Copper and polymetallic sulphides deposits contain gold in several forms, free or as fine particles hosted in iron sulphides. In general, gold associated with a particular base metal is recovered by flotation with the mineral, but sometimes when gold is hosted by pyrite appear some problems to the process. Basically, coarse free gold can be recovered by gravimetric devices ahead of flotation circuit. Fine gold must recovered in a copper or copper-lead concentrate, but never into the zinc flotation circuit because the extractive process of copper and lead concentrate includes the recovery of precious metals. The treatment of zinc concentrates is not a good option for precious metals. Base metal concentrates receives an extra pay for gold and silver. Then is attractive try to concentrate precious metals into copper and lead concentrates.
Sometimes, gold can be hosted by pyrite and its recovery will be achieved after recovering copper, lead and zinc. In this case, a pyrite concentrate with gold content will be obtained and the possibility of including a cyanidation process is attractive.