When reviewing Methods of EliminatingCopperfromGold Oreswe see that several methods have been suggested to eliminatecopperfromoresprior to cyanidation. Preliminaryextractionof thecopperwith sulphuric or sulphurous acids may be applicable toorescontaining oxidizedcopperminerals such as malachite, azurite and chrysocolla but these acids have but little effect on sulphidecopper...