Silver demand in 2016 was about 32,000 tonnes or just over 1 billion ounces. The metal was used in four broad categories; industrial applications (55%), bullion (20%), jewellery (20%) and silver (5%). Four countries account for over 50% of silver demand; the United States (22%), China (18%), India (16%) and Japan (9%).
The electronics sector is the largest industrial consumer of silver, accounting for 40% of annual demand. In many cases, silver cannot be substituted. Silver’s indispensable use in the electrical and electronics sector is due to the metal’s high electrical conductivity, high thermal conductivity, high temperature performance and corrosion resistance.
Soldering a silver circuit board
Electrical power distribution depends on silver contacts in switches and circuit breakers. Silver contacts are standard in control panels in the heavy equipment industry, in process control instrumentation in the chemical industry, in railway traffic controls and in elevators. High density silver oxide, silver-zinc and silver-cadmium batteries have twice the capacity of lead-acid batteries. Every electrical action in a modern car is activated with silver coated contacts. Over 36 million ounces of silver are used annually in the automobile industry.
Other industrial applications of silver include consumer electronics, conductors in radio frequency engineering, engine bearings, fuses, printed electronic circuits, wiring, solar photovoltaic panels and water purification systems. Silver fulminate (AgONC) is a powerful touch sensitive explosive used in blasting caps and silver cyanide, soluble in water, is used for electroplating silver. Silver brazing and photography each consumed about 5% of the total industrial demand in 2016.
The light sensitivity of silver halide crystals is the basis of the traditional photographic film process. Silver dissolves readily in nitric acid (HNO3) to produce silver nitrate (AgNO3) which is the precursor chemical for manufacturing silver chlorides and bromides used in photographic film emulsions. Film is now used primarily in the graphic arts sector, radiography and to a lesser extent in the consumer photography sector. The advent of digital photography reduced the demand for photographic silver by 60% during the period 2007 – 2016.
High reflectivity silver mirror
Over 40% of the industrial use of silver is in the ‘Other Industrial’ category. Applications in this category include silver mirrors for telescopes, microscopes and human vanity, control rods to regulate the fission reaction in pressurized water cooled nuclear reactors, silver-mercury amalgams in dentistry, water purification, glass coatings, DVD coatings, bearings in jet engines and heavy equipment, and as a chemical industry catalyst to convert ethylene to ethylene oxide which is widely used in a variety of products from anti-freeze to cosmetics. Silver iodide is used in cloud seeding.
1 kilogram 999 fine silver ingots
Over 205 million ounces of silver were used in 2016 to produce silver bullion coins and bars in a wide variety of designs and weight. The consumers include private investors, commercial banks, investment funds and coin collectors. Silver as an investment is typically viewed as a hedge against inflation, currency devaluation and economic mismanagement. It is also purchased for asset diversification and as a store of value in times of economic crisis or military conflict. Silver quarters and dimes were taken out of general circulation in the United States in 1964 and in Canada in 1968.
Well established silver bullion coins include the American Eagle, the Canadian Maple Leaf, the Chinese Panda, the Australian Kangaroo, the British Britannia and the Mexican Libertad. The purity of all of these coins is guaranteed to be 99.9% silver with the exception of the British Britannia which has a purity of 95.8% silver. Typical coin weights include half-ounce, one-ounce, 10-ounce and one-kilogram. In 2013 the U.S. Mint sold over 44 million ounces of American Eagle coins. Investment quality silver bullion bars are made by mints and refineries in Canada, Australia, Turkey, the United States and the United Kingdom. The bullion bars are of 99.9% pure silver and typically range in weight from one-ounce to one-thousand ounces, and 100-grams to one-kilogram.
Silver Eagle (USA)
Silver Maple Leaf (Canada)
Silver Panda (China)
Silver Kangaroo (Australia)
Silver Brittania (United Kingdom)
Silver Libertad (Mexico)
New jewellery fabrication consumed 207 million ounces (6,437 tons) in 2016. Factors influencing demand for new jewellery include the international silver price, foreign exchange rates, consumer confidence, market restrictions and economic prosperity. Chinese and Indian private consumers are currently driving an expansion in the use of silver for new jewellery.
In 2016, silver accounted for only 52 million ounces (1,672 tons) of total silver demand. This demand is primarily for the manufacture of household silver made from sterling silver, or a silver-plated non-precious metal. Plated silver is typically coated with a thin 20-30 micron layer of silver metal. A small proportion of silver is used to create ceremonial, ornamental and artistic products.
Silver has a long history of use as an antibacterial agent. In ancient Greece and Rome, silver was used to control infection. Hippocrates, the ‘Father of Medicine’, taught that silver healed wounds and controlled disease. Herodotus, the ‘Father of History’ reports that Persian kings on long military campaigns in the 1st millennium BCE would only drink stored water from silver jars. Russian armies from the time of the Napoleonic Wars to the Second World War used silver to clean water.
Persian silver drinking vase – 5th century BCE, Achaemenid Period
In the European Middle Ages, it was believed that the wealthy ‘upper class’ were less prone to the ravages of the plague because they always used silver plate, cups and cutlery for eating and drinking. This belief gave rise to the historical English proverb ‘Every man is not born with a silver spoon in his mouth.’ Therefore, silver ownership was originally associated with the good fortune of being healthy rather than wealthy.
Also, it’s believed that the blue-grey skin tones common amongst the old European aristocracy and upper-classes were due to their frequent use of silver utensils and drinking goblets. This human blue-grey skin disfiguration is now medically defined as argyria. Argyria is a word derived from ‘argyros’, the Ancient Greek word for silver. The medical condition is caused by the ingestion of high levels of silver dust, or silver chemical compounds, and subsequent deposition of the metal in the skin tissue producing a blue-grey colour pigmentation. Argyria is a permanent condition but does not otherwise harm a patient’s health.
The scientific basis for silver’s apparent antibacterial effect was not discovered until 1893 when the Swiss botanist Von Nageli determined that it was the Ag+ ion released by silver in solution that was bioactive and toxic to bacteria.
Anti-bacterial first aid gel
Today, silver compounds are incorporated in wound dressings and used as antibiotic coatings on certain medical devices. A new state-of-the-art anti-bacterial hydrosol is based on a metallic silver nano-particle coated with Ag4O4. According to the manufacturers’, this hydrosol promises a higher bio-availability of the silver ion and therefore enhanced therapeutic effectiveness. Colloidal silver compounds that only deliver metallic silver are not considered effective.