Electrical and electronic markets


The electrical and electronic market accounts for about 28% of the total. In 1997, these two markets became the second largest end user of copper consumption, with a market share of 25%. In many electrical products (such as wires, buses, transformer windings, heavy motors, telephone lines and telephone cables), the service life of copper is quite long. Only after 20 to 50 years, the copper in it can be recycled. The service life of other electrical and electronic products containing copper (such as small electrical appliances and consumer electronics) is relatively short, generally 5 ~ 10 years. Commercial electronic products and large electrical products are usually recycled because they contain other precious metals in addition to copper. Nevertheless, the recovery rate of small consumer electronics products is quite low because there is little copper in them


With the rapid development of science and technology in the electronic field, some old copper containing products are passing the time. For example, in the 1980s, telephone switching stations and central offices were the main sources of copper and copper alloy debris, but the emergence of digital conversion made these heavy, metal intensive things more and more obsolete


Transportation equipment


Transportation equipment is the third largest market for copper, accounting for about 13% of the total, which is basically the same as that in the 1960s. Although the importance of transportation has not changed, the use of copper has changed greatly. For many years, automatic radiator has been the most important end user in this field; However, the use of copper in automatic electrical and electronic products has increased rapidly, while the use in the heat exchanger market has decreased. The average service life of a car is 10-15 years. Almost all copper (including radiator and wiring) is recycled before its overall disassembly and recycling


Industrial machinery and equipment


Industrial machinery and equipment is another major application market, in which copper often has a long service life. Coins and arms are the main end-users in this regard. Bullets are rarely recycled, some coins can be melted, and many are kept by collectors or savers and cannot be recycled. In the manufacture of machinery and transport vehicles, it is used to manufacture industrial valves and accessories, instruments, sliding bearings, molds, heat exchangers and pumps
In the chemical industry, it is widely used in the manufacture of vacuum, distillation pot, brewing pot and so on
In the national defense industry, it is used to manufacture bullets, shells, gun parts, etc. for every 3 million bullets produced, 13 ~ 14 tons of copper are required
In the construction industry, it is used as various pipes, pipe fittings, decorative devices, etc


Medical


In medicine, the bactericidal effect of copper has long been recognized. Since the 1950s, copper has also been found to have very good medical uses. Later, Mexican scientists also found that copper has anti-cancer function. In the new century, British researchers found that copper has a strong bactericidal effect. It is believed that copper will make a great contribution to improving human health in the near future


Organic chemistry


Organic copper lithium compounds are a kind of important organometallic compounds in organic chemistry


Alloy


Copper can be used to make a variety of alloys. The important alloys of copper are as follows:
(1) Brass: brass is an alloy of copper and zinc, named for its yellow color. Brass has good mechanical properties and wear resistance. It can be used to manufacture precision instruments, ship parts, gun casings, etc. Brass sounds good, so gongs, cymbals, bells, horns and other musical instruments are made of brass
(2) Marine brass: an alloy of copper, zinc and tin. It is resistant to seawater erosion. It can be used to make ship parts and balancers
(3) Bronze: the alloy of copper and tin is called bronze, which is named for its green color. It was commonly used in ancient times (such as the Bronze Age in China). Bronze generally has good corrosion resistance, wear resistance, castability and excellent mechanical properties. It is used to manufacture precision bearings, high-pressure bearings, mechanical parts resistant to seawater corrosion on ships, as well as various plates, pipes, bars, etc. Bronze also has an abnormal characteristic & mdash& mdash;& ldquo; Thermal contraction and cold expansion;, It is used to cast statues and expand after cooling, which can make the eyebrows and eyes clearer
(4) Phosphor bronze: an alloy of copper, tin and phosphorus. It is hard and can be used to make springs
(5) White copper: white copper is an alloy of copper and nickel. Its color is the same as silver. It is shiny and not easy to rust. It is often used to make coins, electrical appliances, instruments and decorations
(6) 18K gold (rose gold): an alloy of 6 / 24 copper and 18 / 24 gold. Red and yellow, with high hardness, it can be used to make jewelry and decorations.