Current Developments in the Hydrometallurgical Treatment of ...
Current Developments in the Hydrometallurgical Treatment of ...
Current Developments in the Hydrometallurgical Treatment of ...
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<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and ConcentratesGALVANOX CHEMISTRY‣ Typically, chalcopyrite surfaces are passivated (i.e., <strong>the</strong>ybecome resistant to electrochemical breakdown) <strong>in</strong> ferric sulfatesolutions at even modest solution potential levels.‣ It is widely held that this results from <strong>the</strong> formation <strong>of</strong> some sort<strong>of</strong> passivat<strong>in</strong>g film on <strong>the</strong> m<strong>in</strong>eral surface that most likelyconsists <strong>of</strong> an altered, partially Fe-depleted sulfide layer.‣ Because <strong>of</strong> this, most <strong>in</strong>vestigators have assumed that it is <strong>the</strong>anodic half-cell reaction that limits <strong>the</strong> overall rate <strong>of</strong> leach<strong>in</strong>g.‣ However, we discovered that it is primarily <strong>the</strong> cathodic half-cellreaction (i.e., ferric reduction) that is slow on <strong>the</strong> chalcopyritesurface.