Prehistory in
Copper Country, in 1905 The
Old Copper Complex in North America has been radiometrically dated to around 6500 BCE, at least—making it one of the oldest known examples of copper extraction in the world. 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. 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. 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. The
Pločnik archaeological site in southeastern Europe (
Serbia) contains the oldest securely dated evidence of copper making at high temperature, from 5,000 BCE. 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). The earliest copper work in the
Atacama Desert and the
Andean world as a whole dates to 1432–1132 BC. Ice core studies in Bolivia suggest copper smelting may have begun as early as 700 BC, over 2700 years ago. 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. Tin bronze,
arsenical bronze, and
arsenical copper were valuable goods produced in the
Inca Empire. 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. There is evidence of gold, silver and copper metallurgy at the site, including the production of
bronze. revolutionized Chilean copper mining. In addition to this there was improvements of transport caused by the
development of railroads and steam navigation. Prospector
José Tomás Urmeneta discovered rich orebodies at
Tamaya in 1850, a site that became one of Chile's main copper mines. 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. In some years Chile's copper production made up about 60% of the worlds output and its
export tariff made up more than half the state's income. 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. 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. 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.
Smelting 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. Copper was initially recovered from sulfide ores by directly smelting the ore in a furnace. 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. Initial concentration techniques included hand-sorting 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. 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. It made the development of the giant
Bingham Canyon mine in Utah possible. In the twentieth century, most ores were concentrated before smelting. Smelting was initially undertaken using
sinter plants and
blast furnaces, or with roasters and
reverberatory furnaces. Roasting and reverberatory furnace smelting dominated primary copper production until the 1960s. Thus by the 1980s state owned enterprises overtook the dominant role U.S. companies like
Anaconda Copper and
Kennecott had had until then. 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%). 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. Others have argued for keeping smelting in Valparaíso Region given the existence of nearby mines. The
Guixi Smelter in inland southeastern China is the world's largest copper smelter by capacity. In 2015 it had an annual production capacity of 900,000 tons of copper. ==Concentration (beneficiation)==