I don't know where you are but every country would have scrap metal yards, and from those yards they send aluminium, silver, copper etc to a manufacturer of what is termed here as 'Precious Metal Merchants'. Perhaps you could try googling Silver and Gold suppliers or something like that? It took me a while to locate what I was looking for here via google.
Each major city I would think would have a metal supplier for jewellers and Industry/manufacturing related components. Sorry, don't know what else to suggest.
Search through those companies you found, you may find one or more of those are manufacturers and suppliers of gold/silver/copper etc products, even finished items such as Sterling Silver jewellery, if they do they probly have Pure Fine Silver wire and sheets as well.