at constant collector dosage, the higher the amount of highly or moderately liberated Cu minerals, the lower the attachment time. For example, when flotation pulp was conditioned in the presence of 25 g/t of SIBX, the increased amount of fully liberated Cu minerals in flotation concentrates resulted in decreasing attachment time over 20-fold from 400 ms (36%) to 20 ms (55%). On the other hand, it can be also observed from Fig. 7d, that the relationship between the amount of the poorly liberated Cu minerals and the attachment time is not clear, but this may be dependent on the increased error of measurement for this class. Further repeat tests are recommended to confirm this and evaluate whether a similar relationship to that obtained with the other classes develops or not.