Copper Price Forecast – Longterm development (Chart: TradingView)
In 2025, copper prices rose from around USD 8,100 to nearly USD 12,000 per metric ton. This increase has not only impacted the commodity market but has also significantly raised manufacturing costs across industries such as electronics, electrical equipment, and construction.
In various products including wires, cables, circuit breakers, sockets, and new energy equipment, copper can be said to be everywhere. To understand the reasons behind the rise in copper prices, one must first clarify a fundamental question: what is copper?
What is copper?
Copper is a chemical element with the symbol Cu and an atomic number of 29, and it is a transition metal.
The most common use of copper is in the manufacture of electrical wires. Most wires used today are made of pure copper because its electrical and thermal conductivity are second only to silver, while being much less expensive than silver.
History of copper
Copper was a crucial metal in many ancient civilizations. Archaeologists have unearthed copper beads made of native copper in northern Iraq, proving that the history of copper usage exceeds 10,000 years.
As early as 6,000 years ago, bronze artifacts had already appeared in the Mesopotamian region of ancient Babylon. Among them, large copper knives from the Sumerian civilization, engraved with lion figures, became outstanding representatives of early bronze artifacts.
St. Louis, Missouri engraving on copper plate – via USGS.gov
What are the different processes for producing copper?
Copper smelting can be divided into pyrometallurgy and hydrometallurgy. Pyrometallurgy accounts for more than 80% of global production, while hydrometallurgy mainly focuses on low-grade copper ores or copper-containing scrap.
1.Pyrometallurgy
Pyrometallurgy uses copper sulfide concentrates as the main raw material and extracts metallic copper through high-temperature oxidation reactions.
The core process consists of four steps:
1. Matte smelting
Copper concentrate is mixed with fluxes such as silica sand and limestone, and smelted at high temperature (1200–1300 °C) in a flash furnace or blast furnace.
During this process, copper sulfide is converted into matte (containing 40%–70% copper), while gangue forms low-melting slag (containing about 0.5% copper).
2. Converting
The matte is fed into a converter, where compressed air is blown in at 1250–1350 °C.
Iron and sulfur are preferentially oxidized to form iron oxide and sulfur dioxide, ultimately producing blister copper with a copper content of 98.5%–99.5%, with a sulfur removal rate exceeding 95%.
3. Fire refining of blister copper
After the blister copper is melted, gaseous impurities are removed by inserting wooden poles or blowing inert gas.
Deoxidizers such as silicon and manganese are added to reduce the oxygen content to below 0.03%, producing anode copper with a copper content of 99.2%–99.7%.
4. Electrolytic refining
Anode copper is used as the anode, pure copper starter sheets as the cathode, and direct current is applied in a copper sulfate electrolyte.
The anode copper dissolves and pure copper with a purity of 99.95% is deposited on the cathode, while impurities enter the anode slime for recovery.
2. Hydrometallurgy
Hydrometallurgy uses low-grade copper oxide ores or copper-containing scrap as raw materials and extracts copper through solution-based chemical reactions.
The core process consists of four steps:
1. Leaching
The ore is soaked in sulfuric acid solution through heap leaching or tank leaching. Copper oxides react with sulfuric acid to form copper sulfate solution.
Low-grade ores need to be roasted first to remove sulfur.
2. Solvent extraction
Organic extractants such as hydroxy oximes are added to concentrate copper ions from the leach solution into the organic phase.
This step separates copper from other impurities such as iron and zinc.
3. Stripping
Sulfuric acid solution is used to strip copper ions from the organic phase back into the aqueous phase.
This produces a high-purity copper sulfate solution.
4. Electrowinning
Using stainless steel plates as cathodes, direct current is applied to deposit copper ions onto the cathode.
This process ultimately produces cathode copper with a purity of 99.9%, and the solution can be recycled.
Copper smelting video
Types of copper
Many people believe that there is only one kind of copper and that it is unique. However, there are actually many different types of copper.
For example, alloyed copper: brass is an alloy composed of copper and zinc; cupronickel is an alloy of copper and nickel; bronze is an alloy formed by copper with elements other than zinc and nickel, mainly including tin bronze and aluminum bronze; red copper refers to copper with a very high copper content, in which the total content of other impurities is less than 1%.
Classification of copper processed materials includes copper sulfate, copper chloride, copper rods, copper busbars, copper ingots, copper plates, copper wires, copper alloys, blister copper, copper strips, copper oxide, copper foil, copper pipes, copper sludge, copper castings, electrolytic copper, and other copper alloy materials.
Various shapes made of pure copper or copper alloys, including rods, wires, plates, strips, bars, pipes, foils, etc., are collectively referred to as copper materials.
The processing methods of copper materials include rolling, extrusion, and drawing.
Among copper materials, plates and bars can be hot-rolled or cold-rolled; strips and foils are all cold-rolled; pipes and rods are divided into extruded products and drawn products; wires are all drawn products.
1. Pure copper
Pure copper is a rose-red metal. After an oxide film forms on the surface, it appears purple, so industrial pure copper is often called red copper or electrolytic copper.
Its density is 8–9 g/cm³, and its melting point is 1083 °C. Pure copper has very good electrical conductivity and is widely used in the manufacture of wires, cables, brushes, etc.
It also has good thermal conductivity and is often used to manufacture magnetic instruments and meters that must avoid magnetic interference, such as compasses and aviation instruments.
Its plasticity is excellent, making it easy to process by hot pressing and cold working, and it can be made into copper materials such as pipes, rods, wires, bars, strips, plates, and foils.
Pure copper products include smelted products and processed products.
According to composition, red copper processed materials in China can be divided into four categories: ordinary red copper (T1, T2, T3, T4), oxygen-free copper (TU1, TU2, and high-purity vacuum oxygen-free copper), deoxidized copper (TUP, TUMn), and special copper with small amounts of alloying elements added (arsenic copper, tellurium copper, silver copper).
The electrical and thermal conductivity of pure copper is second only to silver, and it is widely used to manufacture conductive and heat-conductive equipment.
Red copper has good corrosion resistance in the atmosphere, seawater, and certain non-oxidizing acids (hydrochloric acid, dilute sulfuric acid), alkalis, salt solutions, and various organic acids (acetic acid, citric acid), and is used in the chemical industry.
In addition, red copper has good weldability and can be processed into various semi-finished and finished products through cold and hot plastic working.
In the 1970s, the output of red copper exceeded the total output of all other types of copper alloys.
Trace impurities in pure copper have a serious impact on its electrical and thermal conductivity.
Among them, titanium, phosphorus, iron, and silicon significantly reduce electrical conductivity, while cadmium and zinc have very little effect.
Oxygen, sulfur, selenium, and tellurium have very low solid solubility in copper and can form brittle compounds with copper.
They have little effect on electrical conductivity but can reduce processing plasticity.
When ordinary red copper is heated in a reducing atmosphere containing hydrogen or carbon monoxide, hydrogen or carbon monoxide can easily react with cuprous oxide (Cu₂O) at the grain boundaries.
This produces high-pressure water vapor or carbon dioxide gas, which can cause the copper to crack. This phenomenon is often referred to as “hydrogen disease” of copper.
Oxygen is harmful to the weldability of copper.
Bismuth or lead forms low-melting-point eutectics with copper, causing hot brittleness.
When brittle bismuth is distributed in a thin film along grain boundaries, it can also cause cold brittleness in copper.
Phosphorus can significantly reduce the electrical conductivity of copper but can improve the fluidity of molten copper and enhance weldability.
Appropriate amounts of lead, tellurium, and sulfur can improve machinability.
pure copper pipe
2. Brass
Brass is an alloy of copper and zinc.
The simplest brass is a binary alloy of copper and zinc, known as simple brass or common brass.
By changing the zinc content in brass, brasses with different mechanical properties can be obtained.
The higher the zinc content in brass, the higher its strength and the lower its plasticity.
In industry, the zinc content of brass generally does not exceed 45%. If the zinc content is higher, brittleness will occur and the alloy properties will deteriorate.
Brass products can be divided into two categories: cast products and wrought (pressure-processed) products.
2.1 Common brass
It is an alloy composed of copper and zinc.
When the zinc content is less than 39%, zinc can dissolve in copper to form a single α phase, known as single-phase brass.
It has good plasticity and is suitable for both cold and hot pressure processing.
When the zinc content exceeds 39%, both the α phase and a β solid solution based on copper–zinc are present, forming dual-phase brass.
The β phase reduces plasticity but increases tensile strength, making it suitable only for hot pressure processing.
The designation is expressed as “H + number,” where H denotes brass and the number indicates the mass fraction of copper.
For example, H68 indicates brass with a copper content of 68% and a zinc content of 32%.
For cast brass, the letter “Z” is added before the designation, such as ZH62.
H90 and H80 are single-phase brasses with a golden-yellow color, hence they are collectively referred to as gold-colored brasses and are used for coatings, decorative items, medals, and so on.
H68 and H59 are dual-phase brasses and are widely used for structural components in electrical appliances, such as bolts, nuts, washers, and springs.
In general, single-phase brass is used for cold deformation processing, while dual-phase brass is used for hot deformation processing.
2.2 Special brass
Multi-component alloys formed by adding other alloying elements to common brass are called special brasses.
Commonly added elements include lead, tin, and aluminum, resulting in lead brass, tin brass, aluminum brass, etc.
The purpose of adding alloying elements is mainly to improve tensile strength and enhance processability.
Designation is expressed as “H + symbol of the main added element (excluding zinc) + mass fraction of copper + mass fraction of the main added element + mass fraction of other elements.”
For example, HPb59-1 indicates lead brass with a copper mass fraction of 59%, a main added element lead content of 1%, and the remainder being zinc.
brass tube
3. Bronze
Bronze is one of the earliest alloys used in history.
It originally referred to copper–tin alloys and was named bronze because of its bluish-gray color.
In order to improve processing performance and mechanical properties, most bronzes also contain other alloying elements such as lead, zinc, and phosphorus.
Since tin is a scarce element, many tin-free bronzes are used in industry.
These bronzes are not only cheaper but also possess the required special properties.
Bronze products are divided into wrought (pressure-processed) products and cast products.
bronze tube
4. Cupronickel
Copper-based alloys with nickel as the main alloying element appear silver-white in color and are known as cupronickel.
Copper–nickel binary alloys are called common cupronickel, while copper–nickel alloys with added elements such as manganese, iron, zinc, and aluminum are called complex cupronickel.
Adding nickel to pure copper can significantly improve strength, corrosion resistance, electrical resistance, and thermoelectric properties.
Industrial cupronickel is classified into structural cupronickel and electrical cupronickel according to performance characteristics and applications, meeting various requirements for corrosion resistance and special electrical and thermal properties.
1. Identification methods
Cupronickel, brass, red copper (also known as “pure copper”), and bronze (bluish-gray or gray-yellow) can be distinguished by color.
Cupronickel and brass are easy to distinguish; red copper (pure copper with impurities <1%) and bronze (with other alloying elements at about 5%) are slightly more difficult to differentiate.
When unoxidized, red copper has a brighter color than bronze, while bronze appears slightly bluish or yellowish and darker.
After oxidation, red copper turns black, whereas bronze becomes bluish-green (harmful oxidation in moist conditions) or chocolate-colored.
Copper is one of the earliest metals used by human ancestors. It possesses many excellent characteristics and remarkable functions, not only making an indelible contribution to the progress of human society, but also continuously developing new applications as civilization advances.
Copper is both an ancient metal and a modern engineering material full of vitality.
As humanity enters a highly civilized era characterized by electrification and electronic information, copper applications have opened up even broader prospects.
Why use copper, and which properties are mainly utilized?
Copper has excellent electrical and thermal conductivity, ranking first among engineering metal materials. This is the primary reason it plays a pivotal role in today’s electrified and electronic information society.
Copper also has many outstanding comprehensive properties: strong corrosion resistance to the atmosphere, seawater, soil, and many chemical media; a balance of strength and flexibility when used structurally, with good elasticity, friction resistance, and wear resistance; and a colorful appearance that symbolizes a classic and elegant aesthetic favored by people.
In addition to these performance advantages, copper also has excellent processability, including casting, welding, and machinability, which has led to its economical and widespread application.
A. Building construction accounts for 48%: including piping systems (water, heating, gas, fire sprinklers, etc.); building facilities (air conditioners, refrigerators, etc.); architectural decoration (roofs, gutters, ornaments, etc.); communication lines (audio, video, data, etc.); and power supply systems.
B. Equipment manufacturing accounts for 41%: including industrial equipment (motors, transformers, etc.); transportation (automobiles, railways, aircraft, etc.); electronic components; and light industrial products (household appliances, instruments, tools, etc.).
C. Infrastructure accounts for 11%: including large-scale projects (transportation facilities, petrochemical industry, mining and smelting, etc.); the power industry (power transmission and distribution); and communication networks.
It is worth noting that building construction is directly related to improvements in people’s living standards, and copper applications in this area account for the largest proportion.
Especially in China, where residential construction is regarded as an important driver of overall national economic development, this highlights the significant role of actively promoting copper applications for the national economy and people’s livelihood.
Cupronickel tube (copper-nickel alloy tube)
Applications of copper
1. Applications in the electrical industry
(1) Power transmission
Power transmission requires large amounts of highly conductive copper, which is mainly used in power equipment, wires and cables, busbars, transformers, switches, plug-in components, and connectors.
During power transmission through wires and cables, electrical energy is wasted due to resistive heating. From the perspectives of energy conservation and economics, the “optimal cable cross-section” standard is currently being promoted worldwide.
This standard takes into account both the initial installation cost and energy consumption, and appropriately increases cable size to achieve energy savings and optimal overall economic benefits.
According to the new standard, the cable cross-section often needs to be more than twice that of the old standard, which can achieve energy savings of around 50%.
In China, during a past period when steel supply was insufficient, and considering that the density of aluminum is only about 30% that of copper, aluminum was once used instead of copper in overhead high-voltage transmission lines to reduce weight.
Currently, from the perspective of environmental protection, overhead transmission lines are being replaced by underground cables.
In this case, compared with copper, aluminum has disadvantages such as lower electrical conductivity and larger required cable size, making it less competitive.
For the same reasons, replacing aluminum-wound transformers commonly used in the United States and Japan with energy-efficient copper-wound transformers is also a wise choice.
(2) Motor manufacturing
In motor manufacturing, copper alloys with high electrical conductivity and high strength are widely used.
The main copper components are the stator, rotor, and shaft ends.
In large motors, the windings need to be cooled with water or hydrogen, known as double-water internal cooling or hydrogen-cooled motors, which requires long lengths of hollow conductors.
Motors are major consumers of electrical energy, accounting for about 60% of total electricity supply.
The cumulative electricity cost of operating a motor is very high; generally, within the first 500 operating hours, the electricity cost already equals the purchase cost of the motor itself.
Within one year, it amounts to 4–16 times the initial cost, and over the entire service life, it can reach up to 200 times the original cost.
Even a small improvement in motor efficiency can not only save energy but also generate significant economic benefits.
The development and application of high-efficiency motors is currently a global hot topic.
Since energy losses inside motors mainly come from resistive losses in the windings, increasing the cross-sectional area of copper conductors is a key measure in developing high-efficiency motors.
In recent years, some high-efficiency motors developed ahead of others have increased copper winding usage by 25%–100% compared with traditional motors.
At present, the U.S. Department of Energy is funding a development project that plans to use cast-in copper technology to produce motor rotors.
(3) Communication cables
Since the 1980s, due to advantages such as large transmission capacity, optical fiber cables have continuously replaced copper cables in communication trunk lines and have been rapidly promoted and applied.
However, converting electrical energy into optical energy, as well as the lines leading into end users, still require large amounts of copper.
With the development of the communications industry, people’s reliance on communications continues to increase, and demand for both optical fiber cables and copper wires will keep growing.
※ Residential electrical wiring
In recent years, with the improvement of living standards in China and the rapid popularization of household appliances, residential electrical loads have grown quickly.
Residential electricity consumption in China will continue to grow significantly in the future, which will greatly increase the application of copper conductors.
2. Applications in the electronics industry
The electronics industry is an emerging industry.
In the course of its rapid development, new copper products and new application fields have continuously been developed.
At present, its applications have expanded from electron vacuum devices and printed circuits to microelectronics and semiconductor integrated circuits.
(1) Electron vacuum devices
Electron vacuum devices mainly include high-frequency and ultra-high-frequency transmitting tubes, waveguide tubes, magnetrons, etc.
They require high-purity oxygen-free copper and dispersion-strengthened oxygen-free copper.
(2) Printed circuits
Copper printed circuits use copper foil as the surface layer, bonded onto a plastic board that serves as the substrate.
Photographic methods are used to print the circuit wiring pattern onto the copper layer, and excess portions are removed by etching, leaving interconnected circuits.
Then, holes are punched at the connection points between the printed circuit board and external components, into which the leads of discrete components or other terminals are inserted and soldered, thus completing a full circuit assembly.
If immersion plating is used, all joints can be soldered in a single step.
For applications requiring finely arranged circuits, such as radios, televisions, and computers, printed circuits can save a large amount of wiring and circuit-fixing labor.
Therefore, they are widely used and consume large quantities of copper foil.
In addition, various low-cost copper-based brazing materials with low melting points and good fluidity are required for circuit connections.
(3) Integrated circuits
The core of microelectronics technology is the integrated circuit.
An integrated circuit refers to a miniaturized circuit in which components and interconnections forming the circuit are integrated inside, on the surface of, or above a semiconductor crystal material substrate (chip) using specialized process technologies.
Structurally, such microcircuits are thousands or even tens of thousands of times smaller and lighter than the most compact discrete-component circuits.
Their emergence has brought about a major revolution in computers and has become the foundation of modern information technology.
Currently developed very-large-scale integrated circuits can accommodate hundreds of thousands or even millions of transistors on a single chip area smaller than a little fingernail.
Recently, the internationally renowned computer company IBM (International Business Machines) has replaced aluminum with copper for interconnects in silicon chips, achieving breakthrough progress.
This new type of copper-based microchip can achieve a 30% performance gain, reduce circuit line widths to 0.12 micrometers, and enable up to 2 million transistors to be integrated on a single chip.
This has opened up new prospects for the application of the ancient metal copper in the latest technological field of semiconductor integrated circuits.
(4) Lead frames
To protect the normal operation of integrated circuits or hybrid circuits, they need to be packaged.
During packaging, the many connections within the circuit must be led out from the sealed body.
These leads require a certain level of strength and form the supporting framework of the integrated packaged circuit, known as the lead frame.
In actual production, to achieve high-speed mass production, lead frames are usually continuously stamped from a metal strip according to a specific arrangement.
The frame material accounts for about 1/3 to 1/4 of the total cost of an integrated circuit and is used in large quantities; therefore, low cost is essential.
Copper alloys are inexpensive, have high strength, good electrical and thermal conductivity, excellent processability, solderability, and corrosion resistance.
Their properties can be controlled over a wide range through alloying.
They can well meet the performance requirements of lead frames and have become an important material for lead frames.
They are currently the most widely used material in microelectronic devices.
3. Applications in the energy and petrochemical industries
(1) Energy industry
Both thermal power generation and nuclear power generation rely on steam to perform work.
The steam cycle is as follows:
The boiler generates steam → the steam drives the turbine to perform work → the spent steam is sent to the condenser → it is cooled into water → and then returned to the boiler to be converted into steam again.
The main condenser consists of tube sheets and condenser tubes.
Because copper has good thermal conductivity and can resist water corrosion, admiralty brass, aluminum brass, or cupronickel is used to manufacture them.
According to available data, every 10,000 kW of installed capacity requires 5 tons of condenser tubes.
A 600,000 kW power plant therefore requires 300 tons of condenser tubing.
The utilization of solar energy also requires a large number of copper tubes.
For example, a swimming pool at a hotel near London, UK, is equipped with a solar heating system that can maintain the water temperature at 18–24°C during summer.
The solar heater contains 784 pounds (356 kg) of copper tubing.
(2) Petrochemical industry
Copper and many copper alloys have good corrosion resistance in aqueous solutions and non-oxidizing acids such as hydrochloric acid.
They are also resistant to organic acids, various alkalis except ammonia, and non-oxidizing organic compounds.
Therefore, they are widely used in the petrochemical industry to manufacture containers, piping systems, filters, pumps, and valves that come into contact with corrosive media.
Their thermal conductivity is also utilized to manufacture evaporators, heat exchangers, and condensers.
Because copper has excellent plasticity, it is particularly suitable for manufacturing heat exchangers with complex structures and interwoven copper tubes used in modern chemical industries.
In addition, bronze tools are used in petroleum refineries because they do not produce sparks upon impact, thereby preventing fires.
(3) Marine industry
The oceans cover more than 70% of the Earth’s surface, and the rational development and utilization of marine resources has attracted increasing attention.
Seawater contains chloride ions that easily cause corrosion.
Many engineering metal materials, such as steel, aluminum, and even stainless steel, are not resistant to seawater corrosion.
In addition, marine biofouling forms on the surfaces of these materials.
Copper stands out, as it not only resists seawater corrosion, but copper ions dissolved in water also have bactericidal effects, which can prevent marine biofouling.
Therefore, copper and copper alloys are extremely important materials in the marine industry.
They have been widely used in seawater desalination plants, offshore oil and gas platforms, and other coastal and subsea facilities.
Examples include piping systems, pumps, and valves used in seawater desalination processes, as well as equipment used on oil and gas platforms, including bolts used in splash zones and underwater environments, anti-biofouling sheathing, pumps, valves, and piping systems.
4. Applications in the Transportation Industry
(1) Ships
Due to their excellent resistance to seawater corrosion, many copper alloys—such as aluminum bronze, manganese bronze, aluminum brass, gunmetal (tin–zinc bronze), cupronickel, and nickel–copper alloys (Monel alloys)—have become standard materials in shipbuilding.
Generally, copper and copper alloys account for 2–3% of the self-weight of warships and merchant vessels.
The propellers of warships and most large merchant ships are made of aluminum bronze or brass.
Each propeller of a large ship weighs 20–25 tons.
The propellers of the Queen Elizabeth and Queen Mary aircraft carriers each weighed as much as 35 tons.
The heavy stern shafts of large ships are often made of “Admiralty” gunmetal, and the conical bolts of rudders and propellers are made of the same material.
Copper and copper alloys are also widely used in engine rooms and boiler rooms.
The world’s first nuclear-powered merchant ship used 30 tons of cupronickel condenser tubes.
In recent years, aluminum brass tubes have been used to make large heating coils for oil tanks.
On a 100,000-ton-class ship, there are 12 such oil storage tanks, and the corresponding heating system is quite large.
The electrical equipment on ships is also very complex.
Engines, motors, communication systems, and others rely almost entirely on copper and copper alloys to operate.
Copper and copper alloys are often used for decoration in the cabins of ships of all sizes.
Even for wooden boats, it is preferable to use copper alloy (usually silicon bronze) screws and nails to fasten wooden structures.
Such screws can be mass-produced by rolling.
To prevent marine biofouling on hulls from affecting navigation, copper sheathing was often used in the past for protection.
Nowadays, the common practice is to apply copper-containing paint.
During the Second World War, to defend against attacks by German magnetic mines on ships, anti-magnetic mine devices were developed.
A copper strip was attached around the steel hull and energized with electric current to neutralize the ship’s magnetic field, thereby preventing the mines from being detonated.
(2) Automobiles
The amount of copper used in automobiles is about 10–21 kg per vehicle, varying with the type and size of the car.
For small passenger cars, it accounts for approximately 6–9% of the vehicle’s total weight.
Copper and copper alloys are mainly used in radiators, brake system piping, hydraulic devices, gears, bearings, brake friction plates, power distribution and electrical systems, gaskets, and various connectors, fittings, and decorative components.
Among these, radiators consume a relatively large amount of copper.
Modern tube-and-fin radiators use brass strips welded into radiator tubes, with thin copper strips folded into cooling fins.
In recent years, many improvements have been made to further enhance the performance of copper radiators and strengthen their competitiveness against aluminum radiators.
In terms of materials, trace elements are added to copper to increase its strength and softening point without sacrificing thermal conductivity.
This allows thinner strip thicknesses and reduces material usage.
In terms of manufacturing processes, high-frequency or laser welding is used for copper tubes.
Copper brazing is employed to replace soft solder that is susceptible to lead contamination when assembling radiator cores.
Compared with brazed aluminum radiators, under the same heat dissipation conditions—that is, with the same pressure drop of air and coolant—new copper radiators are lighter in weight and significantly smaller in size.
In addition, due to copper’s good corrosion resistance and long service life, the advantages of copper radiators become even more evident.
Image source: Tesla Model 3 Performance
(3) Railways
Railway electrification requires a large amount of copper and copper alloys.
Each kilometer of overhead contact line requires more than 2 tons of profiled copper wire.
To improve its strength, small amounts of alloying elements are often added.
These include copper (about 1%) or silver (about 0.1%).
In addition, motors, rectifiers, as well as control, braking, electrical, and signaling systems on trains all rely on copper and copper alloys to operate.
(4) Aircraft
Aircraft operation also relies heavily on copper.
Copper materials are used in aircraft wiring, hydraulic, cooling, and pneumatic systems.
Aluminum bronze tubing is used for bearing cages and landing gear bearings.
Anti-magnetic steel alloys are used in navigation instruments.
Many instruments use beryllium copper elastic components.
5. Applications in the Machinery and Metallurgical Industries
(1) Mechanical Engineering
Copper components can be found in almost all types of machinery.
In addition to the extensive use of copper in motors, electrical circuits, hydraulic systems, pneumatic systems, and control systems, a wide variety of transmission and fastening components made of brass and bronze are ubiquitous.
These include gears, worm wheels, worms, couplings, fasteners, torsion components, screws, and nuts.
Almost all mechanically moving parts require bearings or bushings made of anti-friction copper alloys.
In particular, the cylinder liners and sliding plates of large extrusion presses and forging presses with capacities of tens of thousands of tons are almost all made of bronze.
Individual castings can weigh several tons.
Many elastic components are almost exclusively made of silicon bronze and tin bronze.
Welding tools, die-casting molds, and many other tools are also inseparable from copper alloys.
(2) Metallurgical Equipment
The metallurgical industry is a major consumer of electrical energy and is often referred to as an “electricity tiger.”
In the construction of metallurgical plants, a massive power transmission and distribution system and electrical operating equipment that rely on copper are essential.
In pyrometallurgy, continuous casting technology has become dominant.
Its key component—the mold—is mostly made of high-strength, high-thermal-conductivity copper alloys such as chromium copper and silver copper.
In electrometallurgy, the water-cooled crucibles of vacuum arc furnaces and electroslag furnaces are made of copper tubing.
Various induction heating coils are wound from copper tubes or profiled copper tubes, with water flowing inside for cooling.
(3) Alloying Additives
Copper is an important alloying element in steels, aluminum, and other alloys.
Adding a small amount of copper (0.2–0.5%) to low-alloy structural steels can improve strength as well as resistance to atmospheric and marine corrosion.
Adding copper to corrosion-resistant cast iron and stainless steel can further enhance their corrosion resistance.
High-nickel alloys containing about 30% copper are the well-known Monel alloys, which are widely used in the nuclear industry.
Many high-strength aluminum alloys also contain copper.
Through quenching and aging heat treatment, finely dispersed precipitates form in the alloy, significantly increasing strength.
This is known as age-hardened aluminum alloy.
A well-known example is duralumin, also known as hard aluminum.
It is an aluminum alloy containing copper, manganese, and magnesium, and is an important structural material for aircraft and rockets.
6. Applications in Light Industry
Light industry products are closely related to daily life and come in a wide variety of forms.
Owing to copper’s excellent overall properties, it plays an important role in many areas.
(1) Air Conditioners and Refrigerators
The temperature control of air conditioners and refrigerators is mainly achieved through the evaporation and condensation processes in copper tubes of heat exchangers.
The dimensions and heat-transfer performance of heat exchanger tubes largely determine the efficiency and degree of miniaturization of the entire system.
These machines use profiled copper tubes with high thermal conductivity.
Taking advantage of copper’s excellent workability, internally grooved and high-fin heat transfer tubes have recently been developed.
These tubes are used in heat exchangers in air conditioners, refrigerators, chemical equipment, and waste heat recovery systems.
They can achieve an overall heat transfer coefficient 2–3 times that of ordinary tubes.
They are also 1.2–1.3 times more efficient than conventional low-fin tubes.
As a result, about 40% of copper can be saved, and the heat exchanger volume can be reduced by more than one-third.
(2) Clocks and Watches
In modern clocks, watches, timers, and clockwork-equipped devices, most working components are made of “clock brass.”
This alloy contains 1.5–2% lead, offering excellent machinability and suitability for mass production.
Gears are cut from long extruded brass rods.
Balance wheels are stamped from strips of appropriate thickness.
Engraved watch dials, as well as screws and connectors, are made of brass or other copper alloys.
Large numbers of inexpensive watches are made from gunmetal or are plated with nickel silver.
Some famous large clocks are made of steel and copper alloys.
The hour hand of the British “Big Ben” is made from a solid gunmetal rod.
The minute hand is made from a 14-foot-long copper tube.
A modern clock and watch factory, using copper alloys as its primary material and employing presses and precision molds, can produce 10,000 to 30,000 clocks and watches per day at very low cost.
Brass clocks
(3) Papermaking
In today’s rapidly changing information society, paper consumption is very high. Although paper appears simple on the surface, the papermaking process is actually very complex, involving many steps and a wide variety of machines, including coolers, evaporators, beaters, and paper machines.
Many components—such as various heat-exchange tubes, rollers, beaters, semi-fluid pumps, and wire meshes—are mostly made of copper alloys.
For example, the long-wire paper machine currently in use sprays prepared pulp onto a rapidly moving wire cloth with fine mesh openings (40–60 mesh).
The wire cloth is woven from brass and phosphor bronze wires and is very wide, generally over 20 feet (6 meters), requiring it to remain perfectly flat.
The wire cloth runs over a series of small brass or copper rollers. As it carries the sprayed pulp forward, moisture is vacuumed away from below.
At the same time, the wire vibrates to help fine fibers in the pulp bond together. The wire cloth of large papermaking machines can reach widths of 26 feet 8 inches (8.1 meters) and lengths of 100 feet (30.5 meters).
Wet pulp not only contains water but also chemical agents used in the papermaking process, making it highly corrosive.
To ensure paper quality, the requirements for wire cloth materials are very strict: they must have high strength and elasticity and also resist corrosion from the pulp. Copper alloys are fully capable of meeting these requirements.
(4) Printing
Copper plates are used for photographic plate making in printing. A polished copper plate is sensitized with a photosensitive emulsion, and an image is formed on it through photography.
After exposure, the copper plate is heated to harden the emulsion. To prevent softening due to heat, copper often contains a small amount of silver or arsenic to raise its softening temperature.
The plate is then etched to form a printing surface with a distribution of recessed and raised dots.
In automatic typesetting machines, type forms are produced by arranging brass type blocks, which is another important use of copper in printing.
Type blocks are usually made of leaded brass, and sometimes of copper or bronze.
(5) Brewing
Copper plays an important role in beer brewing worldwide. Copper is often used as the lining material for mash tuns and fermentation tanks.
Some well-known breweries are equipped with more than ten such large vessels, each with a capacity exceeding 20,000 gallons.
In fermentation tanks, steel pipes carrying water are commonly used for cooling. Steel pipes are also used to carry steam for heating during brewing and to transport beer.
When distilling whisky and other spirits, copper stills are usually used.
Whisky malt spirit must be distilled twice, requiring two large copper stills.
(6) Medicine
In the pharmaceutical industry, various distillation, boiling, and vacuum devices are all made of pure copper.
In medical instruments, zinc cupronickel is widely used. Copper alloys are also common materials for eyeglass frames, and so on.
7. Copper for Construction and Art
(1) Piping Systems
Copper water pipes offer many advantages, including aesthetic appeal, durability, ease of installation, safety, fire resistance, and hygienic benefits.
Compared with galvanized steel pipes and plastic pipes, copper pipes have a clear advantage in price-performance ratio.
In residential and public buildings, copper piping systems for water supply, heating, gas supply, and fire-sprinkler systems are increasingly favored and have become the preferred material.
In developed countries, copper water supply systems already account for a large proportion.
In the Manhattan Building in New York, known as the world’s sixth tallest building, the water supply system alone used 60,000 feet (10,000 kilometers) of copper pipe.
In Europe, the consumption of copper pipes for drinking water is very high: in the UK, the average consumption is 1.6 kg per person per year, while in Japan it is 0.2 kg.
Because galvanized steel pipes are prone to corrosion, many countries have explicitly banned their use. Promoting copper piping systems in China’s building construction is imperative.
(2) Building Decoration
The use of copper sheets for roofing and eaves has a long tradition in Europe. In Nordic countries, copper is even used for wall decoration.
Copper has excellent resistance to atmospheric corrosion, long service life, recyclability, and good workability that allows it to be easily formed into complex shapes. It also has an attractive color, making it very suitable for building decoration.
Its application on the roofs of churches and other ancient buildings has a long history and still shines today, and its use in modern large buildings, apartments, and residences is also increasing.
For example, in London, the “Commonwealth Institute” building, which represents modern British architectural art, has a complex roof made of copper sheets weighing about 25 tons.
The Crystal Palace Sports Centre, opened in 1966, used 60 tons of copper to form a wave-shaped roof.
According to statistics, the average annual per-capita consumption of copper sheets for roofing is 0.8 kg in Germany and 0.2 kg in the United States.
In addition, interior fittings such as door handles, locks, shutters, railings, lamps, wall decorations, and kitchen utensils made of copper are not only durable and hygienic but also add an elegant atmosphere, making them very popular.
(3) Statues and Handicrafts
No other metal has been used as extensively as copper in the manufacture of various handicrafts, from ancient times to the present, without decline.
In modern urban construction, large quantities of cast copper alloys are used for monuments, bells, ceremonial tripods, statues, Buddha figures, and antique-style products.
Modern musical instruments, such as flutes, are made of cupronickel, while saxophones are made of brass.
Various exquisite artworks, affordable gold-plated items, and imitation gold and silver jewelry also require copper alloys of different compositions.
The Tian Tan Buddha in Hong Kong, completed in 1996, was cast and assembled from tin-zinc-lead bronze. It is 26 meters high and weighs 206 tons.
The South Sea Guanyin Buddha on Mount Putuo in Zhejiang, completed in 1997, is 20 meters high and weighs 70 tons. It is the world’s first giant copper statue built using imitation gold materials.
Subsequently, an 88-meter-high bronze statue of Sakyamuni Buddha was completed in Wuxi.
(4) Coinage
Since humans began using coins for trade, copper and copper alloys have been used to make currency, a tradition that has continued to this day.
With the development of modern coin-operated telephones, transportation, shopping, and other public conveniences, the demand for copper in coinage has continued to increase.
In the application of copper coins, in addition to varying dimensions, different alloy compositions and colors can be conveniently used to manufacture and distinguish different denominations.
Common examples include “silver coins” containing 25% nickel, brass coins containing 20% zinc and 1% tin, and “copper coins” containing small amounts of tin (3%) and zinc (1.5%).
Worldwide, tens of thousands of tons of copper are consumed annually in coin production.
The Royal Mint in London alone produces 700 million copper coins each year, consuming about 7,000 tons of metal.
8. Applications in High Technology
Copper is not only widely used in traditional industries but also plays an important role in emerging industries and high-technology fields, as illustrated below:
(1) Computers
Information technology is the forerunner of high technology. It relies on the crystallization of modern human wisdom—the computer—to process and handle rapidly changing and vast amounts of information.
The heart of a computer consists of a microprocessor (including the arithmetic unit and control unit) and memory.
These basic components (hardware) are large-scale integrated circuits, with tens of millions of interconnected transistors, resistors, and capacitors distributed on tiny chips to perform rapid numerical and logical operations and large-scale information storage.
These integrated-circuit chips must be assembled through lead frames and printed circuit boards in order to function.
As seen in the earlier chapter on “Applications in the Electronics Industry,” copper and copper alloys are not only important materials for lead frames, solders, and printed circuit boards, but also play an important role in the interconnection of microscopic components in integrated circuits.
(2) Superconductivity and Cryogenics
For most materials (except semiconductors), electrical resistance decreases as temperature drops. When the temperature is lowered sufficiently, the resistance of certain materials disappears completely; this phenomenon is known as superconductivity.
The highest temperature at which superconductivity occurs is called the superconducting critical temperature of the material.
The discovery of superconductivity has opened a new realm for the use of electricity. Because resistance is zero, a very small applied voltage can produce enormous (theoretically infinite) current, generating huge magnetic fields and forces.
When current passes through the material, there is no voltage drop or energy loss. Clearly, its practical application could bring revolutionary changes to human production and life, attracting great attention.
However, for ordinary metals, superconductivity only appears when the temperature is lowered to very close to absolute zero (−273 °C), which is difficult to achieve in engineering practice.
In recent years, some superconducting alloys have been developed with higher critical temperatures than pure metals. For example, the Nb₃Sn alloy has a critical temperature of 18.1 K. Yet their application still relies heavily on copper.
First, these alloys must operate at extremely low temperatures, which are achieved through gas liquefaction.
For example, the liquefaction temperatures of liquid helium, liquid hydrogen, and liquid nitrogen are 4 K (−269 °C), 20 K (−253 °C), and 77 K (−196 °C), respectively.
Copper retains good toughness and plasticity at such low temperatures and is an indispensable structural and piping material in cryogenic engineering.
In addition, superconducting alloys such as Nb₃Sn and NbTi are very brittle and difficult to process into shapes, so copper is used as a cladding material to bind them together.
These superconducting materials are currently used to make powerful magnets for medical MRI diagnostic equipment and certain high-intensity magnetic separators in mining.
Planned magnetic levitation trains with speeds exceeding 500 km/h will also rely on these superconducting magnets to levitate the train, eliminating wheel-rail contact resistance and enabling high-speed operation.
(3) Aerospace Technology
In rockets, satellites, and space shuttles, in addition to microelectronic control systems and instruments, many critical components also require copper and copper alloys.
For example, the liners of rocket engine combustion chambers and thrust chambers use copper’s excellent thermal conductivity for cooling, keeping temperatures within allowable limits.
The combustion chamber liner of the Ariane 5 rocket is made of a copper–silver alloy, with 360 cooling channels machined into the liner, through which liquid hydrogen is passed for cooling during launch.
In addition, copper alloys are standard materials for load-bearing structural components in satellites.
The solar panels on satellites are usually made of alloys of copper with several other elements.
(4) High-Energy Physics
Revealing the mysteries of material structure is a major fundamental pursuit of scientists. Each step forward in understanding brings significant impacts to humanity, as exemplified by the application of atomic energy.
Modern physics has discovered that the smallest constituent units of matter are not molecules or atoms, but quarks and leptons, which are billions of times smaller.
Research on these fundamental particles often requires extremely high reaction energies, hundreds of times greater than those in atomic bomb explosions, a field known as high-energy physics.
Such high energies are achieved by accelerating charged particles over long distances in strong magnetic fields toward fixed targets (high-energy accelerators), or by colliding particle beams accelerated in opposite directions (colliders).
For this purpose, copper is used to wind coils that create long-distance strong magnetic field channels.
Similar structures are also required in controlled thermonuclear fusion devices. To reduce temperature rise due to heating from large currents, these magnetic channels are wound with hollow profiled copper bars to allow cooling media to pass through.
9. Applications of Copper Compounds
Copper compounds mainly include copper sulfate (pentahydrate, monohydrate, and anhydrous), copper acetate, copper oxide and cuprous oxide, copper chloride and cuprous chloride, copper oxychloride, copper nitrate, copper cyanide, copper fatty acid salts, copper naphthenate, and others. They are widely used in agriculture, animal husbandry, industry, and medical and health fields.
The most widely used is copper sulfate, usually copper sulfate pentahydrate (CuSO₄·5H₂O), which is blue in color and commonly known as blue vitriol. It is often also a raw material for producing many other salts.
Human use of copper compounds can be traced back more than 5,000 years. Tombs have revealed that ancient Egyptians used copper sulfate as a mordant in dyeing, a practice that continues today.
According to statistics, there are currently more than 100 copper sulfate producers worldwide, with an annual global consumption of about 200,000 tons, of which approximately three-quarters is used in agriculture and animal husbandry, mainly as fungicides.
(1) Applications in Agriculture and Animal Husbandry
Copper compounds are effective fungicidal pesticides for controlling pests and diseases and can control virtually all diseases caused by molds or fungi.
In addition to directly soaking seeds in copper sulfate, copper salt mixtures are commonly used in orchards and farmland. The most important include Bordeaux mixture (lime–copper sulfate solution), named after the famous French wine-growing region, and Burgundy mixture (soda–copper sulfate solution), as well as Paris green and other fungicides.
Copper sulfate crystals
According to reports, copper-based fungicides can prevent and control more than 300 types of diseases that commonly occur in over one hundred kinds of crops. These crops include:
Grapes, citrus, bananas, apples, pears, peaches, and other perennial fruit trees;
Economic crops such as coffee, rubber, cotton, and sugar beets;
Cereals such as wheat, rice, corn, barley, and oats;
Legumes, tomatoes, potatoes, and lettuce.
Copper is an essential trace nutrient required to maintain the healthy growth of crops and livestock. Generally, when the available copper content in farmland soil is lower than 2 ppmm (1 ppmm equals one hundredth of a percent), crops will suffer yield reduction due to copper deficiency; in severe cases, there may be complete crop failure.
When the available copper content in pasture soil is lower than 5 ppmm, livestock may suffer from copper deficiency diseases.
At present, due to intensive high-yield farming practices and the extensive use of chemical fertilizers that contain no copper or very low copper content, land degradation has occurred, making copper deficiency an increasingly important global concern.
To correct and prevent copper deficiency, copper salts should be supplemented in a timely manner.
They can be added directly or mixed with nitrogen- and phosphorus-rich fertilizers; they can be used to improve soil for long-term effect, or sprayed annually on crop seedlings.
For livestock and poultry, in addition to improving pasture conditions, copper salts can be mixed into feed or administered directly to animals showing symptoms of copper deficiency.
Copper sulfate is also a growth promoter for pigs and chickens, as it can improve appetite and enhance feed conversion. Adding 0.1% copper sulfate to feed can significantly promote weight gain in pigs and broiler chickens.
Copper ions have strong disinfecting and bactericidal effects and can prevent the spread of some common livestock diseases.
For example, a small amount of copper in water (less than 1 ppm) can eliminate mollusks such as snails and slugs that breed in water; these mollusks are intermediate hosts of schistosomiasis, so their control can prevent liver fluke disease common in tropical and temperate animals.
Copper sulfate can also be used to disinfect pens to prevent the spread of foot rot in cattle and sheep, swine erysipelas, and bovine dysentery.
In addition, annoying green algae pollution in ponds, rice fields, irrigation channels, rivers, and lakes can be eliminated by adding copper salts.
Copper salts can also be used as antifungal preservatives for the storage of grains, fruits, and vegetables. One simple method is to use packaging paper that has been soaked in copper salts.
(2) Applications in Industry
Copper compounds are widely used in industry, and almost every industry uses them to some extent. A few examples are given below.
Copper sulfate is a commonly used dyeing agent in printing and dyeing processes to improve color durability and wash fastness, and is widely applied in the textile and leather industries.
Copper compounds are available in blue, green, red, black, and other colors, and can be used as colorants for glass, ceramics, cement, and enamel.
They are also components of certain hair dyes. Adding copper nitrate to fireworks produces green light, and so on.
Paints containing copper compounds have anti-marine biofouling properties.
Some organic copper compounds are effective preservatives used for the protection of pulp, wood, wood products, and canvas fabrics.
Certain copper compounds are important chemical agents in the production of rubber, petroleum, and synthetic fibers, playing roles in catalysis and purification.
Copper sulfate electrolytes are used for copper plating, the production of electrolytic copper foil, and copper refining.
In the mining industry, copper sulfate is used as an activator for the flotation of minerals such as lead, zinc, aluminum, and gold.
(3) Applications in Human Health
Copper is an indispensable trace nutrient for human health and has important effects on the blood, central nervous system and immune system, hair, skin, and bone tissues, as well as the development and function of the brain and internal organs such as the liver and heart.
Copper is mainly obtained through daily diet.
The World Health Organization recommends that, to maintain health, adults should consume 0.03 mg of copper per kilogram of body weight per day. Pregnant women and infants should consume double this amount.
Copper deficiency can cause various diseases and can be corrected by taking copper-containing supplements and pills.
Copper ions can disinfect and sterilize for hygiene and epidemic prevention.
For example, they can kill bacteria such as Escherichia coli and dysentery pathogens that easily breed in water, eliminate mollusks such as slugs and snails that transmit schistosomiasis through water, and destroy mosquito larvae that spread malaria.
Copper ions can also be used in swimming pools to prevent green algae pollution and the transmission of athlete’s foot through floors.
Copper compounds can be used to treat certain diseases.
In some Western countries, copper salts were used early on to treat lung diseases and mental disorders; in some African and Asian countries, they have been used to treat ulcers and skin diseases. Copper-containing medicines are currently under continuous development.
Why can’t copper be replaced?
1. Electrical conductivity
Copper has excellent electrical conductivity, ranking second only to silver at room temperature.
However, because silver is far more expensive than copper, copper has become the preferred conductor material for wires, cables, sockets, switches, circuit breakers, and various electrical connectors.
2. Processability
Copper has excellent ductility and plasticity. It can be drawn into extremely fine copper wires and can also be formed into complex structures through stamping, bending, riveting, and other processes.
In modern manufacturing plants, mass production relies on automated equipment and stable process parameters.
Copper materials are not prone to cracking during forming and offer high dimensional consistency, which helps improve production efficiency and yield rates.
At the same time, copper surfaces are easy to tin-plate or nickel-plate, further enhancing oxidation resistance and soldering reliability, which is crucial for the long-term stable operation of electrical products.
3. Stability and reliability
Manufactured products, especially electrical products, often need to operate for long periods under complex conditions such as high temperatures, humidity, and frequent switching.
Copper exhibits good chemical stability and corrosion resistance under these conditions and is not easily subject to performance degradation due to environmental changes.
Compared with some alternative materials, copper shows more controllable performance changes after long-term energization, slower growth of contact resistance, and higher connection reliability.
This is why copper remains the mainstream choice in industrial equipment, commercial buildings, and public facilities where high safety and long service life are required.
In conclusion
In summary, copper has the following advantages:
- It has excellent electrical conductivity, second only to silver, and is the most widely used conductor in electrical and electronic components worldwide.
- It has very good thermal conductivity and is therefore used in heat exchangers such as condensers in refrigeration and air-conditioning equipment.
- It has corrosion resistance, especially in water and seawater applications, and is therefore widely used in piping systems for water supply.
- It has good ductility and can be bent relatively easily, making it easy to apply in piping systems and cable routing.
- It has antibacterial properties, which are very useful in water supply systems and medical applications and help protect human health.
However, due to production stoppages caused by a collapse triggered by an earthquake at Chile’s largest copper mine, and production halts caused by mining accidents at the world’s second-largest copper mine, the Grasberg copper mine in Indonesia, UBS predicts that due to shutdowns and output reductions, the market shortfall will reach 230,000 tons in 2025.
Global copper mine output is declining, while copper demand is surging. Moreover, copper has become closely linked with AI, electricity, new energy, and even national defense security.
Economic development, technological breakthroughs, and military equipment upgrades all require the support of copper.
Copper prices are expected to continue rising in the future, and UBS is optimistic that copper prices will exceed USD 13,000 per ton in 2026.
In response to the continued rise in copper prices, downstream enterprises can formulate reasonable procurement strategies based on market fluctuation trends and lock in costs through financial instruments such as hedging.
Upstream and midstream enterprises can optimize inventory management and seize business opportunities during the upward price cycle.