Journal articles: 'Platinum group metals (PGEs)'

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O’Connor, Cyril, and Tatiana Alexandrova. "The Geological Occurrence, Mineralogy, and Processing by Flotation of Platinum Group Minerals (PGMs) in South Africa and Russia." Minerals 11, no. 1 (January 7, 2021): 54. http://dx.doi.org/10.3390/min11010054.

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Russia and South Africa are the world’s leading producers of platinum group elements (PGEs). This places them in a unique position regarding the supply of these two key industrial commodities. The purpose of this paper is to provide a comparative high-level overview of aspects of the geological occurrence, mineralogy, and processing by flotation of the platinum group minerals (PGMs) found in each country. A summary of some of the major challenges faced in each country in terms of the concentration of the ores by flotation is presented alongside the opportunities that exist to increase the production of the respective metals. These include the more efficient recovery of minerals such as arsenides and tellurides, the management of siliceous gangue and chromite in the processing of these ores, and, especially in Russia, the development of novel processing routes to recover PGEs from relatively low grade ores occurring in dunites, black shale ores and in vanadium-iron-titanium-sulphide oxide formations.

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O’Connor, Cyril, and Tatiana Alexandrova. "The Geological Occurrence, Mineralogy, and Processing by Flotation of Platinum Group Minerals (PGMs) in South Africa and Russia." Minerals 11, no. 1 (January 7, 2021): 54. http://dx.doi.org/10.3390/min11010054.

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Russia and South Africa are the world’s leading producers of platinum group elements (PGEs). This places them in a unique position regarding the supply of these two key industrial commodities. The purpose of this paper is to provide a comparative high-level overview of aspects of the geological occurrence, mineralogy, and processing by flotation of the platinum group minerals (PGMs) found in each country. A summary of some of the major challenges faced in each country in terms of the concentration of the ores by flotation is presented alongside the opportunities that exist to increase the production of the respective metals. These include the more efficient recovery of minerals such as arsenides and tellurides, the management of siliceous gangue and chromite in the processing of these ores, and, especially in Russia, the development of novel processing routes to recover PGEs from relatively low grade ores occurring in dunites, black shale ores and in vanadium-iron-titanium-sulphide oxide formations.

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Frazzoli, Chiara, Roberta Cammarone, and Sergio Caroli. "Uptake of platinum-group elements with the diet: A preliminary investigation." Pure and Applied Chemistry 78, no. 1 (January 1, 2006): 69–78. http://dx.doi.org/10.1351/pac200678010069.

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Over the past decade, the increasing use of car catalytic converters based on platinum-group elements (PGEs) has been raising more and more concern. Human exposure to these metals occurs indirectly also through the diet. Thus, a pilot investigation was undertaken in order to ascertain the actual intake of PGEs through bread and cow milk. All manipulations were performed in a Class-100 clean room so as to minimize the risk of sample contamination. Digestion of samples was achieved by means of a mixture of HNO3 and H2O2 with the assistance of microwave irradiation.Determinations were performed by sector field inductively coupled plasma-mass spectrometry (SF-ICP-MS) to quantify Pd, Pt, and Rh. The isotopes 105Pd+, 103Rh+, and 195Pt+ were used for the quantification. Major interferences were caused by 40Ar65Cu+ on 105Pd+, 179Hf16O+ on 195Pt+, and 87Rb16O+ and 87Sr16O+ on 103Rh+. Both physical and mathematical approaches for the interference correction were used. The mean values for PGEs were found to be as follows (in ng kg-1): full-cream milk: Pd, 3790; Pt, 83.2; Rh, 1680; skim milk: Pd, 12 400; Pt, 83.6; Rh, 1090; wholemeal bread: Pd, 3210; Pt, 171; Rh, 139; white bread: Pd, 27 400; Pt, 257; Rh, 2230. The preliminary data obtained in this study are probative of the significant portion of the total exposure to PGEs, which is due to the diet.

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Liu, Si Qing, Bao Xu Song, Quan Jun Liu, and Wan Ping Wang. "Process Mineralogy of a Low Grade Cu-Ni-PGM Sulphide Ore and its Implications for Mineral Processing." Advanced Materials Research 524-527 (May 2012): 1023–28. http://dx.doi.org/10.4028/www.scientific.net/amr.524-527.1023.

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Based on process mineralogical study of a low-grade Cu-Ni-platinum group metal(PGM) sulfide ore in SW China, the occurrence of Cu and Ni, the distribution of platinum group minerals (PGMs) and their relationships with other minerals are determined in detail, which provides scientific reference for forthcoming mineral processing and extractive metallurgy. The mineralogical results show that 18 individual PGMs containing all the 6 platinum group elements (PGEs) are investigated, and it can be concluded that the PGMs in the ores mainly occur as individual minerals. SEM images show that the PGMs are mainly disseminated in sulphides, most occur as inclusions or semi-inclusions, and part are inlayed along the other minerals to form coarse compound grains. Due to the the complex mineral composition and texture, processing the Cu-Ni-PGM ores by traditional flotation may be difficult to get a good processing performance.

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Yang, Sai-Hong, Ben-Xun Su, Xiao-Wen Huang, Dong-Mei Tang, Ke-Zhang Qin, Yang Bai, Patrick Sakyi, and Melesse Alemayehu. "Platinum-Group Mineral Occurrences and Platinum-Group Elemental Geochemistry of the Xiadong Alaskan-Type Complex in the Southern Central Asian Orogenic Belt." Minerals 8, no. 11 (November 1, 2018): 494. http://dx.doi.org/10.3390/min8110494.

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Alaskan-type complexes commonly contain primary platinum-group element (PGE) alloys and lack base-metal sulfides in their dunite and chromite-bearing rocks. They could therefore host PGE deposits with rare sulfide mineralization. A detailed scanning electron microscope investigation on dunites from the Xiadong Alaskan-type complex in the southern Central Asian Orogenic Belt revealed: various occurrences of platinum-group minerals (PGMs) that are dominated by inclusions in chromite grains containing abundant Ru, Os, S and a small amount of Pd and Te, indicating that they mainly formed prior to or simultaneously with the crystallization of the host minerals; A few Os–Ir–Rurich phases with iridium/platinum-group element (IPGE) alloy, anduoite (Ru,Ir,Ni)(As,S)2−x and irarsite (IrAsS) were observed in chromite fractures, and as laurite (RuS2) in clinopyroxene, which was likely related to late-stage hydrothermal alteration. The rocks in the Xiadong complex display large PGE variations with ∑PGE of 0.38–112 ppb. The dunite has the highest PGE concentrations (8.69–112 ppb), which is consistent with the presence of PGMs. Hornblende clinopyroxenite, hornblendite and hornblende gabbro were all depleted in PGEs, indicating that PGMs were likely already present at an early phase of magma and were mostly collected afterward in dunites during magma differentiation. Compared with the regional mafic–ultramafic intrusions in Eastern Tianshan, the Xiadong complex show overall higher average PGE concentration. This is consistent with the positive PGE anomalies revealed by regional geochemical surveys. The Xiadong complex, therefore, has potential for PGE exploration.

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POPOOLA, A. I., and J. E. LOWTHER. "COMPUTATIONAL STUDY OF PLATINUM GROUP SUPERALLOYS." International Journal of Modern Physics B 28, no. 09 (March 5, 2014): 1450066. http://dx.doi.org/10.1142/s0217979214500660.

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Various properties of substitutional alloys formed from aluminium and the platinum group metals (PGMs) are examined using density functional (D-F) theory and show strong variations depending on metal type. A similar pattern for the binary alloys is observed using molecular dynamics modeling employing Sutton Chen potentials. All results suggest that several of the PGMs could have superior properties to the presently used Ni 3 Al alloy for high temperature applications. Some phases are predicted to be stable with extremely high melting temperatures (MTs).

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Odularu, Ayodele T., Peter A. Ajibade, Johannes Z. Mbese, and Opeoluwa O. Oyedeji. "Developments in Platinum-Group Metals as Dual Antibacterial and Anticancer Agents." Journal of Chemistry 2019 (November 6, 2019): 1–18. http://dx.doi.org/10.1155/2019/5459461.

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Platinum-group (PG) complexes have been used as antibacterial and anticancer agents since the discovery of cisplatin. The science world still requires improvement on these complexes because of multidrug and antineoplastic resistances. This review observes discoverers and history of these platinum-group metals (PGMs), as well as their beneficial applications. The focus of this study was biological applications of PGMs in relation to human health. Sandwich and half-sandwich PGM coordination compounds and their metal nanoparticles give improved results for biological activities by enhancing efficient delivery of both antibacterial and anticancer drugs, as well as luminescent bioimaging (biomarkers) for biological identifications.

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Yan, Li, and Ji Shou Zhao. "Study Pressure-Cyanide Dissolution Different of Metal Palladium and Platinum Powder." Advanced Materials Research 734-737 (August 2013): 2514–18. http://dx.doi.org/10.4028/www.scientific.net/amr.734-737.2514.

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s: A research study has been undertaken to develop the fundamentals of a method for the direct dissolution of platinum group metals (PGMs). At room temperature and pressures, the reaction between sodium cyanide and platinum group metals (PGMs) does not occur because of poor kinetics. However, at elevated temperatures between 120-180 °C, PGMs can be leached by sodium cyanide like the reaction of gold. In this work, the dissolution of Palladium and Platinum powder were measured in pressure clear cyanide solution. The cyanide leaching reaction mechanism is also discussed.The data at different cyanide concentrations, different temperature and different oxygen pressure are obtained. The dissolution rate off metal Palladium and Platinum powder were found to be a function of the cyanide and oxygen level.

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9

Matthey, Johnson, and Alfa Aesar. "PGMs in the Lab: Platinum Group Metals in Polyoxometalates." Platinum Metals Review 58, no. 1 (January 1, 2014): 40–41. http://dx.doi.org/10.1595/147106713x675787.

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Chaumba, Jeff B., and Caston T. Musa. "Formation of the main sulfide zone at Unki Mine, Shurugwi Subchamber of the Great Dyke, Zimbabwe: Constraints from petrography and sulfide compositions." Geosphere 16, no. 2 (January 16, 2020): 685–710. http://dx.doi.org/10.1130/ges02150.1.

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Abstract The major platinum group element (PGE) occurrence in the Great Dyke of Zimbabwe, the main sulfide zone, is a tabular stratabound layer hosted in pyroxenites, and it is broadly similar in form throughout the length of the Great Dyke. We conducted a petrographic and sulfide composition study on a sulfide-enriched zone from the contact of the mafic sequence–ultramafic sequence through the main sulfide zone at Unki Mine in the Shurugwi Subchamber to its underlying footwall rocks to place some constraints on the origin of the rocks. Pyrrhotite, pentlandite, chalcopyrite, and pyrite are the base metal sulfides that were encountered during the study. Pyrrhotite, pentlandite, and chalcopyrite typically occurred as inclusions in both primary (orthopyroxene, plagioclase, and clinopyroxene) and secondary (amphibole and chlorite) silicate phases, whereas pyrite was observed in only three samples, where it occurred in association with pyrrhotite. The concentrations of PGEs in the base metal sulfides were nearly all at or below minimum detection limits. The intercumulus nature of some of these sulfides in the investigated sequence suggests that they were likely formed during the crystallization history of these rocks. The occurrence of pyrite, which we interpret to be an alteration phase, suggests that a late-stage event, likely formed during hydrothermal alteration, helped to concentrate the mineralization at Unki Mine. In some cases, however, these sulfides occur partially surrounding some chromite and silicate phases. Thus, some sulfides in the Unki Mine area were likely formed early in the crystallization history of the Great Dyke, whereas others were formed late during hydrothermal processes. Low concentrations of PGEs such as platinum (Pt), palladium (Pd), and rhodium (Rh) in base metal sulfides imply that the PGEs in the main sulfide zone and Unki Mine are hosted either in silicates and/or platinum group minerals. Very low Co contents in pentlandites in the rocks under investigation are interpreted to imply that very limited Fe substitution by Co, and also of Ni by Co, occurred. Broadly comparable trends, with minor variations of Fe in pyrrhotite, of Co and Ni in pentlandite, and of Cu in chalcopyrite, for example, likely reflect magmatic processes. The concentrations of these metals in base metal sulfides vary sympathetically, indicating that their original magmatic signatures were subsequently affected by hydrothermal fluids. The spiked pattern displayed by the variations in the percent modal proportions of the base metal sulfides across the entire investigated stratigraphic section is interpreted to reflect remobilization of the sulfides during hydrothermal alteration. Depletions in some elements, which occur near the base and at the top of the investigated succession, are likely a result of this hydrothermal alteration.

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Kamenetsky, Vadim S., and Michael Zelenski. "Origin of noble-metal nuggets in sulfide-saturated arc magmas: A case study of olivine-hosted sulfide melt inclusions from the Tolbachik volcano (Kamchatka, Russia)." Geology 48, no. 6 (April 13, 2020): 620–24. http://dx.doi.org/10.1130/g47086.1.

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Abstract Minerals that contain platinum-group elements (PGEs) and occur in some magmatic Cu-Ni sulfide deposits have been ascribed to crystallization from an originally PGE-rich sulfide liquid. The occurrence of PGE-bearing minerals (PGMs) in some sulfide-undersaturated primitive melts has been envisaged and recently reported, whereas direct crystallization of PGMs in sulfide-saturated silicate magmas is seemingly hindered by strong partitioning of PGE into immiscible sulfide melts. In this study, we discovered abundant nanoparticles containing noble metals in association with sulfide melt inclusions entrapped inside primitive olivine phenocrysts (Fo85–92) from the recent basaltic magma of the Tolbachik volcano (Kamchatka arc, Russia). These nuggets occur in swarms on the surface of the sulfide globules and are represented by native metals, sulfides, and alloys of Pd, Pt, Au, Pb, and Bi. The nuggets on different globules can be either Pd- or Pt-rich nuggets, and the compositions are highly variable, even among adjacent nuggets. We argue that the diffusive supply of Pd from the external nuggets can be responsible for significant uptake of Pd (up to 2 wt%) in the sulfide melt. We consider direct crystallization of PGMs in a primitive basaltic melt undergoing sulfide unmixing, and possibly sulfide breakdown due to oxidation, as another mechanism additional to their “classic” origin from the PGE-rich sulfide melt in response to solidification.

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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.

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Le Vaillant, Margaux, Stephen J. Barnes, Marco L. Fiorentini, Sarah-Jane Barnes, Adam Bath, and John Miller. "Platinum-group element and gold contents of arsenide and sulfarsenide minerals associated with Ni and Au deposits in Archean greenstone belts." Mineralogical Magazine 82, no. 3 (April 13, 2018): 625–47. http://dx.doi.org/10.1180/minmag.2017.081.100.

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ABSTRACTPost-magmatic alteration of certain magmatic Ni sulfide ores in Western Australia, the Miitel deposit and the Sarah's Find prospect, produced Ni–As–PGE haloes around massive sulfides. A study of the composition of arsenide grains from these hydrothermal haloes, along with arsenides from various magmatic and hydrothermal mineralized environments in other localities, was conducted in order to compare their composition, and assess their potential use as indicator minerals for exploration vectoring, as well as to gain knowledge on their crystallization history. Concentrations in trace elements such as platinum-group elements (PGEs), Au and other metals was obtained by laser ablation inductively coupled plasma mass spectroscopy analyses. Results show that variations in PGEs and Au compositions can be related to the magmaticvs.hydrothermal origin of the grains; and to their provenance from deposits enriched in either Ni, Au or both. Magmatic NiCoFe sulfarsenides have strongly correlated, high IPGE (Os, Ir, Ru, Rh) contents up to 100 ppm Ir, compared with maximum values in hydrothermal sulfarsenides of ~1 ppm. Gold in hydrothermal sulfarsenides from Au-mineralized ultramafic rocks extends up to 500 ppm, with typical values of 3–30 ppm; similar values are also found in nickeline (also called niccolite). These results suggest that nickel arsenides could potentially be used as indicator minerals for nickel and gold exploration. Trace-element contents of arsenide grains in shear zones could be used to deduce the presence of Ni or Au mineralization upstream in the fluid pathway.

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Akizawa, Norikatsu, Tetsu Kogiso, Akira Miyake, Akira Tsuchiyama, Yohei Igami, and Masayuki Uesugi. "Formation process of sub-micrometer-sized metasomatic platinum-group element-bearing sulfides in a Tahitian harzburgite xenolith." Canadian Mineralogist 58, no. 1 (January 16, 2020): 99–114. http://dx.doi.org/10.3749/canmin.1800082.

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ABSTRACT Base-metal sulfides (BMSs) are minerals that host platinum-group elements (PGE) in mantle peridotites and significantly control the bulk PGE content. They have been investigated in detail down to the sub-micrometer scale to elucidate PGE behavior in the Earth's interior. Base-metal sulfides are supposedly subjected to supergene and seawater weathering, leading to the redistribution of PGEs at low temperatures. Careful and thorough measurements of BMSs are thus required to elucidate PGE behavior in the Earth's interior. In the present study, a sub-micrometer-sized PGE-bearing sulfide inclusion in a clinopyroxene crystal in a harzburgite xenolith from Tahiti (Society Islands, French Polynesia) was investigated in detail (down to the sub-micrometer scale) using transmission electron microscopy with energy-dispersive X-ray spectroscopy (TEM-EDS). The sulfide inclusion is of carbonatitic metasomatic origin, as it is enveloped by carbonaceous glass, and forms a planar inclusion array with other PGE-bearing sulfide inclusions. The following sulfide phases were identified using TEM-EDS: Fe- and Ni-rich monosulfide solid solutions (MSSs), Fe- and Ni-rich pentlandite, sugakiite, heazlewoodite, chalcopyrite, and Cu-Ir-Pt-Rh-thiospinel (cuproiridsite–malanite–cuprorhodsite). We established the formation process of the metasomatic PGE-bearing sulfide inclusion by considering morphological and mineral characteristics in addition to the chemical composition. A primary MSS first crystallized from metasomatic sulfide melt at ca. 1000 °C, followed by the crystallization of an intermediate solid solution (ISS) below 900 °C. A high-form (high-temperature origin) Fe-rich pentlandite simultaneously crystallized with the primary MSS below ca. 850 °C and recrystallized into a low-form (low-temperature origin) Fe-rich pentlandite below ca. 600 °C. The primary MSS decomposed to Fe- and Ni-rich MSSs, low-form Ni-rich pentlandite, sugakiite, and heazlewoodite. The ISS decomposed to chalcopyrite below ca. 600 °C. Meanwhile, a Cu-Ir-Pt-Rh-thiospinel crystallized directly from the evolved Cu-rich sulfide melt below ca. 760 °C. Thus, Ir, Pt, and Rh preferentially partitioned into the melt phase during the crystallization process of the metasomatic sulfide melt. Metasomatic sulfide melts could be a significant medium for the transport and condensation of Pt together with Ir and Rh during the fractionation process in the Earth's interior. We hypothesize that the compositional variability of PGEs in carbonatites is due to the separation of sulfide melt leading to the loss of PGEs in the carbonatitic melts.

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Mack, C. L., B. Wilhelmi, J. R. Duncan, and J. E. Burgess. "Biosorptive recovery of platinum from platinum group metal refining wastewaters by immobilised Saccharomyces cerevisiae." Water Science and Technology 63, no. 1 (January 1, 2011): 149–55. http://dx.doi.org/10.2166/wst.2011.025.

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The process of platinum group metal (PGM) refining can be up to 99.99% efficient at best, and although it may seem small, the amount of valuable metal lost to waste streams is appreciable enough to warrant recovery. The method currently used to remove entrained metal ions from refinery wastewaters, chemical precipitation, is not effective for selective recovery of PGMs. The yeast Saccharomyces cerevisiae has been found capable of sorbing numerous precious and base metals, and is a cheap and abundant source of biomass. In this investigation, S. cerevisiae was immobilised using polyethyleneimine and glutaraldehyde to produce a suitable sorbent, capable of high platinum uptake (150–170 mg/g) at low pH (<2). The sorption mechanism was found to be a chemical reaction, which made effective desorption impossible. When applied to PGM refinery wastewater, two key wastewater characteristics limited the success of the sorption process; high inorganic ion content and complex speciation of the platinum ions. The results proved the concept principle of platinum recovery by immobilised yeast biosorption and indicated that a more detailed understanding of the platinum speciation within the wastewater is required before biosorption can be applied. Overall, the sorption of platinum by the S. cerevisiae sorbent was demonstrated to be highly effective in principle, but the complexity of the wastewater requires that pretreatment steps be taken before the successful application of this process to industrial wastewater.

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Rydchuk, Mariana, Teodoziya Vrublevska, Mariya Boyko, and Olha Korkuna. "Masking is the Effective Alternative to the Separation during Osmium Determination by Means of Azo Dyes in Complex Samples." Chemistry and Chemical Technology 4, no. 2 (June 15, 2010): 115–24. http://dx.doi.org/10.23939/chcht04.02.115.

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The selectivity of the spectrophotometric methods for determination of microgram quantities of osmium (IV) with acidic monoazo dyes Tropaeolin O (TpO) and Tropaeolin OOO-I (TpOOOI) in the presence of concomitant metals, particularly platinum group, heavy and rare earths (RE) has been studied. The tolerance ratios of interfering elements have been established. The selectivity of the interaction of TpOOOI with osmium (IV) relatively to platinum group elements (PGEs) is much better than TpO. It has been established that the influence of interfering ions can be easily eliminated by means of masking agents viz. EDTA, tartrate, citrate, pyrophosphate and fluoride, and thereby the selectivity of the methods of osmium determination with TpO and TpOOOI has been sufficiently improved. The methods have been approved during the analyses of various model solutions containing ruthenium, platinum, palladium, rhodium and iridium and the masking reagents. Also osmium content has been determined in the intermetallic alloy Nd20Os15Sі65. The standard deviations did not exceed typical values for spectrophotometric methods (RSDs < 5 %). Thus the elaborated methods with various masking agents may be used for direct determination of osmium in complex samples without any preliminary separation of osmium in the form of OsO4 as well as without the extraction of matrices elements.

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Fornalczyk, A., M. Kraszewski, J. Willner, J. Kaduková, A. Mrážiková, R. Marcinčáková, and O. Velgosová. "Dissolution of Metal Supported Spent Auto Catalysts in Acids." Archives of Metallurgy and Materials 61, no. 1 (March 1, 2016): 233–36. http://dx.doi.org/10.1515/amm-2016-0043.

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Metal supported auto catalysts, have been used in sports and racing cars initially, but nowadays their application systematically increases. In Metal Substrate (supported) Converters (MSC), catalytic functions are performed by the Platinum Group Metals (PGM): Pt, Pd, Rh, similarly to the catalysts on ceramic carriers. The contents of these metals make that spent catalytic converters are valuable source of precious metals. All over the world there are many methods for the metals recovery from the ceramic carriers, however, the issue of platinum recovery from metal supported catalysts has not been studied sufficiently yet. The paper presents preliminary results of dissolution of spent automotive catalyst on a metal carrier by means of acids: H2SO4, HCl, HNO3, H3PO4. The main assumption of the research was the dissolution of base metals (Fe, Cr, Al) from metallic carrier of catalyst, avoiding dissolution of PGMs. Dissolution was the most effective when concentrated hydrochloric acid, and 2M sulfuric acid (VI) was used. It was observed that the dust, remaining after leaching, contained platinum in the level of 0.8% and 0.7%, respectively.

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Zhao, J. S., and J. H. Dai. "Kinetics and Mechanism of Platinum Pressure-Cyanide Dissolution." Applied Mechanics and Materials 522-524 (February 2014): 424–28. http://dx.doi.org/10.4028/www.scientific.net/amm.522-524.424.

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A research study has been undertaken to develop the fundamentals of a method for the direct dissolution of metal platinum. At room temperature and pressures, the reaction between sodium cyanide and platinum group metals (PGMs) does not occur because of poor kinetics. However, at elevated temperatures, PGMs can be dissolved by sodium cyanide like the reaction of gold. In this work, the dissolution of Platinum was measured in pressure clear cyanide solution. The data at different cyanide concentrations, temperature and oxygen pressure are obtained. With increasing cyanide concentration and oxygen pressure, the dissolution first increased to a maximum value and then decreased. With increasing temperature the dissolution is increased.

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Fedoseev, I. V., V. V. Vasekin, and N. V. Rovinskaya. "Hydrocarbonyl Processes for Conversion of Platinum-Rhodium-Palladium Alloys : Technological possibilities of a new process for pgms extraction." Johnson Matthey Technology Review 64, no. 1 (January 1, 2020): 42–47. http://dx.doi.org/10.1595/205651320x15700992885660.

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A novel process for the recovery of platinum group metals (pgms) from ternary alloys using a hydrocarbonyl process is proposed. The hydrocarbonyl process involves treatment of a chloride solution of the pgms with carbon monoxide at ambient pressure. The results demonstrate that the process can provide high purity pgms from a ternary platinum-rhodium-palladium alloy such as that obtained from palladium-nickel catchment alloys used with platinum-rhodium gauzes during high temperature ammonia oxidation.

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Zhang, Meng, Ying Lv, Zhanglian Xu, Sheng Wang, and Jie Wang. "The Removal of Platinum Group Metals, Cs, Se, and Te from Nuclear Waste Glass Using Liquid Sb Extraction and Phase Separation Methods." Materials 13, no. 22 (November 23, 2020): 5305. http://dx.doi.org/10.3390/ma13225305.

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Recovery of platinum group metals (PGMs: Pd, Ru, Rh), Cs, Se, and Te from molten borosilicate glass containing simulated high level radwaste through the combination of liquid metal extraction and phase separation method under reductive heat-treatment was studied. In this process, the PGMs were extracted in recovered liquid metal phase, where Sb and Bi metals were used as the collecting metals. Meanwhile, Cs, Se, and Te were enriched in the phase separated potassium-rich materials on glass surface, which were extracted by water. The type of liquid metals had profound influence on the extraction behaviors of PGMs and other fission products from the glass melt. As a result, except the near extraction efficiency of Pd, Sb showed higher affinity for Ru and Rh than Bi metal. The higher phase separation efficiency of potassium-rich materials led to the higher extraction efficiencies of Cs, Se, and Te in liquid Sb extraction than Bi. Among the examined conditions, using liquid Sb extraction, the Pd, Ru, and Rh extraction efficiencies were 78.6%, 62.1% and 100% in liquid Sb metal phase, and 93.76% of Cs, 60.4% of Se, and 23.65% of Te in leachate were obtained.

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Dyer, Richard D., and Peter J. Barnett. "Multimedia exploration strategies for PGEs: insights from the Surficial Geochemistry Case Studies Project, Lake Nipigon Region Geoscience Initiative, northwestern Ontario." Canadian Journal of Earth Sciences 44, no. 8 (August 1, 2007): 1169–202. http://dx.doi.org/10.1139/e07-031.

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The Surficial Geochemistry Case Studies Project in the Lake Nipigon region involved detailed Quaternary mapping and multimedia geochemical sampling within five case study areas. Two of these areas, Lac des Iles and Tib Lake, contain known platinum group element (PGE) mineralization. The other three case study areas feature drainage catchments with lakes that contain anomalous levels of PGEs in bottom sediment. Surficial media sampled included till, soils, stream sediment, lake sediment, peat, surface water, and groundwater. Over Archean terrain, such as at Lac des Iles and Tib Lake, there is excellent geochemical contrast between the PGE prospective rock type (mafic to ultramafic intrusive) and the surrounding rock type (e.g., granitoid rocks). This geochemical contrast is mirrored in the geochemistry of most surficial media sampled during this project. Over the Nipigon Embayment, the geochemical contrast between mafic and ultramafic rocks (e.g., Seagull-type intrusions) and the surrounding diabase sill rocks is inherently weaker due to the relatively high background levels for copper, palladium, and gold in the Nipigon diabase sills. However, the results of stream-water geochemistry over the Seagull and Disraeli ultramafic intrusions highlight their unique geochemical footprint on the surficial landscape, in particular with respect to Cr, Mg, and Ni, compared with the surrounding Nipigon diabase. In addition, lake sediments underlain by the Seagull, Disraeli, and Hele intrusions have distinctly elevated Cr concentrations and Gd/Yb ratios compared with the surrounding areas underlain by Nipigon diabase sills or Sibley Group rocks. Therefore, exploration value can be maximized over the Nipigon Embayment by exploiting these geochemical contrasts in surficial media to discriminate between ultramafic rocks and the surrounding Nipigon diabase sills. The results of this study highlight the importance of chromium concentrations in surficial media as a diagnostic feature for the presence of ultramafic rocks, regardless of their age or location. In general, a cost-effective exploration strategy for PGE mineralization includes targeting the associated metals (Cr, Ni) within drift deposits (C-horizon till) and drainage media (stream sediment, lake sediment) to vector to prospective mafic–ultramafic intrusive rocks, prior to detailed (property scale) follow-up, involving the determination of base metals and PGEs within soil, till, stream sediment, and peat samples. Relative to the metals copper, nickel, and chromium (ppm levels), the PGEs have significantly lower initial concentrations (ppb levels), are less mobile in the surficial environment, have significantly shorter glacial dispersion trains, and are less reliably determined at the laboratory.

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Kiseleva, Ol’ga, Evgeniya Airiyants, Dmytriy Belyanin, and Sergey Zhmodik. "Hydrothermal remobilization platinum group elements and their secondary minerals in chromitite deposits of the Eastern Sayan ophiolites (Russia)." E3S Web of Conferences 98 (2019): 08014. http://dx.doi.org/10.1051/e3sconf/20199808014.

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Serpentinization is an important post-magmatic process in spreading and subducted zones. This process is the cause of the remobilization and redistribution of highly mobile elements, platinum group elements (PGE) and base metals. Secondary platinum group minerals (PGMs) formed because of PGE remobilization under the action of mantle and crustal fluid on the rocks. The formation of the secondary PGMs can occur in several stages. Under the effect on the chromitites of reduced mantle fluids, native PGE alloys were formed during early serpentinization. Under dehydrating subducted slab fluid phase was caused in serpentinization mantle peridotites and have been dissolved magmatic high-temperature platinum group minerals. During the obduction of ophiolites, an inversion from reducing to oxidizing condition took place with the formation of nickel arsenides and As, Sb – bearing PGMs.

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Hughes, Anthony E., Nawshad Haque, Stephen A. Northey, and Sarbjit Giddey. "Platinum Group Metals: A Review of Resources, Production and Usage with a Focus on Catalysts." Resources 10, no. 9 (September 20, 2021): 93. http://dx.doi.org/10.3390/resources10090093.

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The major applications of PGMs are as catalysts in automotive industry, petroleum refining, environmental (gas remediation), industrial chemical production (e.g., ammonia production, fine chemicals), electronics, and medical fields. As the next generation energy technologies for hydrogen production, such as electrolysers and fuel cells for stationary and transport applications, become mature, the demand for PGMs is expected to further increase. Reserves and annual production of Ru, Rh, Pd, Ir, and Pt have been determined and reported. Based on currently available resources, there is around 200 years lifetime based on current demand for all PGMs, apart from Pd, which may be closer to 100 years. Annual primary production of 190 t/a for Pt and 217 t/a for Pd, in combination with recycling of 65.4 t/a for Pt and 97.2 t/a for Pd, satisfies current demand. By far, the largest demand for PGMs is for all forms of catalysis, with the largest demand in auto catalysis. In fact, the biggest driver of demand and price for Pt, Pd, and Rh, in particular, is auto emission regulation, which has driven auto-catalyst design. Recovery of PGMs through recycling is generally good, but some catalytic processes, particularly auto-catalysis, result in significant dissipation. In the US, about 70% of the recycling stream from the end-of-life vehicles is a significant source of global secondary PGMs recovered from spent auto-catalyst. The significant use of PGMs in the large global auto industry is likely to continue, but the long-term transition towards electric vehicles will alter demand profiles.

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Willner, J., and A. Fornalczyk. "Dissolution of Ceramic Monolith of Spent Catalytic Converters by Using Hydrometallurgical Methods / Rozpuszczanie Monolitu Ceramicznego Zużytych Katalizatorów Na Drodze Hydrometalurgicznej." Archives of Metallurgy and Materials 60, no. 4 (December 1, 2015): 2945–48. http://dx.doi.org/10.1515/amm-2015-0470.

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Catalytic converters contain the catalytic substance in their structure, which is a mixture of Platinum Group Metals (PGMs): platinum, palladium and rhodium. The prices of these metals and a growing demand for them in the market, make it necessary to recycle spent catalytic converters and recovery of PGMs. The ceramic monolith of catalytic converters is still a predominant material in its construction among of multitude of catalytic converters which are in circulation. In this work attempts were made to leach additional metals (excluding Pt) from comminuted ceramic monolith. Classic leachant oxidizing media 10M H2SO4, HCl and H3PO4 were used considering the possibility of dissolution of the ceramic monolith.

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Odjegba, V., M. Brown, and A. Turner. "Studies on the effects of platinum group metals (PGMs) on Lactuca sativa L." Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology 146, no. 4 (April 2007): S261. http://dx.doi.org/10.1016/j.cbpa.2007.01.661.

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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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Schäfer, J., D. Hannker, J. D. Eckhardt, and D. Stüben. "Uptake of traffic-related heavy metals and platinum group elements (PGE) by plants." Science of The Total Environment 215, no. 1-2 (April 1998): 59–67. http://dx.doi.org/10.1016/s0048-9697(98)00115-6.

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Rinkovec, Jasmina. "Platinum, palladium, and rhodium in airborne particulate matter." Archives of Industrial Hygiene and Toxicology 70, no. 4 (December 1, 2019): 224–31. http://dx.doi.org/10.2478/aiht-2019-70-3293.

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AbstractMeasurable quantities of platinum, palladium, and rhodium, even in remote areas of the planet, evidence the global nature of pollution with these metals, mostly from catalytic converters of modern vehicles (other sources are jewellery production, chemical industry, and anticancer drugs). The amount of the platinum group metals (PGMs) emitted from automobile catalysts varies with the type, age, and condition of the engine and the catalyst, as well as the style of driving. Current literature suggests that the concentrations of these metals have increased considerably over the last twenty years, palladium concentrations in particular, as it has been proved more effective catalyst than platinum. However, whether and to what extent the emitted PGMs are toxic for people is still a controversy. The potential health risk from exposure to these elements is most likely for those living in urban environments with busy roads or along major highways. Because of the importance of PGMs and their trace levels in particulate matter, sensitive methods are required for reliable determination. This review discusses particular steps of analytical procedures for PGM quantification in airborne particulate matter and addresses the common preparation, detection, and determination methods.

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Kim, Jihye, John Anawati, and Gisele Azimi. "Matrix complexity effect on platinum group metals analysis using inductively coupled plasma optical emission spectrometry." Journal of Analytical Atomic Spectrometry 33, no. 8 (2018): 1310–21. http://dx.doi.org/10.1039/c8ja00158h.

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Brzozowski, M. J., I. M. Samson, J. E. Gagnon, D. J. Good, and R. L. Linnen. "On the Mechanisms for Low-Sulfide, High-Platinum Group Element and High-Sulfide, Low-Platinum Group Element Mineralization in the Eastern Gabbro, Coldwell Complex, Canada: Evidence from Textural Associations, S/Se Values, and Platinum Group Element Concentrations of Base Metal Sulfides." Economic Geology 115, no. 2 (March 1, 2020): 355–84. http://dx.doi.org/10.5382/econgeo.4708.

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Abstract The Eastern Gabbro, Coldwell Complex, hosts several geochemically and mineralogically distinct Cu-platinum group element (PGE) deposits, including the high-grade W Horizon (>100 ppm Pd-Pt-Au over 2 m). Several magmatic and/or hydrothermal models have previously been proposed to explain the range of enrichment in PGEs observed in the Marathon deposit, but no work has integrated textural and compositional variations in sulfides to elucidate which of these models is most suitable. Additionally, comparatively little work has been done to characterize the genesis of Cu-PGE mineralization that occurs to the northwest of the Marathon deposit in the Eastern Gabbro. Through integration of base metal sulfide (BMS) mineralogy, texture, and trace element chemistry, a wide range of magmatic and postmagmatic processes have been characterized that contributed to the formation of these deposits. In all zones of mineralization in the Eastern Gabbro, chalcophile elements were remobilized from primary chalcopyrite by hydrothermal fluids and precipitated as secondary chalcopyrite, which occurs as a replacement of pyrrhotite and as intergrowths with hydrous silicates. BMSs in the mineralized zones in the Marathon deposit (Footwall zone, Main zone, and W Horizon) experienced higher R factors than those deposits located northwest of the Marathon deposit (Four Dams, Area 41, and Redstone), with BMSs in the W Horizon having experienced the highest R factors. The silicate melts from which the Footwall zone crystallized likely experienced some degree of sulfide segregation at depth, albeit to a much lesser degree than the northern deposits. Additionally, the melts from which the mineralized zones in the Marathon deposit crystallized were likely contaminated by high-S/Se Archean sedimentary rocks, whereas the northern deposits were likely contaminated by low-S/Se igneous and/or metamorphic rocks. BMSs in a chalcopyrite-rich pod located within the vicinity of the Coldwell Complex experienced both high R factors and high degrees of contamination (cf. W Horizon and Footwall zone, respectively). This study illustrates the complexity of processes that generate and modify mineralization in conduit-type Ni-Cu-PGE systems.

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Yan, L., and J. S. Zhao. "Study on Pressure-Cyanide Dissolution of Metal Platinum Powder." Advanced Materials Research 554-556 (July 2012): 541–45. http://dx.doi.org/10.4028/www.scientific.net/amr.554-556.541.

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A research study has been undertaken to develop the fundamentals of a method for the direct dissolution of Metal Platinum. At room temperature and pressures, the reaction between sodium cyanide and platinum group metals (PGMs) does not occur because of poor kinetics. However, at elevated temperatures between 20°C and 180°C, PGMs can be dissolved by sodium cyanide like the reaction of gold. In this work, the dissolution of Platinum was measured in pressure clear cyanide solution. The data at different cyanide concentrations, different temperature and different oxygen pressure are obtained. With increasing cyanide concentration and oxygen pressure, the dissolution first increased to a maximum value and then decreased. With increasing temperature the dissolution is increased. The dissolution was found to have a relation of the cyanide and oxygen level. The dissolution was independent of rotation speed for oxygen-saturated solutions and cyanide concentrations above 5 mol.m-3 and was well below chemical reaction-limited for cyanide and oxygen.

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Madzokere, Tatenda Crispen, Kudzai Rusere, and Haleden Chiririwa. "Nano-Silica based mineral flotation frother: Synthesis and flotation of Platinum Group Metals (PGMs)." Minerals Engineering 166 (June 2021): 106881. http://dx.doi.org/10.1016/j.mineng.2021.106881.

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Julsing, H. G., and R. I. McCrindle. "The recovery of precious metals from acidic effluents using sodium formate." Water Science and Technology 42, no. 5-6 (September 1, 2000): 63–69. http://dx.doi.org/10.2166/wst.2000.0496.

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At Western Platinum Refinery in South Africa, zinc was used for the reduction of the platinum group metals (PGMs) in acidic effluent (palladium filtrate). Owing to the increasing cost of zinc and the risk of zinc pollution, sodium formate was investigated as an alternative reductant. It was found that pH 1.5 was the optimum starting pH for sodium formate reduction. The optimum concentration of sodium formate was found to be 18 g/dm3 at a temperature of approximately 100°C where the process time was 5 hours. The addition of sodium formate increased the pH of the final reaction mixture to approximately pH 4.5. Palladium was the most effectively reduced PGM, exhibiting an average precipitation efficiency of 98%. Difficulty was experienced with the precipitation of platinum (average precipitation efficiency of 47%). The precipitated PGMs were readily dissolved in hydrochloric acid (6 M) and sodium chlorate (2%). A reduction in costs resulted from the discontinuation of the use of zinc for reduction purposes. An additional advantage was that zinc was no longer introduced into the PGM refinery circuits. This effectively reduced the pollution potential of the acidic effluent.

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Willner, J., J. Kaduková, A. Fornalczyk, A. Mrážiková, R. Marcinčáková, and O. Velgosová. "Possibilities Of Metals Extracton From Spent Metallic Automotive Catalytic Converters By Using Biometallurgical Method." Archives of Metallurgy and Materials 60, no. 3 (September 1, 2015): 1877–80. http://dx.doi.org/10.1515/amm-2015-0320.

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Abstract The main task of automotive catalytic converters is reducing the amount of harmful components of exhaust gases. Metallic catalytic converters are an alternative to standard ceramic catalytic converters. Metallic carriers are usually made from FeCrAl steel, which is covered by a layer of Precious Group Metals (PGMs) acting as a catalyst. There are many methods used for recovery of platinum from ceramic carriers in the world, but the issue of platinum and other metals recovery from metallic carriers is poorly described. The article presents results of preliminary experiments of metals biooxidation (Fe, Cr and Al) from spent catalytic converters with metallic carrier, using bacteria of the Acidithiobacillus genus.

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Aleksandrova, Tatyana, and Cyril О’Connor. "Processing of platinum group metal ores in Russia and South Africa: current state and prospects." Journal of Mining Institute 244 (July 30, 2020): 462–73. http://dx.doi.org/10.31897/pmi.2020.4.9.

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The presented study is devoted to a comparative review of the mineral raw material base of platinum group metals (PGMs) and technologies of their processing in South Africa and Russia, the largest PGM producers. Mineralogical and geochemical classification and industrial value of iron-platinum and platinum-bearing deposits are presented in this work. The paper also reviews types of PGM ore body occurrences, ore processing methods (with a special focus on flotation processes), as well as difficulties encountered by enterprises at the processing stage, as they increase recovery of the valuable components. Data on mineralogical features of PGM deposits, including the distribution of elements in the ores, are provided. The main lines of research on mineralogical features and processing of raw materials of various genesis are identified and validated. Sulfide deposits are found to be of the highest industrial value in both countries. Such unconventional PGM sources, as black shale, dunites, chromite, low-sulfide, chromium and titanomagnetite ores, anthropogenic raw materials, etc. are considered. The main lines of research that would bring into processing non-conventional metal sources are substantiated. Analysis of new processing and metallurgical methods of PGM recovery from non-conventional and industrial raw materials is conducted; the review of existing processing technologies for platinum-bearing raw materials is carried out. Technologies that utilize modern equipment for ultrafine grinding are considered, as well as existing reagents for flotation recovery; evaluation of their selectivity in relation to platinum minerals is presented. Basing on the analysis of main technological processes of PGM ore treatment, the most efficient schemes are identified, i.e.,gravity and flotation treatment with subsequent metallurgical processing.

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Matsumoto, Kazuya, Yuto Sezaki, Yuki Hata, and Mitsutoshi Jikei. "Selective Recovery of Platinum (IV) from HCl Solutions Using 2-Ethylhexylamine as a Precipitant." Separations 8, no. 4 (April 1, 2021): 40. http://dx.doi.org/10.3390/separations8040040.

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The selective separation and recovery of specific platinum-group metals (PGMs) from metal mixtures is a significant challenge owing to the similarity of these metals in terms of chemical and physical properties. Among the typical PGMs (Pd, Pt, and Rh), the selective recovery of Pt prior to the recovery of Pd and Rh is in high demand. In this study, we attempted the selective precipitation of Pt(IV) from mixed-metal HCl solutions using 2-ethylhexylamine (2EHA) as a precipitant and achieved the selective precipitation of Pt(IV) from Pd(II) and Rh(III) over a wide range of HCl concentrations. Selective precipitation of Pt(IV) was also achieved from HCl solutions with high levels of base metals, such as Al, Cu, Fe, and Zn. High yields of undegraded 2EHA remaining in the HCl solution after Pt(IV) precipitation were recovered using hydrophobic porous resins. X-ray photoelectron spectroscopy and thermogravimetric measurements revealed that the Pt(IV)-containing precipitate was an ion-pair comprising one [PtCl6]2− and two ammonium cations of 2EHA. The steric hindrance and high hydrophilicity of 2EHA suppressed the formation of Rh(III)- and Pd(II)-containing precipitates, respectively, resulting in the selective precipitation of Pt(IV).

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Gutfleisch, O., N. Schlorke-de Boer, N. Ismail, M. Herrich, A. Walton, J. Speight, I. R. Harris, A. S. Pratt, and A. Züttel. "Hydrogenation properties of nanocrystalline Mg- and Mg2Ni-based compounds modified with platinum group metals (PGMs)." Journal of Alloys and Compounds 356-357 (August 2003): 598–602. http://dx.doi.org/10.1016/s0925-8388(02)01283-5.

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Park, Hyun-Seo. "A study on recovery of Platinum Group Metals(PGMs) from spent automobile catalyst by melting technology." Journal of the Korean Institute of Resources Recycling 20, no. 2 (April 29, 2011): 74–81. http://dx.doi.org/10.7844/kirr.2011.20.2.074.

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Tobón, Mónica, Marion Weber, Joaquín A. Proenza, Thomas Aiglsperger, Sebastián Betancur, Júlia Farré-de-Pablo, Carlos Ramírez, and Núria Pujol-Solà. "Geochemistry of Platinum-Group Elements (PGE) in Cerro Matoso and Planeta Rica Ni-Laterite deposits, Northern Colombia." Boletín de la Sociedad Geológica Mexicana 72, no. 3 (November 28, 2020): A201219. http://dx.doi.org/10.18268/bsgm2020v72n3a201219.

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Platinum-group elements (PGE) are included among the so-called critical metals, and are essential metals for the technological industry. However, there are very few deposits in the world from which these metals can be extracted. The present work investigates three Ni-laterite profiles (hydrous Mg silicate type) formed over the ultramafic rocks of Cerro Matoso and Planeta Rica in Colombia. The main goal is to determine their PGE concentration and distribution, as well as to identify the carrier phases of these noble metals. The highest PGE contents in Cerro Matoso and Planeta Rica are concentrated in the limonite horizon (141–272 ppb), showing a strong decrease towards the saprolite and the underlying serpentinized peridotite (parent rock; < 50 ppb). The highest concentrations correspond to Pt>Ru>Pd and the lowest to Rh<Os<Ir. Such distribution indicates that PGE are mobilized in different proportions by the laterization processes. The high affinity between PGE and Fe favors the formation of PGE-Fe mineral alloys such as the Pt-Ir-Fe-Ni minerals hosted by Fe-oxyhydroxide found in the limonite–saprolite transition zone in Planeta Rica. In addition, in the same zone, nanoparticles of Pt (< 1 µm) were found within framboidal pyrite. Both types of platinum group minerals (PGM) are secondary in origin. In the case of Pt-Ir-Fe-Ni alloys, this interpretation is supported by their morphology and chemical composition, which is comparable with PGE-Fe-Ni alloys found in laterites of Dominican Republic. In the case of Pt nanoparticle, textural relations suggest the neoformation of PGM adhered to the porous edges of altered pyrite. Cerro Matoso and Planeta Rica should be considered as unconventional PGE deposits, if adequate recovery processes can be applied for their recovery as by-products during Ni (+Co) production.

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Essumang, D. K., C. K. Adokoh, and L. Boamponsem. "Levels of Platinum Group Metals in Selected Species (Sarotherodon melanotheron,Chonophorus lateristriga,Macrobrachium vollenhoveniiandCrassostrea tulipa) in Some Estuaries and Lagoons Along the Coast of Ghana." Scientific World JOURNAL 10 (2010): 1971–87. http://dx.doi.org/10.1100/tsw.2010.197.

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The use of some biota as bioindicators of heavy metal pollution has been demonstrated as particularly adequate due to their capacity of bioconcentration. This study evaluated the levels of platinum group metals (PGMs) in some selected species along the coastal belt of Ghana, using the neutron activation analysis (NAA) method. The result was processed to evaluate pollution indices in order to map the distribution of the metals in those species in the lagoons and estuaries along the costal belt of Ghana. The analysis showed significant levels of all PGMs in blackchin tilapia (Sarotherodon melanotheronCichlidae), brown goby (Chonophorus lateristrigaGobiidae), shrimp (Macrobrachium vollenhoveniiPalaemonidae), and mangrove oysters (Crassostrea tulipaOstreidae) in the lagoons and river Pra estuary. However, the oysters showed an elevated mean concentration of 0.13 μ/g (dry weight) Pd. From the pollution indices, most of the sampling sites registered mean contamination factor (CF) values between 1.20 and 3.00 for Pt, Pd, and Rh. The pollution load index (PLI) conducted also gave an average pollution index between 0.79 and 2.37, indicating progressive contamination levels. The results revealed that anthropogenic sources, industrial and hospital effluent, etc., together with vehicular emissions, could be the contributing factors to the deposition of PGMs along the Ghanaian coast.

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Mwase, James M., Jochen Petersen, and J. J. Eksteen. "A conceptual flowsheet for heap leaching of platinum group metals (PGMs) from a low-grade ore concentrate." Hydrometallurgy 111-112 (January 2012): 129–35. http://dx.doi.org/10.1016/j.hydromet.2011.11.012.

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Patel, Charula, Nilesh Bhatt, and Srinivas Palanki. "Assessment of Manganese Oxide and Cobalt Oxide Catalysts for Three Way Catalytic Converter." Kataliz v promyshlennosti 20, no. 4 (July 20, 2020): 286–302. http://dx.doi.org/10.18412/1816-0387-2020-4-286-302.

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Raising number of vehicles emits pollutants responsible for one third of total air pollution. Carbon monoxide (CO), unburned hydrocarbons (HC), and nitrogen oxides (NOx) are the main pollutants from petrol engines. It requires stringent vehicular emission norms to be followed for controlling it. Three Way Catalytic Converter (TWCC) contain Platinum Group Metals (PGMs) as catalyst to reduce exhaust emission and is widely used method that fulfills these standards. Because of high cost of PGMs and considerable advancement in metal oxide preparatory methods, metal oxide catalysts have gained more attraction. Manganese oxide (MnOx) and Cobalt Oxide (CoOx) have displayed impressive redox reactions at lower temperature. MnOx seems to be a suitable contender of Oxygen Storage Capacity (OSC) and Cobalt oxide (CoOx) has displayed an excellent catalytic activity for HC and CO oxidation. Hence, these catalysts attract the attention of researchers. Present paper assesses the prospect of MnOx and CoOx as catalysts for the TWCC for redox reactions of CO, HC and NOx and also in terms of OSC and T50 temperature. It is found that CoOx and MnOx both low cost metal oxide catalysts stand a good chance to replace the noble metals for TWCC.

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Garuti, Giorgio, Massimo Oddone, and José Torres-Ruiz. "Platinum-group-element distribution in subcontinental mantle: evidence from the Ivrea Zone (Italy) and the Betic – Rifean cordillera (Spain and Morocco)." Canadian Journal of Earth Sciences 34, no. 4 (April 1, 1997): 444–63. http://dx.doi.org/10.1139/e17-037.

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The six platinum-group elements (PGE's) Os, Ir, Ru, Rh, Pt, and Pd and Au were analyzed by instrumental neutron-activation analysis after nickel sulfide fire assay, in peridotites and dyke rocks from the orogenic ultramafic massifs of the Ivrea Zone in the Italian western Alps (Baldissero, Balmuccia, Finero) and the Betico–Rifean cordillera in southern Spain and northern Morocco (Ronda, Beni Bousera). The peridotites are considered as variably depleted, and reenriched low lithosphere, whereas the dyke rocks represent polybaric derivatives of basaltic melts (pyroxenites and gabbros), most coming from the underlying asthenosphere. The peridotites have total PGE content in the range 8.6–54.7 ppb, while mantle-normalized patterns generally grade from nearly flat and PGE rich, in less depleted lherzolites, to negative and PGE poor, in residual harzburgites and dunites. Dyke rocks have total PGE's in the range 5.4 – 250 ppb and positive mantle-normalized patterns. Negative anomalies of Ir – Pt are frequently observed in dykes, indicating that both metals were probably retained in the mantle source of these melts. Most of the peridotites display positive anomaly of Au, and in some case are enriched in Ru, Rh, and Pd, but exhibit the same negative anomalies in Ir and Pt as the dykes. These features are ascribed to reintroduction of noble metals into the residual mantle by reaction with the basaltic melts that generated the dykes, or alternatively by recycling of "dyke material" during further partial melting of the host mantle. The role of the sulfide phase as carrier of the recycled PGE is stressed by clear interelemental correlation in peridotites from the Ivrea Zone. Present data provide evidence that zones of PGE enrichment can origin; this way in the subcontinental mantle, and may constitute a potential reservoir for noble metal fertile volcanism in continental rift systems.

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Mbaba, Mziyanda, Taryn M. Golding, and Gregory S. Smith. "Recent Advances in the Biological Investigation of Organometallic Platinum-Group Metal (Ir, Ru, Rh, Os, Pd, Pt) Complexes as Antimalarial Agents." Molecules 25, no. 22 (November 12, 2020): 5276. http://dx.doi.org/10.3390/molecules25225276.

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In the face of the recent pandemic and emergence of infectious diseases of viral origin, research on parasitic diseases such as malaria continues to remain critical and innovative methods are required to target the rising widespread resistance that renders conventional therapies unusable. The prolific use of auxiliary metallo-fragments has augmented the search for novel drug regimens in an attempt to combat rising resistance. The development of organometallic compounds (those containing metal-carbon bonds) as antimalarial drugs has been exemplified by the clinical development of ferroquine in the nascent field of Bioorganometallic Chemistry. With their inherent physicochemical properties, organometallic complexes can modulate the discipline of chemical biology by proffering different modes of action and targeting various enzymes. With the beneficiation of platinum group metals (PGMs) in mind, this review aims to describe recent studies on the antimalarial activity of PGM-based organometallic complexes. This review does not provide an exhaustive coverage of the literature but focusses on recent advances of bioorganometallic antimalarial drug leads, including a brief mention of recent trends comprising interactions with biomolecules such as heme and intracellular catalysis. This resource can be used in parallel with complementary reviews on metal-based complexes tested against malaria.

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Hedrich, Sabrina, Dennis Kraemer, Malte Junge, Herwig Marbler, Michael Bau, and Axel Schippers. "Bioprocessing of oxidized platinum group element (PGE) ores as pre-treatment for efficient chemical extraction of PGE." Hydrometallurgy 196 (September 2020): 105419. http://dx.doi.org/10.1016/j.hydromet.2020.105419.

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Dimitrijevic, Mile, Snezana Milic, Sladjana Alagic, and Ana Radojevic. "Recovery of platinum-group metals (PGMs) from spent automotive catalysts: Part I: The primary and secondary sources of PGMs and their use." Reciklaza i odrzivi razvoj 7, no. 1 (2014): 9–21. http://dx.doi.org/10.5937/ror1401009d.

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Eliopoulos, Demetrios G., and Maria Economou-Eliopoulos. "Trace Element Distribution in Magnetite Separates of Varying Origin: Genetic and Exploration Significance." Minerals 9, no. 12 (December 6, 2019): 759. http://dx.doi.org/10.3390/min9120759.

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Abstract:

Magnetite is a widespread mineral, as disseminated or massive ore. Representative magnetite samples separated from various geotectonic settings and rock-types, such as calc-alkaline and ophiolitic rocks, porphyry-Cu deposit, skarn-type, ultramafic lavas, black coastal sands, and metamorphosed Fe–Ni-laterites deposits, were investigated using SEM/EDS and ICP-MS analysis. The aim of this study was to establish potential relationships between composition, physico/chemical conditions, magnetite origin, and exploration for ore deposits. Trace elements, hosted either in the magnetite structure or as inclusions and co-existing mineral, revealed differences between magnetite separates of magmatic and hydrothermal origin, and hydrothermal magnetite separates associated with calc-alkaline rocks and ophiolites. First data on magnetite separates from coastal sands of Kos Island indicate elevated rare earth elements (REEs), Ti, and V contents, linked probably back to an andesitic volcanic source, while magnetite separated from metamorphosed small Fe–Ni-laterites occurrences is REE-depleted compared to large laterite deposits. Although porphyry-Cu deposits have a common origin in a supra-subduction environment, platinum-group elements (PGEs) have not been found in many porphyry-Cu deposits. The trace element content and the presence of abundant magnetite separates provide valuable evidence for discrimination between porphyry-Cu–Au–Pd–Pt and those lacking precious metals. Thus, despite the potential re-distribution of trace elements, including REE and PGE in magnetite-bearing deposits, they may provide valuable evidence for their origin and exploration.

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Locatelli, Clinio. "Simultaneous square wave stripping voltammetric determination of platinum group metals (PGMs) and lead at trace and ultratrace concentration level." Analytica Chimica Acta 557, no. 1-2 (January 2006): 70–77. http://dx.doi.org/10.1016/j.aca.2005.10.004.

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Dimitrijevic, Mile, Snezana Milic, Sladjana Alagic, and Ana Radojevic. "Recovery of platinum-group metals (PGMS) from spent automotive catalysts: Part II: Automotive catalysts: Structures and principle of operation." Reciklaza i odrzivi razvoj 8, no. 1 (2015): 1–11. http://dx.doi.org/10.5937/ror1501001d.

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Yan, L., and J. S. Zhao. "Study on Pressure-Cyanide Dissolution of Metal Palladium Powder." Advanced Materials Research 554-556 (July 2012): 695–99. http://dx.doi.org/10.4028/www.scientific.net/amr.554-556.695.

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A research study has been undertaken to develop the fundamentals of a method for the direct dissolution of Metal Palladium. At room temperature and pressures, the reaction between sodium cyanide and platinum group metals (PGMs) does not occur because of poor kinetics. However, at elevated temperatures between 100°C and 180°C, PGMs can be dissolved by sodium cyanide like the reaction of gold. In this work, the dissolution of Palladium was measured in pressure clear cyanide solution. The data at different cyanide concentrations, different temperature and different oxygen pressure are obtained. With increasing cyanide concentration and oxygen pressure, the dissolution first increased to a maximum value and then decreased. With increasing temperature the dissolution is increased. The dissolution was found to have a relation of the cyanide and oxygen level. The dissolution were independent of rotation speed for oxygen-saturated solutions and cyanide concentrations above 5 mol.m-3 and were well below chemical reaction-limited for cyanide and oxygen.

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Journal articles on the topic 'Platinum group metals (PGEs)'

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