Introduction

Platinum is a metallic, silvery-white element. It is a chemical element of the 10th group of the periodic system with an atomic number of 78. The 37 isotopes are known from ¹⁶⁶Pt until ²⁰²Pt. The five of these isotopes are stable: ¹⁹²Pt, ¹⁹⁴Pt, ¹⁹⁵Pt, ¹⁹⁶Pt, ¹⁹⁸Pt and one radioisotope ¹⁹⁰Pt (T_1/2=6.5^•10⁺¹¹ years). The major source of Platinum is the platinum arsenide (PtAs₂), sperrylit associated with nickel ores. Also the rare sulfide mineral cooperite, (Pt,Pd,Ni)S, contains platinum along with palladium and nickel.  The unique physical properties of Platinum and related alloys have found many applications in modern industry.

Physical Properties of Platinum

   Few of us are aware of the range of uses for platinum group metals (PGMs). Today's catalytic converters and tomorrow's fuel cells are just two of the many applications that offer great promises to benefit our environment. Yet PGMs are also used in applications that contribute to our health and well-being, acting as key components in certain anti-cancer drugs, and a range of surgical implants and prosthetics.They are also crucial in industrial processes such as fiberglass production and gasoline refining. Many new technologies from mobile telephones to the computer screen on which you're reading this page all owe their operation to PGMs. Even the car you drive may have half a dozen or so functions that rely on one or more of these metals. So when you include their everyday uses in items such as fountain pens, razors and jewellery, you can see that the PGMs are all around us and will increasingly be so in the years to come.

Environmental

   Catalytic Converters

  For years, catalytic converters have been used for their pollution abatement potential. They were first introduced in the USA and since 1981 all cars and light duty trucks sold in the US must include catalytic converters as standard equipment. Not just the US, 85% of cars sold worldwide are now fitted with three way catalytic converters. In fact, the average family car in the US would emit 15 tons of toxic and harmful polluting gases (carbon monoxide, hydrocarbons and nitrogen oxides), over a 10-year life, if catalytic converters were not fitted to all new cars to remove up to 98% of pollution as required by current regulations. Catalytic converters are also an efficient means of reducing pollution from diesel engines. Catalytic converters for diesel vehicles have shown to demonstrably lower not only particulate matter but also carbon monoxide and NOx emissions.

   Fuel Cells

   Fuel cells are a rapidly developing energy conversion technology. Offering higher efficiencies than conventional technologies, they also operate quietly. Their modular construction means they can be economically and easily scaled down to small sizes to fit many applications. These features make fuel cells attractive for a range of potential applications, from combined heat and power (CHP) to distributed power generation to transport and portable power for mobile appliances.

   Electronic Components

   Being good conductors, ductile when annealed and oxidation resistant with high temperature stability, platinum, palladium and ruthenium provide an alternative and more effective plating to gold on connectors and circuit boards. The improved durability and reliability which these metals provide reduces the need for replacement and disposal.

Medical

   Aural Implants : helping the deaf to hear again

   Aural implants to replace damaged or malfunctioning cochlears in those suffering from deafness, by electrically stimulating the auditory nerve, contain platinum and iridium whose electrical conductivity, durability, biological compatibility and oxidation resistance make them perfect for the electrodes in the implants.

   Cancer : effective measures to counter a deadly disease

   PGMs' role in the fight against cancer is twofold: as the active ingredient in chemotherapy drugs and in radio-active implants for radiation therapy (brachytherapy). In the first of these, platinum compounds cisplatinum and carboplatinum have the unique quality of inhibiting the splitting and growth of cancerous cells. These compounds have been particularly successful in the treatment of testicular and ovarian cancers. More recently, palladium compounds have also been successfully tested. In brachytherapy, implants are made of platinum with the active ingredient of iridium isotopes. These are placed directly into tumours, giving a high radiation dose to the tumour while reducing the effect on surrounding healthy tissue.

   Parkinson's Disease : relief for sufferers

   It is estimated that four million people worldwide have Parkinson's disease, a neurological condition with a range of symptoms including essential tremor (shaking) and rigidity. The latest advances in combating this condition are neural implants made of platinum and iridium that generate an electrical impulse which stimulates a targeted area of the brain and reduces the shaking and rigidity almost immediately.

  Micro-precision surgical Tools: safe and effective surgery.

   Ever more complicated and vital surgical procedures require reliable, safe and effective tools to ensure success. The platinum-iridium alloy combines these two metals' strength, durability and biological compatibility to produce surgical tools of exceptional quality and effectiveness.

  Pacemakers and Implantable Defibrillators: saving the lives of those with heart conditions.

   Pacemakers and implantable defibrillators deliver electric shocks of varying strength to the hearts of those suffering from cardiac disorders, helping to effectively regulate the beating of the heart. Durable, conductive and biologically compatible, platinum is perfect for the electrodes and electrical contacts which are crucial to these implants' functioning.

  Retinal Implants: advancing the possibilities for restoring sight.

   A good example of how future technologies are becoming reality today is the advances in retinal implants to improve damaged or deteriorating eyesight. The electrodes and wires in such implants are made of platinum and iridium whose electrical conductivity, durability, biological compatibility and oxidation resistance make them perfect for such a role.

Industrial

  Alloys: improving the hardness and durability of metals.

   Because of their own hardness and density, rhodium, iridium, ruthenium and osmium alloy with platinum and palladium to produce metals which combine the best qualities of each with a unique hardness and durability. PGMs can have a quite remarkable effect on other metals. For example, titanium's corrosion resistance is boosted a hundred times by the addition of just 0.1% of ruthenium. This gives titanium an even more effective and durable role in aerospace and marine applications where resistance to extremes of temperature and salt water is crucial. Application for alloys between the PGMs include fuel cells, industrial crucibles and tools, and jewellery.

  Industrial Crucibles: producing everyday goods, reducing the impact on the environment.

   Because of their hardness, high melting points and high temperature stability PGMs are the perfect coating for industrial crucibles where high temperatures are necessary to produce chemicals and synthetics with the utmost efficiency. The high temperature stability, melting points and corrosion resistance of platinum, rhodium, iridium, ruthenium and their alloys allow for higher temperatures to be achieved in crucibles, a key factor in any chemical process. The "nobility" of PGMs is also crucial. High purity conditions are required for these processes and PGMs' high temperature stability means that they do not contaminate the products being fabricated. Products produced in such ways include: artificial silk; crystals; glass; glass fibre.

  Glass: optical quality for a range of applications.

    Optically pure, flat glass improves the quality of televisions, monitors and Liquid Crystal Displays. It is produced in crucibles made of PGMs and their alloys where extremely high temperatures give maximum efficiency to the reaction necessary to synthesise such glass.

  Glass Fibre.

    Glass fibre's versatility finds its use in a range of applications. These are just a few of its uses: as a reinforcer for plastic and concrete; in insulation for buildings; in the hulls of ships, fuselages of aircraft and walls of petrol tankers, and in everyday products such as ladders and fishing rods. Glass fibre optics are used in telecommunications applications where they have greater capacity, transmission speed and efficiency and are cheaper to maintain than other cables. It is produced in crucibles made of PGMs and their alloys which are resistant to the high temperature and corrociveness of molten glass.

  Petroleum Refining: high performance fuels for the modern automobile.

   Low octane petroleum is converted into high octane with platinum-based reforming catalysts, heat and pressure. This process increases unrefined petroleum's octane number by rearranging hydrocarbon molecules. Platinum's catalytic qualities and high temperature stability, corrosion resistance and high melting point make it ideal for this process.

Technology

  Ceramic Capacitors

   Multi-layer ceramic capacitors store energy in electronic devices in the form of an electrostatic field. Typically, they consists of two coated conducting plates separated by an insulating material called the dielectric. They are used in broadcasting equipment, mobile telephones, computers, electronic lighting and high voltage circuits to name but a few applications. Because of their conductivity, durability, high temperature stability and oxidation resistance, platinum and palladium are used to coat multi-layer ceramic capacitors. For the same reasons, these metals are also used to coat electrodes, the tiny components in all electronic products which help establish electrical contact between non-metallic parts of a circuit and control the flow of electricity. Rhodium and iridium are also used for this.

  Computer Hard Discs

   Computers have impacted on nearly every aspect of our professional and personal lives in the last two decades. Magnetic alloys containing platinum (mainly with cobalt) are now crucial components in the hard disks of virtually all computers manufactured today - at least 90% by the start of 2001. This is the largest single electronic application for platinum and demand doubled between 1998 and 2000. Platinum allows for a greater data storage density and has thus enabled manufacturers to reduce the number of disks in each hard drive, falling from an average of 1.8 to 1.6 in 2000-2001.

   Other sections of this site take you through how platinum group metals (PGMs) are used in automotive, technological, industrial, medical and environmental applications. But elements as versatile and unique as the PGMs have a myriad of uses that improve our lives without falling neatly into those categories.