VOA常速英语2015--新技术降低废金属分离成本（在线收听）

Scrap-Metal Separation May Become Cheaper 新技术降低废金属分离成本

According to the Environmental Protection Agency, the United States throws 14.8 million tons of scrap metal into landfills every year. One of the main reasons is the difficulty of large-scale separation of non-ferrous metals. Scientists at the University of Utah now say they have solved that problem.

华盛顿— 根据环境保护署的数据，美国每年把1千480万吨的废金属丢到垃圾填埋场。一个主要原因是有色金属很难大规模分离。现在，犹他大学的科学家们说他们已经解决了这个问题。

Recycling metals is much cheaper than extracting them from the ore. But chopping up old cars, appliances or industrial equipment results in a mixture of different metal parts.

回收金属比从矿石中提炼金属要便宜许多。但是，旧的汽车、电器或工业设备报废切块之后，各种金属都混在一起。

Iron and steel are easily separated with strong magnets, while others, such as copper, aluminum and titanium, either end up in landfills or are shipped to countries with cheap labor to pick out the different metal by hand.

利用高强度的强磁性很容易把钢铁分离出来，但是其他金属如铜、锡和钛则最终被丢到垃圾填埋场，或运到劳动力成本低廉的国家，把不同的金属人工分拣出来。

Researchers at the University of Utah now say they have developed a method for mechanically separating light metals with high degree of accuracy.

现在，犹他大学的研究人员说，他们已经研发出一种机械分离轻金属的方法，准确率很高。

Don Eggert of O2M Technologies, which partnered with the school in developing the technology, said the system is based on the fact that all metals react to a strong magnetic field.

O2M技术公司的堂·埃格特和犹他大学合作研发这项技术。他说，这个系统依靠的是所有金属都受强磁场影响的原理。

“When the metal falls through the field, even 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,” said Eggert.

他说：“当金属落到磁场中，即使是不受磁铁吸引的有色金属，因为磁铁使金属内部产生电流，使得金属自身产生了磁场。这种磁场和金属所经过的磁场互相作用，而将金属推到了一边。”

Eggert said rapid change in the frequency of the magnetic field results in metal pieces falling into different bins.

埃格特说，磁场频率的快速改变将金属块分类到不同的箱子中。

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

 “所以，比方说，如果我们想分离铝和铜，那么调到合适的频率，铝会比铜被推的更远。所以铜直接落下来，而铝落到不同的桶中。”他说。

This is just one of the technologies for separating different metals but Eggert says it is much cheaper to build since it requires only one large circular magnet and a frequency controller.  

这只是分离不同金属的技术中的一种。但是埃格特说这个便宜的多，因为它只需要用一个大的环形磁铁和一台频率调节器。

“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.”

 “我们目前为止已经计算出了成本与价值的比率，就是你多快可以收回成本。我们目前估计是不到一年。”埃格特说。

At the moment, the separator works only with pellets up to one centimeter wide.  Researchers are now building a bigger magnet with a wider cut to accommodate larger metal parts. They hope to have it installed at a metal shredding facility sometime this year, where they will be able to test it in a real-life environment.

现在，分离器仅对宽度一厘米以内的金属块有效。研究人员正在制造一个更大的磁铁来处理更大的金属件。他们希望在今年把它安装在一个金属粉碎设备上，这样他们可以在真实环境中测试。