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Hydrometallurgical recycling of NdF eB magnets： Complete leaching, iron removal and electrolysis

Journal of Rare Earths 2017年第6期35卷 574-584页

作者： Mehmet Ali Recai Onal Chenna Rao Borra Muxing Guo Bart Blanpain tom van gerven Department of Materials Engineering University of Leuven Kasteelpark Arenberg 44 3001 Leuven Belgium Process Engineering for Sustainable Sys-terns (ProcESS) Department of Chemical Engineering University of Leuven Celestijnenlaan 200F 3001 Leuven Belgium

NdFeB magnets currently dominate the magnet market. Supply risks of certain rare earth metals（REM）, e.g. Nd and Dy, impose efficient recycling schemes that are applicable to different types and compositions of these magnets with minimum use of chemicals and waste generation. In this study, a hydrometallurgical method was studied that could be adjusted to recover not only REM, but also other valuable metals（***, Ni and Cu） that co-existed in the magnet. The magnet powders were completely dissolved in a dilute sulfuric acid solution giving more than 98% of dissolved iron in the ferrous state. Chemical oxidation of Fe-（2＋） into Fe-（3＋） by the addition of MnO 2 required only 1 h at ambient temperature. It was then possible to precipitate more than 99% of this ferric iron by adjusting the pH of the solution above 3 with either Ca（OH）2 or MnO additions. However, the addition of Ca（OH）2 resulted in the formation of gypsum and up to ca. 23% REM losses, possibly via co-precipitation into the gypsum. MnO elevated the Mn-（2＋） concentration in the solution. However, it was found to be problematic that subsequent direct electrolysis removed Mn and Co. Low anodic current efficiencies（ACE） resulted in high energy consumption（EC）, while incomplete Mn and Co removals and undesired REM losses were reported. Pre-electrolysis removals of REM and/or Co by oxalate and/or sulfide precipitation were proven to be successful and selective, but this enlarged the flowsheet considerably with only minor improvement of the Mn removal, ACE and EC.

关键词： electrolysis magnet recycling precipitate leaching anodic subsequent ferrous dissolved leachate

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Characterization of landfilled stainless steel slags in view of metal recovery

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Frontiers of Chemical Science and Engineering 2017年第3期11卷 353-362页

作者： Xuan Wang Daneel Geysen tom van gerven Peter T. Jones Bart Blanpain Muxing Guo Department of Metallurgy and Materials Engineering KU Leuven 3001 Heverlee Belgium Department of Chemical Engineering KU Leuven 3001 Heverlee Belgium Department of Research and Development Group Machiels 3001 Heverlee Belgium

The slag samples taken from landfill, which originated from different metallurgical processes, have been characterized in this study. The slags were categor- ized as electric arc furnace （EAF） slag, argon oxygen decarburization/metal refining process slag and vacuum oxygen decarburization slag based on chromium content and basicity. EAF slags have higher potential in metal recovery than the other two slags due to its higher iron and chromium contents. The size of the iron-chromium-nickel alloy particles varies from a few ~tm up to several cm. The recoveries of large metal particles and metal-spinel aggregates have potential to make the metal recovery from landfilled slags economically viable.

关键词： landfilled stainless steel slag metal recovery characterization

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Mechanochemical-Assisted Leaching of Lamp Phosphors： A Green Engineering Approach for Rare-Earth Recovery

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Engineering 2018年第3期4卷 398-405页

作者： Steff van Loy Koen Binnemans tom van gerven Department of Chemical Engineering KU Leuven Heverlee B-3001 Belgium Department of Chemistry KU Leuven Heverlee B-3001 Belgium

Rare-earth elements （REEs） are essential metals for the design and development of sustainable energy applications, Recycling these elements from waste streams enriched in them is crucial for securing an independent future supply for sustainable applications, This study compares the mechanisms of mechan- ical activation prior to a hydrometallurgical acid-leaching process and a solvometallurgical mechanochemical leaching process for the recovery of REEs from green lamp phosphor, LaPO4：Ce3＋, Th3＋, After 60 min of processing time, the REE leaching rates showed a significant enhancement of 60% after cycled mechanical activation, and 98% after the combined mechanochemical leaching process, High-resolution transmission electron microscopy （HR-TEM） imaging disclosed the cause for the improved REE leaching rates： The improved leaching and leaching patterns could he attributed to changes in the crystal morphology from monocrystalline to polycrystalline, Reduction of the crystallite size to the nanoscale in a polycrystalline material creates irregular packing of chemical units, resulting in an increase in defect-rich grain boundaries in the crystals, which enhances the leaching process, A solvometallurgical method was developed to combine the mechanical activation and leaching process into a single step, which is beneficial for operational cost, This results in an efficient and simple process that provides an alternative and greener recycling route for lamp phosphor waste,

关键词： Mechanochemistry Rare-earth elements Lamp phosphor waste Ball-milling Solvometallurgy

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Auto immune hepatitis

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World Journal of Gastroenterology 2016年第19期22卷 4651-4661页

作者： nicole mf van gerven ynto s de boer chris jj mulder carin mj van nieuwkerk gerd bouma department of gastroenterology and hepatology vu university medical centre1081 HV Amsterdam The Netherlands

To provide an update of the latest trends in epidemiology, clinical course, diagnostics, complications and treatment of auto immune hepatitis(AIH). A search ofthe MEDLINE database was performed using the search terms: "auto immune hepatitis", "clinical presentation", "symptoms", "signs", "diagnosis", "auto antibodies", "laboratory values", "serology", "histopathology", " h i s t o l o g y ", " g e n e t i c s ", "HLA g e n e s ", "non-HLA genes", "environment", "epidemiology", "prevalence", "incidence", "demographics", "complications", "HCC", "PBC", "PSC", "corticosteroid", "therapy", "treatment", "alternative treatment". English-language full-text articles and abstracts were considered. Articles included reviews, meta-analysis, prospective retrospective studies. No publication date restrictions were applied. AIH is an immune meditated progressive inflammatory liver disease that predominantly affects middle-aged females but may affect people of all ages. The clinical spectrum of AIH is wide, ranging from absent or mild symptoms to fulminant hepatic failure. The aetiology of AIH is still unknown, but is believed to occur as the consequence of an aberrant immune response towards an un-known trigger in a genetically susceptible host. In the absence of a gold standard, diagnosis is based on the combination of clinical, biochemical and histopathological criteria. Immunosuppressive treatment has been the cornerstone of treatment since the earliest description of the disease in 1950 by Waldenstr?m. Such treatment is often successful at inducing remission and generally leads to normal life expectancy. Nevertheless, there remain significant areas of unmet aetiological a clinical needs including fundamental insight in disease pathogenesis, optimal therapy, duration of treatment and treatment alternatives in those patients unresponsive to standard treatment regimens.

关键词： Auto immune hepatitis Diagnosis Liver Epidemiology Treatment

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The Vérard et al.(2015) method for 3D palaeogeographic reconstructions:How solid is its base?

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Journal of Palaeogeography 2015年第3期4卷 244-247页

作者： A.J.(tom) van Loon Geocom Valle del Portet 1703726 BenitachellSpain

Verard and co-workers proposed in an earlier issue of this journal a method to reconstruct the 3D palaeogeography ＂anywhere in the world at any time＂. The present contribution is a discussion of some of the assumptions on which the method of Verard et al. is based. The reason for this discussion is that the method will give, at least seemingly, illogical outcomes for numerous situations. Moreover, some assumptions used by Verard and his team pose theoretical probtems. It is deduced that the method developed by Verard and co-workers may occasionally help, indeed, to obtain a rough picture of the altitude of the sedimentary surface on the continents and of the depth of the sedimentary surface in the oceans in the geological past. The outcomes should, however, be treated with utmost care as severat of the assumptions on which the interpretative 3D method is based have no solid basis, so that even the rough outcomes of the method must be considered questionable.

关键词： pataeogeography reconstruction 3D model

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The response of stromatolites to seismic shocks： tomboliths from the Palaeoproterozoic Chaibasa Formation, E India

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Journal of Palaeogeography 2016年第4期5卷 381-390页

作者： A.J. (tom) van Loon Rajat Mazumder Shuvabrata De Geocom Consultants Valle del Portet 17 03762 Benitachell Spain Department of Applied Geology Faculty of Science and Engineering Curtin University Sarawak CDT 250 98009 Miri Sarawak Malaysia Indian Institute of Science Education and Research Department of Earth and Environmental Sciences Bhopal By-pass Road Bhopal 462066 Madhya Pradesh India

It is demonstrated here for the first time how Palaeoproterozoic stromatolites survived seismic disturbance of their substrate. The stromatolites under study could have been cyanobacteria or any other photo-autotrophic microbes, which formed mats that covered a substrate of very fine-grained sandstones and mudstones of the Chaibasa Fm. in eastern India. The sediments represent a shelf environment. The local abundance of the stromatotites suggests that the tow-energy environment formed a suitable habitat. The common phases of tectonic quiescence were, however, occasionally interrupted by seismic shocks. These were sufficiently strong to deform the mat layers, the tower parts of which might already have been （semi-） consolidated. The mats became partly folded, partly faulted, and already consolidated parts of the stromatotite layers broke off. This can be deduced from the angular shapes of part of the broken-off fragments. It appears, however, that part of these fragments were stilt sufficiently soft to become rounded and deformed by rotting over the seafloor, probably under the influence of tidal currents. When come to rest, these fragments served as a new substrate for new generations of the microorganisms. These micro-organisms thus survived by continued growth on the reworked fragments and built up new stromatolites that may show an ‘angular disconformity＇ with the stromatotites of their substrate. It thus is shown that stromatotites have an adequate response to a sudden disturbance of their habitat, and that they survive earthquakes by colonization of broken-off fragments. We call the ‘healed＇ fragments ‘tombotiths＇（tumbled stones）.

关键词： Stromatolites Seismic shocks Soft-sediment deformation structures Pataeoproterozoic Singhbhum craton tombotiths India

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A new 'superassemblage' model explaining proximal-to-distal and lateral facies changes in fluvial environments,based on the Proterozoic Sanjauli Formation(Lesser Himalaya,India)

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Journal of Palaeogeography 2016年第4期5卷 391-408页

作者： Ananya Mukhopadhyay Priyanka Mazumdar A.J. (tom) van Loon Department of Earth Sciences Indian Institute of Engineering Science & Technology Shibpur Howrah West Bengal 711103 India Geocom Consulting Valle del Portet 17 03726 Benitachell Spain

Facies analysis of fluvial deposits of the Proterozoic Sanjauli Formation in the Lesser Himalaya was combined with an architectural analysis. On this basis, a model was developed that may be applied to other fluvial systems as well, whether old or recent. The new model, which might be considered as an assemblage of previous models, explains lateral variations in architecture and facies but is not in all respects consistent with the standard fluvial models. The Sanjauli fluvial model is unique in that it deals with lateral facies variations due to shifts of the base-level along with fluctuations in accommodation space owing to changes in palaeoclimate.

关键词： Ftuvial model Braided river Sanjauli Formation Simta Basin Proterozoic Lesser Himalaya India

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Geochemical,mineralogical,and petrological analyses for the interpretation of the sedimentary environment of the Middle-Late Ordovician Majiagou Formation(northern China)as a tool for more effective gas exploration

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Petroleum Science 2022年第6期19卷 2519-2532页

作者： Jie Gao Da-Wei Lv A.J.(tom) van Loon Dun Wu Shandong Provincial Key Laboratory of Depositional Mineralization and Sedimentary Minerals Shandong University of Science and TechnologyQingdaoShandong266590China Laboratory for Marine Mineral Resources Qingdao National Laboratory for Marine Science and TechnologyShandong266071China College of Earth Science and Engineering Shandong University of Science and TechnologyShandong266590China Exploration Research Institute Anhui Provincial Bureau of Coal GeologyHefeiAnhui230088China

Core samples from the deeply buried Ordovician Majiagou Formation below the Huainan Coalfield(E China) have been investigated for their carbonate types,major and trace elements(including rare earth elements) and C and O isotopes,The objective was to get a better insight into the possible occurrences of gas(and possibly oil) derived from Carboniferous *** was found that the carbonates are dolomites with strongly varying amounts of CaO and *** low concentrations of SiO_(2),Al_(2)O_(3),and Fe_(2)O_(3)indicate deposition in a normal marine environment with little terrigenous input,The Na_(2)O/K_(2)O,Fe/Mn and Sr/Ba ratios,as well as the Ga values indicate mainly a marine salinity and a hot and humid *** slight depletion of Ce and Eu,the depletion of heavy rare earth elements(HREE) and the enrichment of light rare earth elements(LREE) indicate deposition in a reducing *** thus appears that the Majiagou Formation below the Huainan Coalfield closely resembles that in the eastern part of the Ordos Basin,where several gas reservoirs are present,so that the Majiagou Formation under the Huainan Coalfield represents a promising target for hydrocarbon exploration.

关键词： Majiagou Formation Middle Ordovician Major-element analysis REE analysis Trace-element analysis Hydrocarbon exploration

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The hyperpycnite problem: comment

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Journal of Palaeogeography 2019年第3期8卷 314-320页

作者： A.J.(tom) van Loon Heiko Hüneke Thierry Mulder Geocom Consulting Valle del Portet 17 03726 Benitachell Spain College of Earth Science and Engineering Shandong University of Science and Technology Qingdao 266590 Shandong China Institute of Geography and Geology Greifswald University Greifswald Germany UMR CNRS EPOC University of Bordeaux Allee Geoffroy St-Hilaire 33615 Pessac Cedex France

A recent review article("The hyperpycnite problem") by Shanmugam(Journal of Palaeogeography 7(3):197–238,2018) in this journal has some shortcomings, comes to scientifically incorrect conclusions, and calls for student education in a way that would significantly diminish the students’ changes for a geological career. Having studied--and still studying--hyperpycnites in the field, it seems only appropriate to inform the readers of this journal about our concerns regarding the review article mentioned ***, the article by Shanmugam(Journal of Palaeogeography 7(3):197–238, 2018) is not a review paper but rather a comment, criticizing al researchers who have come to the conclusion, on the basis of both field research and theory,that hyperpycnal flows result in sediments(hyperpycnites) with characteristics that make it possible to distinguish them from deposits formed in another way. This is also the essence of Shanmugam’s comment: as he states himself, he is"an ardent critic of al genetic facies models".

关键词： review Shanmugam critic

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The effect of host plants on genotype variability in fitness and honeydew composition of Aphis fabae

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Insect Science 2017年第5期24卷 781-788页

作者： Sharon Schillewaert Amelie vantaux Wim van den Ende tom Wenseleers Laboratory of Socioecology and Social Evolution Biology Department Zoological Institute University of Leuven Leuven Belgium Institut Pasteur du Cambodge Unite d'Epidemiologie Moleculaire du Paludisme Phnom Penh Cambodia Laboratory of Molecular Plant Biology Biology Department University of Leuven Leuven Belgium

Aphid species can be polyphagous, feeding on multiple host plants across genera. As host plant species can have large variation in their phloem composition, this can affect aphid fitness and honeydew composition. Previous research showed significant intraspecific genotype variation in the composition of the honeydew carbohydrates of the black bean aphid Aphis fabae, with the ant attractant trisaccharide melezitose showing especially large variation across different genotypes. In this study, we test if variation in melezitose and carbohydrate composition of aphid honeydew could be linked to the adap- tation of specific aphid genotypes to particular host plants. To this end, 4 high and 5 low melezitose secreting genotypes of the black bean aphid Aphisfabae were reared on 4 com- mon host plants： broad bean, goosefoot, beet, and poppy. The carbohydrate composition, and in particular melezitose secretion, showed important aphid genotype and host plant in- teractions, with some genotypes being high melezitose secreting on 1 host plant but not on another. However, the interaction effects were not paralleled in the fitness measurements, even though there were significant differences in the average fitness across the different host plants. On the whole, this study demonstrates that aphid honeydew composition is influenced by complex herbivore-plant interactions. We discuss the relevance of these findings in the context of ant-aphid mutualisms and adaptive specialization in aphids.

关键词： aphids Aphis fabae ecological specialization fitness honeydew hostplants Melezitose polyphagous

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