Uses of silver: Historically, silver has been used in coins, silverware, and jewelry, but today, these uses account for less than half of all silver consumption. Silver has become a material of innovation that appears in many unexpected places. Images copyright iStockphoto / Jorge Farres Sanchez, Tatiana Buzuleac, Nigel Spooner, and Stephanie Frey.
The White Metal
Silver, the white metal, has an illustrious reputation for its use in jewelry and coins, but today, silver's primary use is industrial. Whether in cell phones or solar panels, new innovations are constantly emerging to take advantage of silver's unique properties.
Silver is a precious metal because it is rare and valuable, and it is a noble metal because it resists corrosion and oxidation, though not as well as gold. Because it is the best thermal and electrical conductor of all the metals, silver is ideal for electrical applications. Its antimicrobial, non-toxic qualities make it useful in medicine and consumer products. Its high luster and reflectivity make it perfect for jewelry, silverware, and mirrors. Its malleability, which allows it to be flattened into sheets, and ductility, which allows it to be drawn into thin, flexible wire, make it the best choice for numerous industrial applications. Meanwhile, its photosensitivity has given it a place in film photography.
Because it is more abundant, silver is much less expensive than gold. Silver can be ground into powder, turned into paste, shaved into flakes, converted into a salt, alloyed with other metals, flattened into printable sheets, drawn into wires, suspended as a colloid, or even employed as a catalyst. These qualities ensure that silver will continue to shine in the industrial arena, while its long history in coinage and jewelry will sustain its status as a symbol of wealth and prestige.
Silver paste in electronics: Printed electronics like RFID tags rely on silver paste. Image copyright iStockphoto / JacobH.
Uses of silver in the U.S.: The United States Geological Survey has tabulated the amount of silver used in the United States by category of use. This data is shown in the graphic above. The "Other" category accounts for almost a quarter of the silver used and is fragmented into hundreds of different uses. Many of these are described below.
Uses of Silver in Electronics
The number one use of silver in industry is in electronics. Silver's unsurpassed thermal and electrical conductivity among metals means it cannot easily be replaced by less expensive materials.
For example, small quantities of silver are used as contacts in electrical switches: join the contacts, and the switch is on; separate them and the switch is off. Whether turning on a bedroom light using a conventional switch or turning on a microwave using a membrane switch, the result is the same: the current can pass through only when the contacts are joined. Automobiles are full of contacts that control electronic features, and so are consumer appliances. Industrial strength switches use silver, too.
How does silver get from the earth to these electronic devices? Silver comes from silver mines or from lead and zinc mines from which silver is a by-product. Smelting and refining removes silver from the ore. Then, the silver is usually shaped into bars or grains. Electronics demand silver of the highest purity: 99.99% pure, also known as having a fineness of 999.9.
Dissolving pure silver in nitric acid produces silver nitrate, which can be formed into powder or flakes. This material, in turn, can be fabricated into contacts or silver pastes, like conductive paste made with a silver-palladium alloy.