Technical silver: properties, grades and applications

Technical silver is refined (high-purity) silver intended for industrial use rather than jewellery or coinage. It is one of the key industrial metals of our time, possessing a unique combination of physical properties: record electrical and thermal conductivity, high ductility, chemical inertness and the ability to form strong alloys with other metals. Technical silver is indispensable for electrical engineering, electronics, chemical catalysis, medicine and the production of highly reliable brazed joints.

Chemical Nature and Physicochemical Properties

Silver (Ag) is a silver-white noble metal, atomic number 47, atomic mass 107.87 g/mol. Its density is 10.49 g/cm³ at 20 °C. The melting point is 960–961.9 °C, and the boiling point is about 2212 °C.

The key physical property of silver that determines its industrial value is the highest electrical conductivity among all metals — its electrical resistivity is 1.59 μΩ·cm at 20 °C. Silver also has the highest thermal conductivity among metals, surpassing even copper. Its high reflectivity in the visible and infrared ranges makes it in demand in optics and mirrors.

The chemical resistance of silver is lower than that of gold and platinum: in air it slowly tarnishes due to the formation of a sulfide film under the action of hydrogen sulfide. However, silver is resistant to most acids (except nitric and hot concentrated sulfuric) and does not react with water or alkalis. In massive form, silver is non-toxic, but its dust and aerosols belong to hazard class 2 (highly hazardous substances) with a maximum allowable concentration (MAC) in the working area of 1 mg/m³.

Classification, Grades and Standards

Requirements for silver and its alloys in Russia and CIS countries are established by GOST 6836-2002 "Silver and silver base alloys. Marks". The standard applies to grades of silver and alloys intended for the production of industrial products, including semi-finished products in the form of sheets, strips, bands, foil, wire, pipes, profiles and cast blanks.

Depending on the mass fraction of silver, the following grades are established:

• Ag 99.99 — silver content of at least 99.99%. The purest grade, used for critical electrical and optical applications.

• Ag 99.9 — silver content of at least 99.90%. The main industrial grade for electrical engineering, catalysts and brazing.

• Ag 99 — silver content of at least 99.0%. Used for less critical technical purposes.

For each grade, the content of impurities is standardised: lead, iron, antimony, bismuth, copper and other elements. For example, for grade Ag 99.99, the lead content must not exceed 0.003%, iron — 0.004%, antimony — 0.001%. For grade Ag 99.9, the impurity tolerances are somewhat wider: lead — up to 0.035%, iron — up to 0.10%.

In addition to pure silver, the standard establishes grades of silver alloys, such as AgCu 50 (silver-copper), AgPd (silver-palladium) and others, which are used for electrical contacts, brazing alloys and special products.

Production Technology and Refining

The production of technical silver includes the mining of silver-bearing ores, the production of crude silver (usually as a by-product of processing lead-zinc, copper and gold ores) and subsequent refining — purification to high purity.

The main industrial refining method is electrolytic refining. Crude silver (with a silver content of more than 79%) is cast into anodes and subjected to electrolysis in a silver nitrate solution with the addition of nitric acid. When direct current is passed, silver deposits on the cathode in the form of crystals with a purity of up to 99.99%, while impurities (copper, lead, bismuth) pass into the electrolyte or anode slime. The cathode deposit is washed, dried and remelted into ingots or granules.

For processing complex raw materials with a high content of impurities, hydrometallurgical methods are used: dissolution in nitric acid followed by precipitation of silver chloride and its reduction. Modern technologies allow silver of 99.995% purity and higher to be obtained. The resulting technical silver is supplied in the form of ingots, granules, powder, as well as semi-finished products (wire, strip, foil).

Applications

Electrical engineering and electronics. This is the largest industrial consumer of technical silver. Due to its maximum electrical conductivity, silver is used for the manufacture of relay contacts, switches, connectors, current collectors and printed conductors in high-frequency and precision electronics. Silver brazing alloys and pastes are used for mounting critical electronic components. In 2025, global silver consumption in electrical and electronics (including photovoltaics) amounted to about 449.5 million troy ounces.

Photovoltaics (solar energy). Silver is a key component of conductive pastes for solar cells. Despite active efforts to reduce specific consumption, solar energy remains one of the largest consumers of technical silver — about 186.6 million ounces in 2025.

Chemical industry and catalysis. Silver and its alloys are used as catalysts in oxidation reactions, in particular in the production of formaldehyde and ethylene oxide. Silver catalysts are also used in gas purification processes and chemical synthesis.

Brazing and high-temperature solders. Silver brazing alloys provide strong and electrically conductive joints of metals and are widely used in the automotive, aerospace and instrument-making industries. In 2025, silver consumption in brazing alloys amounted to about 50.5 million ounces.

Medicine and biocidal materials. Silver has pronounced bactericidal properties. Technical silver is used in medical instruments, sensors, antibacterial coatings and dressings.

Optics and mirrors. Due to its high reflectivity, silver is used for applying reflective coatings in mirrors, optical instruments and heat-shielding screens.

Other applications. Technical silver is used in the production of batteries (silver-zinc cells), in the jewellery industry (as a raw material for alloys), and as an alloying additive in special steels and alloys.

Safety and Storage

Technical silver in massive form (ingots, wire, strip) does not present a chemical hazard when standard precautions are observed. However, silver dust and aerosols belong to hazard class 2 (highly hazardous substances) with a MAC in the working area air of 1 mg/m³. Prolonged inhalation of silver dust can lead to the accumulation of metal in the body and the development of argyria (grey-blue pigmentation of the skin and mucous membranes). When working with powders and aerosols, respirators, safety goggles and effective ventilation must be used.

Silver is non-flammable, but in a finely dispersed state (powder, chips) it can be fire-hazardous. Storage of technical silver is carried out in closed dry premises protected from moisture and hydrogen sulfide, in individual packaging that prevents tarnishing and mechanical damage. Ingots and semi-finished products are stored under conditions that exclude contact with chemically active substances.

Market and Trends

The global technical silver market is closely linked to the overall silver market. In 2025, total silver demand amounted to about 1.13 billion ounces, with industrial demand reaching 657.4 million ounces, or about 58% of total consumption. After four years of strong growth, industrial demand declined by 3% in 2025 due to the high metal price and reduced consumption in photovoltaics, but demand from electronics (excluding solar) and brazing alloys remained stable.

Key growth drivers remain the development of artificial intelligence (AI infrastructure), electric vehicles and power grid modernisation. Silver demand in AI equipment is estimated to have grown from 15 million ounces to about 78 million ounces per year. At the same time, the solar industry is actively reducing specific silver consumption through thrifting and substitution with copper, which led to a forecast of a 19% drop in photovoltaic demand in 2026.

The largest consumers of technical silver are China, the USA, European countries and Japan. The market is characterised by a structural deficit: in 2025, it was recorded for the fifth consecutive year. Producers with access to quality refined silver and modern processing technologies occupy stable positions.

Conclusion

Technical silver remains a strategically important industrial material, supporting the development of electronics, solar energy, chemical catalysis and highly reliable joints. Understanding the grade composition according to GOST 6836-2002, refining technologies and safety requirements is the basis for competent material selection and the organisation of efficient supplies. Selecting the silver grade for specific technological tasks and organising logistics requires an individual approach taking into account metal purity and delivery form.