Platinum

{ syn. }

{ syn. }

0.01 %

{ syn. }

0.79%

{ syn. }

32.9 %

33.8 %

25.3%

{ syn. }

7.2%

{ syn. }

{ syn. }

Powder

Risk

Powder

Platinum is a chemical element with the chemical symbol Pt and atomic number 78 in the periodic table it is in the group 10 ( in the old part count of subgroup 8 ) or nickel group. Platinum is a heavy, malleable, ductile, gray-white transition metal. The precious metal is highly corrosion resistant and is used for the manufacture of jewelery, automotive catalysts, laboratory equipment, dental implants and contact materials.

History

The name derives from the Spanish word platina, the pejorative diminutive of plata " silver " from. The first European record comes from the Italian humanist Julius Caesar Scaliger. He describes a mysterious white metal that eluded all melting experiments. A more detailed description of the features found in a 1748 report by Antonio de Ulloa.

Platinum was probably first used around 3000 BC in Ancient Egypt. The British explorer Sir William Matthew Flinders Petrie (1853-1942) discovered in 1895 ancient Egyptian jewelry and found that platinum was included in a small amount.

Platinum was also used by the Indians of South America. There was on winning gold dust in the washing gold as an accompaniment and could not be explicitly separated. The Forge at the time took advantage of unconscious of the fact that it is possible native platinum grains of gold dust in the glow of angefachtem with Blasebalgen charcoal fire weld well, with the gold like a Lot looked and by repeated forging and heating a relatively homogeneous, bright, in the forging heat could produce malleable metal alloy. This could not be melted again and was as solid as gold, but from whitish -silver -like color. Already about a 15 percent share of platinum leads to a light gray color. However, pure platinum was still unknown.

In the 17th century platinum in the Spanish colonies as a troublesome companion material in the search for gold was a major problem. It was considered " immature " gold and threw it back into the rivers of Ecuador. Since it has a specific weight similar to gold and not even started in the fire, it was used the same for tampering. Thereafter, the Spanish government issued a ban on exports. They even considered, all the sink so far got platinum in the sea to forestall platinum smuggling and counterfeiting and deterring.

Alchemy of the 18th century were called for because the distinguishing of pure gold and extracting designed with the then techniques to be extremely difficult. But the interest was piqued. 1748 Antonio de Ulloa published a detailed report on the properties of this metal. 1750, the English physician William Brownrigg ago purified platinum powder. Louis Bernard Guyton de Morveau found in 1783 a way to process platinum industry to win.

Platinum as mineral deposits and

Platinum is solid, that is in elemental form in nature and is therefore of the International Mineralogical Association (IMA ) recognized as a mineral. In the scheme of minerals by Strunz ( 9th edition ), it is in the mineral class of " elements " and the Department of " metals and intermetallic compounds " where there is a namesake of the subdivision " platinum - group elements " along with iridium, palladium and rhodium, the unnamed group 1.AF.10 forms. In the outdated but still in use 8th edition platinum wore the system no. I/A.14-70 ( elements - metals, alloys, intermetallic compounds ).

By Hans Merensky discovered in 1924 known as the Merensky Reef of the commercial mining of platinum was economical.

The most important producing nations of platinum in 2011 were South Africa with 139 tonnes, Russia with 26 tons and Canada with 10 tons, whose share amounted to the global production of 192 tons of 91 per cent ( See also: Promotion by country - platinum). The platinum price is currently about 10 percent higher than the price of gold (July / August 2013).

Worldwide, platinum so far (as of 2011) are detected at around 380 localities, including, inter alia in several regions of Ethiopia, Australia, Brazil, Bulgaria, China, the Democratic Republic of Congo, Germany, France, Guinea, Indonesia, Ireland, Italy, Japan, Colombia, Madagascar, Mexico, Myanmar, New Zealand, Norway, Papua New Guinea, Philippines, Sierra Leone, Zimbabwe, Slovakia, Spain, Turkey, the United Kingdom and the United States of America (USA).

Platinum also comes in the form of chemical compounds in numerous minerals. So far, about 50 platinum minerals are known (as of 2011).

Extraction and production

Metallic platinum (platinum soaps) is today rarely mined. Extensive platinum mining is only available in the South African Bushveld complex, also on the Great Dyke in Zimbabwe and in the Stillwater Complex in Montana. The South African mines include, for example, Lonmin, Anglo American Platinum and Impala Platinum.

Sources of platinum are also the non-ferrous metal production ( copper and nickel) in Greater Sudbury (Ontario) and Norilsk (Russia). This fall, the platinum group metals as a by- product of nickel refining. As a platinum metal side is called five metals that are similar in their chemical behavior of the platinum so that the separation and purification of previously made ​​great difficulties. 1803 were iridium discovered osmium, palladium and rhodium; 1844 was followed by ruthenium.

Platinum sponge formed in the annealing of Ammoniumhexachloridoplatinat or upon heating of the paper, which is impregnated with a platinum salt solution.

For recycling of platinum is dissolved in aqua regia this either by oxidation, a mixture of nitric and hydrochloric acid, or in a mixture of sulfuric acid and hydrogen peroxide. In these solutions, then platinum is in the form of complex compounds present (eg in the case of aqua regia as chloroplatinic (IV ) acid ) and can be obtained therefrom by reduction again. Researchers at the National Chung Hsiang University ( Taiwan) have developed a novel method is electrochemically dissolved at the platinum in a mixture of zinc chloride and a special ionic liquid. Under ionic liquid is meant an organic salt that is present is melted at temperatures below 100 ° C and has a high conductivity. The platinum is used in the form of an electrode, which is connected as an anode, and used to heat the surrounding ionic liquid to about 100 ° C. The platinum dissolves it on oxidative. Then can the dissolved platinum as pure metal deposited on a carrier electrode again.

Properties

Physical Properties

Platinum is a corrosion resistant, malleable and soft heavy metal.

Due to its high durability, stain resistance and rarity to platinum is particularly suitable for the production of high-quality jewelery.

Chemical Properties

Platinum shows, like the other metals of the platinum group, a contradictory behavior. On the one hand there is precious metal typically chemically inert, on the other hand highly reactive, catalytically - selectively to certain substances and reaction conditions. Also at high temperatures is platinum stable behavior. It is therefore of interest for many industrial applications.

Add salt and in nitric acid alone is insoluble in each case. In hot aqua regia, a mixture of hydrochloric and nitric acid, it is, however, attacked the formation of red-brown Hexachloroplatinum (IV ) acid. Platinum but is severely attacked even in the presence of oxygen from hydrochloric acid and hot fuming nitric acid. Also of alkali, peroxide, nitrate, sulfide, cyanide and other molten salts is attacked. Many metals form with platinum alloys, such as iron, nickel, copper, cobalt, gold, tungsten, gallium, tin, etc. Particularly noteworthy is that platinum partly under compound formation with hot sulfur, phosphorus, boron, silicon, carbon, in any form reacts, that is also in hot flame gases. Also many oxides react with platinum, which is why only certain materials may be used as the crucible material. When melting the metal with, for example, a propane - oxygen flame, therefore, must be used to schwachoxidierender neutral flame. Best way is to flame-free electric- inductive heating of the molten material in zirconia ceramics.

Catalytic Properties

Both hydrogen, oxygen and other gases are bound platinum in the activated state. It therefore has remarkable catalytic properties; Hydrogen and oxygen react explosively with one another in his presence to water. Furthermore, it is the catalytic active species in the catalytic reforming. However, platinum catalysts become inactive due to aging and contamination ( poisoned ) and must be regenerated. Porous platinum, which has a particularly large surface is also referred to as a platinum sponge. The large surface area to better catalytic properties result.

Use

Due to their availability and the excellent features, there are many different uses for platinum and platinum alloys. So Platinum is a favored material for the production of laboratory equipment, since it produces no flame coloration. There are, for example, uses thin platinum wires to hold fabric samples into the flame of a Bunsen burner.

Platinum is also used in an almost unmanageable number of areas:

• Platinum is a noble and currently before gold is the most valuable precious metal - it is almost sixty times more expensive than silver. It was, and is therefore used for expensive jewelery and pens, as well as cash and investments. For this purpose is platinum, such as gold, used in the form of alloys, as it is hardly harder than gold in the pure state. The Platinum Bullion Coins Canadian Maple Leaf and American Platinum Eagle are still issued. 1828 and 1846, coins were made ​​of platinum in Russia between embossed, platinum rubles. First, there were coins from about 10.3 grams of platinum worth 3 rubles, and later included coins of twice and four times the value and the corresponding platinum weight.
• Thermocouples
• Resistance thermometers (eg Pt100)
• Heating resistors
• Contact materials and electrodes, for example in spark plug
• Catalysts. Examples include not only vehicle catalysts including diesel oxidation catalysts and catalysts in fuel cells, but also those for large-scale industrial processes such as production of nitric acid and platinum -rhodium alloys. A historically important example is the Döbereinersche lighter. For 2005, the consumption of platinum for the catalyst preparation is estimated at 3.86 million ounces, which is about 120.1 tons.
• Magnetic Materials
• Chemical Plant, laboratory and analysis equipment
• Crucibles for glass production
• Glaseinschmelzlegierungen
• Medical implants, alloying addition in dental materials (see also: biomaterial )
• Pacemaker
• Thrusters, fairings for rockets
• Spinnerets
• Platinum mirror ( mirror and partially transparent mirror, which in contrast to silver mirrors can not start )
• Laser printer ( charge corona )
• Coatings of turbine vanes in aircraft engines
• Platinum equipment for the special glass melt. For the visual and technical specialty glass melt thousands of devices from platinum materials are produced. About laboratory crucibles made ​​of pure Pt, PtIr, PtRh or PtAu materials for the first trial heats to complete continuous When systems that can have several 100 kg of platinum weight. In addition to refining chambers, jars and pipe systems PtIr or PtRh additional devices such as stirrers, lids, electrodes, discharge rings and nozzles are used.

The most commonly used material for the device for production of optical glass is pure Pt or Pt with 0.3 to 1.0 % of Ir to the crucible and tube systems as well as to PtRh3 PtRh10 for strongly mechanically stressed devices, such as stirrers.

Wherein the devices for the production of technical glass used PtRh10 to PtRh30 materials. This mechanically stable high-percentage PtRh materials can not be used in optical glass melt, since the Rh a slightly yellowish color in the melt leaves, which leads to transmission losses in the optical glass products.

Also FKS (fine grain stabilized ) and ODS ( Oxide Dispersion Strengthened ) materials are used in the optical and technical specialty glass melt for special applications. This powder produced Pt, PtRh, PtIr, PtAu and materials are doped with approximately 0.2% of yttrium and zirconia, in order to prevent premature grain growth at the devices in the glass melting process of platinum.

The main problem with the processing of these materials is the limited weldability in device manufacturing.

• In contrast to the above uses, the use of platinum as the metal, there is also a highly effective and therefore important class of anticancer drugs ( cytostatics ) containing platinum compounds such as cisplatin, carboplatin and oxaliplatin.

The International prototype of the kilogram, which is kept in a vault of the Bureau International des Poids et Mesures ( BIPM), consists of an alloy of 90 % platinum and 10% iridium.

From the same alloy the International meter prototype of 1889, which defined the meter to 1960.

As a platinum within the meaning of the Combined Nomenclature, the expression defined in the note to Chapter 4.B 71 platinum, iridium, osmium, palladium, rhodium and ruthenium.

Alloys / Materials

Fasserplatin is an alloy consisting of about 96% pure platinum and about 4 % pure palladium (melting point: 1750 ° C Density 20.8 g/cm3, Brinell hardness: 55, Tensile Strength: 314 N/mm2 elongation at break: 39).

Jeweler platinum is an alloy consisting of about 96% pure platinum and 4% of pure copper (melting point: 1730 ° C Density 20.3 g/cm3 Hardness: 110, tensile strength: 363 N/mm2 elongation at break: 25).

Both alloys are often used in the jewelry industry for platinum jewelry.

• Pt1Ir is an alloy of 99% platinum and 1 % of iridium for the production of devices for the optical glass melt.
• Pt3Ir is an alloy of 97% platinum and 3% for the production of iridium agitators for the optical glass melt.
• Pt5Rh is an alloy of 95% platinum and 5 % rhodium for producing agitators for the optical glass melt.
• Pt10Rh is an alloy of 90% platinum and 10 % rhodium for the production of technical equipment for the glass melt.
• Pt20Rh is an alloy of 80% platinum and 20 % rhodium for the production of technical equipment for the glass melt.
• Pt30Rh is an alloy of 70% platinum and 30 % rhodium for the production of technical equipment for the glass melt.
• FCS Pt is a material of pure Pt with about 0.2 % of zirconium oxide in the manufacture of devices for the optical glass melt.
• FCS Pt10Rh is an alloy of 90% platinum and 10% rhodium, with about 0.2 % of zirconium oxide for the manufacture of equipment for the technical glass melt.
• ODS Pt is a material of pure Pt with about 0.2 % of yttrium oxide for the production of devices for the optical glass melt.
• ODS Pt10Rh is an alloy of 90% platinum and 10% rhodium, with about 0.2 % of yttrium oxide for the manufacture of equipment for the technical glass melt.
• ODS Pt20Rh is an alloy of 80% platinum and 20% rhodium, with about 0.2 % of yttrium oxide for the manufacture of equipment for the technical glass melt.

The ODS and FKS materials have approximately the same physical properties, but are made of patent law with yttrium or zirconium oxide.

These alloys are used by the special glass manufacturers such as Hoya and Asahi in Japan, Corning in the USA, Saint- Gobain in France and Schott in Germany for countless devices in glass melting technology.

Compounds

• Platinum (IV ) oxide hydrate ( PtO2 · x H2O) brown black powder is used as a catalyst broad applications in organic chemistry
• Platinum ( VI) -oxide ( PTO3 )
• Platinum (II ) chloride ( PtCl2 ), platinum (IV ) chloride ( PtCl4 )
• Tetrachloroplatin (II ) acid (H 2 [ PtCl 4 ] )
• Hexachloridoplatin (IV) acid ( H2 [ PtCl6 ] )
• Platinum ( IV ) fluoride ( PtF4 )
• Platinum ( V ) fluoride ( PtF5 )
• Platinum ( VI ) fluoride ( PtF6 )
• Platinum (II) bromide ( PtBr2 )
• Platinum (IV) bromide ( PtBr4 )
• Platinum (II ) iodide ( PtI2 )
• Platinum (IV ) iodide ( PtI4 )
• Platinum (II ) oxide ( PtO )
• Platinum (II ) sulphide ( pts)

An example of a compound with platinum in the oxidation state 0 is

• Tetrakis (triphenylphosphine ) platinum ( Pt ( PPh3) 4 )

Silicon compounds (such as infra-red cameras):

• PtSi
• Pt2Si
• Pt3Si

Connections with aluminum:

• PtAl2 is a crystalline, brittle, golden-yellow compound
• Pt3Al is also crystalline, but silver

Platinum price

The term for platinum, which is traded on the stock market is, XPT. The International Securities Identification in stock market trading is: ISIN XC0009665545.