Precious Metals in Industry

Silver

Another key use for silver is in the millions of water purifiers that are sold each year. Silver prevents bacteria and algae from building up in their filters so that they can do their job to rid drinking water of bacteria, chlorine, trihalomethanes, lead, particulates and odor. Silver, in concert with oxygen, acts as a powerful sanitizer that offers an alternative or an augmentation to other disinfectant systems.

Silver ions are also starting to be added to water purification systems in hospitals, community water systems, pools and spas. Silver also eradicates Legionnaires’ disease, which is caused by buildup in pipes, connections and water tanks.
Water-born illness is a major problem in developing nations. The full extent to which silver can help treat the issue of clean drinking water has yet to be seen but ongoing research is showing its usage to be an exciting development for the global water supply.

More and more, we are turning to solar energy as a viable alternative to fossil fuels, whose scarcity and pollutant effects are and will continue to be increasingly problematic in coming years.
Solar energy is cost-effective, environmentally responsible and provides an immediate source of power. From single-family homes to corporations and multinational companies, solar energy is expected to proliferate in the United States and abroad and has already made serious inroads as a replacement for traditional fuel-based power.

What many don’t know is that silver is a primary ingredient in the photovoltaic cells that catch the sun’s rays and transform them into energy. 90 % of crystalline silicon photovoltaic cells (the most common cell) use silver paste and close to 70 million ounces of silver are projected for use by solar energy by 2016.

Silver has long been revered by the medical community. Hippocrates, “the father of medicine,” knew of its healing and anti-disease properties. In World War I, before the event of antibiotics, it was an important weapon against disease on the battlefield. More recently, the FDA approved a breathing tube with a fine coating of silver, after it was established that it reduced the risk of ventilator-associated pneumonia. And that’s just one example of the many roles silver plays in medicine today. It is also added to bandages and wound-dressings, catheters and other medical instruments and is a key part of the technology behind X-rays.

Given its many applications, it is likely that you have encountered silver at a visit to the doctor, hospital or even being treated at home.

From non-corroding electrical switches to chemical-producing catalysts, silver is an essential component in nearly every industry. Its unique elemental properties make it impossible to substitute and its uses span almost every sector of industrial application.

Electric power, the most important source of power in global industry, depends on the distribution of electric power depends upon silver contacts in switches and circuit breakers. Silver contacts in membrane switch panels are now standard in control panels for machinery, chemical industry processes, railway traffic controls and elevator buttons.

Silver oxide and zinc batteries have twice the capacity of lead-acid batteries, making them the power source of choice for television and film crews, aircraft and submersibles. Unlike other substances, silver performs well at high temperatures. For example, silver batteries are the only kind that can function at the high temperatures found deep in oil wells.
Another important use is in radiography, the use of photo film to evaluate the internal condition of materials. This technique is key for the discovery of structural flaws.

For more information on silver’s use in industrial applications, go to this link for a report on the future of silver industrial demand.

Silver bearings are an essential component in many types of engines. With their high temperatures and continuous functioning, engines require a stronger type of bearing than other machinery.

When steel ball bearings are electroplated with silver, they become stronger than any other type of bearing. Jet engines, for example, rely on silver bearings because they can function continuously and at very high temperatures.

Placing a layer of silver between the steel ball bearing and its housing reduces friction between the two, increasing the performance and longevity of the engine. Despite high internal temperatures, silver-coated bearings provide superior performance and a critical margin of safety for engines. Even in the event of an oil pump failure, silver-plated bearings provide enough lubrication to allow a safe engine shutdown before more serious damage can occur.

Almost all electronics are configured with silver. From turning out the lights to turning on your television, if it has an on/off button, it’s likely that silver is playing an important role, behind the scenes.

Its excellent electrical conductivity makes it a natural choice for everything from printed circuit boards to switches and TV screens.

Silver membrane switches, which require only a light touch, are used in buttons on televisions, telephones, microwave ovens, children’s toys and computer keyboards. These switches are highly reliable and last for millions of on/off cycles. Silver is also used in conventional switches likes those used for controlling room lights.

For printed circuit boards, used in consumer items from mobile phones to computers, silver-based inks and films are applied to composite boards to create electrical pathways. Similarly, silver-based inks produce so-called RFID tags (radio frequency identification) antennas used in hundreds of millions of products to prevent theft and allow easy inventory control. They are also used in prepaid toll road passes.

CDs, DVDs and plasma display panels are also fabricated using silver.

Chances are you own plenty of items that owe their fabrication to the unique properties of silver catalysts.

A catalyst is a substance that facilitates a chemical process without itself undergoing any transformation. Because of its unique chemical properties, silver is an important catalyst in the production of two major industrial chemicals. Because the silver is not affected by the reaction, it is almost completely recovered after it is used.

More than 150 million ounces of silver are used each year to produce ethylene oxide and formaldehyde, both of which are essential ingredients in plastics. Approximately 90% of the silver employed as an industrial catalyst is used for the production of ethylene oxide from ethylene. Ethylene oxide is the foundation for plastics including polyester, the textile used in both mainstream fashion and specialty clothing. This same substance is an ingredient in molded items like insulating handles for stoves, key tops for computers, electrical control knobs, domestic appliance components, and electrical connector housings. About 25% of ethylene oxide production is used to produce antifreeze coolant for automobiles and other vehicles.

Formaldehyde, a chemical produced from methanol, is the building block of solid plastics adhesives, laminating resins for construction plywood and particle board. Formaldehyde also helps to produce finishes for paper and electronic equipment, textiles, surface coatings that resist heat and scratches, dinnerware and buttons, casings for appliances, handles and knobs, packaging materials, automotive parts, thermal and electrical insulating materials, toys and many other products.

In the soldering and brazing of pipes, faucets, ducts and joints, silver provides safety, strength and quality unrivaled by any other material.

Brazing occurs when materials are joined at temperatures above 600 degrees Celsius while soldering is the term for when this happens at temperatures below 600 degrees Celsius. Adding silver to the process of soldering or brazing helps produce smooth, leak-tight and corrosion-resistant joints. Silver brazing alloys are used widely in everything from air-conditioning and refrigeration to electric power distribution. They are also important in the automobile and aerospace industries.

Silver brazes and solders combine high tensile strength, ductility and thermal conductivity. Silver-tin solders are used for bonding copper pipe in homes, where they not only eliminate the use of harmful lead-based solders, but also provide the piping with silver’s natural antibacterial action. Major faucet manufacturers also use silver-based bonding materials to incorporate these advantages. Refrigerator manufacturers use silver-based bonding materials to provide the ductility required for constant changes in temperature of the cooling tubes.

Because of health concerns, the traditional 63% tin/37% lead solder used to build electronic equipment is quickly being replaced by a combination of silver, tin and copper solder. The movement was boosted by the Restriction of Hazardous Substances (RoHS) legislation that applies throughout the European Union (EU). The law bans all products containing more than a trace amount of lead, mercury, cadmium and several other hazardous substances. Although the laws apply only to EU countries, there is a worldwide movement toward using safer solder. Silver is and will continue to be a popular substitution for the metals that are currently being phased out.

Silver stays with you on the road, too. Every time you drive a car or ride in a motor vehicle, you are taking advantage of a number of the myriad uses of this element. Over 36 million ounces of silver are used annually in automobiles.

Every electrical action in a modern car is activated with silver coated contacts. Basic functions such as starting the engine, opening power windows, adjusting power seats and closing a power trunk are all activated using a silver membrane switch.

Another feature that is very important to our driving safety is the silver-ceramic lines fired into the rear window. The heat generated by these conductive paths is sufficient to clear the rear window of frost and ice. Finally, the active ingredient in antifreeze is ethylene oxide, which is a compound made from silver.



Platinum


Platinum has the ability, in certain chemical forms, to inhibit the division of living cells. The discovery of this property in 1962 led to the development of platinum-based drugs to treat a wide range of cancers. Cisplatin, the first platinum anti-cancer drug, began to be used in treatment in 1977. Testicular cancer was found to be susceptible to treatment with cisplatin and there were other successes with ovarian, head and neck cancers.

Researchers at the Institute of Cancer Research and the Royal Marsden Hospital in London achieved a significant step when they found a compound similar to cisplatin in terms of activity, but much less toxic. This drug, carboplatin, was first approved in 1986. Recent research has sought to identify new platinum compounds which will treat tumors which do not respond to or which become resistant to cisplatin and carboplatin. The first of these drugs to reach commercialization is oxaliplatin, which is being marketed under the trade name Eloxatin.

Upcoming platinum anti-cancer drugs include satraplatin, which is being developed for treatment of prostate cancer. It is claimed that the use of satraplatin results in a higher survival rate than with existing chemotherapy treatments. Satraplatin will also be the first platinum anti-cancer drug that can be administered orally instead of intravenously, allowing patients to be treated at home. The drug is currently undergoing clinical trials.

Platinum can be fabricated into very tiny, complex components. As it is inert, platinum does not corrode inside the body, while allergic reactions to platinum are extremely rare. Platinum also has good electrical conductivity, which makes it an ideal electrode material.

Pacemakers, used to treat heart disorders which result in slow or irregular heartbeat, usually contain at least two platinum-iridium electrodes, through which pulses of electricity are transmitted to stabilise the heartbeat. Platinum electrodes are also found in pacemaker-like devices which are used to help people at risk of fatal disturbances in the heart's rhythm. This risk can be minimised by implanting a device known as an Internal Cardioverter Defibrillator (ICD) which sends a massive electric charge to the heart as soon as it detects a problem.

Catheters, flexible tubes which can be introduced into the arteries, are widely used in modern, minimally-invasive treatments for heart disease. Many catheters contain platinum marker bands and guide wires, which are used to help the surgeon guide the device to the treatment site. The radio-opacity of platinum, which makes it visible in x-ray images, enables doctors to monitor the position of the catheter during treatment.

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Many chemical processes employ platinum group metal catalysts to improve the efficiency of various reactions.  Platinum-based catalysts have now been used in the commercial manufacture of nitric acid for a century.

Nitric acid is made in three stages. The first step is the oxidation of ammonia gas with air to form nitric oxide. In order to achieve a high conversion efficiency, this is normally carried out at pressure over a platinum-rhodium catalyst. The nitric oxide is cooled and further oxidised to form nitrogen dioxide, which is then absorbed in water to nitric acid.

The principal end-use of nitric acid is in the production of nitrogen fertilizers, an important source of plant nutrients. Non-fertilizer uses include the production of: explosive-grade ammonium nitrate; adipic acid, for making nylon, and toluene diisocyanate, for manufacturing polyurethane.

Pgm catalysts for nitric acid production take the form of a gauze made out of fine wire. When nitric acid was first produced commercially in 1904, a platinum-only catalyst was used. Rhodium was later added for strength and to reduce the amount of platinum lost during conversion of the gas.

Palladium-based "catchment" or "getter" gauze was introduced in 1968 to further reduce losses of platinum and rhodium, which can be as high as 300 mg per tonne of acid produced. The catchment sits downstream of the gas flow and collects pgm vapourised from the catalyst.

Until 1990, the catalysts and catchments used in ammonia oxidation were in the form of woven gauze. Johnson Matthey Noble Metals  then introduced a revolutionary knitted gauze, increasing the efficiency of conversion and extending the catalyst life. This has since become the industry standard.

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Many chemical processes employ platinum catalysts but the most significant in terms of platinum demand is the manufacture of speciality silicones. Addition of a platinum compound to the silicone mixture catalyses the cross-linking or 'curing' process which results in the formation of a silicone product with the
Silicones are highly durable materials with excellent resistance to chemical corrosion, fire and extremes of temperature. They are also pliable, waterproof and electrically insulating. It is not surprising, therefore, that silicone materials have a large number of uses in everyday life.
One of the major applications of silicones is in release liners, used to provide 'release surfaces' against aggressive adhesives and other sticky surfaces. They are commonly used for coating the backing paper of sticky labels, allowing the label to be peeled away easily without splitting. Release liners also provide resealability as they allow the sticky surface to be removed and reapplied without loss of adhesion. Aside from use in label backing applications, silicone-based release liners are used extensively in the baking industry. Pre-baked goods are placed upon release paper, which after baking can be removed cleanly and without damaging the product.
Other types of silicones that require platinum catalysts are water repellent coatings, high consistency rubbers and liquid silicone rubbers. Between them, these products have a vast number of applications which include furniture polishes and cleaning products, aero and automotive engine seals and gaskets, construction sealants, medical devices, high voltage cable covers and personal care products such as lipsticks and shampoos.

The use of silicones in medical elastomers is one that is showing strong growth going forward. For wound healing they have excellent properties, in that they will stick to dry skin, while not sticking to and damaging the wet wound. Silicones are also air and moisture permeable which improves the healing process.

Other applications include automotive airbag coatings. Here silicone is used to protect the nylon bag from the explosive system. The platinum cured systems are very stable in terms of being folded up for years on end without degradation. Deep sea lagging of pipes employs silicone's ability to survive extreme temperatures and pressures to keep oil flowing preventing freezing and pipe blockages.

One less industrial application is in the production of costumes and prosthetics for the film industry. Platinum curing is used as it provides the fastest curing, highest quality material. This technology has been extensively used in the recent Harry Potter films.

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The amount of data requiring digital storage continues to grow at a fantastic rate. No longer confined to use in computers, hard disk drives can now be found in televisions, games consoles and other home entertainment systems as a store of non-volatile data. The amount of platinum and ruthenium has increased rapidly over the years as storage densities have increased to meet demand. The first hard disk drive, introduced in 1957, used fifty disks, each measuring 24 inches in diameter, to store just 5 megabytes of data. Today hard disk drives are available which can store upwards of 3 terabytes.
A hard disk drive operates using several of the same principles as an old-fashioned record player. Information is recorded and retrieved by a magnetic head mounted on a moveable arm, which moves over a rapidly spinning disk (also called a platter). Each drive contains one or more platters, made of highly polished aluminium or glass, stacked together with one read/write head per side of each disk.

The platters are produced by depositing several very thin layers of materials to provide the required smoothness, magnetic storage capability and lubrication. The first pgm containing layer is the "soft magnetic underlayer". This layer is unique to the current perpendicular magnetic recording (PMR) disks and is needed to enhance the perpendicular field needed to write the data. This typically consists of two Co-Ni-Fe layers separated by a 4 atom thick layer of ruthenium. The magnetic storage layer consists of a Co-Cr-Pt alloy composing several sub layers. The cobalt provides the necessary orientation of the crystals; the chromium improves the signal-to-noise ratio, while the platinum provides thermal stability. Ruthenium is also to be found here, although performing a somewhat different role than in the soft underlayer. Its role is to help orientate the magnetic grains, as well as reducing interference between layers.

The vital roles played by both ruthenium and platinum have enabled hard disk manufacturers to produce massive leaps in storage density and they will continue to play a role in the next generation of hard disk drives and the new technology that uses them.


Palladium is widely used in electronics applications on account of its electrical conductivity and its durability.

Palladium-containing components are used in virtually every type of electronic device, from basic consumer products to complex military hardware.  Although each component contains only a fraction of a gram of metal, the sheer volume of units produced results in significant consumption of palladium.

The largest area of palladium use in the electronics sector is in multi-layer ceramic (chip) capacitors (MLCC). Smaller amounts of palladium are used in conductive tracks in hybrid integrated circuits (HIC) and for plating connectors and lead frames.

Capacitors are components that help to control the flow of an electric current through the various parts of a circuit by storing a charge of electricity until it is required.  They consist of layers of conductive electrode material (usually palladium or palladium-silver) sandwiched between insulating ceramic wafers.

In the early 1990s MLCC manufacturers responded to the drive towards miniaturisation of consumer goods by producing ever smaller capacitors using less palladium per unit. Soon afterwards came the development of technology to substitute palladium with nickel. This was not significant until 1997, when the increasing palladium price encouraged manufacturing of nickel-based capacitors on a much larger scale. However, the shares of nickel and palladium have stabilised, with palladium still preferred in certain more demanding applications such as automotive engine management systems.

A hybrid integrated circuit consists of a ceramic substrate on which are mounted a number of different electronic components, including integrated circuits and capacitors. They are linked by conductive silver-palladium tracks. The function of the palladium is to hold the silver in place, without which it would migrate. The automotive industry is the largest market for HIC.
Components inside computers are linked by connectors plated with a conductive layer of precious metal. Palladium is used as an alternative plating material to gold for connectors as it has a lower density and so less weight of metal is required for a coating of similar thickness.

Lead frames are used to connect integrated circuits to other electronic devices. Some manufacturers use palladium to plate the frames as an environmentally preferable alternative to tin-lead solder. 

Electronics demand for palladium since 1980 is estimated in our market data tables.


Platinum and to a much greater extent palladium are the principal platinumgroup metals used in dental restorations. The metals are usually mixedwith gold or silver as well as copper and zinc in varying ratios to produce alloys suitable for dental inlays, crowns and bridges. Small amounts of ruthenium or iridium are sometimes added.

The most common application is in crowns, where the alloy forms the core onto which porcelain is bonded to build up an artificial tooth. The aim of using platinum group metals in dental alloys is to provide strength, stiffness and durability whilst the other alloyed metals provide malleability.

Alloy types
There are two main types of precious metal alloys used in dentistry:

  • High gold alloys, normally alloyed with a small amount (around 10%) of platinum
  • Low gold alloys, predominantly palladium based with a palladium content typically ranging from 50% to 80%

Development of the market for palladium
Platinum-containing high gold alloys have been used by dentists for many decades but the use of palladium in dentistry is relatively recent. It dates from the 1980s, when a rise in the price of gold encouraged palladium to be introduced as a lower-cost alternative.

In Japan, the government operates a specific mandate stating that all government-subsidized dental alloys have to include a palladium content of 20%. This alloy is known as the kinpala alloy and is used in around 90% of all Japanese dental treatment. Hence, Japan is the largest palladium-consuming region for dental applications, followed by North America and then Europe.

Dental demand for palladium since 1980 is estimated in our market data tables.


In 1949, Universal Oil Products pioneered the use of platinum catalysts as the active agent in the upgrading of low octane petroleum naphtha to high-quality products. The technology quickly became the principal method of producing high octane gasoline for automobiles and piston-engine aircraft. Platinum catalysts are also used to make petrochemical feedstocks which are the basic raw materials for the manufacture of plastics, synthetic rubber and polyester fibers.

What Platinum Does
The input for all petroleum refineries is crude oil, which is a mixture of hydrocarbons classified as light fractions and heavy fractions. Crude varies from region to region but in general it has a high content of heavy fractions. Gasoline and chemical feedstocks comprise mostly light fractions and so the refining process is largely devoted to converting heavy fractions into more useful lighter ones.

Platinum is used in the processes known as reforming and isomerization, which create the higher octane components for gasoline. Platinum is key to the production of gasoline - without it, refineries would not be able to produce enough gasoline to meet current requirements.

Palladium is used by a limited number of refiners for upgrading certain refinery feeds in a process known as hydrocracking. Iridium can also be used in conjunction with platinum in a few niche reforming applications.
Reforming and isomerisation processes use catalysts made by coating platinum onto an alumina substrate in the form of small pellets or beads. The platinum content of the catalyst is normally less than 0.6 per cent by weight. In most modern refineries platinum is combined with tin or rhenium for improved performance.
When platinum reforming was first introduced, consumption of platinum by the petroleum industry became a major component of industrial demand for the metal. Technical developments in refining processes over the years have led to greater catalyst efficiency, which has reduced the unit amount of platinum required. In addition, new petroleum refining catalysts have been developed with lower platinum loadings. This has been largely balanced by the rise in demand for gasoline products, leaving annual demand for platinum fairly stable.

Petroleum demand for platinum since 1975 is estimated in our market data tables.

Industrial Precious Metals text found @
Silverinstitute.org and platinum.matthey.com