scholarly journals Palladogermanide Pd2Ge from sulfidized anorthosite of the Yoko-Dovyren intrusion: first finding in Russia

2019 ◽  
Vol 485 (6) ◽  
pp. 741-744 ◽  
Author(s):  
E. M. Spiridonov ◽  
D. A. Orsoev ◽  
A. A. Ariskin ◽  
E. V. Kislov ◽  
N. N. Korotaeva ◽  
...  
Keyword(s):  
Noble Metal ◽  
Layered Intrusion ◽  
Sulfide Ores ◽  
Bottom Part ◽  
First Finding

The Yoko-Dovyren ultramafic-mafic layered intrusion includes the Baikal deposit of Cu-Ni sulfide ores with Pt-Pd mineralization in the bottom part, and “horizons” and pockets of low-sulfide ores with Pt-Pd mineralization at the upper levels of the section. The highest concentration of Pd, Pt, Au, Ag, Hg, and Cd, as well as the widest variability in the noble-metal minerals, is typical of the vein-like bodies of anorthosite and pegmatoid anorthosite in the upper part of the critical horizon at the boundary between troctolite and the overlying gabbronorite. Most of the noble-metal minerals are the postmagmatic pneumatolytic (fluid-metasomatic) phases. Among them are palladogermanide with 19.8 wt % Ge, paolovite with 8.1% Ge, and zvyagintsevite with 0.55% Ge. The composition of palladogermanide is Pd2.03(Ge0.80As0.15Bi0.02)0.97; Ge is significantly replaced with As in this phase, which is typical of endogenic Ge minerals.

scholarly journals Germanium-rich palladium minerals – palladogermanide pd2ge, paolovite pd2 (sn, ge), zvyagintsevite in sulfide-bearing anorthosites of the Yoko-Dovyren pluton, Baikal region

2019 ◽  
Vol 64 (5) ◽  
pp. 554-558
Author(s):  
E. M. Spiridonov ◽  
D. A. Orsoev ◽  
A. A. Ariskin ◽  
E. V. Kislov ◽  
N. N. Korotaeva ◽  
...  
Keyword(s):  
Intermetallic Compounds ◽  
Noble Metal ◽  
Baikal Region ◽  
Sulfide Ores ◽  
Bottom Part ◽  
Sulfide Ore ◽  
Carbonaceous Shales ◽  
Ultramafic Intrusion ◽  
Critical Unit

The bottom part of the Yoko-Dovyren layered mafic–ultramafic intrusion hosts the Baikalskoe deposit of Cu–Ni sulfide ores with Pt–Pd mineralization, and the stratigraphically higher portion of the intrusion includes units and pockets with low-sulfide ore with Pt–Pd mineralization. The maximum Pd, Pt, Au, Ag, Hg, and Cd concentrations and the greatest number of noble-metal minerals, including those containing Ge, are typical of vein-shaped sulfide-bearing anorthosite bodies and pegmatoid anorthosites in the upper part of the Critical Unit, at the boundary between the troctolite unit and overlying gabbronorite. The noble-metal minerals were produced mostly by postmagmatic pneumatolytic (fluid–metasomatic) processes. These minerals are kotulskite, moncheite, zvyagintsevite, telargpalite, paolovite, and other Pd and Pt chalcogenides and intermetallic compounds, including palladogermanide that contains 19.8 wt % Ge (the first find in Russia), paolovite with 8.1 wt % Ge (first find), and Au-rich zvyagintsevite that bears 0.55 wt % Ge. The palladogermanide has the composition Pd2.03(Ge0.80As0.15Bi0.02)0.97, and much of its Ge is substituted for As, as is typical of endogenic Ge minerals. The composition of the Ge-paolovite isPd2.02(Sn0.54Ge0.35Sb0.05As0.04)0.98. The possible source of the germanium is contact-metasomatic pyrite-bearing paralic carbonaceous shales hosting the intrusion.

scholarly journals New Geochemical and Mineralogical Data on Rocks and Ores of the NE Flank of the Oktyabr’skoe Deposit (Norilsk Area) and a View on Their Origin

Minerals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 44
Author(s):  
Nadezhda Krivolutskaya ◽  
Yana Bychkova ◽  
Bronislav Gongalsky ◽  
Irina Kubrakova ◽  
Oksana Tyutyunnik ◽  
...  
Keyword(s):  
Complex Structure ◽  
Massive Sulfide ◽  
Geological Structure ◽  
Chemical Compositions ◽  
Olivine Gabbro ◽  
Sulfide Ores ◽  
Intrusive Body ◽  
Bottom Part ◽  
Entire Area ◽  
Almost All

The Oktyabr’skoe deposit in the Norilsk ore district is the largest platinum-copper-nickel deposit in the world. It contains a huge main orebody (2.4 km3) of massive sulfide ores and some smaller sulfide bodies. Almost all publications on this deposit are devoted to the main orebody. However, to solve the problems of the deposit genesis, it is necessary to take into account the geological structure of the entire area and the composition of all orebodies. For the first time we present data on the inner structure, geochemical and mineralogical characteristics of the intrusive body, and related the disseminated and massive sulfide ores (orebody number C-5) in the northeastern flank of the deposit. The intrusion studied in the core of the borehole RG-2 consists of several horizons including the following rock varieties (from bottom to top): olivine gabbro-dolerites, taxitic gabbro-dolerites, picritic gabbro-dolerites, troctolites, olivine-free gabbro-dolerites, ferrogabbro, and leucogabbro. The intrusion shows a strong differentiated inner structure where high-Mg rocks (up to 25 wt.% MgO troctolites and picritic gabbro-dolerites) in the bottom are associated with low-Mg rocks (6–7 wt.%, gabbro-dolerites, leucogabbro, ferrogabbro) without intermediate differentiated members (8–12 wt.% MgO olivine gabbro-dolerites). Rocks are characterized by low TiO2 content (≤1 wt.%). Taxitic gabbro-dolerites, picritic gabbro-dolerites, and troctolites contain disseminated sulfide chalcopyrite-pyrrhotite mineralization (32 m thick). Cu and Ni concentrations reach up 0.74 and 0.77 wt.%, respectively. Massive ores (27 m) occur in the bottom part of the intrusion. The ores consist of pentlandite, chalcopyrite and pyrrhotite, the latter mineral dominates. Their chemical composition is stable: Cu/Ni ~1, Pd/Pt varies from 5 to 6. The C-5 orebody is similar to the C-3 orebody in terms of mineral and chemical compositions, and differ from the nearby the C-4 orebody which is characterized by a Cu/Ni ratio changing from 5 to 8. On the basis of geochemical and mineralogical data, it is assumed that orebodies C-3 and C-5 are associated with one intrusion, while the orebody number C-4 is related to another intrusive body. Thus, the deposit has a more complex structure and includes several more intrusions than is usually considered.

Analytical Electron Microscopy study of two vehicle-aged automotive exhaust catalysts having dissimilar activities

1989 ◽  
Vol 47 ◽  
pp. 272-273
Author(s):  
Sooho Kim ◽  
M. J. D’Aniello
Keyword(s):  
Electron Microscopy ◽  
Particle Size ◽  
Noble Metal ◽  
Catalyst Deactivation ◽  
Analytical Electron Microscopy ◽  
Microscopy Study ◽  
Metal Particles ◽  
Automotive Exhaust ◽  
Exhaust Catalysts ◽  
Analytical Electron

Automotive catalysts generally lose-agtivity during vehicle operation due to several well-known deactivation mechanisms. To gain a more fundamental understanding of catalyst deactivation, the microscopic details of fresh and vehicle-aged commercial pelleted automotive exhaust catalysts containing Pt, Pd and Rh were studied by employing Analytical Electron Microscopy (AEM). Two different vehicle-aged samples containing similar poison levels but having different catalytic activities (denoted better and poorer) were selected for this study.The general microstructure of the supports and the noble metal particles of the two catalysts looks similar; the noble metal particles were generally found to be spherical and often faceted. However, the average noble metal particle size on the poorer catalyst (21 nm) was larger than that on the better catalyst (16 nm). These sizes represent a significant increase over that found on the fresh catalyst (8 nm). The activity of these catalysts decreases as the observed particle size increases.

Interlayer confinement synthesis of Ir nanodots/dual carbon as an electrocatalyst for overall water splitting

2020 ◽  
Author(s):  
Yaru Li ◽  
Yu-Quan Zhu ◽  
Weili Xin ◽  
Song Hong ◽  
Xiaoying Zhao ◽  
...  
Keyword(s):  
Water Splitting ◽  
Noble Metal ◽  
High Efficiency ◽  
Overall Water Splitting ◽  
Highly Dispersed

Rationally designing low-content and high-efficiency noble metal nanodots offers opportunities to enhance electrocatalytic performances for water splitting. However, the preparation of highly dispersed nanodots electrocatalysts remains a challenge. Herein, we...

Sign in / Sign up

Export Citation Format

Share Document