VOA慢速英语20060731a
时间：2019-01-02 作者：英语课 分类：2006年慢速英语（七）月
DEVELOPMENT REPORT - Recycling Scrap 1 Metal Into MoneyBy Gary Garriott
Broadcast: Monday, July 31, 2006
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 are recycled. They are ferrous metals, non-ferrous metals and precious metals.
Ferrous metals contain iron. They are low in cost and recycled in huge amounts. Metallic 2 iron called pig iron is produced when iron is heated in a hot industrial stove. This kind of stove is called a blast furnace. Pig iron also contains another element, carbon. Pig iron is useful because it can be formed into solid, heavy objects or objects with unusual shapes.
Steel recycling
Another kind of iron is steel, which is iron without the carbon. Making steel is simply removing the carbon by burning it away. This makes the steel stronger and easier to cut than iron. Both pig iron and steel waste or scrap are useful because they can be melted to make new products.
In countries where there is a shortage of steel scrap, old tin cans are sometimes used. Tin cans are mostly steel. They can be melted. If the scrap is heated before the temperature gets to the melting point, the blast furnace can be more simply designed and less costly 3. These simpler furnaces are called foundries. Products are made in foundries all over the world, but especially in Asia.
Non-ferrous metals include copper 4 and aluminum 5. Copper is the perfect material for recycling. It is valuable, easy to identify and easy to clean. People who operate foundries around the world buy copper wire and cable to recycle.
Aluminum is another very popular non-ferrous scrap metal. It is cheap to produce and very easy to work with. In developing countries, small foundries produce aluminum bars, sheets and wire.
Precious metals like silver also are recycled. Silver can be found in pictures made with old cameras. And it can be found in X-rays after they have been developed. X-ray film is very valuable for recycling silver, because both sides of the film are usually developed.
And that's the VOA Special English Development Report. You can learn more about recycling metals through VITA, Volunteers in Technical Assistance. VITA is on the Web at enterpriseworks.org. And Internet users can find transcripts 6 and archives of all of our reports at www.unsv.com. This is Shep O'Neal.
- A man comes round regularly collecting scrap.有个男人定时来收废品。
- Sell that car for scrap.把那辆汽车当残品卖了吧。
- A sharp metallic note coming from the outside frightened me.外面传来尖锐铿锵的声音吓了我一跳。
- He picked up a metallic ring last night.昨夜他捡了一个金属戒指。
- It must be very costly to keep up a house like this.维修这么一幢房子一定很昂贵。
- This dictionary is very useful,only it is a bit costly.这本词典很有用，左不过贵了些。
- The students are asked to prove the purity of copper.要求学生们检验铜的纯度。
- Copper is a good medium for the conduction of heat and electricity.铜是热和电的良导体。
- The aluminum sheets cannot be too much thicker than 0.04 inches.铝板厚度不能超过0.04英寸。
- During the launch phase,it would ride in a protective aluminum shell.在发射阶段，它盛在一只保护的铝壳里。
- Like mRNA, both tRNA and rRNA are transcripts of chromosomal DNA. tRNA及rRNA同mRNA一样，都是染色体DNA的转录产物。 来自辞典例句
- You can't take the transfer students'exam without your transcripts. 没有成绩证明书，你就不能参加转学考试。 来自辞典例句