Extracting copper. Recycling.

page 4

Recycling

Picture 6. A car contains copper wiring and a radiator made from copper and brass. The total weight of copper and copper alloys is between 15 kg and 25 kg. This can all be recycled.

	Why recycle?

		Copper is one of many metals that can be recycled. The reasons for recycling copper are: price limited resources energy efficiency landfill costs the environment.

	1. Price

		It is cheaper to recycle copper than to mine and extract new copper. Recycled copper is worth up to 90% of the cost of the original copper. Recycling helps to keep the cost of copper products down.

	2. Limited resources

		To date, only 12% to 13% of all known reserves have been mined. However, it still makes sense to conserve the remaining ore by recycling.

	3. Energy efficiency

		Recycling a tonne of copper uses 15% of the energy that would be used to mine and extract the same copper. So recycling helps to conserve the world's supply of fossil fuels and reduce carbon dioxide emissions.

	4. Landfill costs

		Waste from household and industry is usually dumped in holes in the ground - called landfill. These holes are rapidly getting filled up and the cost of using the ones that are left has risen. Disposing of waste in landfill has become a very expensive option. This cost can be avoided by recycling.

	5. Environment

		When any metal is mined and refined, gases and dust are released. Although these are collected by metal producers, with recycling there are virtually no emissions. This helps the environment.

Picture 7. An undersea copper cable. This can be recycled AND made from recycled copper.

	Where does the recycled copper come from?

		There are two types of copper scrap: Old scrap comes from the public. It is collected from discarded, dismantled or obsolete products at the end of their lives. For example: copper pipes from old buildings, old taps from a bathroom renovation, old hot water cylinders or disused electrical cable. New scrap comes from factories which make articles from copper, brass or bronze. Their machines will produce offcuts and shavings that can be collected and returned for recycling. Copper is made with different purities depending on the application. The highest grade copper is electrical grade. It is 99.99% pure and is used for electrical cables because it has the best electrical conductivity. Electrical grade scrap must never be mixed with any of the lower purity grades such as plumbing tube scrap. This contains too much phosphorus which drastically reduces the electrical conductivity. The lower grades of scrap can be used to make copper alloys or chemicals. The copper sulphate you use in your school laboratory has probably been made with scrap copper. Brass scrap (such as old taps) must only be used for melting down and making into new brass articles. (see recycling properties)