Researchers have completed the first survey of valuable materials they say are waiting to be mined from Europe's vast landfills and scrapyards.

A group of 17 organizations on Wednesday launched an online database for "urban mining" detailing precious raw materials slumbering in discarded batteries, electronics and cars across the continent.

The project, known by the acronym ProSUM, aims to highlight where billions of dollars worth of aluminum, copper and gold could be retrieved each year.

The group, which includes the United Nations University, said vehicles are an increasingly rich source of raw materials including lithium — from electric cars — steel and magnesium.

Smartphones, meanwhile, have concentrations of gold that are more than 25 times as high as the richest underground ores and are far easier to extract.