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Hiroaki Onoda - One of the best experts on this subject based on the ideXlab platform.
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selective preparation of Neodymium phosphates from iron mixed solution by two step precipitation
Journal of environmental chemical engineering, 2020Co-Authors: Hiroaki Onoda, Atsuya IinumaAbstract:Abstract Neodymium iron boron alloy, Nd2Fe14B, is used in the manufacture of magnets. Neodymium is one of the rare earth elements, so it is valuable and expensive. In order to protect this rare earth resource, it is required to collect, reuse, and recyle rare earth elements. Recently, a new method for recovering Neodymium phosphate from mixed solutions has been reported, avoiding the difficulties reported by previous methods. Since rare earth phosphate is the main component of rare earth ore, this new phosphate process was proposed. Neodymium phosphate was precipitated selectively from iron-Neodymium mixed aqueous solution by 2 step processes with pH adjustments in this work. With this method, it was possible to separate Neodymium and iron without using high temperatures or specialized equipment. The optimum conditions were determined by evaluating precipitation by yield, Fe/Nd ratio, hue, UV–visible reflectance spectra, X-ray diffraction, and infrared spectroscopy. In step I where pH was adjusted using sodium hydroxide, iron hydroxide was precipitated. Then, phosphoric acid was added, and the pH was further adjusted to obtain a Neodymium phosphate precipitate as step II. The optimum conditions of this separation method were clarified.
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Synthesis of Neodymium phosphate from iron-Neodymium solution using sodium sulfite
Journal of Environmental Chemical Engineering, 2016Co-Authors: Hiroaki Onoda, Ryo FukatsuAbstract:Abstract Iron-Neodymium alloys are generally used for producing magnets. Neodymium falls under the class of rare earth elements, which are precious and expensive, and are thus often recovered by recycling processes as a cost saving measure. There are a few reported processes for the recycling of rare earth elements; however, these processes have disadvantages, including the requirement for high temperatures and the use of harmful gases. In this study, a novel technique for recovery of Neodymium while circumventing the difficulties reported in previous methods is presented. Because rare earth phosphates are the main components of rare earth ore, a novel phosphate process is suggested in this work. In this process, an iron-Neodymium solution was mixed with phosphoric acid solution and then adjusted to several different pH values using sodium hydroxide solution and nitric acid. The precipitates were filtered and dried. The ratio of Neodymium to iron in the precipitates and filtered solutions was estimated by the inductively coupled plasma (ICP) method. As an ideal phenomenon, Neodymium phosphate was filtered off and the cationic iron species were contained in the filtrate. The Fe/Nd and P/(Fe + Nd) ratios, concentrations of Neodymium, iron, and phosphoric acid, and pH were varied to study precipitation of the Neodymium compounds. The Neodymium cation was recovered from the iron-Neodymium solution using phosphoric acid. This novel process was demonstrated to be useful for the recovery of Neodymium, and may find applications in the recycling and recovery of other rare earth elements of interest.
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Recovery of Neodymium from an iron-Neodymium solution using phosphoric acid
Journal of Environmental Chemical Engineering, 2014Co-Authors: Hiroaki Onoda, Reiichiro NakamuraAbstract:Abstract The iron–Neodymium alloy is generally used for magnets. Neodymium is one of the rare earth elements; since these elements are precious metals and therefore rare and expensive, recycling processes are often used to save costs. There are a few reported processes for the recycling of rare earth elements; however, these processes have disadvantages, including requirements for high temperatures and harmful gases. In this paper, a novel technique is presented to recover Neodymium without the difficulties reported in previous methods. Because rare earth phosphates are main components of rare earth ore, a novel phosphate process is suggested in this work. The iron–Neodymium solution was mixed with phosphoric acid solution and then adjusted to pH with sodium hydroxide solution. Ascorbic acid was added to the iron–Neodymium solution to reduce ionic valence of iron. The precipitates were filtered off and dried. The ratio of Neodymium and iron in precipitates and filtered solutions was estimated with an ICP method. As an ideal phenomenon, Neodymium phosphate was filtered off, and the filtered solution contained all cationic iron. The ratios of Nd/Fe, P/(Fe + Nd), the concentration of ascorbic acid, and pH were varied to study the precipitation of Neodymium compounds. In this work, over 99% of Neodymium cation was recovered from an iron–Neodymium solution using phosphoric acid and ascorbic acid. This novel process was observed to be useful for the recovery of Neodymium, and may have applications in the recycling and recovery of other rare earth elements of interest.
Catherine Jeandel - One of the best experts on this subject based on the ideXlab platform.
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Rapid Neodymium release to marine waters from lithogenic sediments in the Amazon estuary
Nature Communications, 2015Co-Authors: Tristan C. C. Rousseau, Jeroen E. Sonke, Jérôme Chmeleff, Pieter Van Beek, Marc Souhaut, Geraldo Boaventura, Patrick Seyler, Catherine JeandelAbstract:Neodymium isotopes are tracers for past and present ocean circulation and biogeochemistry. Here, the authors combine observations of Neodymium and radium isotopes in the Amazon estuary and show that the rapid release of Neodymium from river suspended sediments leaves a strong imprint on coastal sea water. Rare earth element (REE) concentrations and Neodymium isotopic composition (ɛNd) are tracers for ocean circulation and biogeochemistry. Although models suggest that REE release from lithogenic sediment in river discharge may dominate all other REE inputs to the oceans, the occurrence, mechanisms and magnitude of such a source are still debated. Here we present the first simultaneous observations of dissolved (
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Neodymium isotopic composition and rare earth element concentrations in the deep and intermediate Nordic Seas: Constraints on the Iceland Scotland Overflow Water signature
Geochemistry Geophysics Geosystems, 2004Co-Authors: François Lacan, Catherine JeandelAbstract:Neodymium isotopic composition and rare earth element concentrations were measured in seawater samples from eleven stations in the Nordic Seas. These data allow us to study how the Iceland Scotland Overflow Water (ISOW) acquires its Neodymium signature in the modern ocean. The waters overflowing the Faroe Shetland channel are characterized by ɛNd = −8.2 ± 0.6, in good agreement with the only other data point, published 19 years ago. In the Greenland and Iceland Seas the water masses leading to the formation of the ISOW display lower Neodymium isotopic composition, with ɛNd around −11 and −9, respectively. Since no water masses in the Nordic Seas are characterized by ɛNd > −8, the radiogenic signature of the ISOW likely reflects inputs from the highly radiogenic Norwegian Basin basaltic margins (Jan-Mayen, Iceland, Faroe, with ɛNd ≈ +7). In addition to the Neodymium isotopic composition, the rare earth element patterns suggest that these inputs occur via the remobilization (which includes resuspension and dissolution) of sediments deposited on the margins. Whereas the Neodymium isotopic composition behaves conservatively in the oceans in the absence of lithogenic inputs, and can be used as a water mass tracer, these results emphasize the role of interactions, between sediments deposited on margins and seawater, in the acquisition of the Neodymium isotopic composition of water masses. These results should allow a better use of this parameter to trace the present and the past circulation in the North Atlantic.
Rudolf Kawalla - One of the best experts on this subject based on the ideXlab platform.
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Synthesis of Mg–Zn–Nd Master Alloy in Metallothermic Reduction of Neodymium from Fluoride–Chloride Melt
Crystals, 2020Co-Authors: I. I. Beloglazov, S. A. Savchenkov, Vladimir Yuryevich Bazhin, Rudolf KawallaAbstract:In the presented article, a differential thermal analysis was carried out and the temperatures of thermal effects were established that arise during the reduction of Neodymium from a technological salt mixture KCl–NaCl–CaCl2–NdF3 with a magnesium–zinc alloy. The results of experimental studies on the reduction of Neodymium from a fluoride–chloride melt in a shaft electric furnace at temperatures of 550, 600, 650, 700 °C are presented. In order to increase the degree of extraction of Neodymium into the Mg–Zn–Nd master alloy, the study of the influence of technological parameters on the degree of extraction of Neodymium was carried out. It was experimentally proven that when zinc is added to a reducing agent (magnesium), the degree of extraction of Neodymium into the master alloy is 99.5–99.7%. The structure of the obtained master alloy samples, characterized by a uniform distribution of ternary intermetallic compounds (Mg3,4NdZn7) in the volume of a double magnesium–zinc eutectic, was studied by optical and electron microscopy.
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synthesis of mg zn nd master alloy in metallothermic reduction of Neodymium from fluoride chloride melt
Crystals, 2020Co-Authors: I. I. Beloglazov, S. A. Savchenkov, Vladimir Yuryevich Bazhin, Rudolf KawallaAbstract:In the presented article, a differential thermal analysis was carried out and the temperatures of thermal effects were established that arise during the reduction of Neodymium from a technological salt mixture KCl–NaCl–CaCl2–NdF3 with a magnesium–zinc alloy. The results of experimental studies on the reduction of Neodymium from a fluoride–chloride melt in a shaft electric furnace at temperatures of 550, 600, 650, 700 °C are presented. In order to increase the degree of extraction of Neodymium into the Mg–Zn–Nd master alloy, the study of the influence of technological parameters on the degree of extraction of Neodymium was carried out. It was experimentally proven that when zinc is added to a reducing agent (magnesium), the degree of extraction of Neodymium into the master alloy is 99.5–99.7%. The structure of the obtained master alloy samples, characterized by a uniform distribution of ternary intermetallic compounds (Mg3,4NdZn7) in the volume of a double magnesium–zinc eutectic, was studied by optical and electron microscopy.
Gilbert N. Hanson - One of the best experts on this subject based on the ideXlab platform.
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Rare earth element redistribution and its effects on the Neodymium isotope system in the austin Glen Member of the Normanskill Formation, New York, USA
Geochimica et Cosmochimica Acta, 1994Co-Authors: Barbara Bock, Scott M. Mclennan, Gilbert N. HansonAbstract:Abstract Three groups of REE patterns are observed for the sandstones and shales of the Middle Ordovician Austin Glen Member of the Normanskill Formation. One sandstone sample is enriched in middle and light rare earth elements. The majority of samples are light rare earth element (LREE) enriched with negative Eu-anomalies and flat heavy rare earth elements (HREEs), whereas a third group appears to have lost LREEs and middle rare earth element (MREEs). Homogeneous Neodymium isotopic compositions for all samples at about the time of deposition, ϵNd (470 Ma) = −8.2 ± 1.1(2SD), indicate that the source of the Austin Glen Member was well mixed and that the Neodymium had a long-term enriched history. The differences in the shape and abundances of the REE patterns combined with the Neodymium isotope characteristics of the samples lead us to the conclusion that samarium and Neodymium were fractionated and that the Neodymium isotopic system might have been disturbed at about the time of deposition (470 Ma). Most samples appear to have been affected by this process. The two most altered shales lost about half of their Neodymium and their Sm Nd ratios are higher than the Sm Nd ratios of average shales. These two shales give clearly erroneous mantle-extraction ages, but the average TDM of the provenance can still be deduced (1700–1800 Ma) from the least disturbed sandstones with normal upper crustal Sm Nd ratios. Accordingly, this study demonstrates that the REEs may be transported and Neodymium isotopes may be reequilibrated under certain sedimentary conditions (e.g., diagenesis). However, in spite of evidence for REE redistribution, provenance information (TDM, original REE patterns) may still be inferred.
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REE Redistribution and its Effects on the Nd-isotopes System in the Austin Glen Member of the Normaskill Formation, New York
1994Co-Authors: Barbara Bock, Scott M. Mclennan, Gilbert N. HansonAbstract:Three groups of REE patterns are observed for the sandstones and shales of the Middle Ordovician Austin Glen Member of the Normanskill Formation. One sandstone sample is enriched in middle and light rare earth elements. The majority of samples are light rare earth element (LREE) enriched with negative Eu-anomalies and flat heavy rare earth elements (HREEs), whereas a third group appears to have lost LREEs and middle rare earth element (MREEs). Homogeneous Neodymium isotopic compositions for all samples at about the time of deposition, ϵNd (470 Ma) = −8.2 ± 1.1(2SD), indicate that the source of the Austin Glen Member was well mixed and that the Neodymium had a long-term enriched history. The differences in the shape and abundances of the REE patterns combined with the Neodymium isotope characteristics of the samples lead us to the conclusion that samarium and Neodymium were fractionated and that the Neodymium isotopic system might have been disturbed at about the time of deposition (470 Ma). Most samples appear to have been affected by this process. The two most altered shales lost about half of their Neodymium and their ratios are higher than the ratios of average shales. These two shales give clearly erroneous mantle-extraction ages, but the average TDM of the provenance can still be deduced (1700–1800 Ma) from the least disturbed sandstones with normal upper crustal ratios. Accordingly, this study demonstrates that the REEs may be transported and Neodymium isotopes may be reequilibrated under certain sedimentary conditions (e.g., diagenesis). However, in spite of evidence for REE redistribution, provenance information (TDM, original REE patterns) may still be inferred.
Ryo Fukatsu - One of the best experts on this subject based on the ideXlab platform.
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Synthesis of Neodymium phosphate from iron-Neodymium solution using sodium sulfite
Journal of Environmental Chemical Engineering, 2016Co-Authors: Hiroaki Onoda, Ryo FukatsuAbstract:Abstract Iron-Neodymium alloys are generally used for producing magnets. Neodymium falls under the class of rare earth elements, which are precious and expensive, and are thus often recovered by recycling processes as a cost saving measure. There are a few reported processes for the recycling of rare earth elements; however, these processes have disadvantages, including the requirement for high temperatures and the use of harmful gases. In this study, a novel technique for recovery of Neodymium while circumventing the difficulties reported in previous methods is presented. Because rare earth phosphates are the main components of rare earth ore, a novel phosphate process is suggested in this work. In this process, an iron-Neodymium solution was mixed with phosphoric acid solution and then adjusted to several different pH values using sodium hydroxide solution and nitric acid. The precipitates were filtered and dried. The ratio of Neodymium to iron in the precipitates and filtered solutions was estimated by the inductively coupled plasma (ICP) method. As an ideal phenomenon, Neodymium phosphate was filtered off and the cationic iron species were contained in the filtrate. The Fe/Nd and P/(Fe + Nd) ratios, concentrations of Neodymium, iron, and phosphoric acid, and pH were varied to study precipitation of the Neodymium compounds. The Neodymium cation was recovered from the iron-Neodymium solution using phosphoric acid. This novel process was demonstrated to be useful for the recovery of Neodymium, and may find applications in the recycling and recovery of other rare earth elements of interest.
