Copper extraction and production

Copper occurs in natural ore deposits around the world. Here we explain the ore-bearing rock production path to the final product, which is the highest pure trading metal available and used in a variety of applications essential to modern life.

copper minerals

Copper minerals are found throughout the earth's crust. They occur both in sedimentary rocks and in igneous rocks. The outer 10 km of the crust contain 33 g of copper for every ton of rock and in some places deposited volcanic activity millions of years ago molten copper concentrated in one place. It is these areas that are mined today because they contain enough copper to make mining profitable. In addition to the valuable copper, there is a lot of pebble (also called gangue), which must be removed.

In nature, copper usually forms in basaltic lavas, either in the form of "copper-red", shiny metallic nuggets (solidified from the melt) or in branched structures, so-called dendrites. Occasionally, crystalline training can be found. Copper occurs in paragenesis with various, mostly secondary, copper minerals such as bornite, chalcocite, cornwallite, cuprit, azurite and malachite as well as tenorite, but may also be associated with many other minerals such as calcite, clinoclas, prehnite, pumpellyite, quartz and silver.

Copper ores are common. For example, copper is made from chalcopyrite (chalcopyrite, CuFeS2), chalcocite (chalcocite, Cu2S), more rarely from bornite (copper chalcopyrite, Cu5FeS4), atacamite (CuCl2 · Cu (OH) 2), malachite (Cu2 [(OH) 2 | CO3] ) and other ores. In 2019 636 copper minerals were known. The minerals with the highest copper concentration in the compound are cuprite (up to 88,8%) and algodonite (up to 83,6%) as well as paramelaconite, tenorite and chalcocite (up to 79,9%).

copper deposits

Copper is found in the earth's crust with a content of about 0,006% and is therefore in relation to the frequency of elements in the earth's crust on the 23. Job. Often, copper appears solid, that is, in elemental form. Currently 2019 is well-known for its copperplate copper (3100), including Afghanistan, Argentina, Australia, Belgium, Bolivia, Brazil, Bulgaria, Chile, China, Democratic Republic of the Congo, Germany, Finland, France, Greece, India, Iran, Ireland, Italy, Japan, Canada, Kazakhstan, Morocco, Mexico, Mongolia, Namibia, New Zealand, Norway, Austria, Peru, the Philippines, Poland, Portugal, Romania, Russia, Zambia, Sweden, Switzerland , Zimbabwe, Slovakia, Spain, South Africa, the Czech Republic, Turkey, Ukraine, Hungary, the United States of America (USA) and the United Kingdom (UK).

Also in several rock samples from the Mid-Atlantic Ridge as well as from the Moon, which brought the probe of the Luna 24-Mission from Mare Crisium, gedieges copper was detected. 

Copper mining

The following is an overview of how copper is extracted from its ore and converted into pure metal.

Natural deposits of solid copper, that is, in its elemental form, were known well before the founding of the International Mineralogical Association (IMA). Copper is therefore recognized as a so-called grandfathered mineral, as an independent mineral species.

The most important copper producer is Chile, followed by Peru and the USA by a long way. In Europe, Poland, Portugal and Sweden are noteworthy. The main exporters were organized from 1967 to 1988 at CIPEC. The CIPEC included Chile, Peru and Papua New Guinea, on whose island Bougainville one of the world's largest copper mines 1988 led to a civil war.

Historically significant were the copper mines on the Keweenaw Peninsula in the Upper Lake (USA). There was the world's largest deposit of solid copper. Degradation took place there already in pre-Columbian times. In Germany, copper slate was mined in the Mansfelder Land until 1990, and in Cornwall it is mainly in the 18. and 19. Century given significant copper mining.

The 10 largest copper producers are:

Codelco (Corporación Nacional del Cobre de Chile) is a Chilean copper mining company. He is the largest copper producer and the second largest producer of molybdenum in the world.

1.Corporacion Nacional del Cobre (Codelco)

The Chilean state-owned company Codelco occupies the top position. The company produced 1.827 kilotons of copper last year. That's a slight drop of 3 percent. Less was produced in the El Abra, Anglo American Sur and Andina Division mines, which was only partially caught in the Salvador, El Teniente and Radomiro Tomic mines. Thanks to favorable exchange rates and lower operating costs, Codelco reduced its production costs by 9 percent to 1,26 US dollars per pound. In 2018, 1,9 megatons of fine copper and 28 kilotons of molybdenum were produced, generating a surplus of 1,08 billion dollars. Codelco is a privately-held state-owned company fully owned by the Chilean state, structured in eight divisions (7 Mines and 1 Refinery). There are numerous subsidiaries and participations all over the world.

2. Freeport McMoRan

Freeport-McMoRan Inc. is an American company in the mining industry. The company is based in Phoenix. Freeport stock has been traded on the New York Stock Exchange since 1988 and is listed in the S&P 500 stock index.

Freeport-McMoRan Copper Gold Inc. from Phoenix, Arizona, produced around 2018 kilotons of copper in 1.696. That is about 12 percent more than in 2017, which was primarily thanks to the Cerro Verde expansion project in Peru. In addition, a lot of copper and gold ore could still be mined in the Indonesian Grasberg open-cast mine. Here too, production costs fell 18 percent to $ 1,26 per pound. Freeport shares have been traded on the New York Stock Exchange since 1988 and are listed in the S&P 500 stock index.
Mining company Freeport Sulfur was the first foreign company to receive a permit from the Indonesian government in 1967 after Suharto overthrew Sukarno. Later the Freeport-McMoRan Copper & Gold subsidiary PT Freeport Indonesia with Grasberg in western New Guinea operated the largest gold mine and the most cost-effective copper mine in the world. Right from the start, Freeport was politically and economically important for the Suharto regime. In the USA the company acted as a lobby group for the government in Jakarta. Freeport became Indonesia's largest taxpayer, by far the largest investor, one of the largest employers and one of the largest social commitments - Suharto described it as essential for the Indonesian economy. On the other hand, the company is also the most controversial foreign investor in terms of its mining methods.

3 Glencore

Glencore plc is the world's largest commodity trading group. Its operational headquarters are in Baar, Switzerland. The Group was fully privately owned by management and key personnel by May of May 2011. Since its IPO on the London Stock Exchange 2011, Glencore shares have been publicly traded. Glencore is a member of the UK's leading index FTSE 100.

Glencore International, a producer based in Switzerland, has been promoting 2016 about 1.288 kilotons of copper. This is about 2 percent less than in the year 2015, which were mainly caused by production losses at African Copper. Glencore is a production cost of 0,87 dollars per pound of copper. In terms of sales, Glencore is the largest Swiss company before Vitol. Directly or indirectly, 62.000 employees are employed by 60.000 at 19 sites in 12 countries; 2.000 employees in 40 countries are responsible for marketing.
With a turnover of 205,4 billion US dollars, with a profit of 5,8 billion USD, Glencore stands according to the Forbes Global 2000 on place 64 of the world largest enterprises (conditions: year 2018). The company came into 2018 at the beginning of a market capitalization of approximately 76 billion USD.

4 BHP Billiton

The BHP Group, until November 18, 2018 BHP Billiton, is an Australian-British raw materials group under the publicly used company name "BHP" and is one of the world's three largest mining companies with Vale and Rio Tinto Group.

BHP Billiton is from Melbourne, Australia. In the past year, the Group reduced its production by 6 percent to 1.113 kilotons of copper. This was primarily due to the lower production of the Olympic Dan mine (South Australia). In Pampa Norte (Chile), maintenance was hampering production, and copper mined in Antamina, Peru, lagged behind expectations in terms of quality.

The BHP Group, listed on the New York Stock Exchange, London, Sydney and Johannesburg, was formed following the merger of British Billiton and Australian BHP (Broken Hill Proprietary Company) in 2001. The Australian company holds 60 percent of the shares and the involved UK holding company 40 percent. The Dual-listed Company is registered as BHP Group Limited in the Companies Register in Melbourne and as BHP Group Plc in the Companies Register in London. Melbourne is the head office of BHP Group Limited and the global headquarters of BHP Billiton Group, London is the headquarters of BHP Group Plc.

In the Forbes Global 2000 of the largest listed companies BHP Billiton took the 108. Place (as of: GJ 2018). The company came in mid-2018 to a stock market value of over 133 billion USD.

5. Southern Copper

Southern Copper Corporation is an American mining company owned by Grupo México. The company mainly mines copper and by-products molybdenum, zinc and silver.

Southern Copper is a subsidiary of Grupo México, based in Phoenix, Arizona. The company boosted 21 percent more, reaching 900 kilotonnes. Here, too, operating costs per pound of copper extracted decreased by 14 percent to 0,95 US dollars.

1952 was formed by the Southern Peru Copper Corporation (SPCC), which included 1955 ASARCO (51,5%), Cerro de Pasco Corporation (22,5%), Phelps Dodge (16%) and Newmont Mining (10%). Cerro de Pasco brought in the claim Cuajone. 1959, the Toquepala opencast mine and the smelter in Ilo were put into operation. From 1969 to 1976 the open pit Toquepala was opened up. The Alvarado government also set up its own refinery in Ilo, which was supplied with blister copper by SPCC.

2004 acquired Grupo México's 54,2% stake in Southern Peru Copper Corporation. In October 2005 was renamed the Southern Copper Corporation.

6. KGHM

KGHM Polska Miedź is a Polish mining company based in Lubin (Lower Silesia). It is listed on the WIG 20 stock index on the Warsaw Stock Exchange. The Polish Ministry of Treasury owned 2010 31,79% of KGHM shares.

The KGHM Polska Miedź Group from Lubin / Poland lands in sixth place among the largest copper conveyors with 677 kilotons of copper. But production output dropped 2016 by 6 percent. The falling zloty price and austerity measures reduced production costs by 11 percent. KGHM is mining copper (571.000 t in the year 2011) and silver (1260 t in the year 2011) as well as gold, lead and rock salt. The company generated 2011 with 18.615 employees sales of 20,1 billion złoty. The ores are smelted in their own copper smelter in Legnica. KGHM is the most important silver producer in the EU with an annual production of more than 1.200 tons and is based on 3. Place worldwide. The company is involved in 19 companies; In total, 30 companies belong to the capital group.

7 Rio Tinto

Rio Tinto is an 1873 based British-Australian mining company. Alongside Vale and BHP Billiton, it is one of the three largest mining companies in the world and, since the acquisition of Alcan, the world's leading aluminum producer.

The Australian-Australian company Rio Tinto slightly increased its copper production by 4 per cent to 523 kilo tonnes in the year 2016. Above all, the output from the Bingham Canyon Mine (Utah, USA) became more.

In the Forbes Global 2000 of the largest listed companies occupies Rio Tinto square 111 (as of fiscal year 2018). The company came in mid-2018 to a stock market value of over 99 billion USD.

Since 1995, Rio Tinto is a dual-listed company. Rio Tinto Limited, formerly CRA, is listed on the Australian Stock Exchange and Rio Tinto plc (formerly RTZ) is also listed on the London Stock Exchange and the New York Stock Exchange. Both companies are managed by a common management board with the same voting rights and dividends. The RTZ owners contributed 76,7% of the assets, which are managed from London. The Chief Executive Officer is Jean-Sébastien Jacques (previously Sam Walsh), the Chairman is Jan du Plessis.

8. First Quantum

First Quantum Minerals Ltd. is a Canadian mining company based in Vancouver.

Headquartered in Vancouver, Canada, First Quantum is a relatively new player among the largest copper producers. Production in the Sentinel Mine (Zambia), in Las Cruces (Spain) and Kansanshi (also Zambia) together accounted for a production of 494 kilotons. That's an increase of 29 percent. Production costs were 2016 at 1,06 US dollars per pound.

The purpose of the company is the exploration and mining of ores in Africa and Scandinavia. The main products are currently copper and gold.

The company currently operates seven mines.

9. Antofagasta

Antofagasta plc is a Chilean mining company based in the United Kingdom. The company mainly produces copper, but also molybdenum and gold. It is listed on the London Stock Exchange and listed in the FTSE 100 Index.

The Chilean mining company has increased its copper production by 15 percent to 477 kilo tonnes. With 1,20 USD per pound, the net cash costs were 20 percent lower than in the previous year. Incorporated here are the increased prices for gold and molybdenum by - products of copper production.

The group started 1888 as a railway company Antofagasta (Chili) and Bolivia Railway Company (now Ferrocarril de Antofagasta a Bolivia, abbreviated FCAB). The company, founded by British investors, built a rail link from which it still owns today to transport the copper ore between the Pacific coastal city of Antofagasta and the Bolivian seat of government La Paz.

1980 acquired the Luksic family and diversified the company by, among other things, taking the step into mining. The mines in Chile include Los Pelambres, El Tesoro and Michilla.

In a joint venture, it has mining rights in a 60.000 square kilometer area in Peru.

With its equity holding of 65% (mid-2015 level), the Chilean billionaire family Luksic still steers the fortunes of the company today.

10. Voucher

Vale SA, formerly Companhia Vale do Rio Doce (CVRD), headquartered in Rio de Janeiro, is one of the three largest mining companies in the world, alongside the Rio Tinto Group and BHP Billiton.

10 is home to Brazilian copper producer Vale. The company has raised 7 percent more copper, mainly from the Sudbury (Canada) and Salobo (Brazil) mines. 453 kilotons of copper came together in 2016. With sales of 34,1 billion dollars, with a profit of 4,6 billion USD, Vale stands according to the Forbes Global 2000 on place 132 of the world largest enterprises (conditions: financial year 2018). The company reached a market value of approximately 2018 billion USD in the middle of 77. Vale was founded by 1942 as a state-owned company, Companhia Vale do Rio Doce (CVRD) in Itabira. 1997 was privatized the company. With the acquisition of the Brazilian mining company Caemi (on 31 March 2006) and the Canadian company Inco (on 24 October 2006) CVRD rose to the second largest mining company in the world. On the 29. November 2007 renamed itself CVRD in Vale and its Canadian subsidiary CVRD Inco in Vale Inco. In March 2008 failed the takeover of the Swiss-British mining group Xstrata on the influence of the Xstrata major shareholder Glencore.

copper mining

The ore is removed from the ground either in open pit or underground mining. Underground - digging a vertical shaft into the earth to reach the copper ore and driving horizontal tunnels into the ore. Opencast mining - 90% of the ore is mined in opencast mining. Ores close to the surface can be mined after the cover layers have been removed.

copper ores

An ore is a rock that contains enough valuable mineral to make it worth mining. In the case of copper, it pays to extract if there are about 2 kg of copper per 1.000 kg of ore (0,2%). Copper minerals can be found in more than a hundred varieties, although only a few are widely used for copper. The most common ores are chalcopyrite and bornite containing both copper and iron sulphides. These make up about 80% of the world's known ores

Copper extraction after the levitation melting process

Copper loops

The ore is crushed and then ground to powder.

Copper ore enrichment

The ore is enriched by a process called foam flotation. Unwanted material (called gangue) sinks to the floor and is removed. The enrichment of the copper ore is carried out by flotation (flotation). The ground ores are stirred with water. Metal sulfides and metal oxides repel water, while the rocks of the gangue (quartz, silicates) are slightly wetted. By adding a foam, the heavy ore particles are transported to the water surface and can be skimmed off.
The cleaned ore is first oxidized in several steps in roasting furnaces to copper oxide, which is then reduced with copper sulfide (from the ore) to impure yarn copper, which has a purity of about 98,5%. However, the purity of Garkupfer is not sufficient for a whole range of production areas, eg for the electrical industry.

"Foam flotation is the most important method in the mining industry to extract valuable raw materials from ore," explains Dr. Ing. Martin Rudolph from the Helmholtz Institute Freiberg for Resource Technology (HIF), which belongs to the HZDR. "At particle sizes below 20 micrometers - less than half the size of human hair - current technology is reaching its limits." Foam flotation exploits the different surface properties of mineral particles. If gas bubbles are added to a liquid containing finely ground particles, the bubbles adhere to particles having a hydrophobic, ie water-repellent surface. These rise with the attached air bubbles up and form a foam layer that can be skimmed off. Reagents tailored to the respective recyclable material ensure that the "right" granules get into the foam. Other adjuvants promote the descent of unwanted particles or stabilize the valuable foam. Factors such as amount of gas supplied and bubble size, degree of turbulence of the flow, reagents used and adherence energies determine the yield.

From copper concentrate to refined copper

The levitation smelting process (Outokumpu process, see graphic above) has established itself today for large quantities - and this extraction process is only economical for such quantities. A reaction shaft is used for roasting and melting the pre-dried concentrates, and a sedimentation hearth underneath separates stone and slag. A waste heat boiler and filter, in which flue dust is separated from the outflowing gases, are connected downstream in an exhaust duct. Sulfuric acid is extracted from the filtered furnace gases, which still contain SO2, in contact systems. The copper stone is cut off from time to time just above the furnace floor and transferred to the converter. The remaining iron sulfide is oxidized by blowing in air, with sulfur being carried off as SO2 with the exhaust gas to produce sulfuric acid and finally the copper sulfide is broken down. In recent times, direct processes, in which all reaction steps, roasting, melting and blowing are combined in one process, are also gaining in importance.
Subsequently, copper is refined in the melt flow and by electrolysis, with refining without subsequent electrolysis only a share of about
10% has.
In fire refining, impurities are removed by blowing air in the refining furnace and then the last remaining sulfur is removed by "poling" the liquid copper matte in the rotary furnace (anode furnace) and, above all, the oxygen content is reduced to 500 ppm to 2 ppm. In the past, "poling" was done by dipping birch or beech trunks into the liquid metal; today, natural gas, propane, naphtha, reforming gas or ammonia are mainly used as reducing agents.

The melting of copper with flux

A flux is a substance that is added to the ore to make it easier to melt. The solid calcine is heated to 1200 ° C and melts. Some impurities are removed to form a mat (a mixture of liquid copper and iron sulfide).

Conversion of mats

Air is blown into the liquid mat and forms blister copper, so-called because the gas bubbles in the solid form are trapped on the surface.

Copper anode casting

The blister is poured into anodes for electrolysis.

Electrolytic refining

The copper is purified by electrolysis to 99,99%. The production path described above shows the transition from a rock containing about 0,2% copper to a copper cathode with 99,99% purity. For a whole range of production areas, eg for the electrical industry, however, the purity of 95% Garkupfer is not sufficient.
Therefore, an electrolytic copper refining is carried out in which electrode plates made of cooking copper are hung in an acidified copper sulphate solution as anodes. The electrolysis is carried out in large electrolysis tanks in which several hundred electrodes are connected in series, at voltages of 0,4 - 1 volt.
At the cathode, those cations of the solution are reduced (Cu2 +), which have the greatest tendency to do so, that is, the largest normal potential (U0) possess. The pure copper deposits on the cathode, while all the less noble metal ions such as iron, zinc and lead ions remain in the solution.

The electrolytic refining, refining to the lowest impurity levels, is necessary because even very small impurities greatly reduce the thermal and electrical conductivity of the copper. For this purpose, the electrolytic baths filled with copper sulphate solution are used to hang the anode plates cast from relatively impure copper and thin cathode start plates made of electrolytic copper or, in more modern electrolysis systems, permanent cathodes made of stainless steel. By applying an electric voltage, the copper dissolves at the anodes and precipitates at the cathodes as very pure copper, while the impurities or companion metals either go into solution or sink down as anode sludge. The cathode plates produced in this way are partly remelted and cast into formats for semifinished product production.

(Concentration approx. 99,99% Cu)

dry out

Leaching offers an alternative to copper mining. First, the ore is treated with dilute sulfuric acid. This trickles slowly through the ore over a period of months, dissolving copper to form a weak solution of copper sulphate. The copper is then recovered by electrolysis. This process is referred to as SX-EW (solvent extraction / electrowinning).

Advantages of these processes are:

It uses much less energy than traditional mining.
There are no emissions released.
Low investment costs
Possibility to be economically operated on a small scale.
It can be used on ore with only 0,1% copper - which is why lye extraction is becoming increasingly important. It is estimated that SX-EW (virtually non-existent before 1960) will account for 21% of total copper refining in 2019.

Recycling of copper

Another important source of copper is recycled scrap, referred to as secondary copper production. Around half of European copper demand is currently covered by recycled materials, which makes an important contribution to the circular economy. To find out more about copper recycling, click here.

Forms of copper

copper bullets
copper strips
copper rods
copper beads
copper block
Copper busbars
Copper cathode plates
Copper cathode squares
Copper cathodes
copper piece
copper coil
Copper conductor paste
copper concentrate
Copper crucible
copper dice
copper blanks
copper cylinder
copper washer
copper electrode
Tungsten-copper electrode
copper flake
Kupferflansche
Copper foam
copper foil
copper gauze
copper granules
Copper honeycomb structure
copper Bar
copper ink
Copper insulated wire
Copper Inquarts
copper nuggets
copper mesh
Copper metal
Copper microfilm
copper particles
copper parts
Copper pellets
coppers
copper plates
copper powder
Copper Puck
Copper stampings
Copper strip
copper rings
copper rod
copper samples
Copper shaving
copper sheets
copper shot
Copper single crystal
copper sleeves
Copper-worm
copper samples
copper bullets
Copper sponge
copper spring
Copper strip
Copper strip
copper pipe
copper shavings
Copper wafers
copper wire
copper wool
Silver-coated copper ink
Silver-coated copper powder
Ultrathin copper foil

ISE / Arndt Uhlendorff - October 2019

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