A crude display of how oxide content (copper) affects the overall recovery of any given ores.  Below are flotation recovery responses of 5 different ores from North and South America. In all cases, the recovery VS %Oxide relationship is obvious.

Samples vary from 0.4% to 1.6% total copper.  The heavy oxide chart (4th one down) being the 1.6% Copper.

Notice the fairly content, 1 to 1 slope (0.89, 0.89, 0.88, 0.94 and 1.04 approximated) relationship between %Oxide and Recovery.

This translates into the fact that most of the copper oxide in the feed sample is not recovered directly be other means than luck, locking or entrainment.

Without trying, a sulfide flotation system might recovery up to 20% of the oxide copper present.