VOA慢速英语2015 废金属分离技术成本可能会降低

AS IT IS 2015-03-25 Scrap¹ Metal Separation May Become Less Costly² 废金属分离技术成本可能会降低

Recycling, or re-using, metals is much less costly than making them from raw materials in the Earth, called “ore.” But when old cars, household appliances and industrial equipment are thrown away, metals are mixed and often difficult to separate. So they are usually placed into landfills without being separated.

The United States Environmental Protection Agency says almost 15 million tons of this “scrap” metal is placed into landfills every year.

Although iron and steel are easily separated with strong magnets, other metals, such as copper³, aluminum⁴ and titanium, are not. So products with a mix of these metals are either sent to landfills or to other countries, where workers separate the different metals by hand. But university scientists working with a private company say they have created a very accurate method to separate these light metals, using a machine.

Don Eggert is the founder⁵ of O2M Technologies. His company worked with the University of Utah to develop the metal separation technology. Mr. Eggert says the system is based on the knowledge that all metals react to a strong magnetic field.

“When the metal falls through the field, even (if/though) it’s non-ferrous, it’s not attracted to the magnet, but the magnet causes there to be an electric current inside the metal, and that causes the metal to have a magnetic field itself, which interacts with the magnetic field that it’s falling through and pushes it to the side.”

Mr. Eggert says changing the frequency of the magnetic field causes metal pieces to fall into different containers.

“So, for example, if we want to separate aluminum and copper we hit the right frequency for it and the aluminum would push more (further) away from the magnet than the copper will. So the copper falls straight down, (and) the aluminum falls into a different bucket.”

Mr. Eggert says the separator is not costly to build.

Words in This Story

appliance – n. a machine (such as a stove, microwave or dishwasher) that is powered by electricity and that is used in people’s houses to perform a particular job

accurate – adj. able to produce results that are correct; not making mistakes

ferrous – adj. of, relating to or containing iron

magnetic field – n. of or relating to a magnet or magnetism⁶; the magnetic effect of electric currents and magnetic materials

frequency – n. the number of times that something such as a sound wave or radio wave is repeated in a period of time

“What we have calculated so far is that the expense-to-value ratio -- that is, how quickly you can pay back the cost of the technology over time -- we’re currently estimating it to be less than one year.”

The separator works only with metal pieces up to one centimeter wide. But the researchers are building a bigger magnet to separate larger metal parts. They hope to begin operating it at a metal shredding⁷ center by the end of this year. There, they will be able to test it in a real-life environment.

1 scrap   

n.碎片；废料；v.废弃，报废

参考例句：

• 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。

2 costly   

adj.昂贵的，价值高的，豪华的

参考例句：

• 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。

3 copper   

n.铜；铜币；铜器；adj.铜(制)的；(紫)铜色的

参考例句：

• 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。

4 aluminum   

n.(aluminium)铝

参考例句：

• 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。

5 Founder   

n.创始者，缔造者

参考例句：

• He was extolled as the founder of their Florentine school.他被称颂为佛罗伦萨画派的鼻祖。
• According to the old tradition,Romulus was the founder of Rome.按照古老的传说，罗穆卢斯是古罗马的建国者。

6 magnetism   

n.磁性，吸引力，磁学

参考例句：

• We know about magnetism by the way magnets act.我们通过磁铁的作用知道磁性是怎么一回事。
• His success showed his magnetism of courage and devotion.他的成功表现了他的胆量和热诚的魅力。

7 shredding   

v.撕碎，切碎( shred的现在分词 )；用撕毁机撕毁（文件）

参考例句：

• Like the Tehran experience, the shredding may be all for naught. 如同德黑兰事件中的情况一样，切碎文件可能是徒劳的。 来自时文部分
• How shredding began is subject to some guesswork. 粉碎处理行业的起源是个有争议的问题。 来自时文部分