Specialty metals, which include rare earth elements such as indium, gallium and germanium, are used in small amounts for very precise technological purposes, such as red phosphors, high-strength magnets, thin-film solar cells and computer chips.
Recovery and recycling can be so technologically and economically challenging that the attempt is seldom made, the researchers said.
"A recycling rate of zero for specialty metals is alarming when we consider that their use is growing quickly," Barbara Reck, co-author of a Yale study published in the journal Science, said.
Modern technology has produced a Catch-22 situation, the researchers said; the more intricate the product and the more diverse the materials it uses, the better it's likely to perform but the more difficult it is to recycle.
"Specialty metals are used in products in only small amounts, but their value typically does not provide enough incentive to invest in a complicated recovery process," study co-author Thomas Graedel said.
"The situation clearly calls for international policy initiatives to minimize the seemingly bizarre situation of spending large amounts of technology, time, energy and money to acquire scarce metals from the mines and then throwing them away after a single use."