Scrap copper??? Just leave it outside your gate and somebody'll nick it in a couple of minutes!!
Seriously, a desguace is a scrap yard for cars and they might accept scrap metal, I don't know, and chatarrero is a scrap metal dealer - usually a bloke who comes around in a van with a loud speaker shouting "chatarreo chatarraro!!" They might want to charge you to take it away... You could try looking both words up in yellow pages and see if you come with anything near you.
Apart from that there's el punto limpio the recycling facilities run by the town hall.