Less than 15 percent of the gold and silver used to make cellphones and other electronic products is recovered from the resulting e-waste, a U.N. report says. At least 320 tons of gold and more than 7,500 tons of silver are now used annually to make PCs, cell phones, tablet computers and other new electronic and electrical products worldwide, adding more than $21 billion in value each year to metals eventually available through \"urban mining\" of e-waste, the United Nations University reported Friday. Most of those valuable metals will be lost, however, as less than 15 percent is recovered from e-waste today in developed and developing countries alike, the report said. \"More sustainable consumption patterns and material recycling are essential if consumers [are to] continue to enjoy high-tech devices that support everything from modern communications to smart transport, intelligent buildings and more,\" said Luis Neves, chairman of the Global e-Sustainability Initiative. Electronic waste now contains precious metal \"deposits\" 40 to 50 times richer than ores mined from the ground, experts told participants from 12 countries at an e-Waste Academy for policymakers and small businesses organized in Accra, Ghana, by the United Nations University and the GeSI. \"Rather than looking at e-waste as a burden, we need to see it as an opportunity,\" Alexis Vandendaelen of Belgium-based Umicore Precious Metals Refining told the participants. Notions of \"waste management\" should be replaced with \"resource management,\" he said.