Copper
Also: Cu, Cuprum, Red Metal
Copper (Cu, atomic number 29) is a reddish transition metal with outstanding electrical and thermal conductivity, considered the oldest metal deliberately used by humans and today an indispensable industrial raw material.
Copper is one of humanity's oldest utility metals: more than 10,000 years ago it was cold-hammered in Anatolia and Mesopotamia, and its alloy with tin ushered in the Bronze Age. Today copper is a global leading indicator for economic activity and industrial development — traders therefore like to call it "Dr. Copper", because the copper price often signals economic turning points early. The current copper price and historical price developments can be found on the respective overview pages.
Properties and occurrence
Copper is a soft, ductile metal with a characteristic reddish colour. Its most important physical properties:
| Property | Value |
|---|---|
| Density | 8.96 g/cm³ |
| Melting point | 1,085 °C |
| Electrical conductivity | 58.1 MS/m |
| Thermal conductivity | 401 W/(m·K) |
| Mohs hardness | 3.0 |
Only silver conducts electricity better than copper — at a fraction of the cost. This property makes it the preferred material for cables, windings, and electronic components worldwide.
Copper occurs both native (as pure metal in nature) and in numerous ores. The most important copper ores are chalcopyrite (CuFeS₂), malachite (Cu₂(CO₃)(OH)₂), and bornite (Cu₅FeS₄). Chile is by far the world's largest producer, accounting alone for approximately 25–28% of global annual output.
Extraction and processing
Primary production takes place predominantly in open-pit mines. The extracted ore passes through several processing stages:
- Flotation – Concentration of copper ore to 25–35% Cu content (concentrate)
- Smelting and converting – Production of blister copper (~98–99% Cu)
- Electrolytic refining – Purification to electrolytic copper (≥ 99.99% Cu, cathode)
The formula for copper content in ore (ore grade) is:
Ore grade (%) = (mass of Cu in ore / total mass of ore) × 100
Modern copper mines operate with ore grades often as low as 0.5–1.5% Cu; economic minimum grades depending on the project are approximately 0.3–0.5%.
Important alloys
Copper is one of the most widely used alloying partners in metallurgy:
| Alloy | Composition | Properties |
|---|---|---|
| Bronze | Cu + Sn (tin) | hard, corrosion-resistant |
| Brass | Cu + Zn (zinc) | easily machined, decorative |
| Gunmetal | Cu + Sn + Zn + Pb | pressure-tight, for fittings |
| Nickel silver | Cu + Ni + Zn | silver-like, corrosion-resistant |
| Tombac | Cu + Zn (10–20%) | gold-coloured, for medals |
Copper also plays a central role in precious metal processing: in 585 gold (14 karat) and red gold, copper is the most important alloying partner, determining hardness and colour.
Applications and markets
Approximately 65% of global copper consumption goes to the electrical industry — from power cables to transformers and electric motors. Other significant consumer sectors include:
- Construction (water pipes, roofing, heating pipes)
- Mechanical engineering and automotive (radiators, brake lines, wiring harnesses)
- Renewable energy (wind turbines and photovoltaic installations require significantly more copper than conventional power plants)
- Electronics and telecommunications (printed circuit boards, semiconductor bonding)
The growing demand from electric mobility and the energy transition is regarded as a structural demand driver: an electric vehicle contains on average three to four times as much copper as a combustion engine vehicle.
Copper as a traded commodity
The global copper price is traded primarily on the London Metal Exchange (LME) and the COMEX in New York, quoted in US dollars per tonne. Common trading units are:
- LME lots: 25 tonnes (standard contract)
- Cathodes, granules, wire in physical trade
As an industrial metal — and therefore not a precious metal in the strict sense — copper is subject to the standard rate of VAT when purchased. Price developments are strongly influenced by global economic cycles, China's construction sector, and the pace of expansion of energy infrastructure. Current USD/EUR rates for price conversion can be retrieved using the exchange rate calculator.
Note: This article does not constitute investment or tax advice.
Recycling
Copper is virtually infinitely recyclable without loss of quality. Around 35% of global copper demand is already covered by secondary copper (recycling). So-called urban mining — the recovery of copper from electronic scrap, old cables, and fittings — is gaining increasing importance in light of declining ore grades and rising extraction costs.
In brief
Copper connects history and future like almost no other metal: as the material of humanity's first metal processing and simultaneously as a key raw material for electrification and the energy transition, it remains an indispensable commodity. The copper price is regarded by economists as a reliable leading indicator of global economic development.