Abstract: Copper is an element in Group 1B of the 4th period of the periodic table of elements, and is an important heavy non-ferrous metal. The element symbol is Cu, the atomic number is 29, and the relative atomic mass is 63.546. Copper is solid at room temperature, the new cross section is purple-red, and it is easily oxidized when heated. Copper has excellent electrical and thermal conductivity, good corrosion resistance, low deformation resistance, and can withstand a high degree of cold deformation without cracking. It is an important heavy non-ferrous metal material, mainly used in electronics, electrical engineering, machinery, Industrial sectors such as construction and transportation. There are hundreds of copper compounds, but not many are produced on an industrial scale. The most important of them is copper sulfate pentahydrate, or gall vitriol (CuSO4·5H2O), followed by Bordeaux mixture (Cu(OH)2 ·CuSO4), copper metaarsenite (Cu(AsO2)2), copper acetate [Cu(CH3COO)2] complex, copper cyanide (CuCN), copper chloride (CuCl2), cuprous oxide (Cu2O ), copper oxide (CuO), basic copper carbonate and copper naphthenate, etc. Copper salts can be used as agricultural fungicides. Copper sulfate can be used as an emetic and as a topical antidote for yellow phosphorus burns.

Copper is an element in Group 1B of Period 4 of the periodic table of elements, an important heavy non-ferrous metal. The element symbol is Cu, the atomic number is 29, and the relative atomic mass is 63.546. Copper is solid at room temperature, the new cross section is purple-red, and it is easily oxidized when heated. Copper has excellent electrical and thermal conductivity, good corrosion resistance, low deformation resistance, and can withstand a high degree of cold deformation without cracking. It is an important heavy non-ferrous metal material, mainly used in electronics, electrical engineering, machinery, Industrial sectors such as construction and transportation. There are hundreds of copper compounds, but not many are produced on an industrial scale. The most important of them is copper sulfate pentahydrate, or gall vitriol (CuSO4·5H2O), followed by Bordeaux mixture (Cu(OH)2 ·CuSO4), copper metaarsenite (Cu(AsO2)2), copper acetate [Cu(CH3COO)2] complex, copper cyanide (CuCN), copper chloride (CuCl2), cuprous oxide (Cu2O ), copper oxide (CuO), basic copper carbonate and copper naphthenate, etc. Copper salts can be used as agricultural fungicides. Copper sulfate can be used as an emetic and as a topical antidote for yellow phosphorus burns.

Copper is one of the earliest metals discovered and used by humans. About 10,000 years ago, humans got to know natural copper and hammered it into small cones or nails. The earliest bronze artifacts discovered so far are the scrapers, chisels and awls unearthed in Tepehiya, Iran, which date to about 3800 BC. The tin-bronze knife unearthed in 1978 at the Majiayao Chemicalbook site in Dongxiang, Gansu Province is the earliest bronze device discovered in China so far. Its age is about 2750 BC, which shows that China is the earliest bronze device in the world. One of the countries of bronze. China mastered the technology of shaft furnace copper smelting as early as 770 BC. In the first year of Song and Yuanfeng (1078), copper output reached 7300t, and copper metallurgical technology has reached a considerable level.

Copper is second only to silver as an excellent conductor of electricity and heat. The electrical conductivity and thermal conductivity of copper at room temperature are 94% and 73.2% of silver respectively. The outer electron shell configuration of copper atoms is [Ar]3d104s1. When copper forms a compound, it can lose one electron in the 4s orbit and one electron in the 3d orbit at the same time. Therefore, copper mainly has two valence states: +1 and +2. The oxidation state of copper is mainly +2 at room temperature, and low-valent compounds are stable at high temperatures. Copper has two stable natural isotopes, 63Cu and 65Cu. 63Cu contains 29 protons and 34 neutrons, and 65Cu contains 29 protons and 36 neutrons. Copper is known to have 9 unstable isotopes. Copper can exist stably in dry air at room temperature, but when placed in humid air containing CO2 for a long time, green alkaline copper carbonate will be generated, commonly known as patina. The electrochemical equivalent of divalent copper is 0.329mg/C. Copper cannot replace hydrogen in acidic aqueous solutions, and is not soluble in hydrochloric acid and sulfuric acid without dissolved oxygen, but is soluble in nitric acid which has an oxidizing effect. Copper reacts slowly with alkaline solutions, but easily reacts with ammonia to form complexes. Copper is easily soluble in organic acids such as acetic acid. Soluble copper salts are generally toxic. The crystal structure of copper is a face-centered cubic lattice. Pure copper has very good ductility and can be processed into very fine wires and thin sheets. Copper is an excellent electrical and thermal conductor, and its electrical and thermal conductivity is second only to silver among metals. The presence of trace impurities will greatly reduce the conductivity of copper.

Because copper has many excellent properties, it is widely used in various industrial sectors. Until the 1960s, copper was second only to iron in importance and consumption. After the 1960s, aluminum gave way to the third place with more abundant resources and cheaper prices. The proportion of copper consumption in China in the late 1980s is listed in Table 2. Worldwide, more than half of copper production is used in the power and electronics industry, such as the manufacture of cables, wires, motors and other power transmission and telecommunications equipment. After the 1980s, some of copper's uses in telecommunications were replaced by optical fibers. Copper is also an important material for the defense industry. Because copper has good electrical conductivity, it is widely used in the electrical industry. The manufacture of wires and cables requires pure copper (containing more than 99.95%), which is refined by electrolysis of blister copper. Copper can form many important alloys with zinc, tin, aluminum, nickel, beryllium, etc. Brass (copper-zinc alloy) and bronze (copper-tin alloy) are used to manufacture bearings, pistons, switches, oil pipes, heat exchangers, etc. Aluminum bronze (copper-aluminum alloy) has strong vibration resistance and can be used to make castings that require strength and toughness. Monel alloy among copper-nickel alloys is famous for its corrosion resistance and is mostly used in the manufacture of valves, pumps, and high-pressure steam equipment. White copper is a copper-nickel alloy with good mechanical properties and corrosion resistance, and is used in precision machinery manufacturing. Beryllium bronze (beryllium-containing copper alloy) has mechanical properties that exceed those of high-quality steel and is widely used in the manufacture of various mechanical parts, tools and radio equipment. Copper compounds are important raw materials for pesticides, fungicides, pigments, electroplating, galvanic batteries, dyes and catalysts. Oxygen-free copper is used in waveguides, vacuum tubes and transistor components, glass and metal seals, coaxial cables, and the stabilization of superconducting magnetic windings due to its high purity and lack of hydrogen embrittlement problems. Tough copper is used to make copper busbars, contactors, various types of conductors, radar components, switches and contacts, etc. The above two types of copper treated with silver are used to make devices that require resistance to softening, such as windings of transformers, generators and large synchronous generators. Phosphorus deoxidized copper is mainly used to make tubes for refrigerators and air conditioners, rectifiers, water pipes or gas pipes (when electrical and thermal conductivity, welding performance or brazing performance are required). Free-cutting copper is mainly used to make threaded products and other welding tips, clamps, terminals and switch components.