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Platinum

Platinum

Platinum  Nugget in Russia
Platinum Zwartsfontein Kondor Mine

 Shining Light on Previously Invisible Platinum Crystals Clusters inside Super Carbon Bonds (Deep Space Map Area 51 Star Rock Meteorite) has a great Message of Advance Life Technology Solar Systems (ALTSS). 

Platinum Crystal From Galaxy Gemstones M-51 Rock Star Meteorite (2012) in the United States with
Platinum Triodide
Pt O1 Platium (2) (4) Oxide
Pt O2 Platium Dioxide
Pt O3 Platium (4) Oxide Peroxide
Platinum Trioxide Oxide Peroxide

Platinum (2) Bomide Pt Br2
Platinum(4) Bomide Pt Br4 

Platinum (4) Chloride 5-H2O (Pt Cl4)
Platinum Tetra Chloride5 (Pt Cl4) 5H2O

Platinum (2) Choride,
Platinum Dichlorid Pt6 Cl12

Platinum (2) Iodide Pt I2

Platinum (4) Fluoride (Pt F5)4

Sulfides
Platinum (2) Sulphide
Platinum Sulphide
Platinum Disulpide

 

 

 

 

 

 



Platinum 078 Element

Platinum,  78Pt

Platinum crystals.jpg

General properties

Name, symbol

platinum, Pt

Pronunciation

/ˈplætᵻnəm/
PLAT-i-nǝm

Appearance

silvery white

Platinum in the periodic table

Hydrogen (diatomic nonmetal)

Helium (noble gas)

Lithium (alkali metal)

Beryllium (alkaline earth metal)

Boron (metalloid)

Carbon (polyatomic nonmetal)

Nitrogen (diatomic nonmetal)

Oxygen (diatomic nonmetal)

Fluorine (diatomic nonmetal)

Neon (noble gas)

Sodium (alkali metal)

Magnesium (alkaline earth metal)

Aluminium (post-transition metal)

Silicon (metalloid)

Phosphorus (polyatomic nonmetal)

Sulfur (polyatomic nonmetal)

Chlorine (diatomic nonmetal)

Argon (noble gas)

Potassium (alkali metal)

Calcium (alkaline earth metal)

Scandium (transition metal)

Titanium (transition metal)

Vanadium (transition metal)

Chromium (transition metal)

Manganese (transition metal)

Iron (transition metal)

Cobalt (transition metal)

Nickel (transition metal)

Copper (transition metal)

Zinc (transition metal)

Gallium (post-transition metal)

Germanium (metalloid)

Arsenic (metalloid)

Selenium (polyatomic nonmetal)

Bromine (diatomic nonmetal)

Krypton (noble gas)

Rubidium (alkali metal)

Strontium (alkaline earth metal)

Yttrium (transition metal)

Zirconium (transition metal)

Niobium (transition metal)

Molybdenum (transition metal)

Technetium (transition metal)

Ruthenium (transition metal)

Rhodium (transition metal)

Palladium (transition metal)

Silver (transition metal)

Cadmium (transition metal)

Indium (post-transition metal)

Tin (post-transition metal)

Antimony (metalloid)

Tellurium (metalloid)

Iodine (diatomic nonmetal)

Xenon (noble gas)

Caesium (alkali metal)

Barium (alkaline earth metal)

Lanthanum (lanthanide)

Cerium (lanthanide)

Praseodymium (lanthanide)

Neodymium (lanthanide)

Promethium (lanthanide)

Samarium (lanthanide)

Europium (lanthanide)

Gadolinium (lanthanide)

Terbium (lanthanide)

Dysprosium (lanthanide)

Holmium (lanthanide)

Erbium (lanthanide)

Thulium (lanthanide)

Ytterbium (lanthanide)

Lutetium (lanthanide)

Hafnium (transition metal)

Tantalum (transition metal)

Tungsten (transition metal)

Rhenium (transition metal)

Osmium (transition metal)

Iridium (transition metal)

Platinum (transition metal)

Gold (transition metal)

Mercury (transition metal)

Thallium (post-transition metal)

Lead (post-transition metal)

Bismuth (post-transition metal)

Polonium (post-transition metal)

Astatine (metalloid)

Radon (noble gas)

Francium (alkali metal)

Radium (alkaline earth metal)

Actinium (actinide)

Thorium (actinide)

Protactinium (actinide)

Uranium (actinide)

Neptunium (actinide)

Plutonium (actinide)

Americium (actinide)

Curium (actinide)

Berkelium (actinide)

Californium (actinide)

Einsteinium (actinide)

Fermium (actinide)

Mendelevium (actinide)

Nobelium (actinide)

Lawrencium (actinide)

Rutherfordium (transition metal)

Dubnium (transition metal)

Seaborgium (transition metal)

Bohrium (transition metal)

Hassium (transition metal)

Meitnerium (unknown chemical properties)

Darmstadtium (unknown chemical properties)

Roentgenium (unknown chemical properties)

Copernicium (transition metal)

Ununtrium (unknown chemical properties)

Flerovium (post-transition metal)

Ununpentium (unknown chemical properties)

Livermorium (unknown chemical properties)

Ununseptium (unknown chemical properties)

Ununoctium (unknown chemical properties)

Pd

Pt

Ds

iridium ← platinum → gold

Atomic number (Z)

78

Group, block

group 10, d-block

Period

period 6

Element category

  transition metal

Standard atomic weight (±) (Ar)

195.084(9)[1]

Electron configuration

[Xe] 4f14 5d9 6s1

per shell

2, 8, 18, 32, 17, 1

Physical properties

Phase

solid

Melting point

2041.4 K ​(1768.3 °C, ​3214.9 °F)

Boiling point

4098 K ​(3825 °C, ​6917 °F)

Density near r.t.

21.45 g/cm3

when liquid, at m.p.

19.77 g/cm3

Heat of fusion

22.17 kJ/mol

Heat of vaporization

510 kJ/mol

Molar heat capacity

25.86 J/(mol·K)

vapor pressure

P (Pa)

1

10

100

1 k

10 k

100 k

at T (K)

2330

(2550)

2815

3143

3556

4094

Atomic properties

Oxidation states

6, 5, 4, 3, 2, 1, −1, −2, −3 ​(a mildly basic oxide)

Electronegativity

Pauling scale: 2.28

Ionization energies

1st: 870 kJ/mol
2nd: 1791 kJ/mol

Atomic radius

empirical: 139 pm

Covalent radius

136±5 pm

Van der Waals radius

175 pm

Miscellanea

Crystal structure

face-centered cubic (fcc)

Face-centered cubic crystal structure for platinum

Speed of sound thin rod

2800 m/s (at r.t.)

Thermal expansion

8.8 µm/(m·K) (at 25 °C)

Thermal conductivity

71.6 W/(m·K)

Electrical resistivity

105 nΩ·m (at 20 °C)

Magnetic ordering

paramagnetic

Tensile strength

125–240 MPa

Young's modulus

168 GPa

Shear modulus

61 GPa

Bulk modulus

230 GPa

Poisson ratio

0.38

Mohs hardness

3.5

Vickers hardness

400–550 MPa

Brinell hardness

300–500 MPa

CAS Number

7440-06-4

History

Discovery and first isolation

Antonio de Ulloa (1748)

Most stable isotopes of platinum

iso

NA

half-life

DM

DE (MeV)

DP

190Pt

0.012%

6.5×1011 y

α

3.252

186Os

192Pt

0.782%

>6×1016 y[2]

(α)

2.4181

188Os

193Pt

syn

50 y

ε

193Ir

194Pt

32.864%

(α)

1.5045

190Os

195Pt

33.775%

(α)

1.1581

191Os

196Pt

25.211%

(α)

0.7942

192Os

198Pt

7.356%

>3.2×1014 y

(α)

0.0870

194Os

(ββ)

1.0472

198Hg

Decay modes in parentheses are predicted, but have not yet been observed

Platinum is a chemical element with symbol Pt and atomic number 78. It is a dense, malleable, ductile, highly unreactive, precious, gray-white transition metal. Its name is derived from the Spanish term platina, which is literally translated into "little silver".[3][4]

Platinum is a member of the platinum group of elements and group 10 of the periodic table of elements. It has six naturally occurring isotopes. It is one of the rarer elements in Earth's crust with an average abundance of approximately 5 μg/kg. It occurs in some nickel and copper ores along with some native deposits, mostly in South Africa, which accounts for 80% of the world production. Because of its scarcity in Earth's crust, only a few hundred tonnes are produced annually, and given its important uses, it is highly valuable and is a major precious metal commodity.

Platinum is one of the least reactive metals. It has remarkable resistance to corrosion, even at high temperatures, and is therefore considered a noble metal. Consequently, platinum is often found chemically uncombined as native platinum. Because it occurs naturally in the alluvial sands of various rivers, it was first used by pre-Columbian South American natives to produce artifacts. It was referenced in European writings as early as 16th century, but it was not until Antonio de Ulloa published a report on a new metal of Colombian origin in 1748 that it began to be investigated by scientists.

Platinum is used in catalytic converters, laboratory equipment, electrical contacts and electrodes, platinum resistance thermometers, dentistry equipment, and jewelry. Being a heavy metal, it leads to health issues upon exposure to its salts; but due to its corrosion resistance, metallic platinum has not been linked to adverse health effects.[5] Compounds containing platinum, such as cisplatin, oxaliplatin and carboplatin, are applied in chemotherapy against certain types of cancer.[6]

Contents

 1 Characteristics

Characteristics

Physical

Pure platinum is a lustrous, ductile, and malleable, silver-white metal.[7] Platinum is more ductile than gold, silver or copper, thus being the most ductile of pure metals, but it is less malleable than gold.[8][9] The metal has excellent resistance to corrosion, is stable at high temperatures and has stable electrical properties. Platinum reacts with oxygen slowly at very high temperatures.[10] It reacts vigorously with fluorine at 500 °C (932 °F) to form tetrafluoride.[11] It is also attacked by chlorine, bromine, iodine, and sulfur. Platinum is insoluble in hydrochloric and nitric acid, but dissolves in hot aqua regia to form chloroplatinic acid, H2PtCl6.[12]

Its physical characteristics and chemical stability make it useful for industrial applications.[13] Its resistance to wear and tarnish is well suited to use in fine jewelry.

Chemical

See also: Platinum group

https://upload.wikimedia.org/wikipedia/commons/thumb/9/96/Platin_loest_sich_in_heissem_Koenigswasser.JPG/220px-Platin_loest_sich_in_heissem_Koenigswasser.JPG

Platinum being dissolved in hot aqua regia

The most common oxidation states of platinum are +2 and +4. The +1 and +3 oxidation states are less common, and are often stabilized by metal bonding in bimetallic (or polymetallic) species. As is expected, tetracoordinate platinum(II) compounds tend to adopt 16-electron square planar geometries. Although elemental platinum is generally unreactive, it dissolves in hot aqua regia to give aqueous chloroplatinic acid (H2PtCl6):[14]

Pt + 4 HNO3 + 6 HCl → H2PtCl6 + 4 NO2 + 4 H2O

As a soft acid, platinum has a great affinity for sulfur, such as on dimethyl sulfoxide (DMSO); numerous DMSO complexes have been reported and care should be taken in the choice of reaction solvent.[15]

Isotopes[edit]

Main article: Isotopes of platinum

Platinum has six naturally occurring isotopes: 190Pt, 192Pt, 194Pt, 195Pt, 196Pt, and 198Pt. The most abundant of these is 195Pt, comprising 33.83% of all platinum. It is the only stable isotope with a non-zero spin; with a spin of 1/2, 195Pt satellite peaks are often observed in 1H and 31P NMR spectroscopy (i.e., Pt-phosphine and Pt-alkyl complexes). 190Pt is the least abundant at only 0.01%. Of the naturally occurring isotopes, only 190Pt is unstable, though it decays with a half-life of 6.5×1011 years, causing an activity of 15 Bq/kg of natural platinum. 198Pt can undergo alpha decay, but its decay has never been observed (the half-life is known to be longer than 3.2×1014 years); therefore, it is considered stable. Platinum also has 31 synthetic isotopes ranging in atomic mass from 166 to 202, making the total number of known isotopes 37. The least stable of these is 166Pt, with a half-life of 300 µs, whereas the most stable is 193Pt with a half-life of 50 years. Most platinum isotopes decay by some combination of beta decay and alpha decay. 188Pt, 191Pt, and 193Pt decay primarily by electron capture. 190Pt and 198Pt have double beta decay paths.[16]

Occurrence

https://upload.wikimedia.org/wikipedia/commons/thumb/6/6a/Platinum-nugget.jpg/220px-Platinum-nugget.jpg

A native platinum nugget, Kondyor mine, Khabarovsk Krai

https://upload.wikimedia.org/wikipedia/commons/thumb/7/74/2005platinum_%28mined%29.PNG/220px-2005platinum_%28mined%29.PNG

Platinum output in 2005

Platinum is an extremely rare metal,[17] occurring at a concentration of only 0.005 ppm in Earth's crust.[18][19] It is sometimes mistaken for silver (Ag). Platinum is often found chemically uncombined as native platinum and as alloy with the other platinum-group metals and iron mostly. Most often the native platinum is found in secondary deposits in alluvial deposits. The alluvial deposits used by pre-Columbian people in the Chocó Department, Colombia are still a source for platinum-group metals. Another large alluvial deposit is in the Ural Mountains, Russia, and it is still mined.[12]

In nickel and copper deposits, platinum-group metals occur as sulfides (e.g. (Pt,Pd)S), tellurides (e.g. PtBiTe), antimonides (PdSb), and arsenides (e.g. PtAs2), and as end alloys with nickel or copper. Platinum arsenide, sperrylite (PtAs2), is a major source of platinum associated with nickel ores in the Sudbury Basin deposit in Ontario, Canada. At Platinum, Alaska, about 17,000 kg (550,000 ozt) had been mined between 1927 and 1975. The mine ceased operations in 1990.[20] The rare sulfide mineral cooperite, (Pt,Pd,Ni)S, contains platinum along with palladium and nickel. Cooperite occurs in the Merensky Reef within the Bushveld complex, Gauteng, South Africa.[21]

In 1865, chromites were identified in the Bushveld region of South Africa, followed by the discovery of platinum in 1906.[22] The largest known primary reserves are in the Bushveld complex in South Africa.[23] The large copper–nickel deposits near Norilsk in Russia, and the Sudbury Basin, Canada, are the two other large deposits. In the Sudbury Basin, the huge quantities of nickel ore processed make up for the fact platinum is present as only 0.5 ppm in the ore. Smaller reserves can be found in the United States,[23] for example in the Absaroka Range in Montana.[24] In 2010, South Africa was the top producer of platinum, with an almost 77% share, followed by Russia at 13%; world production in 2010 was 192,000 kg (423,000 lb).[25]

Platinum deposits are present in the state of Tamil Nadu, India.[26] and a MOU has been signed between Geological Survey of India with TAMIN – Tamil Nadu Minerals Ltd.[27]

Platinum exists in higher abundances on the Moon and in meteorites. Correspondingly, platinum is found in slightly higher abundances at sites of bolide impact on Earth that are associated with resulting post-impact volcanism, and can be mined economically; the Sudbury Basin is one such example.[28]

Compounds

Halides

Hexachloroplatinic acid mentioned above is probably the most important platinum compound, as it serves as the precursor for many other platinum compounds. By itself, it has various applications in photography, zinc etchings, indelible ink, plating, mirrors, porcelain coloring, and as a catalyst.[29]

Treatment of hexachloroplatinic acid with an ammonium salt, such as ammonium chloride, gives ammonium hexachloroplatinate,[14] which is relatively insoluble in ammonium solutions. Heating this ammonium salt in the presence of hydrogen reduces it to elemental platinum. Potassium hexachloroplatinate is similarly insoluble, and hexachloroplatinic acid has been used in the determination of potassium ions by gravimetry.[30]

When hexachloroplatinic acid is heated, it decomposes through platinum(IV) chloride and platinum(II) chloride to elemental platinum, although the reactions do not occur stepwise:[31]

(H3O)2PtCl6·nH2O PtCl4 + 2 HCl + (n + 2) H2O

PtCl4 PtCl2 + Cl2

PtCl2 Pt + Cl2

All three reactions are reversible. Platinum(II) and platinum(IV) bromides are known as well. Platinum hexafluoride is a strong oxidizer capable of oxidizing oxygen.

Oxides

Platinum(IV) oxide, PtO2, also known as Adams' catalyst, is a black powder that is soluble in KOH solutions and concentrated acids.[32] PtO2 and the less common PtO both decompose upon heating.[7] Platinum(II,IV) oxide, Pt3O4, is formed in the following reaction:

2 Pt2+ + Pt4+ + 4 O2− → Pt3O4

Other compounds

Unlike palladium acetate, platinum(II) acetate is not commercially available. Where a base is desired, the halides have been used in conjunction with sodium acetate.[15] The use of platinum(II) acetylacetonate has also been reported.[33]

Several barium platinides have been synthesized in which platinum exhibits negative oxidation states ranging from −1 to −2. These include BaPt, Ba
3Pt
2, and Ba
2Pt.
[34] Caesium platinide, Cs
2Pt, a dark-red transparent crystalline compound[35] has been shown to contain Pt2−
anions.
[36] Platinum also exhibits negative oxidation states at surfaces reduced electrochemically.[37] The negative oxidation states exhibited by platinum are unusual for metallic elements, and they are attributed to the relativistic stabilization of the 6s orbitals.[36]

Zeise's salt, containing an ethylene ligand, was one of the first organometallic compounds discovered. Dichloro(cycloocta-1,5-diene)platinum(II) is a commercially available olefin complex, which contains easily displaceable cod ligands ("cod" being an abbreviation of 1,5-cyclooctadiene). The cod complex and the halides are convenient starting points to platinum chemistry.[15]

Cisplatin, or cis-diamminedichloroplatinum(II) is the first of a series of square planar platinum(II)-containing chemotherapy drugs, including carboplatin and oxaliplatin. These compounds are capable of crosslinking DNA, and kill cells by similar pathways to alkylating chemotherapeutic agents.[38] (Side effects of cisplatin include nausea and vomiting, hair loss, tinnitus, hearing loss, and nephrotoxicity.)[39][40]

  • https://upload.wikimedia.org/wikipedia/commons/thumb/e/e3/Hexachloridoplatinat-Ion.svg/160px-Hexachloridoplatinat-Ion.svg.png

The hexachloroplatinate ion

  • https://upload.wikimedia.org/wikipedia/commons/thumb/8/8e/Zeise%27s-salt-anion-3D-balls.png/160px-Zeise%27s-salt-anion-3D-balls.png

The anion of Zeise's salt

  • https://upload.wikimedia.org/wikipedia/commons/thumb/4/46/Dichloro%28cycloocta-1%2C5-diene%29platinum%28II%29-from-xtal-3D-balls-E.png/113px-Dichloro%28cycloocta-1%2C5-diene%29platinum%28II%29-from-xtal-3D-balls-E.png

Dichloro(cycloocta-1,5-diene)platinum(II)

  • https://upload.wikimedia.org/wikipedia/commons/thumb/9/96/Cisplatin-3D-balls.png/160px-Cisplatin-3D-balls.png

Cisplatin

History

Early uses

Archaeologists have discovered traces of platinum in the gold used in ancient Egyptian tombs and hieroglyphics as early as 1200 BC. However, the extent of early Egyptians' knowledge of the metal is unclear. It is quite possible they did not recognize there was platinum in their gold.[41]

The metal was used by pre-Columbian Americans near modern-day Esmeraldas, Ecuador to produce artifacts of a white gold-platinum alloy. They employed a relatively sophisticated system of powder metallurgy. The platinum used in such objects was not the pure element, but rather a naturally occurring mixture of the platinum group metals, with small amounts of palladium, rhodium, and iridium.[42]

European discovery

The first European reference to platinum appears in 1557 in the writings of the Italian humanist Julius Caesar Scaliger as a description of an unknown noble metal found between Darién and Mexico, "which no fire nor any Spanish artifice has yet been able to liquefy".[43] From their first encounters with platinum, the Spanish generally saw the metal as a kind of impurity in gold, and it was treated as such. It was often simply thrown away, and there was an official decree forbidding the adulteration of gold with platinum impurities.[42]

A left-pointing crescent, tangent on its right to a circle containing at its center a solid circular dot

This alchemical symbol for platinum was made by joining the symbols of silver and gold.

https://upload.wikimedia.org/wikipedia/commons/thumb/b/b6/Almirante_Antonio_de_Ulloa.jpg/220px-Almirante_Antonio_de_Ulloa.jpg

Antonio de Ulloa is credited with the discovery of platinum.

In 1741, Charles Wood,[44] a British metallurgist, found various samples of Colombian platinum in Jamaica, which he sent to William Brownrigg for further investigation. Antonio de Ulloa, also credited with the discovery of platinum, returned to Spain from the French Geodesic Mission in 1746 after having been there for eight years. His historical account of the expedition included a description of platinum as being neither separable nor calcinable. Ulloa also anticipated the discovery of platinum mines. After publishing the report in 1748, Ulloa did not continue to investigate the new metal. In 1758, he was sent to superintend mercury mining operations in Huancavelica.[43]

In 1750, after studying the platinum sent to him by Wood, Brownrigg presented a detailed account of the metal to the Royal Society, stating that he had seen no mention of it in any previous accounts of known minerals.[45] Brownrigg also made note of platinum's extremely high melting point and refractoriness toward borax.[clarification needed] Other chemists across Europe soon began studying platinum, including Andreas Sigismund Marggraf,[46] Torbern Bergman, Jöns Jakob Berzelius, William Lewis, and Pierre Macquer. In 1752, Henrik Scheffer published a detailed scientific description of the metal, which he referred to as "white gold", including an account of how he succeeded in fusing platinum ore with the aid of arsenic. Scheffer described platinum as being less pliable than gold, but with similar resistance to corrosion.[43]

Means of malleability

Carl von Sickingen researched platinum extensively in 1772. He succeeded in making malleable platinum by alloying it with gold, dissolving the alloy in hot aqua regia, precipitating the platinum with ammonium chloride, igniting the ammonium chloroplatinate, and hammering the resulting finely divided platinum to make it cohere. Franz Karl Achard made the first platinum crucible in 1784. He worked with the platinum by fusing it with arsenic, then later volatilizing the arsenic.[43]

Because the other platinum-family members were not discovered yet (platinum was the first in the list), Scheffer and Sickingen made the false assumption that due to its hardness—which is slightly more than for pure iron—platinum would be a relatively non-pliable material, even brittle at times, when in fact its ductility and malleability are close to that of gold. Their assumptions could not be avoided because the platinum they experimented with was highly contaminated with minute amounts of platinum-family elements such as osmium and iridium, amongst others, which embrittled the platinum alloy. Alloying this impure platinum residue called "plyoxen" with gold was the only solution at the time to obtain a pliable compound, but nowadays, very pure platinum is available and extremely long wires can be drawn from pure platinum, very easily, due to its crystalline structure, which is similar to that of many soft metals.[47]

In 1786, Charles III of Spain provided a library and laboratory to Pierre-François Chabaneau to aid in his research of platinum. Chabaneau succeeded in removing various impurities from the ore, including gold, mercury, lead, copper, and iron. This led him to believe he was working with a single metal, but in truth the ore still contained the yet-undiscovered platinum-group metals. This led to inconsistent results in his experiments. At times, the platinum seemed malleable, but when it was alloyed with iridium, it would be much more brittle. Sometimes the metal was entirely incombustible, but when alloyed with osmium, it would volatilize. After several months, Chabaneau succeeded in producing 23 kilograms of pure, malleable platinum by hammering and compressing the sponge form while white-hot. Chabeneau realized the infusibility of platinum would lend value to objects made of it, and so started a business with Joaquín Cabezas producing platinum ingots and utensils. This started what is known as the "platinum age" in Spain.[43]

In 2007, Gerhard Ertl won the Nobel Prize in Chemistry for determining the detailed molecular mechanisms of the catalytic oxidation of carbon monoxide over platinum (catalytic converter).[48]

Production

https://upload.wikimedia.org/wikipedia/commons/thumb/1/16/Platinum_Mining.jpg/220px-Platinum_Mining.jpg

An aerial photograph of a platinum mine in South Africa. South Africa produces 80% of the world production and has most of the worlds known platinum deposits.

https://upload.wikimedia.org/wikipedia/commons/thumb/7/7d/Platinum_world_production.svg/220px-Platinum_world_production.svg.png

Time trend of platinum production[49]

Platinum, along with the rest of the platinum-group metals, is obtained commercially as a by-product from nickel and copper mining and processing. During electrorefining of copper, noble metals such as silver, gold and the platinum-group metals as well as selenium and tellurium settle to the bottom of the cell as "anode mud", which forms the starting point for the extraction of the platinum-group metals.[50]

If pure platinum is found in placer deposits or other ores, it is isolated from them by various methods of subtracting impurities. Because platinum is significantly denser than many of its impurities, the lighter impurities can be removed by simply floating them away in a liquid. Platinum is paramagnetic, whereas nickel and iron are both ferromagnetic. These two impurities are thus removed by running an electromagnet over the mixture. Because platinum has a higher melting point than most other substances, many impurities can be burned or melted away without melting the platinum. Finally, platinum is resistant to hydrochloric and sulfuric acids, whereas other substances are readily attacked by them. Metal impurities can be removed by stirring the mixture in either of the two acids and recovering the remaining platinum.[51]

One suitable method for purification for the raw platinum, which contains platinum, gold, and the other platinum-group metals, is to process it with aqua regia, in which palladium, gold and platinum are dissolved, whereas osmium, iridium, ruthenium and rhodium stay unreacted. The gold is precipitated by the addition of iron(II) chloride and after filtering off the gold, the platinum is precipitated as ammonium chloroplatinate by the addition of ammonium chloride. Ammonium chloroplatinate can be converted to platinum by heating.[52] Unprecipitated hexachloroplatinate(IV) may be reduced with elemental zinc, and a similar method is suitable for small scale recovery of platinum from laboratory residues.[53]

Applications[edit]

https://upload.wikimedia.org/wikipedia/commons/thumb/7/7a/Aufgeschnittener_Metall_Katalysator_f%C3%BCr_ein_Auto.jpg/220px-Aufgeschnittener_Metall_Katalysator_f%C3%BCr_ein_Auto.jpg

Cutaway view of a metal-core catalytic converter

Of the 218 tonnes of platinum sold in 2014, 98 tonnes were used for vehicle emissions control devices (45%), 74.7 tonnes for jewelry (34%), 20.0 tonnes for chemical production and petroleum refining (9.2%), and 5.85 tonnes for electrical applications such as hard disk drives (2.7%). The remaining 28.9 tonnes went to various other minor applications, such as medicine and biomedicine, glassmaking equipment, investment, electrodes, anticancer drugs, oxygen sensors, spark plugs and turbine engines.[54]

Catalyst[edit]

The most common use of platinum is as a catalyst in chemical reactions, often as platinum black. It has been employed as a catalyst since the early 19th century, when platinum powder was used to catalyze the ignition of hydrogen. Its most important application is in automobiles as a catalytic converter, which allows the complete combustion of low concentrations of unburned hydrocarbons from the exhaust into carbon dioxide and water vapor. Platinum is also used in the petroleum industry as a catalyst in a number of separate processes, but especially in catalytic reforming of straight-run naphthas into higher-octane gasoline that becomes rich in aromatic compounds. PtO2, also known as Adams' catalyst, is used as a hydrogenation catalyst, specifically for vegetable oils.[29] Platinum also strongly catalyzes the decomposition of hydrogen peroxide into water and oxygen[55] and it is used in fuel cells[56] as a catalyst for the reduction of oxygen.[57]

Standard

https://upload.wikimedia.org/wikipedia/commons/thumb/b/bb/Platinum-Iridium_meter_bar.jpg/220px-Platinum-Iridium_meter_bar.jpg

Prototype International Meter bar

From 1889 to 1960, the meter was defined as the length of a platinum-iridium (90:10) alloy bar, known as the International Prototype Meter bar. The previous bar was made of platinum in 1799. The International Prototype Kilogram remains defined by a cylinder of the same platinum-iridium alloy made in 1879.[58]

The standard hydrogen electrode also uses a platinized platinum electrode due to its corrosion resistance, and other attributes.[59]

As an investment

https://upload.wikimedia.org/wikipedia/commons/thumb/4/48/One_litre_of_Platinum.jpg/220px-One_litre_of_Platinum.jpg

1,000 cubic centimeters of 99.9% pure platinum, worth about US$696,000 at 29 Jun 2016 prices[60]

Main articles: Platinum as an investment and Platinum coin

Platinum is a precious metal commodity; its bullion has the ISO currency code of XPT. Coins, bars, and ingots are traded or collected. Platinum finds use in jewellery, usually as a 90–95% alloy, due to its inertness. It is used for this purpose for its prestige and inherent bullion value. Jewellery trade publications advise jewellers to present minute surface scratches (which they term patina) as a desirable feature in attempt to enhance value of platinum products.[61][62]

In watchmaking, Vacheron Constantin, Patek Philippe, Rolex, Breitling, and other companies use platinum for producing their limited edition watch series. Watchmakers appreciate the unique properties of platinum, as it neither tarnishes nor wears out (the latter quality relative to gold).[63]

https://upload.wikimedia.org/wikipedia/commons/thumb/5/57/Pt_price_92_12.jpg/220px-Pt_price_92_12.jpg

Average price of platinum from 1992 to 2012 in US$per troy ounce (~$20/g)[64]

The price of platinum, like other industrial commodities, is more volatile than that of gold. In 2008, the price of platinum dropped from $2,252 to $774 per oz,[65] a loss of nearly 2/3 of its value. By contrast, the price of gold dropped from ~$1,000 to ~$700/oz during the same time frame, a loss of only 1/3 of its value.

During periods of sustained economic stability and growth, the price of platinum tends to be as much as twice the price of gold, whereas during periods of economic uncertainty,[66] the price of platinum tends to decrease due to reduced industrial demand, falling below the price of gold. Gold prices are more stable in slow economic times, as gold is considered a safe haven. Although gold is used in industrial applications, its demand is not so driven by industrial uses. In the 18th century, platinum's rarity made King Louis XV of France declare it the only metal fit for a king.[67]

Other uses

In the laboratory, platinum wire is used for electrodes; platinum pans and supports are used in thermogravimetric analysis because of the stringent requirements of chemical inertness upon heating to high temperatures (~1000 °C). Platinum is used as an alloying agent for various metal products, including fine wires, noncorrosive laboratory containers, medical instruments, dental prostheses, electrical contacts, and thermocouples. Platinum-cobalt, an alloy of roughly three parts platinum and one part cobalt, is used to make relatively strong permanent magnets.[29] Platinum-based anodes are used in ships, pipelines, and steel piers.[12]

https://upload.wikimedia.org/wikipedia/commons/thumb/b/b7/Platinum_nuggets.jpg/220px-Platinum_nuggets.jpg

An assortment of native platinum nuggets

Platinum's rarity as a metal has caused advertisers to associate it with exclusivity and wealth. "Platinum" debit and credit cards have greater privileges than "gold" cards.[68] "Platinum awards" are the second highest possible, ranking above "gold", "silver" and "bronze", but below diamond. For example, in the United States, a musical album that has sold more than 1 million copies, will be credited as "platinum", whereas an album that sold more than 10 million copies will be certified as "diamond".[69] Some products, such as blenders and vehicles, with a silvery-white color are identified as "platinum". Platinum is considered a precious metal, although its use is not as common as the use of gold or silver. The frame of the Crown of Queen Elizabeth The Queen Mother, manufactured for her coronation as Consort of King George VI, is made of platinum. It was the first British crown to be made of this particular metal.[70]

Health issues

According to the Centers for Disease Control and Prevention, short-term exposure to platinum salts may cause irritation of the eyes, nose, and throat, and long-term exposure may cause both respiratory and skin allergies. The current OSHA standard is 2 micrograms per cubic meter of air averaged over an 8-hour work shift.[71] The National Institute for Occupational Safety and Health has set a recommended exposure limit (REL) for platinum as 1 mg/m3 over an 8-hour workday.[72]

Platinum-based antineoplastic agents are used in chemotherapy, and show good activity against some tumors.

As platinum is a catalyst in the manufacture of the silicone rubber and gel components of several types of medical implants (breast implants, joint replacement prosthetics, artificial lumbar discs, vascular access ports, etc.), the possibility that platinum could enter the body and cause adverse effects has merited study. The Food and Drug Administration and other institutions have reviewed the issue and found no evidence to suggest toxicity in vivo.[73][74]

See also

References

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  31. Schweizer, A. E.; Kerr, G. T. (1978). "Thermal Decomposition of Hexachloroplatinic Acid". Inorganic Chemistry. 17 (8): 2326–2327. doi:10.1021/ic50186a067. 
  32. Perry, D. L. (1995). Handbook of Inorganic Compounds. CRC Press. pp. 296–298. ISBN 0-8493-8671-3. 
  33. Ahrens, Sebastian; Strassner, Thomas (2006). "Detour-free synthesis of platinum-bis-NHC chloride complexes, their structure and catalytic activity in the CH activation of methane". Inorganica Chimica Acta. 359 (15): 4789. doi:10.1016/j.ica.2006.05.042. 
  34. Karpov, Andrey; Konuma, Mitsuharu; Jansen, Martin (2006). "An experimental proof for negative oxidation states of platinum: ESCA-measurements on barium platinides". Chemical Communications (8): 838–840. doi:10.1039/b514631c. PMID 16479284. 
  35. Karpov, Andrey; Nuss, Jürgen; Wedig, Ulrich; Jansen, Martin (2003). "Cs2Pt: A Platinide(-II) Exhibiting Complete Charge Separation". Angewandte Chemie International Edition. 42 (39): 4818. doi:10.1002/anie.200352314. 
  36. Jansen, Martin (2005). "Effects of relativistic motion of electrons on the chemistry of gold and platinum". Solid State Sciences. 7 (12): 1464. Bibcode:2005SSSci...7.1464J. doi:10.1016/j.solidstatesciences.2005.06.015. 
  37. Ghilane, J.; Lagrost, C.; Guilloux-Viry, M.; Simonet, J.; et al. (2007). "Spectroscopic Evidence of Platinum Negative Oxidation States at Electrochemically Reduced Surfaces". Journal of Physical Chemistry C. 111 (15): 5701. doi:10.1021/jp068879d. 
  38. Richards, A.D.; Rodger, A. (2007). "Synthetic metallomolecules as agents for the control of DNA structure". Chemical Society Reviews. 36 (3): 471–483. doi:10.1039/b609495c. PMID 17325786. 
  39. Carinder, James A.; Morrison, Pilar M.; Morrison, David G.; Jack E. Saux, III (7 July 2014). Practical Oncology Protocols. Mill City Press, Incorporated. p. 22. ISBN 978-1-62652-816-1. Retrieved 11 June 2016.  Cite uses deprecated parameter |coauthors= (help)
  40. Taguchi, Takashi; Nazneen, Arifa; Abid, M. Ruhul; Razzaque, Mohammed S. (2005). "Cisplatin-Associated Nephrotoxicity and Pathological Events": 107–121. doi:10.1159/000086055. 
  41. Rayner W. Hesse (2007). Jewelrymaking Through History: An Encyclopedia. Greenwood Publishing Group. pp. 155–156. ISBN 0-313-33507-9. 
  42. Donald McDonald, Leslie B. Hunt (1982). A History of Platinum and its Allied Metals. Johnson Matthey Plc. pp. 7–8. ISBN 0-905118-83-9. 
  43. Weeks, M. E. (1968). Discovery of the Elements (7th ed.). Journal of Chemical Education. pp. 385–407. ISBN 0-8486-8579-2. OCLC 23991202. 
  44. Dixon, Joshua; Brownrigg, William (1801). The literary life of William Brownrigg. To which are added an account of the coal mines near Whitehaven: And Observations on the means of preventing epidemic fevers. p. 52. 
  45. Watson, Wm; Brownrigg, William (1749). "Several Papers concerning a New Semi-Metal, Called Platina; Communicated to the Royal Society by Mr. Wm. Watson F. R. S" (PDF). Philosophical Transactions. 46 (491–496): 584–596. doi:10.1098/rstl.1749.0110. 
  46. Marggraf, Andreas Sigismund (1760). Versuche mit dem neuen mineralischen Körper Platina del pinto genannt. 
  47. Platinum. mysite.du.edu
  48. Ertl, Gerhard (2008). "Reactions at Surfaces: From Atoms to Complexity (Nobel Lecture)". Angewandte Chemie International Edition. 47 (19): 385–407. doi:10.1002/anie.200800480. PMID 18357601. 
  49. Kelly, Thomas D. and Matos, Grecia R. (2013) Historical Statistics for Mineral and Material Commodities in the United States, U.S. Geological Survey
  50. Loferski, P. J. (October 2011). "2010 Minerals Yearbook; Platinum-group metals" (PDF). USGS Mineral Resources Program. Retrieved 17 July 2012. 
  51. Heiserman, David L. (1992). Exploring Chemical Elements and their Compounds. TAB Books. pp. 272–274. ISBN 0-8306-3018-X. 
  52. 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. 
  53. Kauffman, George B.; Teter, Larry A. & Rhoda, Richard N. (1963). "Recovery of Platinum from Laboratory Residues". Inorg. Synth. Inorganic Syntheses. 7: 232. doi:10.1002/9780470132388.ch61. ISBN 978-0-470-13238-8. 
  54. Loferski, P. J. (July 2016). "2014 Minerals Yearbook; Platinum-group metals" (PDF). USGS Mineral Resources Program. Retrieved 11 July 2016. 
  55. Petrucci, Ralph H. (2007). General Chemistry: Principles & Modern Applications (9th ed.). Prentice Hall. p. 606. ISBN 0-13-149330-2. 
  56. Laramie, James; Dicks, Andrew (2003). Fuel Cell System Explained. John Wiley & Sons Ltd. ISBN 0-470-84857-X. 
  57. Wang, C.; Daimon, H.; Onodera, T.; Koda, T.; Sun, S. (2008). "A general approach to the size- and shape-controlled synthesis of platinum nanoparticles and their catalytic reduction of oxygen". Angewandte Chemie International Edition. 47 (19): 3588–3591. doi:10.1002/anie.200800073. 
  58. Gupta, S. V. (2010). "Chapter 4. Metre Convention and Evolution of Base Units". Springer Series in Materials Science, Volume 122. p. 47. doi:10.1007/978-3-642-00738-5_4. 
  59. Feltham, A. M.; Spiro, Michael (1971). "Platinized platinum electrodes". Chemical Reviews. 71 (2): 177. doi:10.1021/cr60270a002. 
  60. "21.09kg Pt". WolframAlpha. Retrieved 14 July 2012. 
  61. "Professional Jeweler's Magazine Archives, issue of August 2004". Retrieved 19 June 2011. 
  62. "Platinum primer". Diamond Cutters International. Retrieved 18 June 2011. 
  63. "Unknown Facts about Platinum". watches.infoniac.com. Retrieved 9 September 2008. 
  64. "Fixing Statistics". The London Platinum and Palladium Market. Retrieved 13 June 2010. 
  65. "One Year Platinum". Kitco. Retrieved 28 June 2011. 
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  67. "Platinum". Minerals Zone. Retrieved 9 September 2008. 
  68. Gwin, John (1986). "Pricing Financial Institution Products". Journal of Professional Services Marketing. 1 (3): 91. doi:10.1300/J090v01n03_07. 
  69. Crouse, Richard (1 May 2000). Big Bang Baby: The Rock Trivia Book. p. 126. ISBN 978-0-88882-219-2. 
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  71. "Occupational Health Guideline for Soluble Platinum Salts (as Platinum)" (PDF). Centers for Disease Control and Prevention. Retrieved 9 September 2008. 
  72. "CDC - NIOSH Pocket Guide to Chemical Hazards - Platinum". www.cdc.gov. Retrieved 2015-11-21. 
  73. "FDA Backgrounder on Platinum in Silicone Breast Implants". U.S. Food and Drug Administration. Archived from the original on 24 July 2008. Retrieved 9 September 2008. 
  74. Brook, Michael (2006). "Platinum in silicone breast implants". Biomaterials. 27 (17): 3274–3286. doi:10.1016/j.biomaterials.2006.01.027. PMID 16483647. 

Further reading

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Categories:

Platinum Group Metals

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

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Rh

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Ag

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I

Xe

Cs

Ba

*

Hf

Ta

W

Re

Os

Ir

Pt

Au

Hg

Tl

Pb

Bi

Po

At

Rn

Fr

Ra

**

Rf

Db

Sg

Bh

Hs

Mt

Ds

Rg

Cn

Uut

Fl

Uup

Lv

Uus

Uuo

 *

La

Ce

Pr

Nd

Pm

Sm

Eu

Gd

Tb

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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 (abbreviated as the PGMs; alternatively, 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][1]

The six platinum-group metals are ruthenium, rhodium, palladium, osmium, iridium, and platinum. They have similar physical and chemical properties,[clarification needed] 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 traditional periodic table (iron, nickel and cobalt) are all ferromagnetic, these being the only known transition metals with this property.

Contents

 

History

Naturally occurring platinum and platinum-rich alloys have been known by pre-Columbian Americans for many years.[4] 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").[4]

The Spaniards named the metal platina ("little silver") when they first encountered it in Colombia. They regarded platinum as an unwanted impurity in the silver they were mining.[4][5]

Properties and uses

https://upload.wikimedia.org/wikipedia/commons/8/85/National_prototype_kilogram_K20_replica.jpg

Replica of the NIST national prototype kilogram standard, made in 90%platinum - 10%iridium alloy.

As of 1996, the largest applications of platinum metals were, in millions of troy ounces/year: Pd for autocatalysts (4470), Pt for jewelry (2370), Pd for electronics (2070), Pt for autocatalysts (1830), Pd for dental (1230), Rh for autocatalysts (490), and Pd for chemical reagents (230).[1]

The platinum metals have many useful catalytic properties. They are highly resistant to wear and tarnish, making platinum, in particular, well suited for fine jewelry. Other distinctive properties include resistance to chemical attack, excellent high-temperature characteristics, and stable electrical properties. All these properties have been exploited for industrial applications.[6]

PGM minerals[edit]

Typical ores for PGMs contain ca. 10 g PGM/ton ore, thus the identity of the particular mineral is unknown.[7]

Platinum

Sperrylite (platinum arsenide, PtAs2) ore is a major source of this metal. 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.[8][9] Platinum and palladium are also mined commercially from the Stillwater igneous complex in Montana, USA.

Osmium

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.[9][10]

Iridium

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.[9]

Ruthenium

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.[9]

Rhodium

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 river sands of the Ural Mountains, in 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.[11]

Palladium

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.[11][dead link]

Production

https://upload.wikimedia.org/wikipedia/commons/thumb/0/01/PtMetalExtraction_II.jpg/220px-PtMetalExtraction_II.jpg

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. Thus, the extraction process is very energy intensive with environmental consequences. Classical purification methods exploit differences in chemical reactivity and solubility of several compounds of the metals under extraction.[6] 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: (NH4)2PtCl6, PdCl2(NH3)2, the volatile OsO4 and RuO4, the poorly soluble (NH4)2IrCl6, and [RhCl(NH3)5]Cl2.[7]

Production in nuclear reactors

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.[12] 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.[13][14][15]

See also

Notes

  1. 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. 
  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. Weeks, M. E. (1968). Discovery of the Elements (7 ed.). Journal of Chemical Education. pp. 385–407. ISBN 0-8486-8579-2. OCLC 23991202. 
  5. Woods, Ian (2004). The Elements: Platinum. Benchmark Books. ISBN 978-0-7614-1550-3. 
  6. 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. 
  7. 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
  8. Xiao, Z.; Laplante, A. R. (2004). "Characterizing and recovering the platinum group minerals—a review". Minerals Engineering. 17 (9–10): 961–979. doi:10.1016/j.mineng.2004.04.001. 
  9. "Platinum–Group Metals" (PDF). U.S. Geological Survey, Mineral Commodity Summaries. January 2007. Retrieved 2008-09-09. 
  10. 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. 
  11. Chevalier, Patrick. "Mineral Yearbook: Platinum Group Metals" (PDF). Natural Resources Canada. Retrieved 2008-10-17. 
  12. 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. 
  13. 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. 
  14. Kolarik, Zdenek; Renard, Edouard V. (2005). "Potential Applications of Fission Platinoids in Industry" (PDF). Platinum Metals Review. 49 (2): 79. doi:10.1595/147106705X35263. 
  15. 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. 

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