Humans have used copper and its alloys for thousands of years. The main mining area of ​​copper in ancient Rome was Cyprus, so it was originally named cyprium (meaning the metal of Cyprus) and later became cuprum, which is English: copper, French: cuivre and German: the source of Kupfer. Divalent copper salts are common copper compounds, often blue or green, and are sources of mineral colors such as azurite and turquoise, and have been widely used as pigments in history. The copper building structure is corroded to produce patina (basic copper carbonate). Art Deco mainly uses metallic copper and copper-containing pigments [1].　　　　
Copper is a non-ferrous metal that is closely related to human beings. It is widely used in electrical, light industry, machinery manufacturing, construction industry, national defense industry, etc., and is second only to aluminum in the consumption of non-ferrous metal materials in China. Copper is a red metal and a green metal. It is said to be a green metal, mainly because it has a low melting point and is easily remelted and re-smelted, so recycling is quite cheap.　　　　　　
Pure copper is a soft metal. When the surface is cut, it is red-orange with metallic luster, good ductility, high thermal conductivity and high electrical conductivity. Therefore, it is the most commonly used material in cable and electrical and electronic components, and can also be used as building materials. And a variety of alloys. Copper alloys have excellent mechanical properties and low electrical resistivity, the most important of which are bronze and brass. In addition, copper is also a durable metal that can be recycled multiple times without compromising its mechanical properties. Ores are usually smelted in two ways:　　　　
1. Fire method copper smelting. Cathodic copper, also known as electrolytic copper, is produced by melt smelting and electrolytic fine smelting, and is generally suitable for high-grade copper sulfide ore. Pyrometallurgical smelting is generally carried out by adding a few or a few thousand of the original ore containing copper to 20 to 30% through beneficiation. As a copper concentrate, it is built in a closed blast furnace, reverberatory furnace, electric furnace or flash furnace.锍 smelting, the produced smelting (copper) is then sent to the converter for blowing into blister copper, and then oxidized and refined in another reverberatory furnace, or cast into an anode plate for electrolysis, and the grade is up to 99.9%. Electrolytic copper. The process is short and adaptable, and the recovery rate of copper can reach 95%. However, the sulfur in the ore is discharged as sulfur dioxide exhaust gas in the two stages of smelting and blowing, which is difficult to recycle and easily causes pollution. In the 1990s, molten pool smelting such as the silver method, the Noranda method, and the Japanese Mitsubishi method appeared, and the smelting of the fire method gradually progressed toward continuous and automated development.　　
2. Wet copper smelting. A boat is suitable for low-grade copper oxide, and the produced refined copper is called electrowinning copper. Modern wet smelting has sulphation roasting-leaching-electrowinning, leaching-extraction-electrowinning, bacterial leaching, etc., suitable for low-grade complex ore, copper oxide ore, copper-containing waste ore heap leaching, tank leaching or Leaching. Wet smelting technology is gradually being promoted. It is expected to reach 20% of the total output by the end of the century. The introduction of wet smelting will greatly reduce the cost of copper smelting.