Guinea has joined the quest to earn bigger share from profits of foreign mining companies. Careful readers of the article will also note that Mineweb believes "Zambia expects to earn US$650 million in additional revenue this year" from its new regime. This figure is higher than the $415m previously quoted. If $650m is the new "additional" estimate, then overall copper revenues might well be around $750m on 600k tonnes in 2008. But without knowing precise the methodology used to assess the $650m its difficult to believe any of these figures. There's also the additional complexity of other measures (e.g the 15% export tax on copper concentrates).