T wenty-two kilograms of gold, worth about $785,000 US, were recovered from discarded cellphones collected in a campaign by the Japanese government, according to the Economy, Trade and Industry Ministry.

About 567,000 cellphones were collected during the campaign, which started in November in an effort to recycle precious and rare metals used in mobile phones.

In addition to gold, 79 kilograms of silver, 5,670 kilograms of copper and two kilograms of palladium were recovered, the ministry said.

Cellphones are often referred to as "urban mines" because such precious and rare metals are used in the devices. The retrieved metals will be sold to refiners for recycling.

It is believed that about 200 million unused cellphones are in homes and elsewhere in the country. Many people keep their old cellphones to use as telephone directories and cameras.