The Old Copper Complex in North America has been radiometrically dated to around 6500 BCE, at least^[8]—making it one of the oldest known examples of copper extraction in the world.^[9] The earliest evidence of the cold-hammering of native copper comes from the excavation at Çayönü Tepesi in eastern Anatolia, which dates between 7200 and 6600 BCE.^[10] Among the various items considered to be votive or amulets, there was one that looked like a fishhook and one like an awl. Another find, at Shanidar Cave in Mergasur, Iraq, contained copper beads, and dates back to 8,700 BCE.^[11]

One of the world's oldest known copper mines, as opposed to usage of surface deposits, is at Timna Valley, Israel, and has been used since the fourth millennium BC, with surface deposit usage occurring in the fifth and sixth millennium.^[12][13]

The Pločnik archaeological site in southeastern Europe (Serbia) contains the oldest securely dated evidence of copper making at high temperature, from 5,000 BCE.^[14] The find in June 2010 extends for an additional 500 years, dated to 5th millennium BCE, representing the earlier record of copper smelting from Rudna Glava (Serbia).^[15]

The earliest copper work in the Atacama Desert and the Andean world as a whole dates to 1432–1132 BC.^[16][17] Ice core studies in Bolivia suggest copper smelting may have begun as early as 700 BC, over 2700 years ago.^[18] Various sites of Pre-Hispanic mines and metallurgical workshops have been identified in the Atacama Desert including those with remnants of chisels, casting waste and workshop debris.^[19][20] Tin bronze, arsenical bronze, and arsenical copper were valuable goods produced in the Inca Empire.^[21] About 74 km northeast of the Chilean city of Copiapó in Viña del Cerro the Incas had one of their largest mining and metallurgy centres at Qullasuyu.^[22] There is evidence of gold, silver and copper metallurgy at the site, including the production of bronze.^[22] When conquistador Diego de Almagro traversed the Atacama Desert in 1536 his men readily obtained copper horseshoes for their horses.^[23]

Copper smelting technology gave rise to the Copper Age, aka the Chalcolithic Age, and then the Bronze Age. The Bronze Age would not have been possible without the development of smelting technology.^{[citation needed]}

The introduction of reverberatory furnaces to Chile around 1830 by Charles Saint Lambert^[24] revolutionized Chilean copper mining.^[25] In addition to this there was improvements of transport caused by the development of railroads and steam navigation.^[26] Prospector José Tomás Urmeneta discovered rich orebodies at Tamaya in 1850, a site that became one of Chile's main copper mines.^[25] All of this made Chile supply 18% of the copper produced worldwide in the 19th century and the country was from the 1850s to the 1870s the world's top producer.^[27][28] In some years Chile's copper production made up about 60% of the world’s output and its export tariff made up more than half the state's income.^[29]

Lambert's success in modernising the Chilean copper industry during the second quarter of the nineteenth century is thought to have sowed the seeds for the later demise of his own copper smelting business (among others) in Swansea.^[30][31]

By the late 19th century the Chilean mining industry once again lagged behind technological developments (e.g. flotation, leaching, large-scale open-pit mining) contributing to the drop of its share of the world production to 5–6% in the 1890s and similar shares remained in the 1900s and 1910s reaching a low of 4.3% in 1914.^[27][32][33] Up to the 1940s and 1950s there was also a notable lack of major copper exploration efforts by large mining companies that relied on purchasing prospects already known from the activity of small-scale miners and pirquineros.^[34]

Until the latter half of the 20th century, smelting sulfide ores was almost the sole means of producing copper metal from mined ores (primary copper production). As of 2002, 80% of global primary copper production was from copper–iron–sulfur minerals, and the vast majority of these were treated by smelting.^[35]

Copper was initially recovered from sulfide ores by directly smelting the ore in a furnace.^[36] The smelters were initially located near the mines to minimize the cost of transport. This avoided the prohibitive costs of transporting the waste minerals and the sulfur and iron present in the copper-containing minerals. However, as the concentration of copper in the ore bodies decreased, the energy costs of smelting the whole ore also became prohibitive, and it became necessary to concentrate the ores first.^{[citation needed]}

Initial concentration techniques included hand-sorting^[37] and gravity concentration. These resulted in high losses of copper. Consequently, the development of the froth flotation process was a major step forward in mineral processing.^[38] The modern froth flotation process was independently invented in the early 1900s in Australia by C.V Potter and around the same time by G. D. Delprat.^[39] It made the development of the giant Bingham Canyon mine in Utah possible.^[40]

In the twentieth century, most ores were concentrated before smelting. Smelting was initially undertaken using sinter plants and blast furnaces,^[41] or with roasters and reverberatory furnaces.^[42] Roasting and reverberatory furnace smelting dominated primary copper production until the 1960s.^[35]

In the 1960s and 1970s large copper mining operations by U.S. companies were nationalized in many of the main copper producing countries.^[43] Thus by the 1980s state owned enterprises overtook the dominant role U.S. companies like Anaconda Copper and Kennecott had had until then.^[43] In the late 1970s and early 1980s various oil companies like ARCO, Exxon (Exxon Minerals) and Standard Oil Company expanded into copper mining for a few years before selling their copper assets.^[43] Reportedly gains were not as high as anticipated.^[43] Investments in copper mining concentrated in Chile in the 1980s and 1990s given that copper mining in other countries faced problems like political instability (Peru), increased environmental requirements (developed countries) or overall disinterest in foreign investment in a nationalized mining industry (Zaire, Zambia).^[43]

In the 2013-2023 period the copper smelting capacity in China and Zambia have increased while the capacity in Chile and the United States have decreased.^[3] China has by far the largest capacity for copper smelting with over half of the world's total. Besides the previously mentioned countries other countries where there is a significant installed cathode production capacity of the world's total as of 2023 are Japan (8%), Russia (5%), Poland (3-4%) and Bulgaria (3-4%).^[3]

Since the 1990s no new copper smelter have been built in Chile.^[44] Following the 2022 closure of Fundición Ventanas in central Chile there have been a public discussion on building a new large copper smelter in Chile.^[3] Antofagasta Region or Atacama Region has been proposed by Chilean industry scholars as viable replacements.^[45] Others have argued for keeping smelting in Valparaíso Region given the existence of nearby mines.^[45] While some argue the replacement plant should be near the coast, inland Chuquicamata and El Salvador have also been proposed as alternatives.^[45] The president of the National Mining Society (Sonami), Diego Hernández, estimates the construction period for a new smelter plant to be 5 to 7 years.^[45] A 2024 study identified Antofagasta Region as the best place for a new copper smelter given logistical advantages and an existing and expandable supply of copper concentrate from nearby mines.^[5]

The Guixi Smelter in inland southeastern China is the world's largest copper smelter by capacity.^[46] In 2015 it had an annual production capacity of 900,000 tons of copper.^[2][47]

In froth flotation, the crushed ore is wetted, suspended in a slurry, and mixed with reagents that render the sulfide particles hydrophobic. Typical reagents ("collectors") include potassium ethylxanthate and sodium ethylxanthate, but dithiophosphates and dithiocarbamates are also used. The slurry is introduced to a water-filled aeration tank containing a surfactant such as methylisobutyl carbinol (MIBC). Air is constantly forced through the slurry. The air bubbles attach to the hydrophobic copper sulfide particles, which are conveyed to the surface where the froth is skimmed off. These skimmings are generally subjected to a cleaner-scavenger cell to remove excess silicates and to remove other sulfide minerals that can deleteriously impact the concentrate quality (typically, galena), and the final concentrate is sent for smelting. The rock that has not floated off in the flotation cell is either discarded as tailings or further processed to extract other metals such as lead (from galena) and zinc (from sphalerite), should they exist. A variety of measures are taken to improve the efficiency of the froth flotation. Lime is used to raise the pH of the water bath, causing the collector to bond more efficiently to the copper sulfides. The process can produce concentrates with 27–29% and 37–40% copper contents from chalcopyrite and chalcocite, respectively.

Oxidised copper ores include carbonates such as azurite and malachite, the silicate chrysocolla, and sulfates such as chalcanthite. In some cases, sulfide ores are allowed to degrade to oxides. Such ores are amenable to hydrometallurgy. Specifically, such oxide ores are usually extracted into aqueous sulfuric acid, usually in a heap leaching or dump leaching. The resulting pregnant leach solution is purified by solvent extraction (SX). It is treated with an organic solvent and an organic chelators. The chelators bind the copper ions (and no other ions, ideally), the resulting complexes dissolve in the organic phase. This organic solvent is evaporated, leaving a residue of the copper complexes. The copper ions are liberated from the residue with sulfuric acid. The barred (denuded) sulfuric acid recycled back on to the heaps. The organic ligands are recovered and recycled as well. Alternatively, the copper can be precipitated out of the pregnant solution by contacting it with scrap iron; a process called cementation. Cement copper is normally less pure than SX-EW copper.^[48]

Secondary sulfides—those formed by supergene secondary enrichment—are resistant (refractory) to sulfuric leaching.^[49] Secondary copper sulfides are dominated by the mineral chalcocite; a mineral formed from primary sulfides, like chalcopyrite, that undergo chemical processes such as oxidation or reduction.^[50] Typically, secondary sulfide ores are concentrated using froth flotation.^[51] Other extraction processes like leaching are effectively used for the extraction of secondary copper sulfides, but as demand for copper rises, extraction processes tailored for low-grade ores are required, due to the depletion of copper resources.^[52] Processes including in situ, dump, and heap leaching are cost-effective methods that are suitable for extracting copper from low-grade ores.^[53]

Extraction processes for secondary copper sulfides and low-grade ores includes the process of heap bioleaching. Heap bioleaching presents a cost efficient extraction method that requires a less intensive energy input resulting in a higher profit.^[54] This extraction process can be applied to large quantities of low-grade ores, at a lower capital cost with minimal environmental impact.^[54][55]

Generally, direct froth flotation is not used to concentrate copper oxide ores, as a result of the largely ionic and hydrophilic structure of the copper oxide mineral surface.^[56] Copper oxide ores are typically treated via chelating-reagent flotation and fatty-acid flotation, which use organic reagents to ensure adsorption onto the mineral surface through the formation of hydrophobic compounds on the mineral surface.^[56][57]

Some supergene sulfide deposits can be leached using a bacterial oxidation heap leach process to oxidize the sulfides to sulfuric acid, which also allows for simultaneous leaching with sulfuric acid to produce a copper sulfate solution.^[58][59] For oxide ores, solvent extraction and electrowinning technologies are used to recover the copper from the pregnant leach solution.^[60] To ensure the best recovery of copper, it is important to acknowledge the effect copper dissolution, acid consumption, and gangue mineral composition has on the efficacy of extraction.^[60]

Supergene sulfide ores rich in native copper are refractory to treatment with sulfuric acid leaching on all practicable time scales, and the dense metal particles do not react with froth flotation media. Typically, if native copper is a minor part of a supergene profile it will not be recovered and will report to the tailings. When rich enough, native copper ore bodies may be treated to recover the contained copper by gravity separation. Often, the nature of the gangue is important, as clay-rich native copper ores prove difficult to liberate. This is because clay minerals interact with flotation reagents used in extraction processes, that are then consumed, which results in minimal recovery of a high grade copper concentrate.^[61]