Occurrence of Copper
i) Copper pyrite, CuFeS2.
ii) Cuprite or Ruby copper, Cu2O.
iii) Copper glance, Cu2S.
The chief ore of copper is copper pyrite. It yields nearly 76% of the world production of copper.
Use of Copper
- Historically, copper was the first metal to be worked by people. The discovery that it could be hardened with a little tin to form the alloy bronze gave the name to the Bronze Age.
- Traditionally in old age it has been one of the metals used to make coins, along with silver and gold.
- Most copper is used in electrical equipment such as wiring and motors. This is because it conducts both heat and electricity very well, and can be drawn into wires.
- Copper sulfate is used widely as an agricultural poison.
- Copper alloys used in jewellery: Copper is an easily molded base metal that is often added to precious metals to improve their elasticity, flexibility, hardness, colour, and resistance to corrosion.
- Medical uses for copper: As the Egyptians documented, copper is known to kill many germs on contact.
There are more than 400 copper alloys, each with a unique combination of properties, to suit many applications, high quality requirements, manufacturing processes and environments.
|Brass||Cu 60 – 80%|
Zn 40 – 20%
|Bronz|| Cu 60 – 80%|
Sn 40 – 20%
|Cupper-Nickel||Copper-nickel alloys have excellent resistance to marine corrosion. The addition of nickel to copper improves strength and corrosion resistance, but good ductility is retained.|
|Gunmetal||Gun metal, Cu = 85%, Zn = 4%, Sn =8%, Pb =3%|
have been used for at least 2,000 years due to their ease of casting, and good strength and corrosion resistance.