Sources of Copper
The world's copper resources are relatively abundant. It exists in the earth's crust and the ocean. The content of copper in the earth's crust is about 0.01%, and it exists mainly in three forms: natural copper, copper sulfide and copper oxide.
The world's proven copper reserves have reached 880 million physical tons. Among them, Chile has the richest copper reserves, reaching 190 million tons. China ranks sixth in the world's copper reserves, with proven copper reserves of 34.95 million tons. Although China's copper reserves account for a small proportion of the world, China's copper mining and demand are huge, and it still needs to import a large amount of copper concentrate every year. In addition, the global terrestrial copper resources are estimated to be 1.6 billion tons, while the copper resources in manganese nodules in the deep seabed and seamount areas are 700 million tons. Ocean floor or deep-sea polymetallic sulfide deposits also contain a large amount of copper resources.
Application of copper
Copper wire
Copper is a non-ferrous metal that is closely related to humans. It is widely used in electricity, electronics, energy, petrochemicals, machinery, metallurgy, transportation, light industry, emerging industries and other fields. It is second only to aluminum in the consumption of non-ferrous metal materials in China. Ultrapure copper can reach 99.99999% purity. It is a slightly reddish metal (face-centered cubic system) with rich ductility. It can be directly applied as an additive element to super alloys in aerospace and space atomic industries; as a key raw material for sputtering targets, it is suitable for semiconductor integrated circuits, flat-panel displays, mass storage, solar cells and other fields.
Electrical and electronic markets: 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, busbars, transformer windings, heavy motors, telephone lines and telephone cables), the service life of copper is quite long, and only after 20 to 50 years can the copper inside be recycled.
Transportation equipment: about 13% of the total, which is basically the same as in the 1960s. Although the importance of transportation has not changed, the use of copper has changed greatly. For many years, automatic radiators were the most important end-users in this area; however, the use of copper in automatic electrical and electronic products has grown rapidly, while the use of copper in the heat exchanger market has declined. The average life of a car is 10-15 years, and almost all copper (including radiators and wiring) is recycled before it is disassembled and recycled.
Industrial machinery and equipment: Another major application market for copper, in which copper often has a relatively long service life. Coins and munitions 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 transportation vehicles, it is used to manufacture industrial valves and accessories, instruments, sliding bearings, molds, heat exchangers and pumps.
Chemical industry: widely used in the manufacture of vacuum devices, distillation pots, brewing pots, etc.
Defense industry: used to manufacture bullets, shells, gun parts, etc., and 13 to 14 tons of copper are required for every 3 million bullets produced.
Construction industry: used for various pipes, pipe fittings, decorative devices, etc.
Medicine: The bactericidal effect of copper has been recognized for a long time. Since the 1950s, people have also found that copper has very good medical uses. Later, Mexican scientists also found that copper has anti-cancer functions. In the new century, British researchers have discovered that copper has a strong bactericidal effect. For example, it can kill bacteria such as Escherichia coli and dysentery that are easy to breed in water, remove slugs and snails that spread schistosomiasis in water, and mosquito larvae that spread malaria. It can also be used in swimming pools to prevent green algae pollution and the spread of tinea pedis through the floor, etc.
Organic chemistry: organic copper lithium compounds are an important class of metal organic compounds.
Pigments: divalent copper salts are the most common copper compounds. Their hydrated ions are often blue, while chlorine as a ligand is green. It is the source of the color of minerals such as azurite and turquoise. It has been widely used as a pigment in history. Copper building structures will produce verdigris (basic copper carbonate) after corrosion. Decorative art mainly uses metallic copper and copper-containing pigments.
Other uses: Copper can also be used in utensils, artworks, etc., such as Beijing copper hot pot, Houmuwu Ding, Four Sheep Square Zun, Statue of Liberty, etc.
