Characteristics and uses of silver


Use brings supply and demand, and supply and demand determine value. “Prices fluctuate around value.” To understand the value of silver, you need to understand the purpose of silver.

Physical and chemical properties of silver

Silver has a very low abundance in geochemistry, only 110-5%. There is a single natural silver in nature, but it is mainly produced in the form of a compound. Sterling silver is a beautiful silver-white metal. Its English name is Silver, but its chemical symbol Ag comes from its Latin name Argentum, which means “light, bright”, which is the direct reflection of silver. reflect. The melting point of silver is 960.8 ° C and the density is 10.49 g / cm 3 . The silver plasticity is good, and the ductility is second only to gold. If it is crushed into a transparent foil of only 0.003 mm thick, 1 gram of silver particles can be drawn into filaments of about 2 km. Silver’s thermal conductivity and electrical conductivity are also outstanding in metals. Silver has good chemical stability and does not oxidize at normal temperature. However, among all precious metals, silver is the most active chemical. It is soluble in nitric acid to form silver nitrate; it is soluble in hot concentrated sulfuric acid, and forms a silver chloride film on the surface of hydrochloric acid and “aqua regia”; when it is in contact with sulfide Will produce black silver sulfide.

Silver application and consumption

Silver, like gold, is a precious metal with a long history of application. Humans began to mine silver more than 4,000 years ago. Because of the small amount of silver mined at the time, its value was more expensive than gold. The silver price of the Egyptian dynasty in the 14th-16th century BC was twice as high as that of gold. Even in Japan in the 17th century, the government stipulated that the value of gold and silver was equal. The concept of ordinary people for silver is mostly concentrated in silver dollar, silver jewelry, silver tableware and so on. In fact, in addition to the unique physical and chemical properties of silver, it is also an important industrial raw material, widely used in electrical and electronic, photosensitive materials, pharmaceutical and chemical, disinfection and antibacterial, environmental protection, silver jewelry and products. With the great development of the electronics industry, the aviation industry, and the power industry, the industrial demand for silver has been growing steadily and rapidly in recent years.

Here is an introduction to the main industrial applications of silver:

Electronic and electrical materials:

Electronic appliances are the industries with the largest amount of silver, and their use is divided into electrical contact materials, composite materials and welding materials. Silver and silver-based electrical contact materials can be classified into: pure Ag, silver alloys, silver-oxides, and sintered alloys. At present, the annual output of silver and silver-based electrical contact materials in the world is about 2900-3000t. Composite materials are materials prepared by composite technology and are classified into silver alloy composites and silver-based composite materials. From the perspective of silver-saving technology, silver composite materials are a new class of materials with great development prospects. Silver soldering materials such as pure silver solder, silver-copper solder, etc.

Photosensitive material:

Silver halide photographic materials are one of the areas with the largest amount of silver. The most sensitive materials currently produced and sold are photographic film, photographic paper, X-ray film, fluorescent information recording film, electron microscope photographic film and printed film. In the 1990s, the amount of silver used in the world’s photographic industry was about 6,000 to 6,500 tons. Due to the development of electronic imaging and digital imaging technology, the amount of silver halide photosensitive material has been reduced, but the application of silver halide photosensitive material is still irreplaceable in some aspects, and there is still a large market space.

Chemical and chemical materials:

Silver has two main applications in this regard. One is silver catalysts, such as widely used in redox and polymerization, for the treatment of industrial waste gas containing sulfides. The second is the electronic plating industrial preparations, such as silver paste, silver potassium cyanide and the like.

Craft jewelry:

Silver has attractive white luster, high chemical stability and collectible ornamental value, and is favored by people (especially women). Therefore, it has the reputation of “woman’s metal” and is widely used as jewelry, decorations and silverware. , tableware, congratulations gifts, medals and commemorative coins. Silver jewelry has a broad market in developing countries, and silver meals are popular with families. The silver commemorative coins are beautifully designed, with a small circulation, and have the function of maintaining and increasing value. They are well received by coin collectors and coin investors. In the 1990s, only silver for coinage was kept at around 1000-1500 tons per year, accounting for about 5% of silver consumption.

Medicine and antibacterial materials:

In medicine, Ag-Pd alloy is widely used in rehabilitation equipment such as optic nerve repair and pediatric spinal cord bending; silver-based casting alloy and Ag-Cu-Sn amalgam are important materials for tooth repair. Silver series inorganic antibacterial materials have the characteristics of persistence, durability, broad spectrum, good heat resistance, high safety and resistance to drug resistance. Its bactericidal performance is nearly 2000 times stronger than zinc. The use of antibacterial materials can be made into medicinal gauze, antibacterial cloth, antibacterial daily necessities, public goods, personal disinfection products and the like. With the continuous improvement of people’s living standards, the industrial prospects of silver series antibacterial materials are very broad.

Silver utilization

The main consumption areas and consumption structure of silver are roughly: 35% for electronic and electrical, 20% for photosensitive materials, 20% for chemical reagents and chemical materials, 10% for crafts and jewelry, and 15% for other aspects. Although in recent years, great progress has been made in expanding the application of silver and improving the processing depth and added value of silver products, the overall application level of the silver industry is still far different from that of developed countries, such as silver compounds and silver-based materials. , silver-based contact materials, electronic paste and other fields.
Silver is also a good investment

As a precious metal, silver’s value-preserving and hedging function is also very prominent. For the investment public, silver investment is one of the effective means of diversifying investment risks, resisting inflation and preserving wealth. At present, silver has become a generally accepted investment product worldwide. In the United States, participants in individual retirement accounts can invest a portion of the fund in silver and silver bars. For example, between 1971 and 1981, the dollar depreciated by 50%, while silver prices rose nearly fivefold. Due to the eternal intrinsic value of silver, many investment experts advise investors to place them among investment assets.

Due to the slowdown in world silver production growth and the continued growth in demand for silver, demand growth is greater than output growth, coupled with strong investment demand, the international silver price has started to rise from nearly $5 per ounce in 2002. The speculative speculation of international capital and the silver ETF caused the price of silver to rise to 21 US dollars per ounce in 2008, reaching a 20-year high.