HONJO, Japan (Reuters) - Thinking of throwing out your old cell phone? Think again. Maybe you should mine it first for gold, silver, copper and a host of other metals embedded in the electronics -- many of which are enjoying near-record prices.

Printed circuit boards, collected from discarded electronic items, are piled up at Dowa Holdings Co's Eco-System Recycling Co, a recycling plant, in Honjo, north of Tokyo March 28, 2008. Thinking of throwing out your old cell phone? Think again. Maybe you should mine it first for gold, silver, copper and a host of other metals embedded in the electronics -- many of which are enjoying near-record prices. REUTERS/Yuriko Nakao

It’s called “urban mining”, scavenging through the scrap metal in old electronic products in search of such gems as iridium and gold, and it is a growth industry around the world as metal prices skyrocket.

The materials recovered are reused in new electronics parts and the gold and other precious metals are melted down and sold as ingots to jewellers and investors as well as back to manufacturers who use gold in the circuit boards of mobile phones because gold conducts electricity even better than copper.

“It can be precious or minor metals, we want to recycle whatever we can,” said Tadahiko Sekigawa, president of Eco-System Recycling Co which is owned by Dowa Holdings Co Ltd.

A tonne of ore from a gold mine produces just 5 grams (0.18 ounce) of gold on average, whereas a tonne of discarded mobile phones can yield 150 grams (5.3 ounce) or more, according to a study by Yokohama Metal Co Ltd, another recycling firm.

The same volume of discarded mobile phones also contains around 100 kg (220 lb) of copper and 3 kg (6.6 lb) of silver, among other metals.

Recycling has gained in importance as metals prices hit record highs. Gold is trading at around $890 (449 pounds) an ounce, after hitting a historic high of $1,030.80 in March.

Copper and tin are also around record highs and silver prices are well above long term averages.

RECYCLING METALS

Recycling electronics makes sense for Japan which has few natural resources to feed its billion dollar electronics industry but does have tens of millions of old cell phones and other obsolete consumer electronic gadgets thrown away every year.

“To some it’s just a mountain of garbage, but for others it’s a gold mine,” said Nozomu Yamanaka, manager of the Eco-Systems recycling plant where mounds of discarded cell phones and other electronics gadgets are taken apart for their metal value.

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At the factory in Honjo, 80 km (50 miles) southwest of Tokyo, 34-year-old Susumu Arai harvests some of that bounty.

A ribbon of molten gold flows into a mould where it sizzles and spits fire for a few minutes before solidifying into a dull yellow slab, on its way to becoming a 3 kg (6.6 lb) gold bar, worth around $90,000 at current prices.

Wearing plastic goggles to protect his eyes while he works, Arai said he was awestruck when he started his job two years ago.

“Now I find it fun being able to recover not just gold, but all sorts of metals,” he said.

The scrap electronics and other industrial waste is first sorted and dismantled by hand. It is then immersed in chemicals to dissolve unwanted materials and the remaining metal is refined.

Eco-System, established 20 years ago near Tokyo, typically produces about 200-300 kg (440-660 lb) of gold bars a month with a 99.99 percent purity, worth about $5.9 million to $8.8 million.

That’s about the same output as a small gold mine.

Eco-System also recovers metals from old memory chips, cables and even black ink which contain silver and palladium.

RECYCLING CELL PHONES

But despite growing interest in the environment and recycling, the industry struggles to get enough old mobile phones to feed its recycling plants.

Japan’s 128 million population uses their cell phones for an average of two years and eight months.

That’s a lot of cell phone phones discarded every year, yet only 10-20 percent are recycled as people often opt to store them in their cupboards due to concerns about the personal data on their phones, said Yoshinori Yajima, a director at Japan’s Ministry of Economy, Trade and Industry.

Just 558 tonnes of old phones were collected for recycling in the year to March 2007, down a third from three years earlier, industry figures show.

As metals prices rise, the Japanese industry faces growing competition for scrap, which is pushing up prices.

“We are seeing more competition from Chinese firms, and naturally the goods go where the money is,” Dowa’s Takashi Morise said.

In response, Japanese firms are importing used circuit boards from Singapore and Indonesia, as they also contain valuable minor metals that Japan is particularly eager to recover.

These minor metals such as indium, a vital component in the production of flat panel televisions and computer screens, antimony and bismuth are indispensable for producing many high-tech products.

However, they are often not easy to acquire as China has tightened export controls, making it harder for Japanese manufacturers to buy these metals.

That’s where the “urban miners” step in.

“Our wish is to be able to help Japanese manufacturers that need these metals,” Eco-System President Sekigawa said.

(Editing by Nick Trevethan and Megan Goldin)