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Добірка наукової літератури з теми "Platinum Group Metals (PGM)"

Автор: Grafiati
Опубліковано: 8 червня 2024

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Статті в журналах з теми "Platinum Group Metals (PGM)":

1

Thompson, David T. "Catalysis by Gold/Platinum Group Metals." Platinum Metals Review 48, no. 4 (October 1, 2004): 169–72. http://dx.doi.org/10.1595/003214004x484169172.

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The recent surge of new interest in catalysis by gold (–) has led researchers to investigate the effects of adding other metals to the gold. As a result, there are a number of reactions with potential for industrial application where combinations of gold with a platinum group metal (pgm) have been shown to have advantages over either gold or the pgm alone. These findings are expected to lead to applications in chemical processing, pollution control and fuel cell applications. Here, a number of catalytic processes that have benefited from the synergy between a pgm and gold are described, and some interesting reports from recent conferences are highlighted.
2

Kulikov, M., and E. Kopishev. "Review: Extraction of platinum group metals from catalytic converters." BULLETIN of the L.N. Gumilyov Eurasian National University. Chemistry. Geography. Ecology Series 142, no. 1 (2023): 37–71. http://dx.doi.org/10.32523/2616-6771-2023-142-1-37-71.

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Platinum group metals (PGM) are widely used in catalytic industry due to their outstanding physical and chemical properties (high-temperature stability, high catalyst activity, high heat resistance, high corrosion resistances). They are used in medical fields, electronics, oil refining, production of ammonia, fuel cells, automotive industry. Catalytic wastes are an important secondary source of metals because recycling of wastes is more economical and ecological way of metals obtaining compared to mining from ores. Spent automotive catalyst is a rich source of platinum group metals [PGM: platinum (Pt), palladium (Pd), and rhodium (Rh)] which contains higher concentrations of PGM than found in natural ores. This review presents the analysis of the recovery methods of platinum group metals from spent catalysts and their advantages and disadvantages. As a result, all methods were analyzed and the most promising (most environmentally friendly and economical) was pointed out.
3

Kulikov, M., and E. Kopishev. "Review: Extraction of platinum group metals from catalytic converters." BULLETIN of L.N. Gumilyov Eurasian National University. CHEMISTRY. GEOGRAPHY. ECOLOGY Series 142, no. 1 (2023): 36–73. http://dx.doi.org/10.32523/2616-6771-2023-142-1-36-73.

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Platinum group metals (PGM) are widely used in catalytic industry due to their outstanding physical and chemical properties (high-temperature stability, high catalyst activity, high heat resistance, high corrosion resistances). They are used in medical fields, electronics, oil refining, production of ammonia, fuel cells, automotive industry. Catalytic wastes are an important secondary source of metals because recycling of wastes is more economical and ecological way of metals obtaining compared to mining from ores. Spent automotive catalyst is a rich source of platinum group metals [PGM: platinum (Pt), palladium (Pd), and rhodium (Rh)] which contains higher concentrations of PGM than found in natural ores. This review presents the analysis of the recovery methods of platinum group metals from spent catalysts and their advantages and disadvantages. As a result, all methods were analyzed and the most promising (most environmentally friendly and economical) was pointed out.
4

Diac, Cornelia, Florentina Iuliana Maxim, Radu Tirca, Adrian Ciocanea, Valeriu Filip, Eugeniu Vasile, and Serban N. Stamatin. "Electrochemical Recycling of Platinum Group Metals from Spent Catalytic Converters." Metals 10, no. 6 (June 19, 2020): 822. http://dx.doi.org/10.3390/met10060822.

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Platinum group metals (PGMs: Pt, Pd, and Rh) are used extensively by the industry, while the natural resources are limited. The PGM concentration in spent catalytic converters is 100 times larger than in natural occurring ores. Traditional PGM methods use high temperature furnaces and strong oxidants, thus polluting the environment. Electrochemical studies showed that platinum can be converted to their chloride form. The amount of dissolved PGM was monitored by inductively coupled plasma-optical emission spectroscopy and the structure was identified by ultraviolet-visible spectroscopy. An electrochemistry protocol was designed to maximize platinum dissolution, which was then used for a spent catalytic converter. A key finding is the use of potential step that enhances the dissolution rate by a factor of 4. Recycling rates as high as 50% were achieved in 24 h without any pretreatment of the catalyst. The method developed herein is part of a current need to make the PGM recycling process more sustainable.
5

Murray, Angela J., I. P. Mikheenko, Elzbieta Goralska, N. A. Rowson, and Lynne E. Macaskie. "Biorecovery of Platinum Group Metals from Secondary Sources." Advanced Materials Research 20-21 (July 2007): 651–54. http://dx.doi.org/10.4028/www.scientific.net/amr.20-21.651.

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Since 1998 demand for the platinum group metals (PGM) has exceeded supply resulting in large price increases. Undersupply, combined with rising costs prompts environmentally friendly recycling technologies. Leachates containing PGM were produced from secondary waste sources using microwave leaching technology with the aim of recovering precious metals using bacterial biomass. Previous studies showed that metallised biomass exhibits catalytic activity; hence metal is not only recovered but can be converted into a valuable product. Cells of Escherichia coli MC4100 that had been pre-metallised with Pt were more effective at reducing PGM from the leachates. The solid recovered from the leachate onto the bacteria was characterised using X-ray Powder Diffraction (XRD) and Energy Dispersive X-ray Microanalysis (EDX). Metallised biomass was tested for catalytic activity (reduction of Cr(VI) to Cr(III)) to compare the ‘quality’ of polymetallic bacterial-based catalysts versus counterparts made from single and mixed metal model solutions.
6

Du, Lei, Gaixia Zhang, and Shuhui Sun. "Proton Exchange Membrane (PEM) Fuel Cells with Platinum Group Metal (PGM)-Free Cathode." Automotive Innovation 4, no. 2 (April 28, 2021): 131–43. http://dx.doi.org/10.1007/s42154-021-00146-0.

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AbstractProton exchange membrane (PEM) fuel cells have gained increasing interest from academia and industry, due to its remarkable advantages including high efficiency, high energy density, high power density, and fast refueling, also because of the urgent demand for clean and renewable energy. One of the biggest challenges for PEM fuel cell technology is the high cost, attributed to the use of precious platinum group metals (PGM), e.g., Pt, particularly at cathodes where sluggish oxygen reduction reaction takes place. Two primary ways have been paved to address this cost challenge: one named low-loading PGM-based catalysts and another one is non-precious metal-based or PGM-free catalysts. Particularly for the PGM-free catalysts, tremendous efforts have been made to improve the performance and durability—milestones have been achieved in the corresponding PEM fuel cells. Even though the current status is still far from meeting the expectations. More efforts are thus required to further research and develop the desired PGM-free catalysts for cathodes in PEM fuel cells. Herein, this paper discusses the most recent progress of PGM-free catalysts and their applications in the practical membrane electrolyte assembly and PEM fuel cells. The most promising directions for future research and development are pointed out in terms of enhancing the intrinsic activity, reducing the degradation, as well as the study at the level of fuel cell stacks.
7

Devyatykh, E. A., T. O. Devyatykh, and A. N. Boyarsky. "Survey of Methods of Refining Catalysts for the Extraction of Platinum Group Metals." Materials Science Forum 946 (February 2019): 528–32. http://dx.doi.org/10.4028/www.scientific.net/msf.946.528.

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Currently, about 80% of all industrial chemical reactions are carried out with the help of catalysts or depend on catalytic processes. In this case, catalysts containing platinum group metals (hereinafter - PGM) occupy a special position, due to their high catalytic activity and selectivity. A significant part of the net global demand for PGM is for the production of catalysts, accounting for approximately 45% for platinum, 30% for palladium, 92% for rhodium, 35% for ruthenium, 15% for iridium. The most important condition for the economical use of catalysts containing precious metals is their efficient recycling, which will be discussed below.
8

Prichard, Hazel M., Saioa Suárez, Peter C. Fisher, Robert D. Knight, and John S. Watson. "Placer platinum-group minerals in the Shetland ophiolite complex derived from anomalously enriched podiform chromitites." Mineralogical Magazine 82, no. 3 (April 16, 2018): 491–514. http://dx.doi.org/10.1180/minmag.2017.081.099.

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ABSTRACTHighly anomalous platinum-group element (PGE) concentrations in the podiform chromitites at the Cliff and Harold's Grave localities in the Shetland ophiolite complex have been well documented previously. The focus of this study is alluvial platinum-group minerals (PGM) located in small streams that drain from the PGE-rich chromitites. The placer PGM assemblage at Cliff is dominated by Pt-arsenides (64%) and Pd-antimonides (17%), with less irarsite–hollingworthite (11%) and minor Pd-sulfides, Pt–Pd–Cu and Pt–Fe alloys and laurite. Gold also occurs with the PGM. Alluvial PGM have average sizes of 20 µm × 60 µm, with sperrylite the largest grain identified at 110 µm in diameter, matching the range reported for the primary PGM in the source rocks. The placer assemblage contains more Pt-bearing and less Pd-bearing PGM compared with the rocks. The more resistant sperrylite and irarsite–hollingworthite grains which are often euhedral become more rounded further downstream whereas the less resistant Pd-antimonides which are commonly subhedral may become striated and etched. Less stable phases such as Pt- and Pd-oxides and other Ni-Cu-bearing phases located in the rocks (i.e. Ru-pentlandite, PtCu, Pd–Cu alloy) are absent in the placer assemblage. Also the scarce PGM (PdHg, Rh- and Ir-Sb) and Os in the rocks are absent. At Harold's Grave only three alluvial PGM (laurite, Ir, Os) and Au were recovered reflecting the limited release of IPGM from chromite grains in the rocks. In this cold climate with high rainfall, where erosion dominates over weathering, the PGM appear to have been derived directly from the erosion of the adjacent PGE-rich source rocks and there is little evidence of in situ growth of any newly formed PGM. Only the presence of dendritic pure Au and Pd-, Cu-bearing Au covers on the surface of primary minerals may indicate some local reprecipitation of these metals in the surficial conditions.
9

Hutchinson, David, Jeffrey Foster, Hazel Prichard, and Sarah Gilbert. "Concentration of Particulate Platinum-Group Minerals during Magma Emplacement; a Case Study from the Merensky Reef, Bushveld Complex." Journal of Petrology 56, no. 1 (January 1, 2015): 113–59. http://dx.doi.org/10.1093/petrology/egu073.

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Abstract The petrology, mineralogy and geochemistry of a section of the Merensky Reef at Bafokeng Rasimone Platinum Mine (BRPM) are described. A model for the formation of platinum-group minerals (PGM), sulphide and chromitite is proposed that explains the stratigraphic relationships observed in the Merensky Reef, both at BRPM and at other locations in the Bushveld Complex. To achieve this it is necessary to understand platinum-group element (PGE) behaviour in naturally occurring mafic systems and for this reason comparisons are drawn from core TN207 through the Platreef at Tweefontein. The common link between the Platreef and Merensky Reef is the presence of unusually high concentrations of As, Sb, Bi and Te that promote the crystallisation of semi-metal bearing PGM from sulphide liquids. Under conditions of increasing semi-metal contamination, Pt is the first PGE to be extracted from a sulphide liquid followed by Rh, Ru, Os and Ir. While some Pd is released to form Pd-PGM much of it remains within the Ni-rich sulphide phase that crystallizes to form pentlandite. A critical aspect is the timing of their introduction into the magmatic system. For the Merensky magmas, contamination occurred predominantly within a staging chamber owing to wall-rock interaction with Transvaal sediments. This led to the formation of sulphide liquids that captured PGE and, ultimately, the crystallization of Pt- and Ru-PGM. The extreme enrichment in PGE and the high Pt/Pd ratios in the Merensky chromitites are attributed to density-driven concentration of PGM transported by magmas displaced from a staging chamber. Emplacement of these magmas into the Bushveld Complex resulted in thermo-mechanical erosion of the floor and deposition of chromites + sulphides + PGM. In places, these assemblages collected in sedimentary-like scour channels. In the Platreef, contamination occurred largely after magma emplacement owing to interaction with the local Transvaal sediments. As a result, mechanical separation of PGM did not occur and most PGM remain spatially associated with their original sulphide hosts.The Merensky Reef is a prime example of highly efficient PGE concentration resulting from mechanical processes, whereas the Platreef is a prime example of highly efficient PGE removal from sulphide liquids in response to extreme contamination by semi-metals.
10

Men Truong, Van, Julian Richard Tolchard, Jørgen Svendby, Maidhily Manikandan, Hamish A. Miller, Svein Sunde, Hsiharng Yang, Dario R. Dekel, and Alejandro Oyarce Barnett. "Platinum and Platinum Group Metal-Free Catalysts for Anion Exchange Membrane Fuel Cells." Energies 13, no. 3 (January 27, 2020): 582. http://dx.doi.org/10.3390/en13030582.

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The development of active hydrogen oxidation reaction (HOR) and oxygen reduction reaction (ORR) catalysts for use in anion exchange membrane fuel cells (AEMFCs), which are free from platinum group metals (PGMs), is expected to bring this technology one step closer to commercial applications. This paper reports our recent progress developing HOR Pt-free and PGM-free catalysts (Pd/CeO2 and NiCo/C, respectively), and ORR PGM-free Co3O4 for AEMFCs. The catalysts were prepared by different synthesis techniques and characterized by both physical-chemical and electrochemical methods. A hydrothermally synthesized Co3O4 + C composite ORR catalyst used in combination with Pt/C as HOR catalyst shows good H2/O2 AEMFC performance (peak power density of ~388 mW cm−2), while the same catalyst coupled with our flame spray pyrolysis synthesised Pd/CeO2 anode catalysts reaches peak power densities of ~309 mW cm−2. Changing the anode to nanostructured NiCo/C catalyst, the performance is significantly reduced. This study confirms previous conclusions, that is indeed possible to develop high performing AEMFCs free from Pt; however, the challenge to achieve completely PGM-free AEMFCs still remains.
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Статті в журналах Дисертації Книги

Дисертації з теми "Platinum Group Metals (PGM)":

1

Zhang, Jingshu Ph D. Massachusetts Institute of Technology. "A bottom-up prospective dynamic materials flow assessment for platinum group metals (PGM) global demand forecast." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/93048.

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Thesis: S.M., Massachusetts Institute of Technology, Department of Materials Science and Engineering, 2014.
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Includes bibliographical references (pages 71-77).
by Jingshu Zhang.
S.M.
2

Machado, Norma Maria Pereira. "Rheological study of nuclear glass melts containing Platinum Group Metal aggregates." Electronic Thesis or Diss., Université de Lorraine, 2022. http://www.theses.fr/2022LORR0018.

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En France, les produits de fission nucléaire issus du retraitement des combustibles usés sont conditionnés au sein de matrices de verres borosilicatés. Lors du processus de vitrification à haute température (1200 °C), les éléments à confiner réagissent chimiquement avec les additifs de vitrification pour former un verre homogène. Cependant, parmi ces éléments, les platinoïdes ne sont pas solubles dans le bain de verre et restent en suspension sous forme de particules de quelques microns. Ces particules présentent une forte tendance à l'agrégation et les suspensions peuvent alors présenter une viscosité apparente anormalement élevée. Ces systèmes sont caractérisés par un comportement rhéofluidifiant et thixotrope. La présente étude vise à fournir des données importantes sur le comportement rhéologique global de ces systèmes et leurs propriétés, grâce à la caractérisation d'un verre nucléaire simulé contenant 3,0 % massique (1,02 % en volume) de platinoïdes. Une modélisation mathématique du comportement thixotrope de ce verre est présentée pour la première fois en utilisant un modèle similaire à celui proposé par Houska (Houska, 1981). Ce modèle prédictif permet la description des résultats expérimentaux obtenus à partir de mesures en régimes permanent et transitoire. L'impact de la contrainte de cisaillement et du temps sur le degré d'agrégation et la cinétique de sédimentation des particules est déterminé à l'aide d'un rhéomètre à contrainte imposée opéré à haute température et d'analyses d'images obtenues par microscopie électronique à balayage (MEB). Pour la première fois, l'interaction entre le comportement rhéologique du système et le degré d'agrégation est analysé, tout comme le lien avec la sédimentation des particules. Sur la base des données expérimentales acquises, un calcul d'équilibre des forces est réalisé pour illustrer les différents scénarios d'agrégation. Ce travail fournit des nouvelles données pour la modélisation et le contrôle du processus de vitrification
In France, borosilicate glass is used as a matrix to immobilize nuclear fission products resulting from spent fuel reprocessing. In the high-temperature vitrification process (1200 °C), most of elements to be contained react chemically with the vitrification additives to form a homogeneous glass melt. Platinum Group Metal (PGM) particles are not soluble in the melt and therefore are present as suspended particles of few microns. These particles exhibit an intense aggregation tendency and consequently the suspensions may present an anomalously high apparent viscosity. These systems are characterized by a shear-thinning and a thixotropic behaviors. The present study aims to provide important inputs for the overall rheological behavior of this system and its features through the characterization of a simulated nuclear glass melt containing 3.0 wt% (1.02 vol%) of PGM particles. A mathematical modeling of the thixotropic behavior of glass melts containing PGM particles is presented for the first time using a model similar to that proposed by Houska (Houska, 1981). This predictive model allow to describe experimental results obtained both in steady state and transient conditions. The impact of the shear stress and time on PGM aggregation degree and sedimentation kinetics is determined using an imposed-stress rheometer at high temperature and imaging analyses via Scanning Electron Microscopy (SEM). For the first time, the interplay between the rheological behavior of the system and the aggregation degree is provided, as well as the link with the particles settling. Based on the acquired experimental data, a force balance computation is executed to illustrate the different aggregation scenarios. The work provides a new input for the modeling and control of the vitrification process
3

Alshana, Usama Ahmed. "Separation And Quantitation Of Some Platinum Group Metals By Rp-hplc." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/3/12605760/index.pdf.

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In this study, a reversed-phase high performance liquid chromatography (RP-HPLC) method has been developed to separate and determine Pt and Pd after formation of their chelates with N,N-diethyl-N'
-benzoylthiourea (DEBT). With the aim of reducing the number of steps in treating the samples, the method developed does not require the elimination of excess chelating reagent before the analysis of metal chelates. The different physical and chemical parameters affecting separation were examined in details. The whole analysis was completed on a C18 column in 16 min at 280 nm, with the mobile phase of acetonitrile-methanol-water (80:10:10, v:v:v) containing 0.20 mol l-1 pH 5.0 acetate buffer at a flow rate of 0.8 ml min-1. Detection limits of the method, based on 3s, were found as 14.2 ug l-1 for Pd and 0.77 mg l-1 for Pt using a 20-ul sample loop. Reproducibility of the method for ten repeated measurements was found as 2.36 % for 0.60 mg l-1 Pd and 2.58 % for 10.0 mg l-1 Pt as % RSD. The proposed method is a rapid, simple and highly selective method for the simultaneous determination of Pt and Pd by HPLC without the need for any interference elimination process.
4

Kriek, R. J. "Leaching of selected PGMs : a thermodynamic and electrochemical study employing less aggressive lixiviants." Master's thesis, University of Cape Town, 2008. http://hdl.handle.net/11427/5611.

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Historically the platinum group metals (PGMs) have been, and are still being dissolved by means of rather aggressive methods, e.g. aqua regia. Limited research has been conducted into the dissolution of the PGMs using different oxidizing agents. The dissolution of gold on the other hand has been afforded extensive research, and numerous papers and review articles have been published on the subject. The last number of years has seen the biggest application by volume of the PGMs as part of autocatalysts towards the degradation of harmful motor vehicle exhaust gases. This has subsequently sparked research into the recovery of specifically platinum, palladium, and rhodium from spent autocatalysts. Currently pyrometallurgical recovery of PGMs is being employed predominantly. A hydrometallurgical process on the other hand is, based on current technology, still a rather aggressive process that makes for high maintenance costs and an unpleasant environment. Gold has traditionally been dissolved by making use of cyanide, which is still the major route for gold dissolution. Due to environmental concerns lixiviants such as thiosulphate (S2O3 2-), thiourea (H2NCSNH2), and thiocyanate (SCN-) are gaining acceptance due to them being more environmentally friendly and giving good recoveries. These ‘softer’ alternatives have however not been tested on the PGMs. It is therefore the aim of this study to obtain an improved understanding of the leaching of the PGMs using lixiviants less aggressive than aqua-regia. These lixiviants include (i) SCN-, (ii) S2O3 2-, (iii) H2NCSNH2, and (iv) AlCl3/HCl. A thermodynamic study highlighted the fact that thermodynamic data for platinum-, palladium- and rhodium complexes are basically non-existent. To therefore obtain a clearer thermodynamic understanding of the leaching of the platinum group metals by means of these alternative lixiviants, future detailed speciation and thermodynamic investigations need to be conducted. An exploratory electrochemical investigation focusing on open circuit potentials and potentiodynamic scans, showed AlCl3 / HCl / NaOCl to be a good candidate for the leaching of the platinum group metals followed by SCN- / Fe3+ and CS(NH2)2 / Fe3+. Actual leach results, employing virgin autocatalysts as sample material, again highlighted the potential of AlCl3 / HCl / NaOCl as being a good lixiviant system. The surprise package, however, has been SCN- / Fe3+ that rendered very good results for Pd and Pt.
5

Aiglsperger, Thomas Hans. "Mineralogy and geochemistry of the platinum group elements (PGE), rare earth elements (REE) and scandium in nickel laterites." Doctoral thesis, Universitat de Barcelona, 2015. http://hdl.handle.net/10803/396340.

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Ni laterites are considered worthy targets for critical metals (CM) exploration as rare earth elements (REE), Sc and platinum group elements (PGE) can be concentrated during weathering as a result of residual and secondary enrichment. In this investigation geochemical and mineralogical data of CM from two different nickel laterite types (i) from the Moa Bay mining area in Cuba (oxide type) and (ii) from the Falcondo mining area in the Dominican Republic (hydrous Mg silicate type) are presented. Emphasis is given on examining their potential to accumulate CM and on processes involved. Results show that CM are concentrated towards the surface in specific zones: (i) REE in clay minerals rich horizons and within zones composed of secondary Mn oxide(s) (ii) Sc within zones rich in secondary Fe and Mn bearing oxide(s) and (iii) PGE in zones with high concentrations of residual chromian spinel and secondary Fe and Mn bearing oxide(s) at upper levels of the Ni laterite profiles. Concentration factors involve (i) residual enrichment by intense weathering (ii) mobilization of CM during changing Eh and pH conditions with subsequent reprecipitation at favourable geochemical barriers (iii) interactions between biosphere and limonitic soils at highest levels of the profile (critical zone) with involved neoformation processes. Total contents of CM in both Ni laterite types are low when compared with conventional CM ore deposits but are of economic significance as CM have to be seen as cost inexpensive by-products during the Ni (+Co) production. Innovative extraction methods currently under development are believed to boost the significance of Ni laterites as future unconventional CM ore deposits. Two Ni laterite profiles from the Falcondo mining area have been compared for their platinum group element (PGE) geochemistry and mineralogy. One profile (Loma Peguera) is characterized by PGE-enriched (up to 3.5 ppm total PGE) chromitite bodies incorporated within the saprolite, whereas the second profile is chromitite-free (Loma Caribe). Total PGE contents of both profiles slightly increase from parent rocks (36 and 30 ppb, respectively) to saprolite (-50 ppb) and reach highest levels within the limonite zone (640 and 264 ppb, respectively). Chondrite-normalized PGE patterns of saprolite and limonite reveal rather flat shapes with positive peaks of Ru and Pd. Three types of platinum group minerals (PGM) were found by using an innovative hydroseparation technique: (i) primary PGM inclusions in fresh Cr-spinel (laurite and bowieite), (ii) secondary PGM (e.g., Ru-Fe-Os-Ir compounds) from weathering of preexisting PGM (e.g., serpentinization and/or laterization), and (iii) PGM precipitated after PGE mobilization within the laterite (neoformation). Results provide evidence that (i) PGM occurrence and PGE enrichment in the laterite profiles is independent of chromitite incorporation; (ii) PGE enrichment is residual on the profile scale; and (iii) PGE are mobile on a local scale leading to in situ growth of PGM within limonite, probably by bioreduction and/or electrochemical metal accretion. Free grains of PGM with delicate morphologies were discovered in limonite hosted chromitite samples (“floating chromitites”) from highest levels in the Falcondo Ni laterite deposit (Dominican Republic). Textural and chemical evidence obtained via SEM and EMP analysis points to a multistage formation: (i) primary PGM formation at magmatic stage; (ii) transformation to highly porous secondary Os-Ru PGM during serpentinization; (iii) neoformation of Ir-Fe-Ni-(Pt) mineral phases during early stages of lateritization; (iv) neoformation of Pt-(Ir) mineral phases within the critical zone of the profile resulting in nugget shaped accumulation of rounded particulates during late stages of lateritization. The observation of accumulations of most likely biogenic mediated in situ growth of Pt rich nanoparticles in supergene environments could help to explain (i) why Pt bearing nuggets are the most abundant PGM found in surface environments, (ii) why Pt nuggets from placer deposits generally surpass the grain sizes of Pt grains found in parent rocks by several orders of magnitude (few micrometers vs. several millimeters) and (iii) how anthropogenic PGE contamination may affect our biosphere. Osmium chromitite, saprolite and limonite (Falcondo mining area), suggest that serpentinization of the Loma Caribe peridotite has not significantly affected the Re-Os system in Os-rich PGM. This is noted by the fact, that primary PGM formed at magmatic stage and secondary Ru-Os-Mg- isotope characteristics from primary and secondary PGM, separated from Si PGM formed due desulphurization of primary PGM with significant incorporation of Mg silicates, have almost identical Os isotope characteristics, typical of the mantle. However, the Re-Os system can be significantly disturbed during stages of lateritization when porous secondary PGM react with Fe-rich fluids, thus forming hexaferrum and magnetite in the 187 188 interstices of secondary PGM. Here presented data indicate that more radiogenic ratios in higher levels of the weathering profile are linked to steady mobilization of PGE within secondary PGM resulting in subsequent loss of Os counterbalanced by the incorporation of Fe. Os/ Os In this investigation presented data clearly states that PGE are neither noble nor inert in surface environments, at least in those related to tropical Ni laterites from the Northern Caribbean.
6

Van, der Horst Charlton. "Development of a bismuth-silver nanofilm sensor for the determination of platinum group metals in environmental samples." University of the Western Cape, 2015. http://hdl.handle.net/11394/4451.

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Philosophiae Doctor - PhD
Nowadays, the pollution of surface waters with chemical contaminants is one of the most crucial environmental problems. These chemical contaminants enter rivers and streams resulting in tremendous amount of destruction, so the detection and monitoring of these chemical contaminants results in an ever-increasing demand. This thesis describes the search for a suitable method for the determination of platinum group metals (PGMs) in environmental samples due to the toxicity of mercury films and the limitations with methods other than electroanalytical methods. This study focuses on the development of a novel bismuth-silver bimetallic nanosensor for the determination of PGMs in roadside dust and soil samples. Firstly, individual silver, bismuth and novel bismuth-silver bimetallic nanoparticles were chemically synthesised. The synthesised nanoparticles was compared and characterised by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), ultraviolet-visible spectroscopy (UV-Vis), Fourier-transformed infrared spectroscopy (FT-IR), Raman spectroscopy, and transmission electron microscopy (TEM) analysis to interrogate the electrochemical, optical, structural, and morphological properties of the nanomaterials. The individual silver, bismuth, and bismuth-silver bimetallic nanoparticles in the high resolution transmission electron microscopy results exhibited an average particle size of 10-30 nm. The electrochemical results obtained have shown that the bismuth-silver bimetallic nanoparticles exhibit good electro-catalytic activity that can be harnessed for sensor construction and related applications. The ultraviolet-visible spectroscopy, Fourier-transformed infrared spectroscopy, and Raman spectroscopy results confirmed the structural properties of the novel bismuth-silver bimetallic nanoparticles. In addition the transmission electron microscopy and selected area electron diffraction morphological characterisation confirmed the nanoscale nature of the bismuth-silver bimetallic nanoparticles. Secondly, a sensitive adsorptive stripping voltammetric procedure for palladium, platinum and rhodium determination was developed in the presence of dimethylglyoxime (DMG) as the chelating agent at a glassy carbon electrode coated with a bismuth-silver bimetallic nanofilm. The nanosensor further allowed the adsorptive stripping voltammetric detection of PGMs without oxygen removal in solution. In this study the factors that influence the stripping performance such as composition of supporting electrolyte, DMG concentration, deposition potential and time studies, and pH have been investigated and optimised. The bismuth-silver bimetallic nanosensor was used as the working electrode with 0.2 M acetate buffer (pH = 4.7) solution as the supporting electrolyte. The differential pulse adsorptive stripping peak current signal was linear from 0.2 to 1.0 ng/L range (60 s deposition), with limit of detections for Pd (0.19 ng/L), Pt (0.20 ng/L), Rh (0.22 ng/L), respectively. Good precision for the sensor application was also obtained with a reproducibility of 4.61% for Pd(II), 5.16% for Pt(II) and 5.27% for Rh(III), for three measurements. Investigations of the possible interferences from co-existing ions with PGMs were also done in this study. The results obtained for the study of interferences have shown that Ni(II) and Co(II) interfere with Pd(II), Pt(II) and Rh(III) at high concentrations. The interference studies of Cd(II), Pb(II), Cu(II) and Fe(III) showed that these metal ions only interfere with Pd(II) and Pt(II) at high concentrations, with no interferences observed for Rh(III). Phosphate and sulphate only interfere at high concentrations with Pt(II) and Rh(III) in the presence of DMG with 0.2 M acetate buffer (pH = 4.7) solution as the supporting electrolyte. Based on the experimental results, this bismuth-silver bimetallic nanosensor can be considered as an alternative to common mercury electrodes, carbon paste and bismuth film electrodes for electrochemical detection of PGMs in environmental samples. Thirdly, this study dealt with the development of a bismuth-silver bimetallic nanosensor for differential pulse adsorptive stripping voltammetry (DPAdSV) of PGMs in environmental samples. The nanosensor was fabricated by drop coating a thin bismuth-silver bimetallic film onto the active area of the SPCEs. Optimisation parameters such as pH, DMG concentration, deposition potential and deposition time, stability test and interferences were also studied. In 0.2 M acetate buffer (pH = 4.7) solution and DMG as the chelating agent, the reduction signal for PGMs ranged from 0.2 to 1.0 ng/L. The detection limit for Pd(II), Pt(II) and Rh(III) was found to be 0.07 ng/L, 0.06 ng/L and 0.2 ng/L, respectively. Good precision for the sensor application was also obtained with a reproducibility of 7.58% for Pd(II), 6.31% for Pt(II) and 5.37% for Rh(III), for three measurements. In the study of possible interferences, the results have shown that Ni(II), Co(II), Fe(III), Na+, SO42- and PO43- does not interfere with Pd(II) in the presence of DMG with sodium acetate buffer as the supporting electrolyte solution. These possible interference ions only interfere with Pt(II) and Rh(III) in the presence of DMG with 0.2 M acetate buffer (pH = 4.7) as the supporting electrolyte solution.
7

Necib, Ammour Ouarda. "Effect of platinum group metal (PGM) additions on the stress corrosion cracking resistance of type 304 stainless steel in pressurised water reactors." Thesis, University of Manchester, 2010. https://www.research.manchester.ac.uk/portal/en/theses/effect-of-platinum-group-metal-pgm-additions-on-the-stress-corrosion-cracking-resistance-of-type-304-stainless-steel-in-pressurised-water-reactors(d7578933-6268-4fe8-819e-7b9b066f5c2e).html.

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In pressurised water reactors (PWRs), hydrogen overpressure is used to keep the corrosion potential below the threshold for onset of intergranular stress corrosion cracking (IGSCC) in type 304 SS. However, some regions may contain higher oxygen levels resulting in an increase in the potential. These 'dead space' regions are difficult to access and during refuelling; oxygen may become trapped in these locations. The objective of this study was to investigate the influence of PGM additions on IGSCC susceptibility of type 304 stainless steels (SS) in the sensitised state within PWRs. The work presented herein investigates several aspects of the IGSCC problem. Virgin and platinum group metal (PGM)-modified (Ru and Pd) 304 SS have been studied. Material characterisation, including microstructural, tensile properties, hardness and grain size measurements, has been conducted. Crack initiation studies using U-bend samples in autoclaves simulating PWR environments have also been performed. In addition, crack propagation studies using circumferential cracked bar (CCB) specimens under constant extension in potassium tetrathionate solutions, a well-known medium to promote IGSCC on sensitised stainless steels, have been conducted in order to evaluate cracking resistance. Electrochemical studies using model solutions for PWR chemistry (containing boric acid and lithium hydroxide) and also potassium tetrathionate were carried out to look at the influence of the PGM on the kinetics of the main electrochemical reactions. The results revealed that PGM additions appeared to reduce crack initiation on sensitised type 304 SS under oxygenated conditions in high temperature water containing sulphate and chloride. PGM-doped and standard sensitised type 304 stainless steels revealed susceptibility to IGSCC propagation in 0.01 M K2S4O6, at pH=1.5 and 25°C. Electrochemical studies in potassium tetrathionate media showed smaller anodic dissolution peaks with PGM additions and metallography indicated less intergranular attack with PGM additions. In PWR model electrolytes, PGM additions, particularly 1 wt% Ru, were shown to catalyse the oxygen reduction reaction or hydrogen oxidation reaction, depending on the oxygen /hydrogen level. Overall findings showed that Ru additions can improve the IGSCC resistance of sensitised type 304 SS in PWR, while Pd additions are less effective.
8

Sýkora, Jiří. "Využití iontoměničů pro prekoncentraci platinových kovů." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2017. http://www.nusl.cz/ntk/nusl-295670.

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The aim of this thesis is the elaboration of a detailed literature review on the use of ion exchangers for the preconcentration of platinum group metals. This work contains an actual literature review on this issue. In this work you will find information about the current occurrence of platinum metals in the environment, their impact on health, properties, resources and the use. There are also described ways of decomposition, extraction and use of ion exchangers. In the experimental part this thesis deals with optimization of ion exchangers and following application of real samples from the city of Brno.
9

Gxoyiya, Babalwa Siliziwe Blossom. "Synthesis and evaluation of PGM-selective ligands." Thesis, Rhodes University, 2013. http://hdl.handle.net/10962/d1007849.

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A series of polydentate POM-selective, sulfur-containing amide ligands have been synthesized from ro-dibromoalkanes and mercaptoacetanilide, The resulting 3,6- dithiaoctanediamides and 3,7-dithianonanediamides, some of which contain a polymerisable group, were all characterized by high-resolution MS, IR, I Hand I3C NMR spectroscopic methods. Various approaches to the polymerisable ligands were explored, the most efficient proving to be the incorporation of an allyl ether moiety in the mercaptoacetanilide. The corresponding Pd(U) and Pt(II) complexes were also prepared from the metal chloride salts and characterized by elemental analysis and spectroscopic methods. The NMR data indicates that both the cis- and transcomplexes were formed, while the IR data indicates cis- coordination of the chlorine . ligands. Molecularly imprinted polymers (MIP's), prepared using platinum(II) mercaptoacetanilide and 3,6-dithiadiamide complexes, showed high selectivity for , , palladium(II) [in the presence of Pt(II), CoCII), Cu(II) and Ni(II)] as determined by . ICP-MS analysis. The more kinetically inert Pt(II) ions however, slowly displaced Pd(II), confirming the Pt(II) selectivity of the MIP's. Solvent extraction studies were conducted to explore the selectivity of the 3,6- dithiaoctanediamides and 3,7-dithianonanediamides for Pd(U) over CoCII), Cu(U) and Ni(II). The ICP-MS data indicate that, in general, equilibration was achieved within ten minutes and that the longer-chain amides were less selective than the shorter-chain analogues.
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Caddy, Irene. "A platinum life cycle assessment : potential benefits to Anglo Platinum / I. Caddy." Thesis, North-West University, 2011. http://hdl.handle.net/10394/6279.

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There has been an increased awareness of the inter-dependence between man and the environment since the 1960’s. Environmental awareness has evolved from representing fairly radical views opposing all development, to a current emphasis on sustainable development between development and the environment. Life Cycle Assessment (LCA) is defined as the identification and quantification of the environmental impacts of a product, process or service during the entire life cycle being studied. The life cycle starts at the extraction of raw materials and the production of energy used to create the product through the use and final disposal of the product. LCA therefore considers the production, use and disposal of a product, which constitutes the life cycle of the product. LCA can be combined with methodologies that study other parameters such as costs in order to optimise the benefits from LCA. It is suggested that cost implications of processes to reduce environmental impacts should be included in a methodology used for a Platinum LCA. A comment that is consistently raised in the case studies is that the minerals industry regards LCA as an effective tool to determine the impacts of the industry, however extraction & beneficiation of minerals are often grouped together, with accurate data not being available, and databases either not available or not updated. The case studies indicated several benefits from the various LCA’s conducted. A Platinum LCA should clearly define and group the environmental impacts being studied into categories such as greenhouse gas emissions, global warming, acidification, and resource consumption. A Platinum LCA will be resource- and time intensive due to the large scale of the processes involved. It is suggested that a Platinum LCA firstly focuses on the production phase, i.e. cradle-to-gate, with potential future work done on the use and end-of-life stages. It is suggested that individual facility-based LCA’s for AMPLATS and other platinum producers are conducted in order to get a true reflection of the environmental burden of each company, and then selectively share technological improvements to reduce the environmental burden without disclosing sensitive information. The benefit of LCA in the case of platinum will be optimised if it can be used to make business decisions, together with consideration of financial and production benefits in addition to anticipated environmental benefits of alterations to processes. It is essential that LCA is seen as a business tool that will assist the company to make informed business decisions about process improvements, as well as new projects and design of new facilities. LCA on its own will not determine which product or process is the most cost effective or works best. The information developed in a LCA study should be used as one component of a more comprehensive decision making process assessing the trade-offs with cost and performance. The results from a LCA could be used to make informed decisions about optimisation between costs and reduced environmental impacts.
Thesis (M. Environmental Management)--North-West University, Potchefstroom Campus, 2011.
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Книги з теми "Platinum Group Metals (PGM)":

1

Loebenstein, J. Roger. Platinum-group metals. [Washington, D.C.?]: Bureau of Mines, U.S. Dept. of the Interior, 1985.

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Loebenstein, J. Roger. Platinum-group metals. [Washington, D.C.?]: Bureau of Mines, U.S. Dept. of the Interior, 1985.

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Loebenstein, J. Roger. Platinum-group metals. [Washington, D.C.?]: Bureau of Mines, U.S. Dept. of the Interior, 1985.

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4

Loebenstein, J. Roger. Platinum-group metals. [Washington, D.C.?]: Bureau of Mines, U.S. Dept. of the Interior, 1985.

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Loebenstein, J. Roger. Platinum-group metals. [Washington, D.C.?]: Bureau of Mines, U.S. Dept. of the Interior, 1985.

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6

Fogg, Catharine T. Availability of platinum and platinum-group metals. Washington, D.C: U.S. Dept. of the Interior, Bureau of Mines, 1993.

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Black, William. The international platinum group metals trade. Boca Raton, FL: CRC Press, 1999.

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8

Services, Roskill Information. The economics of platinum group metals. 6th ed. London: Roskill Information Services, 1999.

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9

Athayde, P. Platinum-group metals in Manitoba: An inventory. Winnipeg, Man: Manitoba Energy and Mines, Mines Branch, 1989.

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Athayde, P. Platinum-group metals in Manitoba: An inventory. Winnipeg: Manitoba Energy and Mines, Mines Branch, 1989.

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Частини книг з теми "Platinum Group Metals (PGM)":

1

Panda, Rekha, Manis Kumar Jha, and D. D. Pathak. "Commercial Processes for the Extraction of Platinum Group Metals (PGMs)." In Rare Metal Technology 2018, 119–30. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-72350-1_11.

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2

Gunn, Gus. "Platinum-group metals." In Critical Metals Handbook, 284–311. Oxford: John Wiley & Sons, 2013. http://dx.doi.org/10.1002/9781118755341.ch12.

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3

Gasparrini, Claudia. "Platinum Group Elements." In Gold and Other Precious Metals, 193–203. Berlin, Heidelberg: Springer Berlin Heidelberg, 1993. http://dx.doi.org/10.1007/978-3-642-77184-2_10.

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4

Bernfeld, G. J., A. J. Bird, R. I. Edwards, Hartmut Köpf, Petra Köpf-Maier, Christoph J. Raub, W. A. M. te Riele, Franz Simon, and Walter Westwood. "High Purity Platinum-Group Metals." In Pt Platinum, 24–65. Berlin, Heidelberg: Springer Berlin Heidelberg, 1985. http://dx.doi.org/10.1007/978-3-662-10278-7_2.

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Bernfeld, G. J., A. J. Bird, R. I. Edwards, Hartmut Köpf, Petra Köpf-Maier, Christoph J. Raub, W. A. M. te Riele, Franz Simon, and Walter Westwood. "Electrodeposition of the Platinum-Group Metals." In Pt Platinum, 66–91. Berlin, Heidelberg: Springer Berlin Heidelberg, 1985. http://dx.doi.org/10.1007/978-3-662-10278-7_3.

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6

Bernfeld, G. J., A. J. Bird, R. I. Edwards, Hartmut Köpf, Petra Köpf-Maier, Christoph J. Raub, W. A. M. te Riele, Franz Simon, and Walter Westwood. "Platinum-Group Metals, Alloys and Compounds in Catalysis." In Pt Platinum, 92–317. Berlin, Heidelberg: Springer Berlin Heidelberg, 1985. http://dx.doi.org/10.1007/978-3-662-10278-7_4.

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7

Bernfeld, G. J., A. J. Bird, R. I. Edwards, Hartmut Köpf, Petra Köpf-Maier, Christoph J. Raub, W. A. M. te Riele, Franz Simon, and Walter Westwood. "Review on the Recovery of the Platinum-Group Metals." In Pt Platinum, 1–23. Berlin, Heidelberg: Springer Berlin Heidelberg, 1985. http://dx.doi.org/10.1007/978-3-662-10278-7_1.

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8

Leung, Chi-Hung. "Arcing Contact Materials, Platinum-Group Metals." In Encyclopedia of Tribology, 99–100. Boston, MA: Springer US, 2013. http://dx.doi.org/10.1007/978-0-387-92897-5_398.

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9

Mafukata, Mavhungu Abel. "The Impact of the 2008–2009 Global Financial Crisis on Employment Creation and Retention in the Platinum Group Metals (PGMs) Mining Sub-sector in South Africa." In Contributions to Economics, 569–85. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-47021-4_39.

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10

Oliveira, Leiva Casemiro, Antonio Marcus Nogueira Lima, Carsten Thirstrup, and Helmut Franz Neff. "Noble Transition Metals of the Platinum Group." In Surface Plasmon Resonance Sensors, 111–53. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-17486-6_7.

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Тези доповідей конференцій з теми "Platinum Group Metals (PGM)":

1

Zelyakh, Ya D., R. S. Voinkov, K. L. Timofeev, and G. I. Maltsev. "DETERMINATION OF PRETREATMENT EFFECT ON MICROSTRUCTURE OF POLYCOMPONENT RAW MATERIALS CONTAINING PRECIOUS METALS." In XVI INTERNATIONAL CONFERENCE "METALLURGY OF NON-FERROUS, RARE AND NOBLE METALS" named after corresponding member of the RAS Gennady Leonidovich PASHKOVA. Krasnoyarsk Science and Technology City Hall, 2023. http://dx.doi.org/10.47813/sfu.mnfrpm.2023.275-287.

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In today’s context, platinum metals are becoming increasingly important in such areas as automotive industry, electrical engineering, medicine, etc. The number of metals extracted from raw materials is becoming smaller, and they are often difficult to obtain. For JSC «Uralelektromed» platinum group metals (PGM) are byelements in copper electrolytic slime, which is sent for smelting to produce silver-gold alloy (Ag-Au alloy), with Dore alloy being further refined.
2

Borisov, R. V., O. V. Belousov, N. V. Belousova, and A. A. Akimenko. "DISSOLUTION OF PLATINUM GROUP METALS IN AN AUTOCLAVE." In XVI INTERNATIONAL CONFERENCE "METALLURGY OF NON-FERROUS, RARE AND NOBLE METALS" named after corresponding member of the RAS Gennady Leonidovich PASHKOVA. Krasnoyarsk Science and Technology City Hall, 2023. http://dx.doi.org/10.47813/sfu.mnfrpm.2023.339-346.

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Platinum metals (PGMs) find wide practical application in high-tech areas and allow solving a number of economic and environmental problems. Under normal conditions, platinum metals are thermodynamically stable and resistant to the action of mineral acids and alkalis. On the other hand, a feature of PGMs and their compounds is the kinetic inhibition of processes involving them. The constant growth in the consumption of precious metals requires solving the problems of their highly efficient extraction from primary ores and concentrates, secondary raw materials, which are mainly represented by spent catalysts and electronic scrap. Processing is carried out using pyro- and hydrometallurgical methods. Modern hydrometallurgical technologies for the processing of precious metals are most preferable due to their greater environmental friendliness compared to pyrometallurgical processes. The most efficient transfer of platinum group metals into solution can be carried out at elevated temperatures and pressures, which makes it possible to remove kinetic difficulties. To do this, autoclaves are used, the use of which does not lead to losses and contamination with impurities of valuable metals, makes it possible to intensify the processes of dissolution and reduce the environmental burden on the environment. Unfortunately, despite the rapid development of autoclave technologies, there are few studies on the dissolution of pure metals under autoclave conditions. At the same time, the establishment of the mechanism and factors influencing the process of dissolution of metals will make it possible to develop and optimize existing schemes for processing platinum-containing raw materials.
3

Titova, A. N., and T. Y. Kositskaya. "STUDY OF HYDROMETALLURGICAL METHOD OF PROCESSING MAGNETIC FRACTION OF MATTE." In XVI INTERNATIONAL CONFERENCE "METALLURGY OF NON-FERROUS, RARE AND NOBLE METALS" named after corresponding member of the RAS Gennady Leonidovich PASHKOVA. Krasnoyarsk Science and Technology City Hall, 2023. http://dx.doi.org/10.47813/sfu.mnfrpm.2023.328-338.

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The magnetic fraction is one of the components of converter matte formed during pyrometallurgical processing of sulfide copper-nickel feedstock. This intermediate product is formed from the melt during its cooling/hardening and collects in itself up to 90 % of noble metals, among which platinum group metals (PGM) are of primary importance. The relatively high content of precious metals makes it especially important to find ways to reduce losses of these metals, as well as to reduce the volume of unfinished production. One of such directions is the withdrawal of the magnetic fraction (MF) of the highgrade matte from the pyrometallurgical processing and its processing in a separate hydrometallurgical cycle.
4

Pokhitonov, Yu, V. Romanovski, and P. Rance. "Distribution of Palladium During Spent Fuel Reprocessing." In ASME 2003 9th International Conference on Radioactive Waste Management and Environmental Remediation. ASMEDC, 2003. http://dx.doi.org/10.1115/icem2003-4766.

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The principal purpose of spent fuel reprocessing consists in the recovery of the uranium and plutonium and the separation of fission products so as to allow re-use of fissile and fertile isotopes and facilitate disposal of waste elements. Amongst the fission products present in spent nuclear fuel of Nuclear Power Plants (NPPs,) there are considerable quantities of platinum group metals (PGMs): ruthenium, rhodium and palladium. Given current predictions for nuclear power generation, it is predicted that the quantities of palladium to be accumulated by the middle of this century will be comparable with those of the natural sources, and the quantities of rhodium in spent nuclear fuel may even exceed those in natural sources. These facts allow one to consider spent nuclear fuel generated by NPPs as a potential source for creation of a strategic stock of platinum group metals. Despite of a rather strong prediction of growth of palladium consumption, demand for “reactor” palladium in industry should not be expected because it contains a long-lived radioactive isotope 107Pd (half-life 6,5·105 years) and will thus be radioactive for a very considerable period, which, naturally, restricts its possible applications. It is presently difficult to predict all the areas for potential use of “reactor” palladium in the future, but one can envisage that the use of palladium in radwaste reprocessing technology (e.g. immobilization of iodine-129 and trans-plutonium elements) and in the hydrogen energy cycle may play a decisive role in developing the demand for this metal. Realization of platinum metals recovery operation before HLW vitrification will also have one further benefit, namely to simplify the vitrification process, because platinum group metals may in certain circumstances have adverse effects on the vitrification process. The paper will report data on platinum metals (PGM) distribution in spent fuel reprocessing products and the different alternatives of palladium separation flowsheets from HLW are presented. It is shown, that spent fuel dissolution conditions can affect the palladium distribution between solution and insoluble precipitates. The most important factors, which determine the composition and the yield of residues resulting from fuel dissolution, are the temperature and acid concentration. Apparently, a careful selection of fuel dissolution process parameters would make it possible to direct the main part of palladium to the 1st cycle raffinate together with the other fission products. In the authors’ opinion, the development of an efficient technology for palladium recovery requires the conception of a suitable flow-sheet and the choice of optimal regimes of “reactor” palladium recovery concurrently with the resolution of the problem of HLW partitioning when using the same facilities.
5

Zhuang, Shiqiang, Xuan Shi, and Eon Soo Lee. "A Review on Non-PGM Cathode Catalysts for Polymer Electrolyte Membrane (PEM) Fuel Cell." In ASME 2015 13th International Conference on Fuel Cell Science, Engineering and Technology collocated with the ASME 2015 Power Conference, the ASME 2015 9th International Conference on Energy Sustainability, and the ASME 2015 Nuclear Forum. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/fuelcell2015-49602.

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In recent years, people attach high attention to the energy problem owing to the energy shortage of the world. Since the price of energy resources significantly increases, it is a necessary requirement to develop new alternative sources of energy to replace non-renewable energy resources. Polymer electrolyte membrane (PEM) fuel cell technology is one of the promising fields of clean and sustainable power, which is based on direct conversion of fuel into electricity. However, at the present moment PEM fuel cell is unable to be successful commercialization. The main factor is the high cost of materials in catalyst layer which is a core part of PEM fuel cell. In order to reduce the overall system cost, developing active, inexpensive non-platinum group metal (non-PGM) electrode catalysts to replace currently used Platinum (Pt)-based catalysts is a necessary and essential requirement. This paper reviews several important kinds of non-PGM electro-catalysts with different elements, such as nitrogen, transition metal, and metal organic frameworks (MOF). Among these catalysts, transition metal nitrogen-containing complexes supported on carbon materials (M-N/C) are considered the most potential oxidation reduction reaction (ORR) catalysts. The main synthetic methods are high temperature heat treating (800–1000°C). The mechanical and electrochemical properties of the final product will be analyzed by several characterization methods. For example, a RRDE test will be used to measure electron transfer number and ORR reactivity, which are the most important electrochemical properties of the new catalyst. And the morphology, particle size, crystal phase and specific surface area can be analyzed with SEM, TEM, XRD and BET methods. Although great improvement has been achieved in non-PGM catalyst area of research, there are still some challenges in both ORR activity and stability of non-PGM catalysts. Consequently, how to improve the ORR activity and stability are the major challenge of non-PGM catalyst research and development. Based on the results achieved in this area, our future research direction is also presented and discussed in this paper.
6

King, Erica, David Wallace, and E. Robert Becker. "Strategies Toward the Sustainable and Cost-Effective Use of the Platinum Group Metals: An Analysis of Critical Topics Affecting the PGM and Automotive Industries." In SAE 2014 World Congress & Exhibition. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 2014. http://dx.doi.org/10.4271/2014-01-1502.

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7

Pozo Zamora, Guillermo. "Selective recovery of platinum group metals (PGMs) from spent autocatalyst using deep eutectic solvents (DES)." In 15th Mediterranean Congress of Chemical Engineering (MeCCE-15). Grupo Pacífico, 2023. http://dx.doi.org/10.48158/mecce-15.t2-o-09.

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8

Chen, Jian, Xuhua Wang, and Yi Liu. "Emission Control on a Dual Model Hybrid Passenger Car to Meet China 6 Legislation." In WCX SAE World Congress Experience. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 2024. http://dx.doi.org/10.4271/2024-01-2444.

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<div class="section abstract"><div class="htmlview paragraph">With the increasing number of hybrid vehicles in the Chinese market, research on aftertreatment systems for hybrid vehicles has become very popular. China has currently implemented national on-road China 6 regulations for emission control of all gasoline and diesel vehicles, including hybrid ones. So far, there are few papers on the optimization of aftertreatment for hybrid gasoline vehicles. Due to the introduction of electric motors in hybrid vehicles, the engine starts frequently and leads to inconsistent stability of engine operating conditions and brings the challenge to emission control of engine exhaust. This article selects a highly popular hybrid gasoline vehicle in China for research, which is a dual-mode hybrid (DM hybrid) passenger car. There is an obvious correlation between the emissions between the driving pattern and the hybrid strategy. The catalyst temperature is the main influencing factor on the performance of TWC catalysts, while the higher exhaust temperature brings the better conversion efficiency of pollutants. Since less thermal energy is needed to heat up the low mass substrate, the light-off performance of catalyst with same platinum group metals (PGM) loading is achieved earlier. As applied in the DM hybrid vehicle aftertreatment system, the low mass substrate can achieve 10~30% better performance in gaseous emissions reduction on China VI regulated cycle, Worldwide Harmonized Light Vehicles Test Cycle (WLTC), compared to the standard substrate both for fresh and aged catalyst samples. The catalyst coated on low mass substrate also enabled good Real Driving Emissions (RDE) result to meet China 6b.</div></div>
9

Willsey, Aliza M., Thomas S. Welles, and Jeongmin Ahn. "Advancements in Nitric Oxide Emission Control With a Perovskite Based Membrane via High Frequency Electric Potential Oscillations." In ASME 2022 Power Conference. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/power2022-85154.

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Abstract Increased concerns over climate change, limited fossil fuel resources, emissions, and poor air quality has created a greater need for sustainable energy systems. The need for increased sustainable energy systems has created largely two cooperative movements: 1) technologies that are considered renewable or more environmentally friendly and 2) higher efficiency. The automotive industry has long been a target for increasing efficiency and decreasing environmentally harmful emissions. The combustion of hydrocarbon fuels results in harmful and reactive incomplete combustion byproducts. Fully electric and hybrid powertrains are increasing in commonality but have not yet fully penetrated the market. Many automobile manufacturers are still producing vehicles which rely solely on the internal combustion engine and hydrocarbon-based fuels. Currently, manufacturers utilize a combination of three-way catalytic converters and nitrogen oxide traps to rid the exhaust flow of harmful combustion emissions. Catalytic converters use expensive precious platinum group metals (PGM) to simultaneously react unwanted hydrocarbon, carbon monoxide, and nitrogen oxides into less harmful, complete products of combustion, such as nitrogen, carbon dioxide, and water vapor. However, the performance of these devices is highly dependent upon the equivalence ratio of the exhaust. Three-way catalysts require that the exhaust remain at stoichiometric conditions for optimal performance. Prolonged fuel lean engine operation renders the PGM catalyst incapable of reacting nitrogen oxide emissions. Nitrogen oxide, and more specifically nitric oxide (NO), emissions are of significant concern, as such emissions directly contribute to increased smog, acid rain, climate change, and respiratory inflammation within the population. Lean nitrogen oxide traps (LNTs) are incorporated into the exhaust system to temporarily capture excess nitrogen oxide emissions. However, the zeolite-based materials used in LNTs have a finite limit on nitrogen oxide storage capacity. Once nitrogen oxide capacity is reached, the engine must enter a fuel rich combustion condition or additional reactants must be injected directly into the exhaust system to regenerate the LNT’s function. Therefore, current exhaust treatment measures introduce significant complexity into the exhaust system and significant constraints on engine operation. As such, this work investigates the potential for new exhaust treatment materials, capable of maintaining performance across all conditions. Specifically, this work investigates the NO reduction potential of a multilayered ceramic electrochemical catalytic membrane. Prior work has demonstrated that the natural electric potential oscillation, which develops across such a membrane, significantly reduces NO emissions. The ceramic membrane, consisting of two dissimilar metal electrodes, sandwiching a dielectric layer, is able to achieve an NO reduction in excess of 2X that of a traditional PGM three-way catalytic converter [1]. Here, the possibility for externally inducing a low magnitude (&lt; 500 mVpp), high frequency (&gt; 1kHz) electric potential oscillation across the reacting membrane and increasing the conversion of NO into diatomic nitrogen and oxygen is investigated. Electric potential oscillation at the surface generates an altered electrochemical reaction pathway. During the breakdown of NO, N2O is recorded as an intermediate species without the introduction of NH3. This result diverges from traditional theory, which predicts the formation of NO2. This work further explores the relation between externally applied electric potential oscillation, N2O formation, and reduction of NO.
10

Sheikh, Shabbir, Mathias Reum, Moritz Wegener, Nazlim Bagcivan, Joachim Weber, Edgar Schulz, and Jan Martin Stumpf. "Application of Coated Metallic Bipolar Plate for Proton Exchange Membrane (PEM) Fuel Cell." In Symposium on International Automotive Technology. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 2024. http://dx.doi.org/10.4271/2024-26-0172.

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<div class="section abstract"><div class="htmlview paragraph">In the current era of green energy adoption for reaching the zero-carbon target, the mobility sector is extensively working together to use hydrogen as a major source of energy, especially in vehicles with long range requirements. For this, Proton Exchange Membrane Fuel Cells (PEMFC) are employed to convert the chemical energy of hydrogen back into electricity. Acceptability of PEMFC in the automotive field mostly depends on system efficiency, durability &amp; cost of the FC stack. In PEMFC, the bipolar plate (BPP) is a critical component of the system, which realizes the transport of gases to the electrodes, evacuates reactant product water and ensures electrical current collection. In some applications, graphite is used as material for bipolar plates due to good chemical stability and corrosion resistance, whereas it is also a rather brittle material with some manufacturing challenges. In mobile applications, metallic bipolar plates are widely used, as they allow for a significantly higher power density of the stack and have good mechanical strength &amp; electric conductivity. Metallic bipolar plates usually feature a protective coating to improve the durability of the system. In this paper, the role of bipolar plates is discussed, and different coating materials are evaluated for performance &amp; cost. An in-house testing strategy is defined to validate coated metallic bipolar plates, which are tested under various operating conditions. Subsequently, test results are discussed to check the improvement of using noble metal free material over available PGM (Platinum Group Metal) coating materials.</div></div>

Звіти організацій з теми "Platinum Group Metals (PGM)":

1

Alia, Shaun M. Low-Platinum Group (PGM) Metal Catalysts: Cooperative Research and Development Final Report, CRADA Number CRD-16-649. Office of Scientific and Technical Information (OSTI), August 2019. http://dx.doi.org/10.2172/1560121.

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2

Garfunkel, Eric, and Charles Dismukes. Platinum group metal-free (PGM-free) integrated tandem junction photoelectrochemical (PEC) water splitting devices - Final Technical Report. Office of Scientific and Technical Information (OSTI), April 2023. http://dx.doi.org/10.2172/1971134.

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3

Seshadri, Ram. Platinum Group Metal (PGM) Substituted Complex Oxide Catalysts: Design of Robust Materials for Energy-Related Redox Transformations-Final Technical Report. Office of Scientific and Technical Information (OSTI), January 2014. http://dx.doi.org/10.2172/1120568.

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4

Sinclair, W. D., I. R. Jonasson, R. V. Kirkham, and A. E. Soregaroli. Rhenium and other platinum-group metals in porphyry deposits. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 2009. http://dx.doi.org/10.4095/247485.

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5

Gadd, M. G., J. M. Peter, T A Fraser, and D. Layton-Matthews. Paleoredox and lithogeochemical indicators of the environment of formation and genesis of the Monster River hyper-enriched black shale showing, Yukon. Natural Resources Canada/CMSS/Information Management, 2022. http://dx.doi.org/10.4095/328004.

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Northern Yukon hosts occurrences of Middle Devonian hyper-enriched black shale (HEBS) Ni-Mo-Zn-platinum-group element-Au-Re mineralization, including the Monster River showing in the Ogilvie Mountains. This mineralization has been documented predominantly in the Paleozoic Richardson trough; however, the Monster River showing is atypical, occurring within the Blackstone trough, more than 200 km to the west on the southern margin of the Yukon block. The ambient paleoredox conditions of the marine water column and sediments may be primary controlling factors in HEBS formation. We use major and trace element lithogeochemistry to better understand ambient paleoenvironmental redox conditions through the application of robust redox proxies to HEBS mineralization and host rocks. Uniformly negative Ce anomalies (0.6-0.9) indicate that the water column was predominantly suboxic throughout the deposition interval, even during HEBS mineralization. Although there is a strong terrigenous influence on the rare earth element-yttrium (REE-Y) abundances of the sedimentary rocks, superchondritic Y/Ho ratios (&amp;gt;27) indicate that seawater contributed REE-Y to the host rocks and HEBS. High (&amp;gt;10) authigenic Mo/U ratios indicate that a Fe-Mn particulate shuttle operated in the water column; this is corroborated by negative Ce anomalies and high Y/Ho ratios. The data indicate that metalliferous sedimentary rocks formed by hydrogenous metal enrichment (e.g. Ni, Mo, Pt) caused by ferromanganese oxyhydroxide particulate shuttling as chemical sediments; moreover, the REE- and Mo-based paleoenvironmental indicators suggest a complexly redox-stratified depositional environment with an abundant supply of metals, metalloids, and sulfur.
6

Resource appraisal map for porphyry molybdenum-tungsten, platinum-group metals, and epithermal silver deposits in the Wallace 1 degree by 2 degrees Quadrangle, Montana and Idaho. US Geological Survey, 1986. http://dx.doi.org/10.3133/i1509h.

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