Re gold in Brazil, you could look at Serabi Mining (recently listed on AIM, assets in the Tapajas, small production, large exploration potential), Brazauro (TSX-V listed, again in the Tapajas, large bulk tonnage style discovery being worked up with potential for 5m + ounces), Yamana gold (AIM and TSX listed, producer having acquired CVRD's gold assets, also large copper project), Jaguar Mining (TSX-V listed, haven't looked at this).

As far as the larger companies are concerned, I believe that Rio Tinto, TVX Gold, and Eldorado Gold all have operations and possibly Anglo Gold (?).

You may want to look at the USGS website for details of production and reserves etc.