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Platinum group

February 16, 2024

Platinum group metals (PGMs) in the periodic table
H   He
Li Be   B C N O F Ne
Na Mg   Al Si P S Cl Ar
K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr
Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe
Cs Ba * Lu Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn
Fr Ra ** Lr Rf Db Sg Bh Hs Mt Ds Rg Cn Nh Fl Mc Lv Ts Og
 
* La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb
** Ac Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No
   Platinum group metals
   Other noble metals

The platinum-group metals (PGMs), also known as the platinoids, platinides, platidises, platinum group, platinum metals, platinum family or platinum-group elements (PGEs), are six noble, precious metallic elements clustered together in the periodic table. These elements are all transition metals in the d-block (groups 8, 9, and 10, periods 5 and 6).[1]

The six platinum-group metals are ruthenium, rhodium, palladium, osmium, iridium, and platinum. They have similar physical and chemical properties, and tend to occur together in the same mineral deposits.[2] However, they can be further subdivided into the iridium-group platinum-group elements (IPGEs: Os, Ir, Ru) and the palladium-group platinum-group elements (PPGEs: Rh, Pt, Pd) based on their behaviour in geological systems.[3]

The three elements above the platinum group in the periodic table (iron, nickel and cobalt) are all ferromagnetic; these, together with the lanthanide element gadolinium (at temperatures below 20 °C),[4] are the only known transition metals that display ferromagnetism near room temperature.

History edit

Naturally occurring platinum and platinum-rich alloys were known by pre-Columbian Americans for many years.[5] However, even though the metal was used by pre-Columbian peoples, the first European reference to platinum appears in 1557 in the writings of the Italian humanist Julius Caesar Scaliger (1484–1558) as a description of a mysterious metal found in Central American mines between Darién (Panama) and Mexico ("up until now impossible to melt by any of the Spanish arts").[5]

The name platinum is derived from the Spanish word platina “little silver", the name given to the metal by Spanish settlers in Colombia. They regarded platinum as an unwanted impurity in the silver they were mining.[5][6]

By 1815, rhodium and palladium had been discovered by William Hyde Wollaston, and iridium and osmium by his close friend and collaborator Smithson Tennant.[7]

Properties and uses edit

 
Replica of the NIST national prototype kilogram standard, made in 90% platinum, 10% iridium alloy
Significant uses of selected PGMs, 1996[1]
PGM Use Thousand Toz
Palladium autocatalysts 4470
electronics 2070
dental 1830
chemical reagents 230
Platinum jewelry 2370
autocatalysts 1830
Rhodium autocatalysts 490

The platinum metals have many useful catalytic properties. They are highly resistant to wear and tarnish, making platinum, in particular, well suited for fine jewellery. Other distinctive properties include resistance to chemical attack, excellent high-temperature characteristics, high mechanical strength, good ductility, and stable electrical properties.[8] Apart from their application in jewellery, platinum metals are also used in anticancer drugs, industries, dentistry, electronics, and vehicle exhaust catalysts (VECs).[9] VECs contain solid platinum (Pt), palladium (Pd), and rhodium (Rh) and are installed in the exhaust system of vehicles to reduce harmful emissions, such as carbon monoxide (CO), by converting them into less harmful emissions.[10]

Occurrence edit

Generally, ultramafic and mafic igneous rocks have relatively high, and granites low, PGE trace content. Geochemically anomalous traces occur predominantly in chromian spinels and sulfides. Mafic and ultramafic igneous rocks host practically all primary PGM ore of the world. Mafic layered intrusions, including the Bushveld Complex, outweigh by far all other geological settings of platinum deposits.[11][12][13][14] Other economically significant PGE deposits include mafic intrusions related to flood basalts, and ultramafic complexes of the Alaska, Urals type.[12]: 230 

PGM minerals edit

Typical ores for PGMs contain ca. 10 g PGM/ton ore, thus the identity of the particular mineral is unknown.[15]

Platinum edit

Platinum can occur as a native metal, but it can also occur in various different minerals and alloys.[16][17] That said, Sperrylite (platinum arsenide, PtAs2) ore is by far the most significant source of this metal.[18] A naturally occurring platinum-iridium alloy, platiniridium, is found in the mineral cooperite (platinum sulfide, PtS). Platinum in a native state, often accompanied by small amounts of other platinum metals, is found in alluvial and placer deposits in Colombia, Ontario, the Ural Mountains, and in certain western American states. Platinum is also produced commercially as a by-product of nickel ore processing. The huge quantities of nickel ore processed makes up for the fact that platinum makes up only two parts per million of the ore. South Africa, with vast platinum ore deposits in the Merensky Reef of the Bushveld complex, is the world's largest producer of platinum, followed by Russia.[19][20] Platinum and palladium are also mined commercially from the Stillwater igneous complex in Montana, USA. Leaders of primary platinum production are South Africa and Russia, followed by Canada, Zimbabwe and USA.[21]

Osmium edit

Osmiridium is a naturally occurring alloy of iridium and osmium found in platinum-bearing river sands in the Ural Mountains and in North and South America. Trace amounts of osmium also exist in nickel-bearing ores found in the Sudbury, Ontario, region along with other platinum group metals. Even though the quantity of platinum metals found in these ores is small, the large volume of nickel ores processed makes commercial recovery possible.[20][22]

Iridium edit

Metallic iridium is found with platinum and other platinum group metals in alluvial deposits. Naturally occurring iridium alloys include osmiridium and iridosmine, both of which are mixtures of iridium and osmium. It is recovered commercially as a by-product from nickel mining and processing.[20]

Ruthenium edit

Ruthenium is generally found in ores with the other platinum group metals in the Ural Mountains and in North and South America. Small but commercially important quantities are also found in pentlandite extracted from Sudbury, Ontario, and in pyroxenite deposits in South Africa.[20]

Rhodium edit

The industrial extraction of rhodium is complex, because it occurs in ores mixed with other metals such as palladium, silver, platinum, and gold. It is found in platinum ores and obtained free as a white inert metal which is very difficult to fuse. Principal sources of this element are located in South Africa, Zimbabwe, in the river sands of the Ural Mountains, North and South America, and also in the copper-nickel sulfide mining area of the Sudbury Basin region. Although the quantity at Sudbury is very small, the large amount of nickel ore processed makes rhodium recovery cost effective. However, the annual world production in 2003 of this element is only 7 or 8 tons and there are very few rhodium minerals.[23]

Palladium edit

Palladium is preferentially hosted in sulphide minerals, primarily in pyrrhotite.[12] Palladium is found as a free metal and alloyed with platinum and gold with platinum group metals in placer deposits of the Ural Mountains of Eurasia, Australia, Ethiopia, South and North America. However it is commercially produced from nickel-copper deposits found in South Africa and Ontario, Canada. The huge volume of nickel-copper ore processed makes this extraction profitable in spite of its low concentration in these ores.[23]

Production edit

 
Process flow diagram for the separation of the platinum group metals.

The production of individual platinum group metals normally starts from residues of the production of other metals with a mixture of several of those metals. Purification typically starts with the anode residues of gold, copper, or nickel production. This results in a very energy intensive extraction process, which leads to environmental consequences. Carbon dioxide emissions are expected to rise as a result of increased demand for platinum metals and there is likely to be expanded mining activity in the Bushveld Igneous Complex because of this. Further research is needed to determine the environmental impacts.[24] Classical purification methods exploit differences in chemical reactivity and solubility of several compounds of the metals under extraction.[25] These approaches have yielded to new technologies that utilize solvent extraction.

Separation begins with dissolution of the sample. If aqua regia is used, the chloride complexes are produced. Depending on the details of the process, which are often trade secrets, the individual PGMs are obtained as the following compounds: the poorly soluble (NH4)2IrCl6 and (NH4)2PtCl6, PdCl2(NH3)2, the volatile OsO4 and RuO4, and [RhCl(NH3)5]Cl2.[26]

Production in nuclear reactors edit

Main article: Synthesis of precious metals

Significant quantities of the three light platinum group metals—ruthenium, rhodium and palladium—are formed as fission products in nuclear reactors.[27] With escalating prices and increasing global demand, reactor-produced noble metals are emerging as an alternative source. Various reports are available on the possibility of recovering fission noble metals from spent nuclear fuel.[28][29][30]

Environmental concerns edit

It was previously thought that platinum group metals had very few negative attributes in comparison to their distinctive properties and their ability to successfully reduce harmful emission from automobile exhausts.[31] However, even with all the positives of platinum metal use, the negative effects of their use need to be considered in how it might impact the future. For example, metallic Pt are considered to not be chemically reactive and non-allergenic, so when Pt is emitted from VECs it is in metallic and oxide forms it is considered relatively safe.[32] However, Pt can solubilise in road dust, enter water sources, the ground, and increase dose rates in animals through bioaccumulation.[32] These impacts from platinum groups were previously not considered, however[33] over time the accumulation of platinum group metals in the environment may actually pose more of a risk then previously thought.[33] Future research is needed to fully grasp the threat of platinum metals, especially since as more internal combustion cars are driven, the more platinum metal emissions there are.

The bioaccumulation of Pt metals in animals can pose a significant health risk to both humans and biodiversity. Species will tend to get more toxic if their food source is contaminated by these hazardous Pt metals emitted from VECs. This can potentiality harm other species, including humans if we eat these hazardous animals, such as fish.[33]

 
Cisplatin is a platinum based drug used in therapy of human neoplasms. The medical success of cisplatin is conflicted as a result of severe side effects.

Platinum metals extracted during the mining and smelting process can also cause significant environmental impacts. In Zimbabwe, a study showed that platinum group mining caused significant environmental risks, such as pollution in water sources, acidic water drainage, and environmental degradation.[34]

Another hazard of Pt is being exposed to halogenated Pt salts, which can cause allergic reactions in high rates of asthma and dermatitis. This is a hazard that can sometimes be seen in the production of industrial catalysts, causing workers to have reactions.[32] Workers removed immediately from further contact with Pt salts showed no evidence of long-term effects, however continued exposure could lead to health effects.[32]

Platinum use in drugs also may need to be reevaluated, as some of the side effects to these drugs include nausea, hearing loss, and nephrotoxicity.[32] Handling of these drugs by professionals, such as nurses, have also resulted in some side effects including chromosome aberrations and hair loss. Therefore, the long term effects of platinum drug use and exposure need to be evaluated and considered to determine if they are safe to use in medical care.

While exposure of relatively low volumes of platinum group metal emissions may not have any long-term health effects, there is considerable concern for how the accumulation of Pt metal emissions will impact the environment as well as human health. This is a threat that will need more research to determine the safe levels of risk, as well as ways to mitigate potential hazards from platinum group metals.[35]

See also edit

Notes edit

  1. ^ a b Renner, H.; Schlamp, G.; Kleinwächter, I.; Drost, E.; Lüschow, H. M.; Tews, P.; Panster, P.; Diehl, M.; et al. (2002). "Platinum group metals and compounds". Ullmann's Encyclopedia of Industrial Chemistry. Wiley. doi:10.1002/14356007.a21_075. ISBN 3527306730.
  2. ^ Harris, D. C.; Cabri L. J. (1991). "Nomenclature of platinum-group-element alloys; review and revision". The Canadian Mineralogist. 29 (2): 231–237.
  3. ^ Rollinson, Hugh (1993). Using Geochemical Data: Evaluation, Presentation, Interpretation. Longman Scientific and Technical. ISBN 0-582-06701-4.
  4. ^ Lide, D. R., ed. (2005). CRC Handbook of Chemistry and Physics (86th ed.). Boca Raton (FL): CRC Press. p. 4.122. ISBN 0-8493-0486-5.
  5. ^ a b c Weeks, M. E. (1968). Discovery of the Elements (7 ed.). Journal of Chemical Education. pp. 385–407. ISBN 0-8486-8579-2. OCLC 23991202.
  6. ^ Woods, Ian (2004). The Elements: Platinum. Benchmark Books. ISBN 978-0-7614-1550-3.
  7. ^ Platinum Metals Rev., 2003, 47, (4), 175. Bicentenary of Four Platinum Group Metals PART I: RHODIUM AND PALLADIUM – EVENTS SURROUNDING THEIR DISCOVERIES (W. P. Griffith)
  8. ^ Hunt, L. B.; Lever, F. M. (1969). "Platinum Metals: A Survey of Productive Resources to industrial Uses" (PDF). Platinum Metals Review. 13 (4): 126–138. Retrieved 2009-10-02.
  9. ^ Ravindra, Khaiwal; Bencs, László; Van Grieken, René (2004). "Platinum group elements in the environment and their health risk". Science of the Total Environment. 318 (1–3): 1–43. Bibcode:2004ScTEn.318....1R. doi:10.1016/S0048-9697(03)00372-3. hdl:2299/2030. PMID 14654273.
  10. ^ Aruguete, Deborah M.; Wallace, Adam; Blakney, Terry; Kerr, Rose; Gerber, Galen; Ferko, Jacob (2020). "Palladium release from catalytic converter materials induced by road de-icer components chloride and ferrocyanide". Chemosphere. 245: 125578. Bibcode:2020Chmsp.245l5578A. doi:10.1016/j.chemosphere.2019.125578. PMID 31864058. S2CID 209440501.
  11. ^ Buchanan, D. L. (2002). Cabri, L. J. (ed.). "Geology of Platinum Group Elements". CIM Special Volume 54: The Geology, Geochemistry, Mineralogy and Mineral Beneficiation of Platinum-group Elements. Montréal: Canadian Institute of Mining, Metallurgy and Petroleum.
  12. ^ a b c Pohl, Walter L. (2011). Economic Geology : Principles and Practice. Oxford: Wiley-Blackwell. ISBN 978-1-4443-3662-7.
  13. ^ Zereini, Fathi; Wiseman, Clare L.S. (2015). Platinum Metals in the Environment. Berlin: Springer Professional.
  14. ^ Mungall, J. E.; Naldrett, A. J. (2008). "Ore Deposits of the Platinum-Group Elements". Elements. 4 (4): 253–258. doi:10.2113/GSELEMENTS.4.4.253.
  15. ^ Bernardis, F. L.; Grant, R. A.; Sherrington, D. C. (2005). "A review of methods of separation of the platinum-group metals through their chloro-complexes". Reactive and Functional Polymers. 65 (3): 205–217. doi:10.1016/j.reactfunctpolym.2005.05.011.
  16. ^ "Mineral Profile: Platinum". British Geological Survey. September 2009. Retrieved 6 February 2018.
  17. ^ "Search Minerals By Chemistry - Platinum". www.mindat.org. Retrieved 2018-02-08.
  18. ^ Feick, Kathy (28 February 2013). "Platinum | Earth Sciences Museum | University of Waterloo". University of Waterloo. Retrieved 6 February 2018.
  19. ^ Xiao, Z.; Laplante, A. R. (2004). "Characterizing and recovering the platinum group minerals—a review". Minerals Engineering. 17 (9–10): 961–979. Bibcode:2004MiEng..17..961X. doi:10.1016/j.mineng.2004.04.001.
  20. ^ a b c d "Platinum–Group Metals" (PDF). U.S. Geological Survey, Mineral Commodity Summaries. January 2007. Retrieved 2008-09-09.
  21. ^ Bardi, Ugo; Caporali, Stefano (2014). "Precious Metals in Automotive Technology: An Unsolvable Depletion Problem?". Minerals. 4 (2): 388–398. Bibcode:2014Mine....4..388B. doi:10.3390/min4020388. hdl:2158/1086074.
  22. ^ Emsley, J. (2003). "Iridium". Nature's Building Blocks: An A-Z Guide to the Elements. Oxford, England, UK: Oxford University Press. pp. 201–204. ISBN 0-19-850340-7.
  23. ^ a b Chevalier, Patrick. (PDF). Natural Resources Canada. Archived from the original (PDF) on 2011-08-11. Retrieved 2008-10-17.
  24. ^ Sebastien, Rauch (November 2012). "Anthropogenic Platinum Enrichment in the Vicinity of Mines in the Bushveld Igneous Complex, South Africa". Retrieved 14 February 2020.
  25. ^ Hunt, L. B.; Lever, F. M. (1969). "Platinum Metals: A Survey of Productive Resources to industrial Uses" (PDF). Platinum Metals Review. 13 (4): 126–138. Retrieved 2009-10-02.
  26. ^ Bernardis, F. L.; Grant, R. A.; Sherrington, D. C. "A review of methods of separation of the platinum-group metals through their chloro-complexes" Reactive and Functional Polymers 2005, Vol. 65,, p. 205-217. doi:10.1016/j.reactfunctpolym.2005.05.011
  27. ^ R. J. Newman, F. J. Smith (1970). "Platinum Metals from Nuclear Fission – an evaluation of their possible use by the industry" (PDF). Platinum Metals Review. 14 (3): 88.
  28. ^ Zdenek Kolarik, Edouard V. Renard (2003). "Recovery of Value Fission Platinoids from Spent Nuclear Fuel; PART I: general considerations and basic chemistry" (PDF). Platinum Metals Review. 47 (2): 74.
  29. ^ Kolarik, Zdenek; Renard, Edouard V. (2005). "Potential Applications of Fission Platinoids in Industry" (PDF). Platinum Metals Review. 49 (2): 79. doi:10.1595/147106705X35263.
  30. ^ Zdenek Kolarik, Edouard V. Renard (2003). "Recovery of Value Fission Platinoids from Spent Nuclear Fuel; PART II: Separation process" (PDF). Platinum Metals Review. 47 (3): 123.
  31. ^ Gao, Bo; Yu, Yanke; Zhou, Huaidong; Lu, Jin (2012). "Accumulation and distribution characteristics of platinum group elements in roadside dusts in Beijing, China". Environmental Toxicology and Chemistry. 31 (6): 1231–1238. doi:10.1002/etc.1833. PMID 22505271. S2CID 39813004.
  32. ^ a b c d e Khaiwal Ravindra,László Bencs,René Van Grieken (5 January 2004). "Platinum group elements in the environment and their health risk". Science of the Total Environment. 318 (1–3): 1–43. Bibcode:2004ScTEn.318....1R. doi:10.1016/S0048-9697(03)00372-3. hdl:2299/2030. PMID 14654273.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  33. ^ a b c Clare L.S. Wiseman, Fathi Zereini (2012). "Airborne particulate matter, platinum group elements and human health: A review of recent evidence". Science of the Total Environment. 407 (8): 2493–2500. doi:10.1016/j.scitotenv.2008.12.057. PMID 19181366.
  34. ^ Meck, Maideyi; Love, David; Mapani, Benjamin (2006). "Zimbabwean mine dumps and their impacts on river water quality – a reconnaissance study". Physics and Chemistry of the Earth, Parts A/B/C. 31 (15–16): 797–803. Bibcode:2006PCE....31..797M. doi:10.1016/j.pce.2006.08.029.
  35. ^ Hunt, L. B.; Lever, F. M. (1969). "Platinum Metals: A Survey of Productive Resources to industrial Uses" (PDF). Platinum Metals Review. 13 (4): 126–138. Retrieved 2009-10-02.

External links edit

February 16, 2024
platinum, group, metals, pgms, periodic, table, heli, nena, krrb, xecs, rnfr, metals, other, noble, metalsthe, platinum, group, metals, pgms, also, known, platinoids, platinides, platidises, platinum, group, platinum, metals, platinum, family, platinum, group,. Platinum group metals PGMs in the periodic table H HeLi Be B C N O F NeNa Mg Al Si P S Cl ArK Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br KrRb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I XeCs Ba Lu Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At RnFr Ra Lr Rf Db Sg Bh Hs Mt Ds Rg Cn Nh Fl Mc Lv Ts Og La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Ac Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Platinum group metals Other noble metalsThe platinum group metals PGMs also known as the platinoids platinides platidises platinum group platinum metals platinum family or platinum group elements PGEs are six noble precious metallic elements clustered together in the periodic table These elements are all transition metals in the d block groups 8 9 and 10 periods 5 and 6 1 The six platinum group metals are ruthenium rhodium palladium osmium iridium and platinum They have similar physical and chemical properties and tend to occur together in the same mineral deposits 2 However they can be further subdivided into the iridium group platinum group elements IPGEs Os Ir Ru and the palladium group platinum group elements PPGEs Rh Pt Pd based on their behaviour in geological systems 3 The three elements above the platinum group in the periodic table iron nickel and cobalt are all ferromagnetic these together with the lanthanide element gadolinium at temperatures below 20 C 4 are the only known transition metals that display ferromagnetism near room temperature Contents 1 History 2 Properties and uses 3 Occurrence 4 PGM minerals 4 1 Platinum 4 2 Osmium 4 3 Iridium 4 4 Ruthenium 4 5 Rhodium 4 6 Palladium 5 Production 5 1 Production in nuclear reactors 6 Environmental concerns 7 See also 8 Notes 9 External linksHistory editNaturally occurring platinum and platinum rich alloys were known by pre Columbian Americans for many years 5 However even though the metal was used by pre Columbian peoples the first European reference to platinum appears in 1557 in the writings of the Italian humanist Julius Caesar Scaliger 1484 1558 as a description of a mysterious metal found in Central American mines between Darien Panama and Mexico up until now impossible to melt by any of the Spanish arts 5 The name platinum is derived from the Spanish word platina little silver the name given to the metal by Spanish settlers in Colombia They regarded platinum as an unwanted impurity in the silver they were mining 5 6 By 1815 rhodium and palladium had been discovered by William Hyde Wollaston and iridium and osmium by his close friend and collaborator Smithson Tennant 7 Properties and uses edit nbsp Replica of the NIST national prototype kilogram standard made in 90 platinum 10 iridium alloySignificant uses of selected PGMs 1996 1 PGM Use Thousand TozPalladium autocatalysts 4470electronics 2070dental 1830chemical reagents 230Platinum jewelry 2370autocatalysts 1830Rhodium autocatalysts 490The platinum metals have many useful catalytic properties They are highly resistant to wear and tarnish making platinum in particular well suited for fine jewellery Other distinctive properties include resistance to chemical attack excellent high temperature characteristics high mechanical strength good ductility and stable electrical properties 8 Apart from their application in jewellery platinum metals are also used in anticancer drugs industries dentistry electronics and vehicle exhaust catalysts VECs 9 VECs contain solid platinum Pt palladium Pd and rhodium Rh and are installed in the exhaust system of vehicles to reduce harmful emissions such as carbon monoxide CO by converting them into less harmful emissions 10 Occurrence editGenerally ultramafic and mafic igneous rocks have relatively high and granites low PGE trace content Geochemically anomalous traces occur predominantly in chromian spinels and sulfides Mafic and ultramafic igneous rocks host practically all primary PGM ore of the world Mafic layered intrusions including the Bushveld Complex outweigh by far all other geological settings of platinum deposits 11 12 13 14 Other economically significant PGE deposits include mafic intrusions related to flood basalts and ultramafic complexes of the Alaska Urals type 12 230 PGM minerals editTypical ores for PGMs contain ca 10 g PGM ton ore thus the identity of the particular mineral is unknown 15 Platinum edit Platinum can occur as a native metal but it can also occur in various different minerals and alloys 16 17 That said Sperrylite platinum arsenide PtAs2 ore is by far the most significant source of this metal 18 A naturally occurring platinum iridium alloy platiniridium is found in the mineral cooperite platinum sulfide PtS Platinum in a native state often accompanied by small amounts of other platinum metals is found in alluvial and placer deposits in Colombia Ontario the Ural Mountains and in certain western American states Platinum is also produced commercially as a by product of nickel ore processing The huge quantities of nickel ore processed makes up for the fact that platinum makes up only two parts per million of the ore South Africa with vast platinum ore deposits in the Merensky Reef of the Bushveld complex is the world s largest producer of platinum followed by Russia 19 20 Platinum and palladium are also mined commercially from the Stillwater igneous complex in Montana USA Leaders of primary platinum production are South Africa and Russia followed by Canada Zimbabwe and USA 21 Osmium edit Osmiridium is a naturally occurring alloy of iridium and osmium found in platinum bearing river sands in the Ural Mountains and in North and South America Trace amounts of osmium also exist in nickel bearing ores found in the Sudbury Ontario region along with other platinum group metals Even though the quantity of platinum metals found in these ores is small the large volume of nickel ores processed makes commercial recovery possible 20 22 Iridium edit Metallic iridium is found with platinum and other platinum group metals in alluvial deposits Naturally occurring iridium alloys include osmiridium and iridosmine both of which are mixtures of iridium and osmium It is recovered commercially as a by product from nickel mining and processing 20 Ruthenium edit Ruthenium is generally found in ores with the other platinum group metals in the Ural Mountains and in North and South America Small but commercially important quantities are also found in pentlandite extracted from Sudbury Ontario and in pyroxenite deposits in South Africa 20 Rhodium edit The industrial extraction of rhodium is complex because it occurs in ores mixed with other metals such as palladium silver platinum and gold It is found in platinum ores and obtained free as a white inert metal which is very difficult to fuse Principal sources of this element are located in South Africa Zimbabwe in the river sands of the Ural Mountains North and South America and also in the copper nickel sulfide mining area of the Sudbury Basin region Although the quantity at Sudbury is very small the large amount of nickel ore processed makes rhodium recovery cost effective However the annual world production in 2003 of this element is only 7 or 8 tons and there are very few rhodium minerals 23 Palladium edit Palladium is preferentially hosted in sulphide minerals primarily in pyrrhotite 12 Palladium is found as a free metal and alloyed with platinum and gold with platinum group metals in placer deposits of the Ural Mountains of Eurasia Australia Ethiopia South and North America However it is commercially produced from nickel copper deposits found in South Africa and Ontario Canada The huge volume of nickel copper ore processed makes this extraction profitable in spite of its low concentration in these ores 23 Production edit nbsp Process flow diagram for the separation of the platinum group metals The production of individual platinum group metals normally starts from residues of the production of other metals with a mixture of several of those metals Purification typically starts with the anode residues of gold copper or nickel production This results in a very energy intensive extraction process which leads to environmental consequences Carbon dioxide emissions are expected to rise as a result of increased demand for platinum metals and there is likely to be expanded mining activity in the Bushveld Igneous Complex because of this Further research is needed to determine the environmental impacts 24 Classical purification methods exploit differences in chemical reactivity and solubility of several compounds of the metals under extraction 25 These approaches have yielded to new technologies that utilize solvent extraction Separation begins with dissolution of the sample If aqua regia is used the chloride complexes are produced Depending on the details of the process which are often trade secrets the individual PGMs are obtained as the following compounds the poorly soluble NH4 2IrCl6 and NH4 2PtCl6 PdCl2 NH3 2 the volatile OsO4 and RuO4 and RhCl NH3 5 Cl2 26 Production in nuclear reactors edit Main article Synthesis of precious metals Significant quantities of the three light platinum group metals ruthenium rhodium and palladium are formed as fission products in nuclear reactors 27 With escalating prices and increasing global demand reactor produced noble metals are emerging as an alternative source Various reports are available on the possibility of recovering fission noble metals from spent nuclear fuel 28 29 30 Environmental concerns editIt was previously thought that platinum group metals had very few negative attributes in comparison to their distinctive properties and their ability to successfully reduce harmful emission from automobile exhausts 31 However even with all the positives of platinum metal use the negative effects of their use need to be considered in how it might impact the future For example metallic Pt are considered to not be chemically reactive and non allergenic so when Pt is emitted from VECs it is in metallic and oxide forms it is considered relatively safe 32 However Pt can solubilise in road dust enter water sources the ground and increase dose rates in animals through bioaccumulation 32 These impacts from platinum groups were previously not considered however 33 over time the accumulation of platinum group metals in the environment may actually pose more of a risk then previously thought 33 Future research is needed to fully grasp the threat of platinum metals especially since as more internal combustion cars are driven the more platinum metal emissions there are The bioaccumulation of Pt metals in animals can pose a significant health risk to both humans and biodiversity Species will tend to get more toxic if their food source is contaminated by these hazardous Pt metals emitted from VECs This can potentiality harm other species including humans if we eat these hazardous animals such as fish 33 nbsp Cisplatin is a platinum based drug used in therapy of human neoplasms The medical success of cisplatin is conflicted as a result of severe side effects Platinum metals extracted during the mining and smelting process can also cause significant environmental impacts In Zimbabwe a study showed that platinum group mining caused significant environmental risks such as pollution in water sources acidic water drainage and environmental degradation 34 Another hazard of Pt is being exposed to halogenated Pt salts which can cause allergic reactions in high rates of asthma and dermatitis This is a hazard that can sometimes be seen in the production of industrial catalysts causing workers to have reactions 32 Workers removed immediately from further contact with Pt salts showed no evidence of long term effects however continued exposure could lead to health effects 32 Platinum use in drugs also may need to be reevaluated as some of the side effects to these drugs include nausea hearing loss and nephrotoxicity 32 Handling of these drugs by professionals such as nurses have also resulted in some side effects including chromosome aberrations and hair loss Therefore the long term effects of platinum drug use and exposure need to be evaluated and considered to determine if they are safe to use in medical care While exposure of relatively low volumes of platinum group metal emissions may not have any long term health effects there is considerable concern for how the accumulation of Pt metal emissions will impact the environment as well as human health This is a threat that will need more research to determine the safe levels of risk as well as ways to mitigate potential hazards from platinum group metals 35 See also editPlatinum group metals in Africa Merensky Reef Johnson Matthey Technology Review formerly published as Platinum Metals Review Notes edit a b Renner H Schlamp G Kleinwachter I Drost E Luschow H M Tews P Panster P Diehl M et al 2002 Platinum group metals and compounds Ullmann s Encyclopedia of Industrial Chemistry Wiley doi 10 1002 14356007 a21 075 ISBN 3527306730 Harris D C Cabri L J 1991 Nomenclature of platinum group element alloys review and revision The Canadian Mineralogist 29 2 231 237 Rollinson Hugh 1993 Using Geochemical Data Evaluation Presentation Interpretation Longman Scientific and Technical ISBN 0 582 06701 4 Lide D R ed 2005 CRC Handbook of Chemistry and Physics 86th ed Boca Raton FL CRC Press p 4 122 ISBN 0 8493 0486 5 a b c Weeks M E 1968 Discovery of the Elements 7 ed Journal of Chemical Education pp 385 407 ISBN 0 8486 8579 2 OCLC 23991202 Woods Ian 2004 The Elements Platinum Benchmark Books ISBN 978 0 7614 1550 3 Platinum Metals Rev 2003 47 4 175 Bicentenary of Four Platinum Group Metals PART I RHODIUM AND PALLADIUM EVENTS SURROUNDING THEIR DISCOVERIES W P Griffith Hunt L B Lever F M 1969 Platinum Metals A Survey of Productive Resources to industrial Uses PDF Platinum Metals Review 13 4 126 138 Retrieved 2009 10 02 Ravindra Khaiwal Bencs Laszlo Van Grieken Rene 2004 Platinum group elements in the environment and their health risk Science of the Total Environment 318 1 3 1 43 Bibcode 2004ScTEn 318 1R doi 10 1016 S0048 9697 03 00372 3 hdl 2299 2030 PMID 14654273 Aruguete Deborah M Wallace Adam Blakney Terry Kerr Rose Gerber Galen Ferko Jacob 2020 Palladium release from catalytic converter materials induced by road de icer components chloride and ferrocyanide Chemosphere 245 125578 Bibcode 2020Chmsp 245l5578A doi 10 1016 j chemosphere 2019 125578 PMID 31864058 S2CID 209440501 Buchanan D L 2002 Cabri L J ed Geology of Platinum Group Elements CIM Special Volume 54 The Geology Geochemistry Mineralogy and Mineral Beneficiation of Platinum group Elements Montreal Canadian Institute of Mining Metallurgy and Petroleum a b c Pohl Walter L 2011 Economic Geology Principles and Practice Oxford Wiley Blackwell ISBN 978 1 4443 3662 7 Zereini Fathi Wiseman Clare L S 2015 Platinum Metals in the Environment Berlin Springer Professional Mungall J E Naldrett A J 2008 Ore Deposits of the Platinum Group Elements Elements 4 4 253 258 doi 10 2113 GSELEMENTS 4 4 253 Bernardis F L Grant R A Sherrington D C 2005 A review of methods of separation of the platinum group metals through their chloro complexes Reactive and Functional Polymers 65 3 205 217 doi 10 1016 j reactfunctpolym 2005 05 011 Mineral Profile Platinum British Geological Survey September 2009 Retrieved 6 February 2018 Search Minerals By Chemistry Platinum www mindat org Retrieved 2018 02 08 Feick Kathy 28 February 2013 Platinum Earth Sciences Museum University of Waterloo University of Waterloo Retrieved 6 February 2018 Xiao Z Laplante A R 2004 Characterizing and recovering the platinum group minerals a review Minerals Engineering 17 9 10 961 979 Bibcode 2004MiEng 17 961X doi 10 1016 j mineng 2004 04 001 a b c d Platinum Group Metals PDF U S Geological Survey Mineral Commodity Summaries January 2007 Retrieved 2008 09 09 Bardi Ugo Caporali Stefano 2014 Precious Metals in Automotive Technology An Unsolvable Depletion Problem Minerals 4 2 388 398 Bibcode 2014Mine 4 388B doi 10 3390 min4020388 hdl 2158 1086074 Emsley J 2003 Iridium Nature s Building Blocks An A Z Guide to the Elements Oxford England UK Oxford University Press pp 201 204 ISBN 0 19 850340 7 a b Chevalier Patrick Platinum Group Metals PDF Natural Resources Canada Archived from the original PDF on 2011 08 11 Retrieved 2008 10 17 Sebastien Rauch November 2012 Anthropogenic Platinum Enrichment in the Vicinity of Mines in the Bushveld Igneous Complex South Africa Retrieved 14 February 2020 Hunt L B Lever F M 1969 Platinum Metals A Survey of Productive Resources to industrial Uses PDF Platinum Metals Review 13 4 126 138 Retrieved 2009 10 02 Bernardis F L Grant R A Sherrington D C A review of methods of separation of the platinum group metals through their chloro complexes Reactive and Functional Polymers 2005 Vol 65 p 205 217 doi 10 1016 j reactfunctpolym 2005 05 011 R J Newman F J Smith 1970 Platinum Metals from Nuclear Fission an evaluation of their possible use by the industry PDF Platinum Metals Review 14 3 88 Zdenek Kolarik Edouard V Renard 2003 Recovery of Value Fission Platinoids from Spent Nuclear Fuel PART I general considerations and basic chemistry PDF Platinum Metals Review 47 2 74 Kolarik Zdenek Renard Edouard V 2005 Potential Applications of Fission Platinoids in Industry PDF Platinum Metals Review 49 2 79 doi 10 1595 147106705X35263 Zdenek Kolarik Edouard V Renard 2003 Recovery of Value Fission Platinoids from Spent Nuclear Fuel PART II Separation process PDF Platinum Metals Review 47 3 123 Gao Bo Yu Yanke Zhou Huaidong Lu Jin 2012 Accumulation and distribution characteristics of platinum group elements in roadside dusts in Beijing China Environmental Toxicology and Chemistry 31 6 1231 1238 doi 10 1002 etc 1833 PMID 22505271 S2CID 39813004 a b c d e Khaiwal Ravindra Laszlo Bencs Rene Van Grieken 5 January 2004 Platinum group elements in the environment and their health risk Science of the Total Environment 318 1 3 1 43 Bibcode 2004ScTEn 318 1R doi 10 1016 S0048 9697 03 00372 3 hdl 2299 2030 PMID 14654273 a href Template Cite journal html title Template Cite journal cite journal a CS1 maint multiple names authors list link a b c Clare L S Wiseman Fathi Zereini 2012 Airborne particulate matter platinum group elements and human health A review of recent evidence Science of the Total Environment 407 8 2493 2500 doi 10 1016 j scitotenv 2008 12 057 PMID 19181366 Meck Maideyi Love David Mapani Benjamin 2006 Zimbabwean mine dumps and their impacts on river water quality a reconnaissance study Physics and Chemistry of the Earth Parts A B C 31 15 16 797 803 Bibcode 2006PCE 31 797M doi 10 1016 j pce 2006 08 029 Hunt L B Lever F M 1969 Platinum Metals A Survey of Productive Resources to industrial Uses PDF Platinum Metals Review 13 4 126 138 Retrieved 2009 10 02 External links editPlatinum group prices provided by Johnson Matthey spot prices on the global commodities market Platinum Group Metals PGM Database created by Johnson Matthey Platinum Group Metals Statistics and Information from the U S Geological Survey s National Minerals Information Center Retrieved from https en wikipedia org w index php title Platinum group amp oldid 1203975280, wikipedia, wiki, book, books, library,

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