Platinum and Its Use

Platinum is a chemical element with the chemical symbol Pt and the atomic number of 78. Its name is derived from the Spanish term “platina del Pinto”, which is literally translated into “little silver of the Pinto River”. It was discovered in South America by Ulloa in 1753 and by Wood in 1741. The metal was used by pre-Columbian Indians.

Platinum is an extremely rare metal, occurring as only 0.003 ppm in the Earth's crust. Platinum bullion has the ISO currency code of XPT. Platinum is a commodity with a value that fluctuates according to market forces. As of February 2010, platinum was worth on average US $1540 per troy ounce or approximately US $44 per gram.

Platinum is in the Group 10 of the periodic table of elements. A dense, malleable, ductile, precious, gray-white transition metal, platinum is resistant to corrosion and occurs in some nickel and copper ores along with some native deposits.

Platinum occurs natively, accompanied by small quantities of iridium, osmium, palladium, ruthenium and rhodium, all belonging to the same group of metals. These are found in the alluvial deposits of the Ural mountain, Columbia and certain Western American states.

Platinum is a beautiful silvery-white metal, when pure, and is malleable and ductile. It has a coefficient of expansion almost equal to that of soda-lime-silica glass, and is therefore used to make sealed electrodes in glass systems. The metal does not oxidize in air at any temperature, but is corroded by halogens, cyanides, sulfur and caustic alkalis. Platinum is insoluble in hydrochloric and nitric acid, but dissolves in aqua regia to form chloroplatinic acid, H₂PtCl₆.

Platinum's wear- and tarnish-resistance characteristics are well suited for making fine jewelry. Platinum is more precious than gold or silver. Platinum possesses high resistance to chemical attack, excellent high-temperature characteristics, and stable electrical properties. All of these properties have been exploited for industrial applications.

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. 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 650×10⁹ years. ¹⁹⁸Pt undergoes alpha decay, but because its half-life is estimated as being greater than 320×10¹² years, 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, while the most stable is ¹⁹³Pt with a half-life of 50 years. Most of platinum's 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.

The reason why platinum is today the most valuable of precious metals is because it is required in many industrial applications. It is estimated that one-fifth of everything we use either contains platinum or requires platinum in its manufacture. Among all the known modern uses of platinum, most of the annual production is consumed by two dominant categories - catalytic converters and fine jewelry. Together, these two applications consume more than 70% of the world's supply of platinum.

Platinum has multiple and essential applications while new uses for platinum are constantly developed. Fig.1 shows the platinum demand by application in 2006.

Figure 1: Platinum demand by application in 2006.

Automobile Catalyst

As mentioned above, the best known use of platinum is in the catalytic converter that is part of the exhaust system in the automobile. Instead of dispersing harmful carbon monoxides, hydrocarbons and nitric oxide into the atmosphere, catalysts converts these harmful emissions into harmless carbon dioxide and water.

About half of newly mined platinum is used for this purpose. Increased concerns about environment protection has led to tougher emission standards being imposed by governments worldwide, further escalating the demand for the metal.

Petroleum Industry

Beyond cleaning up our air, platinum's excellent catalytic properties also extend to another important industry - the petroleum industry. Platinum mesh or gauze is used in cracking processes in oil refineries. Platinum catalysts play a critical role in extracting gasoline from crude oil and for making high octane fuels.

Jewelry

Platinum jewelry demand was forecast to account for roughly 25% of total platinum demand in 2006 (down from 50% in 2000). High and volatile prices have adversely affected purchases of platinum across the major regions, particularly China.

This precious metal is highly valued for its beauty and purity together with its particular properties. Although in Europe and USA the normal purity is 95%, in certain countries the purity may be down to 85%. Platinum color, strength, hardness and resistance to tarnish are some of the advantages of this metal in jewelry. It provides a secure setting for diamonds and other gemstones, enhancing their brilliance. Moreover, its flexibility is an important element for jewelry designers. Platinum jewelry is regarded as the precious metal for the "New Millennium".

Hard discs

Platinum is used in the production of hard disk drive coatings and fiber optic cables. The increasing number of personal computers will have a positive effect on platinum demand in the future.

The hard drive is the component of the computer where data is stored. Each drive contains one or more platters or disks where data is stored on the magnetic surfaces. The amount of data that can be recorded on a given surface depends very much on the strength of the magnetic field generated by the surface layer.

Back in 1957 when IBM first introduced the hard disk, storing just 5 megabytes of data require fifty disks, each measuring 24 inches in diameter. Fifty years later, a much smaller 3.5 inch disk drive is capable of storing over 500 gigabytes of data. An important process to achieving this remarkable increase in storage capacity is by adding platinum to the cobalt alloy to enhance its magnetic properties, allowing data to be stored at higher densities.

With so much digital content being created (at higher and higher definitions) and then shared online by millions of people over high speed broadband internet, the strong demand for higher capacity disk drives has resulted in more platinum being used in the manufacture of hard disks to enhance their storage capacity. The proportion of platinum in the magnetic alloy has gone up from less than 10 percent in 2002 to 35 percent in 2007.

Electrical and Electronics

Other applications include thermocouples that measure temperature in the glass, steel and semiconductor industries or infra-red detectors for military and commercial applications. It is also used in multi-layer ceramic capacitors and crucibles to grow single crystals.

Chemical

Platinum is used in fertilizers and explosives as a gauze for the catalytic conversion of ammonia to nitric acid. It is also used in the fabrication of silicones for the aerospace, automotive and construction sector.

In the fuel sector it is important as a petrol additive to enhance combustion and reduce engine emissions. Moreover, it is a catalyst in the production of biodegradable elements for household detergents.

Medicine

Platinum also find use in medicine as anti-cancer drugs and in implants. It is also used neurosurgical apparatus and in alloys for dental restorations.

Fuel Cells

The most common type of fuel cell is the proton exchange membrane (PEM) fuel cell, which contains platinum catalysts. Besides being used to power automobiles, PEM fuel cells can also be used in power generation for buildings, instead of batteries or generators in portable equipment.

Investments

As important issue we can mention investment. Platinum is seen as an attractive investment vehicle and as a good way of hedging assets against inflation. This attraction for platinum investment is spreading worldwide and is based on platinum relative scarcity, its historical price performance and unique fundamentals.

Glass

Platinum is used in glassmaking equipment. It is used in the manufacturing of fiberglass reinforced plastic and of glass for liquid crystal displays (LCD). In this context, some new developments in the production of LCD glass and cathode ray tubes, both used in computer screens should be mentioned.