快將沒有的元素(endangered element)

Small but mighty, rare earth elements are key ingredients of green technology. They may soon be in short supply.

Unless you paid really close attention in your high school chemistry class, you won’t have a clue what tantalum, antimony, or indium are. Yet, you know what they do because you and everyone around you use them each day.

endangered elements:
-tantalum
-antimony
-indium

Application:
Tantalum is used in cell phones, while antimony is a common flame retardant, and indium is part of LCD TVs. These elements along with better-known ones such as copper, zinc, silver, and platinum, are relatively rare in our world, and our high tech gadgets are using them up at alarming rates. For instance, in January 2003 indium was selling for around $60 per kilogram, whereas August 2006 it was valued at over $1000 per kilogram.


Some of these information of each element in Chinese:
-tantalum: http://zh.wikipedia.org/wiki/%E9%92%BD
-antimony: http://zh.wikipedia.org/wiki/%E9%94%91
-indium:http://zh.wikipedia.org/wiki/%E9%93%9F


Rare but needed for green
These "rare earth elements," as they are called, are also used in many new green technologies. Indium combined with gallium is a key component of futuristic new solar panels. Hybrid vehicle batteries and compact fluorescent lightbulbs could not function without rare earth elements. And, as some environmentalists have suggested, nuclear energy will need to provide more of our power in an effort to reduce emissions and climate change. However, uranium is not found in great abundance all over the world.

More troubling, some geologists have estimated that as our technologies and populations grow, we could run out of some of these rare earth elements in years or at most decades. Indium might run out in 5-10 years, platinum in 15 years, and even silver resources could be gone in 15-20 years.

Green may become unavailable
What happens when these rare earth elements become even more rare? How will technology and our desire to green our society continue if the building materials are unavailable?

The answer to this problem is not easy. Because these are chemical elements, we can’t produce a man-made replacement. However, we can change our usage of the materials. For instance, many water pipes in homes and businesses are still made out of copper when they could be plastic pipes. As copper stocks become depleted, it might make sense to stop using copper piping and replace all the existing copper piping with the plastic alternative.

Unexplored areas
Our final option is to search for unknown sources of these elements, or sources that before were considering impractical. For instance, many old mines have large waste piles with trace amounts of rare earth elements. As the major deposits dwindle, we may start to pick through our mining trash. Or, if the private space industry takes off, we could start mining the stars as science fiction has suggested for years. Many asteroids and even our moon contain high quantities of elements rare on Earth.

http://www.greenlivingonline.com/Energy/rare-earth-elements-on-the-endangered-list/