It is impossible to imagine our modern society without copper. Its applications include televisions, computers, smartphones, iPods and e-readers, Water pipes, high-voltage cables and railway overhead lines are also made of copper. But what is coper actually? Where does it come from? And why is it so interesting for thieves? Wikismith takes a look at the wonderful world of copper.
Copper is a common substance found in nature. The earth's crust contains important sources of copper, such as malachite and azurite. Copper ore is mainly mined in Chile, Peru and the United States.
The name copper is derived from the Latin word cuprum. This word, in turn, is derived from aes cyprium, which means ore from Cyprus. Copper was mined on this Greek island between 3000-2300 BC, but it was already in use before that. Excavations in the north of what is known today as Iraq show that humans were already using copper around 8700 BC. The oldest known copper utensil dates back to 5000 BC. People discovered methods for extracting copper from ore more than 7,000 years ago.
Pure copper is soft and pliable. 5000 years ago, people discovered that copper became stronger and harder when mixed with another metal. Copper mixed with another metal is also called an alloy. The two most commonly known copper alloys are bronze and brass. Bronze is a mixture of copper and 25% tin and in the past it was mainly used for the development of tools, weapons, containers and jewellery. Today, bronze is used in sculptures, musical instruments, screws and other objects that need to be corrosion-resistant. Brass is a mixture of copper with 5-45% zinc. The Romans were the first to make objects out of brass, such as coins, kettles and jewellery.
Approximately 60% of the total copper production is used as a conductor material in energy and communication technology. Copper wire is processed into solid or multicore wires and cables for use in high, medium and low voltage power grids. It is also often used as (insulated) enamelled wire for coils, electric motors and transformers. Wires made of certain copper alloys act as contact elements in electrical and electronic components. Besides being an excellent conductor, copper is also corrosion resistant in air, moisture and seawater, which makes it very suitable for the production of coins.
Copper wire is drawn from large blocks of copper. The wire is created when a copper block is rolled into a smaller cross-section and then pulled through dies with increasingly smaller openings. The copper wire is wound onto a coil or spool, after which it is ready for further processing. Copper wire consists of red copper and is used to transport electricity between the power source and the consumer. Most copper wires have a round cross-section, but some applications require a different shape, e.g. flat or rectangular. This is called rectangular copper wire. Some copper wires are coated with an insulating coating for improved conductivity.
Copper wire is available in thicknesses from a few tens of µm (micrometres) to a few centimetres. The thicker the wire, the greater the current it is able to withstand. If the current is too high, the wire may heat up and melt and result in a short circuit or fire.