By Mark Rachovides* and Demetris Constantinides**
Copper is an essential part of human life. In fact, it is so ingrained in our daily lives, that we encounter on a daily basis without even noticing it. Due to its high ductility, malleability, thermal and electrical conductivity and resistance to corrosion, it is a key industrial metal with thousands of uses in all sectors, including manufacturing, health, technology and power generation.
Copper is the chemical element with the symbol Cu. In its native mineral and non-oxidized form, it is a soft red metal (Fig. 1). When oxidized, it acquires a greenish and blue colour. It is a ductile and malleable metal with very high thermal and electrical conductivity. Its name comes from the Latin Aes Cyprium, which means the Metal from Cyprus, where copper was mined even long before Roman times. It is one of the few metals found in nature as a pure native element.
Fig. 1: Natural copper
Copper in our Lives
Copper is used mostly as a pure metal, but when greater hardness is required, it is made into alloys such as brass by adding zinc, and bronze by adding tin. It is very useful because of its inherent and beneficial properties, such as its high electrical conductivity, tensile strength, ductility, resistance to deformation and corrosion, low thermal expansion, high thermal conductivity, malleability, ease of welding, and ease of installation.
Copper is a very effective electrical conductor and is used in the production of electrical wires and cable conductors. It is used in roofing, plumbing, industrial machinery and jewellery, as well as integrated circuits in electronics, magnetrons in microwave ovens, and electric motors (Fig. 2). We also find it in our innovative everyday tools, such as mobile phones, tablets, computers, and TVs.
Fig. 2: Copper charges and drives all types of vehicles
Copper is also an essential component of all electricity generation systems from renewable sources (wind farms, solar panels, etc.). A great example is the PS20 solar thermal power plant, located near Seville, Andalusia, which produces 300 MW of solar energy from 1,255 mirrored heliostats. The plant can produce electricity for about 180,000 households, and can therefore meet the needs of the entire city of Seville. Throughout its 25-year life, it will be offsetting emissions of over 600,000t of CO₂ every year.
Fig. 3: The PS20 and PS10 solar thermal power plants near Seville.
Mining and processing methods
Underground mining is relatively expensive and generally limited to richer ores. Copper ores are more frequently extracted from large open-pit mines, especially when the orebodies are extensive, low-grade and relatively near the surface, where they can be exploited after the removal of overburden.
The pyrometallurgical method for copper ore beneficiation begins with the size reduction, followed by concentration done at a flotation plant. The copper concentrate is then sent to a smelter, where it is melted, refined and cast in anodes. The anodes turn into 99.99% Cu cathodes by electrorefining. The hydrometallurgical method also begins with size reduction, followed by leaching, purification and then electrowinning to produce 99.999% Cu cathodes (Fig. 4).
Fig. 4: Copper plates with 99.999% purity will be produced at the metallurgical plant of Venus Minerals and Hellenic Copper Mines Project in Apliki.
Other interesting facts
Copper can be recycled many times without losing any of its properties and efficiency, while its recycling requires up to 85% less energy than primary production. Globally, this means saving 40 million tonnes of CO2 per year.
Copper is an essential nutrient for the human body. Together with iron, it enables the body to form red blood cells. Copper is present in many organs of the human body, such as the liver, brain, heart, kidneys, and skeletal muscle.
* Chairman of EuroMines and Venus Minerals
** Economic geologist and Venus Minerals Board’s Member
Source: https://www.goldnews.com.cy/en/companies/copper-and-our-world
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