Intermetallic compounds, copper and palladium alloys in Au–Pd ore of the Skaergaard pluton, Greenland

Rudashevsky, N. S.; Rudashevsky, V. N.; Nielsen, Thorkild

doi:10.1134/s1075701515080085

Cited by 11 publications

(82 citation statements)

References 21 publications

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“…Although the mass activity on ordered Pt 3 Cr/C was slightly lower than the disordered Pt 3 Cr/C alloy nanoparticles, the Pt 3 Cr intermetallic nanoparticles displayed much higher stability. Recently, Pd-based intermetallic catalysts have also aroused some concerns. − Compared with disordered phase, ordered PdCu (B2-type) phases exhibited lower overpotential and higher oxygen reduction/evolution kinetic rate, which contributed to a remarkable enhancement in cyclic stability and an superior rate capability in Li–O 2 battery . Furthermore, ordered Pd 3 Fe intermetallic has been reported to exhibit significantly enhanced activity and durability toward ORR and Li–air full-cell cycling performance …”

Section: Introductionmentioning

confidence: 99%

Recent Advances of Structurally Ordered Intermetallic Nanoparticles for Electrocatalysis

et al. 2018

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Structurally ordered intermetallic phases have exhibited higher and higher electrocatalytic activity and stability than disordered alloys in many reactions such as the oxygen reduction reaction (ORR) and small-molecule (hydrogen, formic acid, or ethanol) oxidation reactions. The enhanced electrocatalytic activity could be derived from the definite composition and predictable control over structural, geometric, and electronic effects. This review, based on the understanding of the catalytic mechanism of structurally ordered intermetallic nanoparticles, provides a comprehensive acknowledgment of how the particle size and morphology affect the catalytic performance. The strategy for reducing particle size and the impact of particle size on electrocatalysis will be first introduced. Then, recent developments in the synthesis and design of morphology-controlled catalysts are summarized. The structure−activity relationship between the catalytic activity and morphology including core−shell/hollow and porosity will be highlighted. Finally, the current challenges and future developments are provided. On the basis of this review, intermetallic nanoparticles will shed light on the future development of electrocatalysts for fuel cells and metal-air batteries.

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Section: Introductionmentioning

confidence: 99%

Recent Advances of Structurally Ordered Intermetallic Nanoparticles for Electrocatalysis

et al. 2018

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“…Although there is other evidence of aqueous fluid exsolution in the interstitial melt at Skaergaard such as the extensive oxidation exsolution textures of Fe-Ti oxides (Buddington and Lindsley 1964;Bollingberg 1995), and the sulphides and sulphide alloy aggregates at the level of mineralisation associated with inclusions of hydrous minerals (e.g. Godel et al 2014;Rudashevsky et al 2015), there is no conclusive answer from the Cl and F apatite data on how and when a fluid exsolved.…”

Section: The Volatile Content Of Skaergaard Interstitial Apatitementioning

confidence: 99%

The volatile and trace element composition of apatite in the Skaergaard intrusion, East Greenland

Maibom

Ulrich

Whitehouse

et al. 2021

Contrib Mineral Petrol

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“…Neither of these models, however, explain the extremely well-controlled stratigraphic distribution of PGE and Au in the layered gabbros of the Skaergaard intrusion (Nielsen et al 2015), or the lateral variations in the precious metal parageneses (Nielsen et al 2019a). A concordant layer that can be followed across a layered gabbro intrusion is in a classic orthomagmatic model understood to be a time marker.…”

Section: Introductionmentioning

confidence: 97%

“…The mineralisation was initially referred to as the Platinova Reef (Bird et al 1991) and named after the exploration company that discovered the mineralisation. It is not a reef in any common sense of the word, but a series of stratiform, bowl-shaped layers of gabbro enriched in precious metals (Nielsen et al 2015). The mineralised gabbros show remarkable and systematic lateral and stratigraphic variations in ratios between PGE and Au and between precious metals and copper (Andersen et al 1998).…”

Section: Introductionmentioning

confidence: 99%

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The PGE-Au Mineralisation of the Skaergaard intrusion: precious metal minerals, petrography and ore genesis

Rudashevsky¹,

Nielsen²,

Rudashevsky³

2023

GEUS Bulletin

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The Skaergaard PGE-Au Mineralisation, alias the Platinova Reef, is hosted in a series of mineralisation levels within a suite of bowl-shaped macrorhythmic layers in the upper Middle Zone of the Skaergaard intrusion. The intrusion is exposed 68°N in East Greenland. The occurrence defines its own type due to its exceptional structure and mineralogy. A wealth of mineralogical data is available in laboratory reports for individual samples and in peer-reviewed publications, but none of these account for the lateral and stratigraphic distribution of PGE and Au parageneses in the gabbros of the intrusion. In this study, we collate and describe the mineralogical data for the first-formed PGE-rich and last-formed gold-rich mineralisation levels and integrate these with petrogenetic models. Recovery of >4000 grains of precious metal phases allow a detailed study of their distribution and compositions throughout the mineralisation, re-equilibration during cooling, inter-grain relationships and relationships to Cu-Fe sulphides and the gabbroic host rocks. The sulphides are dominated by bornite, chalcocite and minor chalcopyrite. All other sulphides, such as pentlandite, are very rare. Fifty-four different precious metal phases are identified in this study, and include the new IMA approved minerals skaergaardite (PdCu), nielsenite (Pd3Pb) and naldrettite (Pd2Sb). Precious metal phases include (1) intermetallic compounds and alloys of Cu and Pd; (2) intermetallic compounds and alloys of Au and Cu (Ag); (3) sulphides of Pd, Cu (Ag, Cd, Hg, Tl); (4) arsenides of Pd (Pt, Ni) and (5) intermetallic compounds of Pd, Cu with Sn, Pb, Te (Sb, Bi). Skaergaardite (PdCu) is the dominant PGE mineral in the lower and main PGE mineralisation level (Pd5). It is accompanied at the western margin of the intrusions by the sulphides vasilite (Pd16S7) and vysotskite (PdS) but is rare at the eastern margin, which is dominated by plumbide zvyagintsevite (Pd3Pb). Gold phases include a suite of intermetallic compounds and alloys from AuCu3 to native gold and are dominated by tetra-auricupride (AuCu). Gold is concentrated in the tops of individual mineralisation levels and in the uppermost precious metal–bearing mineralisation level, followed by stratiform Cu-rich mineralisation levels. Precious metal parageneses demonstrate formation and re-equilibration from liquidus to subsolidus temperatures and control by local geochemical environments. The mineralisation is syn-magmatic and the result of fractionation and evolution in the remaining bulk-silicate liquid and crystal mushes. Fractionation led to sulphide saturation and formation of immiscible sulphide melt droplets. This was followed by reaction with mush melts and re-equilibration to lower temperatures, first under the roof and subsequently after slumping to the floor in mushes of macrorhythmic layers. Droplets of sulphide melt formed between 1030–1050°C and trapped precious metals. The subsequent reaction between sulphide melt and interstitial Fe-rich immiscible melt at c. 1015°C, and redistribution to coexisting melt and fluid, led to the separation of PGE, Au and Cu and their up- and inward transport. Magmatic fluids as well as volatile-rich residual silicate melts were retained in gabbros at the margins and resulted in precious metal parageneses in equilibrium with hydrous low-temperature silicate parageneses.

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Intermetallic compounds, copper and palladium alloys in Au–Pd ore of the Skaergaard pluton, Greenland

Cited by 11 publications

References 21 publications

Recent Advances of Structurally Ordered Intermetallic Nanoparticles for Electrocatalysis

Recent Advances of Structurally Ordered Intermetallic Nanoparticles for Electrocatalysis

The volatile and trace element composition of apatite in the Skaergaard intrusion, East Greenland

The PGE-Au Mineralisation of the Skaergaard intrusion: precious metal minerals, petrography and ore genesis

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