The system Ag–Pd–Te: phase relations and mineral assemblages

Abstract The phase equilibria in the system Ag−Pd−Te were studied by the technique of using an evacuated silica glass tube at 350° and 450°C. Five ternary phases were synthesized: sopcheite (Pd3Ag4Te4), lukkulaisvaaraite (Pd14Ag2Te9), telargpalite (Pd2−xAg1+xTe) and the previously unknown phases Pd7.5−xAg0.5+xTe3 and Pd2+xAg2−xTe. The synthetic telargpalite has a compositional range from 26 to 29 wt.% Ag, with the formula Pd2−xAg1+xTe, where x varies from 0.09 to 0.22. The phase Pd2+xAg2−xTe has a compositional range from 34 to 35 wt.% Ag, where x varies from 0.18 to 0.24. The phase Pd7.5−xAg0.5+xTe3 forms a solid solution from 4 to 11 wt.% Ag, where x varies from 0.02 to 0.83. Phases Pd20Te7 and Pd13Te3 dissolve up to 3.5 and 2 wt.% Ag, respectively. Other binary palladium tellurides do not dissolve Ag. The phase Pd3Ag4Te4, an analogue of the mineral sopcheite, forms a stable association with hessite and kotulskite it also coexists with lukkulaisvaaraite. Sopcheite is stable up to 383°С. Natural occurrences of hessite, kotulskite and lukkulaisvaaraite together in equilibrium indicate formation above this temperature. Phase relations defined the mineral assemblages that can be expected to occur in nature. The phase Pd7.5−xAg0.5+xTe3 potentially represents a new mineral; it will probably be found in association with lukkulaisvaaraite and telargpalite or telluropalladinite, among other platinum-group minerals. The phase Pd2+xAg2−xTe can be found in association with telargpalite. Mineral assemblages defined in this study can be expected in Cu-Ni-PGE mineral deposits, associated with mafic and ultramafic igneous rocks, particularly in mineralized zones with known silver-palladium tellurides.

[1]  A. Mokhov,et al.  Gold and silver in PGE–Cu–Ni and PGE ores of the Noril’sk deposits, Russia , 2015, Mineralium Deposita.

[2]  F. Laufek,et al.  Lukkulaisvaaraite, Pd14Ag2Te9, a new mineral from Lukkulaisvaara intrusion, northern Russian Karelia, Russia , 2014, Mineralogical Magazine.

[3]  J. Mao,et al.  TELLURIDE AND Bi-SULFOSALT MINERALOGY OF THE YANGZHAIYU GOLD DEPOSIT, XIAOQINLING REGION, CENTRAL CHINA , 2014 .

[4]  S. V. Petrov,et al.  Low-sulfide PGE ore in the Volchetundra gabbro-anorthosite pluton, Kola Peninsula, Russia , 2013, Geology of Ore Deposits.

[5]  Freiburg i. Br.,et al.  Zeitschrift für anorganische und allgemeine Chemie , 2012 .

[6]  M. Drábek,et al.  THE SYSTEM Pd–Sn–Te AT 400°C AND MINERALOGICAL IMPLICATIONS. I. THE BINARY PHASES , 2010 .

[7]  Peter C. Jones,et al.  Footwall-type Cu-Ni-PGE Mineralization in the Broken Hammer Area, Wisner Township, North Range, Sudbury Structure , 2008 .

[8]  T. Grammatikopoulos,et al.  PLATINUM-GROUP MINERALS FROM THE MECHANIC SETTLEMENT PLUTON, SOUTHERN NEW BRUNSWICK, CANADA , 2007 .

[9]  B. Harbrecht,et al.  Crystal Growth, Structure and Properties of the Palladium-rich Telluride Pd13Te3† , 2006 .

[10]  L. Bindi,et al.  Garavellite, FeSbBiS4, from the Caspari mine, North Rhine-Westphalia, Germany: composition, physical properties and determination of the crystal structure , 2005 .

[11]  P. Spry,et al.  Empressite, AgTe, from the Empress-Josephine mine, Colorado, U.S.A.: Composition, physical properties, and determination of the crystal structure , 2004 .

[12]  Y. Thibault,et al.  Pd–Ag TELLURIDES FROM A Cl-RICH ENVIRONMENT IN THE LUKKULAISVAARA LAYERED INTRUSION, NORTHERN RUSSIAN KARELIA , 2001 .

[13]  M. Economou-Eliopoulos,et al.  Palladium, platinum and gold concentration in porphyry copper systems of Greece and their genetic significance , 2000 .

[14]  B. Stribrny,et al.  Platinum-group elements in porphyry copper deposits: a reconnaissance study , 1999 .

[15]  Peter C. Jones,et al.  Platinum-group minerals in fluid inclusions from the Marathon deposit, Coldwell Complex, Canada , 1996 .

[16]  J. Schneider,et al.  X-ray powder diffraction of Ag2Te at temperatures up to 1123 K , 1993 .

[17]  I. P. Laputina,et al.  LOW-SULFIDE PLATINUM GROUP MINERALIZATION OF THE LUKKULAISVAARA PLUTON, NORTHERN KARELIA , 1992 .

[18]  D. H. Watkinson,et al.  Hydrothermal origin of platinum-group mineralization in low-temperature copper sulfide-rich assemblages, Salt Chuck Intrusion, Alaska , 1992 .

[19]  H. Okamoto.  The pd-te system (palladium-tellurium) , 1992 .

[20]  H. Kleykamp,et al.  On the constitution of the Pd-Te system up to 28 at.% Te , 1990 .

[21]  R. Mitchell,et al.  PLATINUM.GROUP MINERALS AND TELLURIDES FROM THE GEORDIE LAKE INTRUSION, COLDWELL COMPLEX, NORTHWESTERN ONTARIO , 1990 .

[22]  G. Y. Chao,et al.  Phase relations in the Pd-Te system , 1990 .

[23]  W. T. Thompson,et al.  The Ag Pd Silver Palladium System , 1988 .

[24]  H. Ipser,et al.  Transition-metal-chalcogen systems X: The Pd-Te phase diagram , 1986 .

[25]  S. K. Khera,et al.  Phase diagram of the PdTe system , 1986 .

[26]  J. Laflamme,et al.  Sopcheite; a second Canadian occurrence, from the Lac-des-Iles Complex, Ontario , 1984 .

[27]  A. Bogdanova,et al.  Sopcheite, Ag4Pd3Te4, a new mineral from copper-nickel ores of the Monchegorsk pluton , 1983 .

[28]  M. Zabel,et al.  A Novel Three-Dimensional Tellurium Array: High-Pressure Synthesis and Crystal Structure of AgTe3† , 1982 .

[29]  J. M. Stewart,et al.  Keithconnite, telluropalladinite and other Pd-Pt tellurides from the Stillwater Complex, Montana , 1979 .

[30]  K. Schubert,et al.  Kristallstruktur von Pd9Te4 , 1978 .

[31]  K. Schubert,et al.  Kristallstruktur von pd3Te2 , 1977 .

[32]  K. Schubert,et al.  Kristallstruktur von Pd20Sb7 und Pd20Te7 , 1977 .

[33]  L. Cabri,et al.  Stibiopalladinite from the type locality , 1976 .

[34]  L. Cabri,et al.  The mineralogy of the platinum-group elements from some copper-nickel deposits of the Sudbury area, Ontario , 1976 .

[35]  V. A. Kovalenker,et al.  Tellurium minerals in copper-nickel sulfide ores at Talnakh and Oktyabr' (Noril'sk district) , 1973 .

[36]  G. Kullerud.  Experimental Techniques in Dry Sulfide Research , 1971 .

[37]  M. El-Boragy,et al.  Kristallstruktur von Pd5Sb2 und Ni5As2 und einigen varianten , 1970 .

[38]  C. J. Ksanda,et al.  Phase relations in the silver-tellurium system , 1966 .

[39]  G. A. Kingston.  The Occurrence of Platinoid Bismuthotellurides in the Merensky Reef at Rustenburg Platinum Mine in the Western Bushveld , 1966 .

[40]  M. Buerger.  X-ray powder data for ore minerals: The Peacock atlas*. , 1962 .

[41]  A. Frueh.  The structure of hessite, Ag2Te-III , 1959 .

[42]  C. Wagner,et al.  Measurements on Galvanic Cells Involving Solid Electrolytes , 1957 .

[43]  F. Grønvold,et al.  On the Sulfides, Selenides, and Tellurides of Palladium. , 1956 .

[44]  Rudolf Ruer.  Über die Legierungen des Palladiums mit Silber , 1906 .