A copper–gold ore with low clay content was crushed to a size
of 2.36 mm before grinding and flotation. The mineral compositions
of this ore analysed by quantitative X-ray Diffraction (XRD)
are shown in Table 1. The major gangue minerals are quartz, albite,
muscovite and clinochlore with minor kaolinite. The elemental
compositions of the ore are shown in Table 2 indicating 0.70% Cu
and 0.47 g/t Au. Diagnostic leaching shows that more than 80%
Cu is associated with primary copper mineral, chalcopyrite and
the rest is associated with secondary copper minerals and oxides.
Mineralogy analysis indicates that 30–40% gold particles are liberated.
This ore was referred to as ‘‘clean ore’’ in this study. Q38 and
bentonite were purchased from Sibelco Group, Australia. Snobrite
was purchased from Unimin Limited, Australia. Quantitative XRD
analysis shows that the Q38 sample contains 85% kaolinite with
4% quartz and 11% muscovite. The bentonite sample contains
63% montmorillonite, 25% albite and 12% quartz. The Snobrite sample
contains 91% kaolinite with 7% quartz and 2% muscovite.