Copper: the metal of an entire era

The brightest experiments with copper

Cop­per is a soft, mal­leable met­al, one of the few met­als that does not have a sil­very or grey col­or – it is gold­en-pink. It has high elec­tric­i­ty and heat con­duc­tiv­i­ty and is only sur­passed by sil­ver in these pa­ram­e­ters.

In na­ture, cop­per is en­coun­tered in its pure form, and also in the com­po­si­tion of var­i­ous met­als, such as bor­nite Cu₅FeS₄, chal­co­sine Cu₂S, chal­copy­rite CuFeS₂, cov­el­line CuS, azu­rite Cu₃(СО₃)₂(ОН)₂, mala­chite Cu₂­CO₃(OH)₂, cuprite Cu₂O, and tenorite CuO. The most im­por­tant for ob­tain­ing cop­per are chal­copy­rite and chal­co­sine

The his­to­ry of cop­per

When the Stone Age was draw­ing to a close, and hu­man­i­ty had not yet en­tered the Bronze Age, be­tween 5,000 and 3,000 BCE peo­ple used cop­per quite wide­ly. This pe­ri­od has even been called the Cop­per Age.

How­ev­er, the old­est cop­per ob­jects found in north­ern Iran are dat­ed to 8,700 BCE. Ini­tial­ly, peo­ple em­ployed a cold­work­ing process, but over time, in dif­fer­ent re­gions tech­nolo­gies for smelt­ing cop­per items were de­vel­oped in­de­pen­dent­ly. In An­cient Egypt, there was a cop­per wa­ter pipe in the Great Pyra­mid in Giza! Ad­di­tion­al­ly, in lat­er times, around 2,400 BCE, An­cient Egyp­tians used cop­per to ster­il­ize wounds.

Grad­u­al­ly, peo­ple be­gan to use al­loys of cop­per with oth­er met­als, par­tic­u­lar with tin, to make bronze. The Bronze Age be­gan. Var­i­ous house­hold items and weapons were made from cop­per and its al­loys.

In an­tiq­ui­ty, cop­per got its name from the Latin “cypri­um” in hon­or of the is­land of Cyprus. At that time, Cyprus was the largest sup­pli­er of cop­per. In An­cient Greece, and lat­er dur­ing the time of alche­my, cop­per was linked with the plane Venus and in­di­cat­ed by the sym­bol of this plan­et. Cop­per played a ma­jor role in the de­vel­op­ment of mon­ey – in An­cient Rome cop­per was used for mak­ing coins from the 6th to the 3rd cen­tu­ry BCE.

Lat­er, al­loys of cop­per with tin and lead be­gan to be used for man­u­fac­tur­ing coins. In the mod­ern age, cop­per con­tin­ued to serve hu­man­i­ty. It was used to make sculp­tures in the Re­nais­sance, and cov­ered roofs of Eu­ro­pean build­ings. Cop­per ac­etate was used as the green pig­ment verdi­gris. Cop­per ox­ides, car­bon­ates, sul­fate and sul­fides form a green film – pati­na – on the sur­face of cop­per and bronze items. It is pati­na that gives a green col­or to cop­per roofs of Eu­ro­pean build­ings and the Stat­ue of Lib­er­ty in the USA.

Cop­per was also used to line wood­en boats, to pro­tect them from mol­lusks, sponges etc. from at­tach­ing them­selves to the hull, and in the 18th cen­tu­ry a pro­tec­tive lay­er of cop­per was used to cov­er the un­der­wa­ter sec­tions of met­al ships.

Where cop­per is used

In many ways, the use of cop­per was de­ter­mined by its high elec­tric­i­ty and heat con­duc­tiv­i­ty. Most cop­per is used in elec­tron­ics in wires and ca­bles. Mi­crochips, elec­tric­i­ty gen­er­a­tors, elec­tri­cal com­mu­ni­ca­tion de­vices and many oth­ers types of equip­ment are made with cop­per. Mo­tors of elec­tri­cal en­gines also con­tain cop­per. 300 hp mo­tors of these kinds can be found in Tes­la cars, for ex­am­ple.

The high heat con­duc­tiv­i­ty of cop­per al­lows it to be used for good heat ex­change de­vices and ra­di­a­tors. If you look in­side your com­put­er or lap­top, you will cer­tain­ly find cop­per ra­di­a­tors, which cool down parts that heat up dur­ing the work process. Al­though in or­di­nary com­put­ers cheap­er but less ef­fi­cient ra­di­a­tors are of­ten used made of alu­minum al­loys.

The soft­ness of cop­per means it can eas­i­ly be used to make pipes and bend them into dif­fer­ent shapes. Cop­per parts of var­i­ous forms are used in stills for mak­ing whiskey, for ex­am­ple.

Cop­per has an­oth­er re­mark­able prop­er­ty – this met­al and its al­loys, for ex­am­ple bronze and brass, are nat­u­ral anti-bac­te­ri­al sub­stances! In these prop­er­ties, cop­per is sim­i­lar to sil­ver, but lags be­hind it in this prop­er­ty. Sci­en­tists have found, for ex­am­ple, that in hos­pi­tals dis­ease-car­ry­ing bac­te­ria can live for up to 30 days on sur­faces which peo­ple touch – door han­dles, rail­ings etc. But if these sur­faces are made from cop­per al­loys, bac­te­ria can­not sur­vive for even a few hours.

Us­ing this knowl­edge, in 2010 the man­age­ment of a hos­pi­tal in Ire­land com­plete­ly re­placed all the or­di­nary door han­dles and oth­er ob­jects which pa­tients touched with al­loys con­tain­ing cop­per. Even ball­point pens are made from cop­per, in which bac­te­ria can­not sur­vive, ac­cord­ing to the man­u­fac­tur­ers. It is in­ter­est­ing that the anti-bac­te­ri­al ef­fect spreads to close sur­faces in a ra­dius of up to half a me­ter! Cop­per com­pounds, for ex­am­ple cop­per sul­fate Cu­SO₄, are used to pro­tect plants from germs that cause var­i­ous dis­eases.

Cop­per is a very mu­si­cal el­e­ment! Cop­per wind in­stru­ments are made from cop­per al­loys. The strings on gui­tars, pi­anos, harp­si­chords and harps, and also bowed in­stru­ments, are made with cop­per or its al­loys. Ad­di­tion­al­ly, cop­per is used in the man­u­fac­ture of var­i­ous per­cus­sion in­stru­ments – gongs, bells and cym­bals.