Terrifying Facts About the World's Deepest Gold Mine

Photo of Mponeng via AngloGold

Oh, the things humans will do to get their grubby hands on gold—a metal mostly prized for its ornamental use, hoarded in bank vaults and jewelry boxes, though we've arbitrarily decided it's worth, uh, its weight in gold.* The deepest gold mine in the world is Mponeng, a 2.5-mile hole in the ground in South Africa. A whole underground city—lightless and lawless—lives inside the mine.

The mine is as deep as 10 Empire State Buildings, and its 236 miles of tunnels are longer than the New York subway.

Every day, 4,000 workers descend into the mine through elevators—or, as they're called in mining parlance, cages. These triple-decked cages fit 120 people at a time, and the first 1.6-mile shaft takes only 6 minutes to descend. A second shaft takes workers deeper down, and the last part is only accessible by foot or vehicle.

The whole, mind-bogglingly huge structure mines a seam of ore only 30 inches wide.

Seriously: the depths humans will do to get to their hands on gold.

The rock is so hot underground that ice has to be pumped down to cool the tunnels.

Because temperatures increase the closer we get to the earth's core, the rock faces in the mine can get as hot as 140º F. "You can imagine what it's like to crawl into a cavity there," Hart said to NPR. "It's like crawling into a pizza oven."

To keep those super-temperatures from becoming deadly, an ice-slurry mixed with salt is pumped down from the surface; huge fans then blow air over the ice, forming a controlled cold-air system within the mine—its own internal weather system. The above-ground ice-making plant goes through 6,000 tons of ice a day. 

Ultimately, this means that many tunnels can be kept at an almost bearable 85 degrees.

Illegal "ghost" miners live, eat, and even visit prostitutes right in the mines.

At least 10% of the gold in South African mines is stolen. Criminal syndicates help illegal "ghost" miners sneak into the mineshaft, where they then hide out for months at a time, turning ghostly from the lack of sunlight. Security guards also tend to let these ghost miners be: the illegal miners are often armed with AK-47s and beer bottle grenades, and it's all too easy to hear someone coming from far off in the mine. The mine is so big, it's difficult to police anyways.

There's also a whole, well, underground economy where legal miners help out their illegal brethren. Since bread, for example, costs twelve time as much in the illegal economy, packing some extra lunch can get you much more than lunch money.

Gold is so expensive, the mine only needs to extract 0.35 ounces from a ton of rock to be profitable.

Mponeng excavates 6,000 tons of rock per day. You do the math.

The world's loneliest ecosystem was discovered in Mponeng.

The rod-shaped bacterium Desulforudis audaxviator lives alone in the dark, hot waters of Mponeng; it is the sole member of the only single-species ecosystem discovered. All life forms need basic nutrients like carbon, hydrogen, nitrogen, and, usually, different bacteria pull different nutrients from the environment to form an ecosystem. But D. audaxviator is self-reliant, capable of producing everything itself. Scientists think the bacterium has not seen the surface of the earth in millions of years.

Bacteria that live in remote places like the depths of the Mponeng mine are called extremophiles for their ability to withstand seemingly impossible conditions. When motivated by money—out of greed or basic economic necessity—humans can do the same, it seems. [National Public Radio via Nature]

*Update: This article originally called gold "mostly useless," which was a reference to the fact that most gold is not used at all except for in cases of personal ornamentation or financial investment. Approximately 12% of the world's gold stocks are used in electronics and industry.

ORIGINAL: Gizmodo

ZHANG on GIZMODO

Elon Musk, the 21st Century Industrialist

ORIGINAL: BusinessWeek

By Ashlee Vance

September 13, 2012

On Fridays, Elon Musk gathers his engineers in an old hangar in Los Angeles. The building, next to a municipal airport a couple miles south of the Hollywood Park race track and casino, is now a research and development facility for Musk’s electric car company, Tesla Motors (TSLA). Musk uses these meetings to check the team’s progress and give straightforward, often withering, design critiques. During one such session in July, versions of the Model S sedan and the skeletal frame of a forthcoming sport-utility vehicle, the Model X, sit in a corner. Drivetrain prototypes lay on the concrete floor next to interior cabin mock-ups.

Musk’s staff huddles around him as he zeroes in on a sun visor. He hates it. He examines the seam and, noticing how it pushes up the fabric, declares it “fish-lipped.” The screws on the hinges feel like knives stabbing him in the eye. He announces he wants to find the best sun visor in the world, and then make a better one.

llustration by R. Kikuo Johnson

The session continues in the parking lot, where a number of competitors’ vehicles—some hybrids, some conventional—await judgment. Musk squeezes his six-foot-two, broad-shouldered frame into the back seat of a luxury sedan from Hyundai and then into an Acura SUV. He scoffs at the cramped third-row seats in the Acura. “That’s like a midget cave,” he says, and the group chuckles on cue. “It’s good to get a sense for just how bad the other cars are.”

Last year alone, Acura’s parent company, Honda Motor (HMC), sold 200,000 hybrids. Toyota Motor (TM) sold 629,000. In nine years, Tesla has built a total of 2,450 vehicles. The auto industry may have had a rough time of late, but Tesla has had buckets of delays, quality issues, and near-death financial crises. That Musk feels no shame dismissing the efforts of vastly larger competitors would not surprise his friends and colleagues, who describe him as Steve Jobs, John D. Rockefeller, and Howard Hughes rolled into one. “He’s a throwback to when people were doing less incrementalist things,” says Peter Thiel, the tech investor who co-founded PayPal with Musk. “The companies he’s started are executing against a vision measured not in years but in decades.” Bruce Leak, a veteran Silicon Valley entrepreneur who once worked with Musk at a video game company, says, “He has that Bill Gates energy where his foot bounces and he’s wiggling just because he’s so smart.” Jon Favreau, a friend and the director of the Iron Man movies, has called Musk the basis for his version of comic book hero Tony Stark, the playboy inventor who builds a flying weaponized suit.

Musk has been having a year good enough for another movie. In May, his Space Exploration Technologies, better known as SpaceX, successfully launched a 227-foot-tall rocket from a platform in Cape Canaveral, docking one of its Dragon capsules with the International Space Station, orbiting 220 miles above the earth—a feat NASA called “absolutely incredible.” Tesla, which went public in 2010, started shipping the all-electric Model S luxury sedan in June and will soon unveil a nationwide network of charging stations. SolarCity, where Musk is chairman of the board, is a player in the residential and commercial solar markets, with more than 28,000 customers, and is expected to go public imminently at a value of about $1.5 billion. Musk is chief executive officer of Tesla and SpaceX, and is the largest shareholder in all three companies. Following the SolarCity IPO, his net worth could be well north of $3 billion.

Biomining: How microbes help to mine copper

ORIGINAL: BBC

By Katia MoskvitchTechnology reporter, BBC News, Santiago, Chile

The BBC's Katia Moskvitch learns how bacteria help us extract copper

Continue reading the main story

Say bacteria. People think infection. Or yogurts.

But in Chile, bacteria are being used to get at something this country heavily depends on: copper.

Chile is the world's biggest copper exporter, and has the planet's largest known reserves of the red metal.

The Atacama Desert, a desolate rocky plateau west of the Andes mountains, is dotted with copper mines.

Every now and then, a mining train passes through the arid landscape. Here and there the ruins of tiny towns still stand where miners used to live decades ago, their mud huts gradually falling to pieces under the baking sun.

Export of the metal is essential for Chile's economy - it amounts to about 70% of all Chilean exports - and the more copper the country digs out, the more money pours in.

The demand for the metal is continually increasing too; copper is used in most of our lives, from electrical wires and telephone lines to roofing materials, from nutritional supplements to jewellery.

It is thought that the element was created billions of years ago in the stars and then became part of the materials that formed the Earth. Volcanoes and other activity caused by the planet's shifting tectonic plates then brought it closer to the surface

Chile is the world's biggest copper exporter, and a mining train is a usual sight in the Atacama Desert

To get it out, you normally have to dig.

Then, to separate copper from ore - the rocks containing it - you have to crush and grind, and then apply sweltering heat and toxic chemicals.

These conventional mining methods are very energy-intensive and thus expensive, and therefore only used on sites where it is estimated that the concentration of copper - called grade - is actually worth spending that much money on its extraction.

Bacteria on board

But as people have been hunting for the Earth's minerals for centuries, high-grade copper sites have become scarce.

“These bacteria need very little to do their work, they use air and mainly oxygen and CO2, and use the mineral itself as a source of energy” Pilar Paddar R&D director of Biosigma.


In the past there were deposits that contained as much as 30% of the red metal. Now many have grades of 1% to 1.8%.

But even when a mine is estimated to contain high-grade ores, the bulk of the material coming out of the pit has a grade below 1%, and is usually discarded as waste.

Unless mini-miners come to help - microbes.

Biosigma is a biotechnology venture set up by Codelco, a Chilean state-owned corporation and the largest copper mining company in the world, together with Japanese firm Nippon Metals and Mining.

Based on the outskirts of Santiago, Biosigma is one of only a handful of biomining companies around the world.

In the main lab, chemists and biologists in white coats and goggles are busy transferring colourful liquids from flasks to tubes and performing peculiar tests in front of an open oven with raging fire.

All the flasks, tubes, containers and huge tanks are full of microbes: Acidithiobacillus ferrooxidans and Thiobacillus ferrooxidans bacteria, harnessed by the firm to break down minerals in order to improve copper recovery rates and reduce operating costs.

"We know that conventional mining methods are not used for low-grade materials that simply get dumped - so the only way to get copper from them is by using new knowledge and capacities - in this case, biotech," says Ricardo Badilla, chief executive of Biosigma.

Using bacteria can result in extracting as much as 90% of the total metal at a pit mine, instead of merely 60%, he adds.

Bioleaching is an alternative method to traditional mining techniques 

But how can microbes help get copper from a rock?

As Pilar Parada, research and development director of Biosigma, walks past a weird-looking installation with wildly shaking flasks, she says the key to success is using microorganisms that are naturally present at mining sites.

"These bacteria need very little to do their work, they use air and mainly oxygen and CO2, and use the mineral itself as a source of energy," she says.

She explains that if a mining site is left alone, microorganisms would eventually liberate copper from rocks, but it could take hundreds of years.

To speed up the process in a biomining lab, scientists use bioleaching.

Ores are placed into acid, and then researchers introduce bacteria that change the solution so that it dismantles the rock and frees copper, in liquid form.

And after a special electrochemical process, it is then turned into solid metal that can be used in the industrial applications we so much depend on.

Future of mining

Some call biomining the "mining of the future".

“Our bet is to export the technology, so that the world can move from just exploiting natural resources to adding a value with the help of biotech.” Gabriel Rodriguez Chile's Ministry of Foreign Affairs

Indeed, it is much cheaper and greener than traditional mining - there are a lot fewer CO2 emissions and carbon and water footprints are lower than using conventional technology.

Furthermore, the toxic chemicals used in traditional mining can be extremely harmful to the environment; there have been accidents before. In the case of biomining, the bacteria are naturally occurring at mining sites anyway, and are not pathogenic.

Biomining is already in use in several countries, including South Africa, Brazil and Australia. Overall, some 20% of the world's copper production comes from bioleaching.

The practice is not limited to copper. Microorganisms are also used to extract gold and uranium. And there are other applications of biomining: scientists are working on using microbes to clean up the corrosive acid pollution left over in mining waste.

But Gabriel Rodriguez, the director for energy, science, technology and innovation at Chile's Ministry of Foreign Affairs, says that the technology needs help to develop.

"There are still not enough microorganisms for doing that job, so more research needs to be done," he says.

"And this is exactly the bet that Chile has been making in the last years.

The 33 miners trapped at the San Jose copper and gold mine had a lucky escape 

"But our bet is also to export the technology, so that the world can move from just exploiting natural resources to adding a value with the help of biotech."

If it works, one day it might be possible to get mine for copper without digging huge pit mines. Instead, miners would simply drill two holes to introduce a solution full of microbes, and then collect it once it contains copper.

This alternative to traditional mining could even help save lives - estimates suggest that some 12,000 people die from mining accidents around the world each year.

The 33 miners who spent 69 days trapped at 700m below the surface at a copper and gold mine in Chile's Copiapó region in 2010 had a lucky escape; not everyone is that lucky.

If microbes take over, the bacteria won't die if they get trapped.

Microbes 'to tackle mine waste'

"How To Grow A Planet": "Life From Light (BBC)"(1/3), "The Power of Flowers" (2/3) and "The Challenger" (3/3)

ORIGINAL: Broadcast (BBC)

Broadcast (2012) How to Grow a Planet We might think humans are the most powerful living thing on Earth, but it's plants that time and again have set the agenda for life. All animals rely on plants for their survival. This is not an accident - they are the most powerful evolutionary force on Earth.

Plants enabled amphibians to leave the water, they had a hand in the rise and fall of the dinosaurs, and they ensured the ultimate triumph of insects, mammals, birds and even us - all for their own benefit. Because plants have only ever had one goal - the total domination of the planet. It is a story of ruthless ingenuity, seduction and deception; of unimaginable power and ambition. An epic tale, How to Grow a Planet offers a stunning new perspective on Earth history. (3 chapters)

1- Life from Light: In this first episode Iain journeys from the spectacular caves of Vietnam to the remote deserts of Africa. He sees how plants first harnessed light from the sun and created our life-giving atmosphere. He uncovers the epic battle between the dinosaurs and the tallest trees on the planet. And, using remarkable imagery, he shows plants breathing - and for the first time talking to each other.

2- The Power of Flowers: In the second episode, Iain discovers how flowers have transformed our planet. He journeys to the remote islands of the South Pacific to track down the earliest flowers. In the deserts of Africa and rainforests of Vietnam, he sees how they brought brilliant colour to the most barren landscapes and sculpted the earth itself. And he learns how they drove the evolution of all animals - kick-starting our human story.

3- The Challenger: In the third episode, Iain discovers the remarkable impact of just one plant: grass. On the savannah of South Africa he sees how grass unleashed a firestorm to fight its greatest enemy, the forests. He shows how cutting your finger on a blade of grass shows us how it transformed life in the oceans. In Senegal, he meets the cleverest chimps in the world. And, in the ruins of the oldest temple on Earth, he tells the extraordinary story of how grass triggered human civilisation.