This is the VOA Special English Development Report.
People have been recycling metals for hundreds of years. Today,re-using metal waste or scrap provides work for many people,especially in developing countries. Three kinds of metals arerecycled. They are ferrous metals, non-ferrous metals and preciousmetals.
Ferrous metals contain iron. Theyare low in cost and recycled in huge amounts. Metallic iron calledpig iron is produced when iron is heated in a hot industrial stove.This kind of stove is called a blast furnace. Pig iron also containsanother element, carbon. Pig iron is useful because it can be formedinto solid, heavy objects or objects with unusual shapes.
Another kind of iron is steel, which is iron without the carbon.Making steel is simply removing the carbon by burning it away. Thismakes the steel stronger and easier to cut than iron. Both pig ironand steel waste or scrap are useful because they can be melted tomake new products.
In countries where there is a shortage of steel scrap, old tincans are sometimes used and melted. Tin cans are mostly steel. Ifthe scrap is heated before the temperature gets to the meltingpoint, the blast furnace can be more simply designed and lesscostly. These simpler furnaces are called foundries. Products aremade in foundries all over the world, but especially in Asia.
Non-ferrous metals include copper and aluminum. Copper is theperfect material for recycling. It is valuable, easy to identify andeasy to clean. People who operate foundries around the world buycopper wire and cable to recycle.
Aluminum is another very popular non-ferrous scrap metal. It ischeap to produce and very easy to work with. In developingcountries, small foundries produce aluminum bars, sheets and wire.
Precious metals like silver also are recycled. Silver can befound in pictures made with an old black-and-white camera. And itcan be found in X-rays after they have been developed. X-ray film isvery valuable for recycling silver, because both sides of the filmare usually developed.
You can learn more about recycling metals from Volunteers inTechnical Assistance, or VITA. VITA is on the Internet at vita.org.
This VOA Special English Development Report was written by GaryGarriott.