFT-DLM theory to describe the spin-orbit coupling inherent in RE-TM magnets as well as mass-velocity and Darwin effects. Practically, our RDFT-DLM calculations involve two steps. In the first step, a self-consistent, scalar-relativistic DFT calculation is performed for a reference magnetic state. This refer- ence magnetic state may be fully ordered (e.g. a ferro- magnetic arrangement of spins) or fully disordered (the DLM/paramagnetic state). The output of this calcula- tion is a set of atom-centered potentials. In the second step these potentials are fed into the fully-relativistic Kohn-Sham-Dirac (KSD) equation, thus treating spin- orbit coupling nonperturbatively. Combining the solu- tions of the KSD equation with the full KKR-CPA ma- chinery allows the Weiss fields and T C to be computed.
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On the factors affecting the high temperature insulator-metal transition in rare-earth manganites

On the factors affecting the high temperature insulator-metal transition in rare-earth manganites

been prepared for this investigation. In addition, we utilize results of our earlier investigation [4]. The powder (of approximate size 0.5 µm) has been prepared by autoignition of citrate-nitrate gel. This method allows preparation of powder at a rather low temperature [6]. The powders thus obtained have been calcined at 1273-1373 K for 24h and finally sintered at around 1650 K for 10h in the pellet form. The phase purity, microstructure as well as compositional homogeneity of all the samples have been studied by X-ray diffraction (XRD), scanning electron microscope (SEM), and EDAX. Thermogravimetric analysis carried out till 1473 K could not detect any weight loss; 1473 K is the highest temperature attained during the resistivity measurements. The resistivities of the samples have been measured in the temperature range 15-1473 K using usual 4-probe technique. At high temperatures we used platinum paste (Make Tanaka K.K., Japan) for making the contacts with thin platinum leads. The contacts have been cured at >1000 o C
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Calculating the magnetic anisotropy of rare earth/transition metal ferrimagnets

Calculating the magnetic anisotropy of rare earth/transition metal ferrimagnets

In conclusion, we have introduced the FPMvB ap- proach to interpret experiments measuring anisotropy of ferrimagnets, particularly RE-TM permanent magnets. We presented the method in the context of our CPA formalism, but any electronic structure theory capable of calculating magnetic couplings relativistically [59–63] should be able to produce FPMvB curves, at least at zero temperature. However standard calculations which neglect the external field should be used with care when comparing to experiments on ferrimagnets. Similarly, the prototype GdCo 5 serves as a reminder that a sim-

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Electrochemical Recovery of Rare Earth Elements from Magnets: Conversion of Rare Earth Based Metals into Rare Earth Fluorides in Molten Salts

Electrochemical Recovery of Rare Earth Elements from Magnets: Conversion of Rare Earth Based Metals into Rare Earth Fluorides in Molten Salts

is formed as the result of the chemical reaction between the additives and the RE-containing components of the magnet, will be subjected to electrolysis to extract the RE as the ca- thodic product. To overcome fluorocarbon formation on the anode a reactive anode was employed instead of the conven- tionally used graphite anode. This reactive anode is anodical- ly dissolved to re-generate the fluorinating agent in-situ in the electrochemical reactor. This method provides a one-step process for direct recycling of rare earth metal from neodym- ium magnet scrap by molten fluoride salt extraction and elec- trolysis.
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Sensitivity of scrap metal prices to global economic conditions

Sensitivity of scrap metal prices to global economic conditions

Scrap metal is a direct input to the production of steel with estimates suggesting the global scrap metal market supplies up to 50% of the ferrous material used for steelmaking. Global crude steel production in September 2011 was 123,567 thousand metric tonnes, of which China produced 45%, the European Union produced 12% and the United States produced 6%. In contrast, Australia produced 0.5%. Hence from an Australian perspective, developments in these overseas markets are likely to have significant implications for Australia’s domestic steel and scrap metal industries. Scrap metals, particularly steel scrap, is a close substitute for types of iron ore used to produce steel and recycling of metals results in significant savings in energy consumption costs when compared to primary metal production, ranging from energy savings of 60% for steel to 95% for aluminium. 1
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Peschke, Simon
  

(2017):


	Synthesis and characterization of rare-earth oxide transition-metal arsenides and selenides.


Dissertation, LMU München: Fakultät für Chemie und Pharmazie

Peschke, Simon (2017): Synthesis and characterization of rare-earth oxide transition-metal arsenides and selenides. Dissertation, LMU München: Fakultät für Chemie und Pharmazie

relatively unusual materials which simultaneously contain oxide and selenide anions, as op- posed to species such as selenates and selenites in which the chalcogen has a positiv formal charge. Materials with mixed anions are interesting as they frequently contain transition metals in unusual chemical or electronic environments which can lead to compounds with unexpected and fascinating electronic, magnetic or optical properties. At the beginning of the present work, several compounds were known that retain a ZrCuSiAs-related structure with modulations in the transition-metal-selenide layers. Among them, La 2 CdSe 2 O 2 [26] contains
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Rare earth doping of silicon

Rare earth doping of silicon

The ground state configuration for the erbium atom is [Xe)4fi^5s^5p^6s^5d^. W hen it becomes ionised, the final four shells become 4 fi^5 s^5 p ^, the 5 d and 6s shells being empty. The first two terms in Eq.(2.1.1) determ ine the electronic structure. The approach to treating is to em ploy the central field approximation^ (Chapter 3). The solutions to the problem can be split into a product of radial and angular functions. While the radial function depends upon the potential formed by the nucleus and all other electrons in the shell, the spherical symmetry ensures that the angular component is identical to that of the hydrogen atom and can therefore be expressed as a sum of spherical harmonics. The solutions are labelled by the quantum numbers, L and 5. L is the total orbital quantum number and S is the total spin quantum number. Linear conibinations of states described by L and S serve as the basis states for evaluating the electron-electron interaction. This interaction splits the single-electron configuration into separate levels The allowed values of L, which are 0, 1, 2, 3... 6 , are expressed by the capital letters S, P, D , F, G, H , and I, respectively. The electronic structure of rare earth ions is dominated by this factor followed by the spin-orbit interaction next in importance. Spin-orbit interaction lifts the degeneracy in total angular momentum and splits the L S terms into J multiplets (where J is the total spin)^.
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Preparation of rare earth metals

Preparation of rare earth metals

The same experiments using a tantalum or molybdenum vessel showed no detectable contamination of the rare earth metal& Work conducted by Daane 11 at the Ames Laboratory, on methods of we[r]

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Electropolishing the rare earth metals

Electropolishing the rare earth metals

Chemical oxidation is the principle method of etching a metal surface for microscopic examination and the rare earths were etched in this manner... At room temperature, the nitric acid-a[r]

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Recycling of Rare Earth Magnet Waste by Removing Rare Earth Oxide with Molten Fluoride

Recycling of Rare Earth Magnet Waste by Removing Rare Earth Oxide with Molten Fluoride

1599 ppm oxygen deceased to 155 ppm by the processing at 1063 K for 257 h. The processing requires long time because the diffusion of oxygen in a solid sample requires long time under the melting point of neodymium (1289 K 22) ). Kamihira et al. tried the deoxidation by using calcium metal as a deoxidation agent. 18) 830 ppm oxygen decreased to 205 ppm by the processing in a calcia crucible at 1143 K for 18 h. However, contamination by calcium is concerned in the method due to the direct contact of calcium with neodymium although the calcium concentration in neodymium after the deoxidation was not described in the report. Sano et al.
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The legal imperative for treating rare disorders

The legal imperative for treating rare disorders

Disability legislation was recently used to overturn a rec- ommendation by NICE. In Eisai v NICE, the High Court found discrimination against patients with Alzheimer’s disease after they were required to perform a mini mental state assessment to qualify for the drug Aricept, as this re- quirement had inadequate regard to those with atypical forms of the disease [27,28]. The claimants were able to demonstrate that certain patients were especially disabled by disease onset and that their cases were therefore unlike those of the majority of patients with this dementia. Simi- larly, patients affected by rare diseases are small groups suffering from particular genetic conditions, and there may be further subgroups within each disease of particu- larly strongly affected individuals.
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Assessment of Potential Risk due to Accidental Melting of Scrap Metal Containing Depleted Uranium Using a Computational Method

Assessment of Potential Risk due to Accidental Melting of Scrap Metal Containing Depleted Uranium Using a Computational Method

Public exposure to products incorporating radioactive scrap metal is most likely to result from external exposure. Melting radioactive source in metal recycle represent high hazard effect for slag worker, while for the public it is especially in tool reuse stage. Based on the zero-threshold linear dose response model, any absorbed dose of uranium is assumed to result in an increased risk of cancer. Since uranium tends to concentrate in specific locations in the body, the risk of cancer in the bone, liver, and blood (such as leukemia) may be increased [20].
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Rare earth elements in Australian sediments

Rare earth elements in Australian sediments

(Condie, 1967; Schnetzler and Philpotts, 1967; Wildeman and Haskin, 1973; Wildeman and Condie, 1973). The "steady state" model of Armstrong (1968) and Armstrong and Hein (1973), which invokes continuous exchange between crust and mantle, has some features in common with the model of Jakes and White (1971). This model does not closely define the petrogenic processes responsible for crust-mantle exchange, and so it is difficult to evaluate. Complex models such as that of Engel et a l . (1974) requiring pronounced episodicity in crustal evolution are based on presumed changes in chemical composition of the crust through time. The sedimentary rare earth data is very useful in evaluating models of this type. Theories calling for the origin of continents through the infall of sialic meteorites have been proposed in recent years by Donn et al. (1965) and Van Bemmelen (1972). The latter author views crustal evolution as a gradual change from the meteoritic composition (sialic material, infalling from dust rings) to an internally derived composition. Such a model must require a continuous change in crustal composition and probably in upper crustal rare earth distribution.
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Multiferroic properties of rare earth manganites

Multiferroic properties of rare earth manganites

applied along the c-axis would cause the spins to rotate about c, i.e. in the a-b plane (illustrated in Figure 4.28). Again referring to Equation 1.6, the result of this magnetic reorientation would be a change in the direction of the electric po- larisation to the a-axis. An increase in the polarisation along the a-axis was indeed found with H//c, but of a much smaller magnitude than that of the polarisation along the c-axis in zero field. This result suggests two possible outcomes: a mag- netic field of 9 T applied along the c-axis is enough to disrupt the b-c cycloid, but not sufficient to completely reorient the spins in the a-c plane; or the switching of the polarisation is strongly dependent on the coupling between the rare earth and the Mn moments in the RMnO 3 systems. With regards to the latter case,
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