Copper
The ‘easily recycled metal’, copper has numerous applications including electrical wiring, roofing materials, and for anti-microbial surfaces.
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Copper’s broad spectrum of desirable properties has led to its use in numerous facets of our lives. Its excellent ductility and electrical conductivity make it a preferred choice for electrical wiring, for integrated circuits, and for printed circuit boards. Gourmets worldwide have long preferred cooking pots with copper bottoms to take advantage of copper’s high thermal conductivity. Likewise, architects prize copper as a roofing material as it is both functional and decorative. The pinkish-orange metal goes through a series of transformations over time ultimately resulting in the characteristic green patina of copper (II) carbonate, known as verdigris, which is highly waterproof and corrosion-resistant.
Since antiquity, it was noticed that water contained in copper vessels formed little or no slime during storage. The anti-microbial properties of pure copper, as well as its alloys such as brass and bronze, have been verified in modern times. Unlike a stainless steel surface, on which bacteria may live for days or weeks, a brass doorknob will be free of bacteria within five hours, and a surface of pure copper is clean within an hour or two. This property even extends to MRSA, Methicillin-resistant Staphylococcus aureus, which is a difficult infection to cure.
Unlike the challenges of recycling plastics, which require sorting materials and dealing with impurities, copper is one of the easiest materials to recycle, and the reclaimed material has no loss in quality compared to the original raw metal. Copper ranks as the third most recycled metal following aluminum and iron, and it is estimated that as much as 80 percent of all the copper ever mined remains in use today.
An extensive history of the uses of copper may be found at http://www.copper.org/education/history/copper.html