Copper was first used as early as 10,000 years ago. A copper pendant was found in 8700 B.C. in Northern Iraq. The early use of copper probably resulted from the natural occurrence of copper in native form. The Copper Age followed the Stone Age.
Around 3000 B.C., large deposits of copper ore were found on the Island of Cyprus in the Mediterranean Sea.
When the Romans conquered Cyprus, they gave a Latin name aes cyprium to the metal, often shortened to cyprium. Later it the name was changed to cuprum, from which the English word copper and the chemical symbol Cu were derived.
General Properties
Copper is one of the basic chemical elements. In its nearly pure state, copper is a reddish-orange metal. Copper is a chemical element with the symbol Cu (Latin: cuprum) and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is rather soft and malleable and a freshly exposed surface has a pinkish or peachy color.
In the United States, the first copper mine was opened in Granby, Connecticut (1705), followed by one in Lancaster, Pennsylvania (1732). The development of more efficient processing techniques in the late-1800s allowed the mining of lower-grade copper ores from huge open-pit mines in the western United States.
Detail
| Name and Symbol | Copper: Cu |
|---|---|
| State | Solid |
| Atomic Number | 29 |
| Element category | Transition Metal |
| Group: Period: Block | 11: 4: d |
| Standard atomic weight | 63.546(3) g·mol−1 |
| Density | 8.94 g·cm−3 |
| Melting point | 1084.62 °C |
| Boiling point | 2562 °C |
| Crystal structure | Face-Centered Cubic |
| Magnetic ordering | Diamagnetic |
| Electrical resistivity | (20 °C) 16.78 nΩ·m |
| Thermal conductivity | (300 K) 401 W·m−1·K−1 |
Copper Minerals
Pure copper is rarely found in nature. It is usually combined with other chemicals in the form of Copper Ores. There are about 15 copper ores commercially mined in 40 countries around the world. The most common ores are known as sulfide ores in which the copper is chemically bonded with sulfur. The other ores are oxide ores, carbonate ores, or mixed ores depending on the chemicals present. Many copper ores also contain significant quantities of gold, silver, nickel and other valuable metals. Most of the copper ores mined in the United States contain only about 1.2 – 1.6% copper by weight.
The average grade of copper ores in the 21st century is below 0.6% Cu, with a proportion of ore minerals being less than 2% of the total volume of the ore rock.
Detail
| Name | Formula |
|---|---|
| Chalcopyrite | CuFeS2 |
| Chalcocite | Cu2S |
| Covellite | CuS |
| Bornite | 2Cu2S•CuS•FeS |
| Tetrahedrite | Cu3SbS3 + x(Fe,Zn)6Sb2S9 |
| Malachite | CuCO3•Cu(OH)2 |
| Azurite | 2CuCO3•Cu(OH)2 |
| Cuprite | Cu2O |
| Chrysocolla | CuO•SiO2•2H2O |
Extraction of Copper
A key objective in the metallurgical treatment of Copper ore is the separation of ore minerals from gangue minerals within the rock. Each process consists of several steps in which unwanted materials are physically or chemically removed and later the concentration of copper is progressively increased. Some of these steps are conducted at the mine site itself, while others may be conducted at separate facilities.
Steps used to process the sulfide ores commonly found in the Central Africa region.
Most sulfide ores are extracted from huge open-pit mines by process of drilling and explosive blasting. In this type of mining the material located above the ore, called the overburden, is first removed to expose the buried ore deposit. This produces an open pit that may grow to be a mile or more. A road to allow access for equipment spirals down the interior slopes of the pit.
The exposed ore is scooped up by large power shovels capable of loading 500-900 cubic feet (15-25 cubic meters) in a single bite. The ore is loaded into giant dump trucks, called haul trucks, and is transported up and out of the pit.
Copper is extracted by smelting from its sulfide ores (e.g. copper pyrites), from which a large amount of copper is obtained.
Concentrating
The copper ore usually contains a large amount of dirt, clay and a variety of non-copper bearing minerals. The first step is to remove some of this waste material. This process is called concentrating and is usually done by the floatation method. Once copper has been concentrated it can be turned into pure copper cathode in two different ways – Leaching & Electro-winning or Smelting and Electrolytic.
Applications
Since 900 B.C., people have been using products derived from Copper and its ore. The demand for copper mainly comes from the electrical and electronics industries. Almost 42% of the share is absorbed by the Electrical & Electronics sector. It is believed that 80% of the copper ever since produced is still in use and continues to be recycled and repeatedly used without losing its property.
Because electrical applications require a very low level of impurities, Copper is one of the few common metals that are refined to almost 100% purity.
The usage of Copper can be significantly categorized as below
In Communication Sector:
Copper products are being used for both long and short-range cables, wires, pipes and links. Copper is also widely used in making of PCB (Printed Circuit Board) for computers and electronic equipments.
In Electricity & Energy Sector:
Copper is a best conductor of electricity and heat. It can be easily transformed to alloy i.e. combined with another metal to make new alloys like bronze and brass. These alloys are stronger, harder, and resistant to corrosion as compared to pure copper.
In Plumbing and Heating:
Copper tubes are the standard plumbing material for potable water and heating systems. It is a preferred material of professional plumbers and heating engineers.
In Transport industry:
Copper is used extensively in automobiles, trains and trucks. It is also used in heat transfer devices such as radiators, oil coolers as well as in bronze sleeve bearings.
In Coinage:
Various countries like European Union, United States, United Kingdom, Australia and New Zealand use Copper to make coins.
As a fungicide:
Copper (II) sulfate is used as a fungicide and for algae control in domestic lakes and ponds. It is used in gardening powders and sprays.
Usage by Industry
| Industry | Usage |
|---|---|
| Electrical & Electronics | 42% |
| Construction | 28% |
| Transportation | 12% |
| Consumer / General | 9% |
| Industrial Machinery | 9% |
Sources
The main countries producing copper ore are Chile and United States. The other countries producing Copper ores are Indonesia, Australia, Peru, Russia, Canada, China, Poland, Kazakhstan, Zambia and Congo.