时间:2019-01-30 作者:英语课 分类:农业与发展


英语课

DEVELOPMENT REPORT - Reusing Metal Waste Provides Work For Many in Developing Countries
By Gary Garriott


Broadcast: Monday, April 04, 2005


I'm Gwen Outen with the VOA Special English Development Report.


People have been recycling metals for hundreds of years. Today, re-using metal waste or scrap 1 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.


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 and melted. Tin cans are mostly steel. 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.


You can learn more about recycling metals from Volunteers in Technical Assistance, or VITA. VITA is on the Internet at vita.org.


This VOA Special English Development Report was written by Gary Garriott. I'm Gwen Outen.



n.碎片;废料;v.废弃,报废
  • 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。
adj.金属的;金属制的;含金属的;产金属的;像金属的
  • 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。
adj.昂贵的,价值高的,豪华的
  • 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。
n.铜;铜币;铜器;adj.铜(制)的;(紫)铜色的
  • 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。
n.(aluminium)铝
  • 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。
学英语单词
6-O-Methylerythromycin
age sex composition
All-souls'-day
almost-certain
aluminium conductor aluminium clad steel reinforced
aphyllous plant
astatic electro dynamometer
bark picture
bloody shame
breeder cockerel
bung fodder
cable ferry
cantacuzinoes
cayugas
cerebral diataxia
Ceylon cinnamon tree
chhertums
chicadees
chip-breaking flute
cholopleth map
closed high
coextend
crane fall
Darwinian
DBMC
DC arc welding
dealings in foreign notes and coins
distorted polyhedra
electrical degree
end breakage rate
endo-dextranase
exhaust column
f.thomas
financial indicator
flexible tube pump
folk dancers
Forkville
freedom of conscience
fundamental diagram
green leech
grill car
grow like a weed
grunberg
high resolution spectrometer
high-wrought
hit your stride
hold on
immediate address mode
impetiginous syphilid
in bad shape
insurrectionary officer
intrazone
kicking horse p.
lead(ii) iodate
ligamenta hyothyreoideum medium
logging machinery
Louys, Pierre
monosalient pole
mumismatics
myeloid metaplasia
nuzzling
Oboke-kyo
oligomenorrhea
osmotic pressures
over-commonly
Parsons table
participant as observer
Pesek, Sungai
pharyngospasmus
plot of land
polybutilate
post-neonatal mortality rate
posty
power-unit failure speed
purnell process
rachitic flat pelvis
rein in a horse
roller bandages
rotary actuator with two pistons
roughs
scarifying rotor
sculpture teeth
sexually attractive
shihab
simultaneous print-plot
spud can base
st-laurent
standing gage block
stream of bits
sun porch
super powder
telemetry acquisition
tensile shear test
text someone
thermomicroscopy
timing program
unpaid expense
warrant of arrest
washtenaw
wave of oscillation
yenikapi
zone transfer