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HowStuffWorks "What happens to abandoned mines?"

HowStuffWorks "What happens to abandoned mines?":



What happens to abandoned mines?

Alaska Image Gallery
Alaska Image Gallery
Some abandoned mines, like this former gold mine, built in 1934 in Alaska, are left with buildings intact. See more Alaska pictures.
Rich Reid/National Geographic/Getty Images
What's the worst thing that could happen to you on a hiking trip? You trip over a rock and twist your ankle? You run into a grizzly bear? Or your friend falls into an abandoned vertical mine shaft? It may sound unbelievable, but about 30 people die each year in theUnited States from accidents involving abandoned mine operations [source: Geology]. These incidents are pretty devastating -- in 2006, a teenager visiting an abandoned mine fell 1,000 feet to his death during an attempt to jump over an exposed 10-foot-wide shaft [source: AP].
Throughout the world there are veritable fields of dangerous, exposed holes from mining operations that were simply abandoned after they stopped yielding minerals or coal. There are an estimated 100,000 to 500,000 abandoned mine sites in just the Western United States; the Bureau of Land Management (BLM) has identified and located 12,204 of those as of April 2008 [source: BLM].
Startlingly, many of those abandoned mines yet to be identified aren’t on any map. And in some cases, there are no warning signs of the danger posed by the abandoned operations. Some of these mines were simply left to fall into disrepair and neglect. This is where that possibility of falling into a mine shaft on your hiking trip comes in.
What's more, abandoned mines could pose a danger to people who don’t even venture forth into the great outdoors. Mine tailings -- the remnants of materials left behind after the desired mineral is extracted -- are often simply piled on-site while a mine is in operation and left behind when the mine is abandoned. These tailings are often toxic, and when rain runs off the piles, it leaches out harmful toxins like lead, mercury and arsenic and caries them into nearby wetlands, threatening wildlife and exposing humans' drinking supplies to risk.
So who's responsible for cleaning up these mine sites, considering they pose such danger? Find out about programs created to address the problem of abandoned mines on the next page.

HowStuffWorks "How Uranium Mining Works"

HowStuffWorks "How Uranium Mining Works":



How Uranium Mining Works

Image Gallery: Nuclear Power
Image Gallery: Nuclear Power
The Grand Canyon is gorgeous. It's also home to a whole lot of uranium, much of which is off-limits for at least 20 years, thanks to a U.S. ban enacted in 2012. See more nuclear power pictures.
Christer Fredriksson/Lonely Planet Images/Getty Images
Mining towns draw monikers from it. Political leaders keep close tabs on it. Others flat out disparage it.
Indeed, uranium owns its share of controversy.
For years, the element has been tied to talk of nuclear weapons and the birth of the atomic age. Today, however, the metal has taken on a different role -- in the form of energy. In fact, much of the enriched uranium stored in nuclear weapons from the arms race has been rededicated to fueling the world's nuclear power reactors, which provided the world with almost 14 percent of its electricity in 2010 [source: Nuclear Energy Institute].
And it's extremely powerful, too. One 7-gram pellet of uranium fuel produces as much energy as 3.5 barrels of oil and 807 kilograms (1,779 pounds) of coal [source:Newfoundland Labrador DNR].
Beyond lighting up homes and businesses through nuclear power, uranium makes radioisotopes that produce radiation, which can help diagnose and treat certain medical conditions. It's also used for shielding and, in its depleted form, as counterweights for aircraft, too.
But where does uranium come from and how is it gathered?
Like other metals, uranium occurs naturally in rocks on the Earth's surface and can be extracted throughuranium mining. Miners originally discovered uranium alongside radium, another element that was used as glowing, decorative paint (at least until people realized its harmful, radioactive effects). Uranium hit the market as a decorative glaze before its nuclear properties were discovered.
This heavy metal comes in several isotopes, or forms of the element with different numbers of neutrons. Depending on the stability of an isotope, some can be more radioactive (likely to give off energetic particles) and fissile (likely to produce nuclear fission) than others. Uranium-238 measures as the most abundant isotope of the element on Earth and can be found in rocks and seawater. But it's not as radioactive as uranium-235, the best-known form of uranium used to create nuclear reactions.
In this article, we'll chart the uranium mining process, tracking the element as it transitions from ore to fuel pellets ready to be used by nuclear reactors. We'll also look at the wax and wane of uranium mining, as well as the risks for humans and the environment by following the contentious debate over mining uranium in the backyard of the U.S.'s most iconic canyon.

HowStuffWorks "How Asteroid Mining Will Work"

HowStuffWorks "How Asteroid Mining Will Work":



How Asteroid Mining Will Work



Strip-mining equipment extracts iron and other raw materials from an asteroid. In the foreground, a mining cart transports the materials to a processing plant.
If you enjoy science fiction, then you know that the thought of colonizing the moon makes for some incredibly imaginative stories. But there is a good possibility that lunar cities will become a reality during the 21st century! Colonizing Mars is another option as well.
Right now, one of the biggest problems with the idea of a mooncolony is the question of building supplies. There is no Home Depot on the moon, so the building supplies have to come from somewhere. The only place to get the supplies right now is the Earth, with the space shuttle acting as a truck. Using the space shuttle in this way is something like using FedEx to get all of the materials for building a house to a construction site -- It's incredibly expensive and not very efficient!
Asteroids may be a much better place to get the supplies. Early evidence suggests that there are trillions of dollars' worth of minerals and metals buried in asteroids that come close to the Earth. Asteroids are so close that many scientists think an asteroid mining mission is easily feasible. Several international organizations are developing plans for going up to get these natural space resources.
In this edition of How Stuff Will Work, we'll examine what valuable resources miners could find on asteroids and discuss how a space mining operation could get those resources out!

Mponeng - World deepest ( 4,1 km ) mine Mponeng Gold Mine | World's most

Mponeng - World deepest ( 4,1 km ) mine Mponeng Gold Mine | World's most:




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