• 07.01.06

There’s Gold in Them Thar Smelly Hills

A single ton of junked PCs has more gold than 17 tons of ore. That’s why landfills might–just might–pay for their own cleanup.

There’s Gold in Them Thar Smelly Hills

Cyle Young bought a house this spring in Springfield, Ohio, planning to remodel and then flip it for a quick profit. But the project cost a lot more than the real-estate broker expected because a band of thieves descended on the vacant house. When Young drove by just two days after buying the property, the aluminum siding was gone. Soon afterward, the robbers had the nerve to come back once more and rip out all the copper.


Young is just one of dozens of victims in a wave of heists in western Ohio. The perpetrators pose as construction workers when they remove the metals from houses, apartment buildings, even churches. Strange cases of metals theft are being reported around the nation: Bandits fled with the copper cables that pulled the vintage trolleys in Yakima, Washington. The streetlights went out in Tucson, Arizona, when someone ran off with eight miles of copper lines. A longtime Third World crime has suddenly become widespread here.

What’s going on? In this interconnected global economy, a crime wave in Ohio must be explained by construction booms in China and India. China is already the world’s biggest consumer of aluminum, copper, iron, and steel. Its hunger for materials to erect its big new cities, seemingly overnight, has caused the market rates for metals to skyrocket toward historic highs. Aluminum, lead, silver, and platinum prices have all doubled in the past three years. Copper and zinc prices have tripled. Gold, that ultimate financial refuge, touched $730 an ounce, its loftiest price in a quarter-century. And while commodities prices recently tumbled, the building boom won’t end anytime soon: Over this decade, the world’s roster of megacities, with populations of 5 million or more, will grow from 41 to 59, with 48 of them in less-developed countries. All of this means that oil isn’t the only vital natural resource in fierce demand. If you’re already losing sleep about the “peak oil” problem, it’s time to worry about “peak metals,” too.

The good news is that private enterprise has a chance to create a market-driven solution to the looming metals crisis. At IBM’s recent Global Innovation Outlook conference, which brought together some big thinkers to hatch breakthrough ideas about the environment and other problems, one speaker captivated the audience by suggesting we could treat landfills as though they were mines–and dig up the valuable metals buried in them.

And there’s plenty to dig for, says Patrick Atkins, the director of energy innovation at Alcoa. North American landfills contain more aluminum than we can produce by mining ores. He thinks the same is probably true of gold and copper, which are used in the circuit boards of computers and electronic gadgets. One ton of scrap from discarded PCs contains more gold than can be produced from 17 tons of gold ore–and humans throw away 20 million tons of electronic waste a year. Americans dispose of 50 million computers annually; by the end of this decade, the Japanese alone will have trashed 610 million cell phones.

Landfill mining is a fascinating sleeper of an idea that’s actually been around for decades. It attracted serious interest in the early 1990s, when the EPA came out with new regulations that forced small communities to close their local dumps. Towns such as Newbury, Massachusetts; Edinburg, New York; and Naples, Florida, tried mining their junk piles for metals and rubber, and burning the leftovers for energy. But as market rates for metals fell in the mid-1990s, the whole notion no longer seemed economical. Now, though, with commodity prices high and a wealthy player like Alcoa sniffing around the dump, landfill mining looks like an idea whose time is finally arriving.

Much of the technology for landfill mining is already proven. As in the 1990s trials, screens and sieves could separate the soil from the waste. The standard techniques of the recycling business would come into play: shredding the waste into very small pieces and using magnets to pull out the ferrous metals. Then comes a new approach, pioneered by recyclers in the past few years, using rotors of magnets that spin very quickly, creating an “eddy current” with a strange electrical effect that makes aluminum and other nonferrous metals levitate and eject from the rest of the heap because they are both lightweight and conductive. If Alcoa gets involved, it could use its highly secretive, proprietary process of “fractional crystallization” for separating alloys from each other, such as copper from aluminum.


The separation process isn’t cost effective yet. But factor in the energy savings: Alcoa is probably the world’s largest purchaser of electricity, and it takes only 5% as much energy to recycle aluminum as it does to produce it from ore. Then add some further innovative thinking and collaboration among companies, such as creating software to simulate the physical environments before the digging and mining take place, and Atkins says landfill mining would become economical.

The idea is one of a number of creative approaches that look at environmental problems as holding the seeds of their own solutions, says Truman Semans of the Pew Center on Global Climate Change. He puts it in the same category as using tapped-out, abandoned oil wells to bury the carbon dioxide produced by burning coal, a promising way to let both the United States and China take advantage of their huge coal supplies without exacerbating global warming. “It’s finding value in otherwise nasty or unused resources,” he says. Landfill mining will probably follow the same trajectory that recycling did, Semans says. While still an infant industry and not yet efficient enough, it will need some initial support from tax breaks, subsidies, and government policies, but eventually, it will become cost effective on its own.

In the meantime, of course, landfills across the country swell and fester. Even with newly mandated plastic linings and such, they’re really not much different than putting your trash in Hefty bags and burying it in the backyard. Eventually, the bag tears or leaks, and the soil gets contaminated. Why not keep those big dumps clean by mining the treasure within?

Alan Deutschman ( is a Fast Company senior writer based in San Francisco.