908 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
with greenish-black streaks. The EDS scan was consistently
reading about 32% Fe, 34% Cu, and 32% S which matches
extremely well with the true elemental composition. The
other two gangue minerals can be seen to be amorphous
rather than crystalline. It is not certain what the minerals
are since there were little to no S content, they are unlikely
to be sulfide. Although not shown here, the most abundant
gangue mineral is quartz which is transparent/translucent
and easily recognisable. However, it is important to note
that all these minerals do not look alike in the microscopy
image and can be easily distinguished from each other.
Table 3 shows several examples of the same analysis
conducted on locked minerals instead.
In these examples, the Chalcopyrite regions can be eas-
ily distinguished from other minerals as they exhibited the
characteristic green-ish black colour. Similarly, Sphalerite
is not as shiny as the other sulfides and exhibits a dark
purple to red colour. Pyrite can also be distinguished from
Table 2. Comparison of fully liberated mineral appearances under SEM, MinDet, and EDS (continued)
SEM Image MinDet Image
EDS Scan Normalised Mass (%)
Mineral O S Cu Fe Zn Pb Others
33.0 34.1 32.9
Chalcopyrite 2.6 32.7 32.2 32.5
32.3 36.2 31.5
43.8 16.6 1.1 38.5 Gangue
(non-sulfide)
40.8 1.3 49.4 8.5 Gangue
(iron oxide bearing)
with greenish-black streaks. The EDS scan was consistently
reading about 32% Fe, 34% Cu, and 32% S which matches
extremely well with the true elemental composition. The
other two gangue minerals can be seen to be amorphous
rather than crystalline. It is not certain what the minerals
are since there were little to no S content, they are unlikely
to be sulfide. Although not shown here, the most abundant
gangue mineral is quartz which is transparent/translucent
and easily recognisable. However, it is important to note
that all these minerals do not look alike in the microscopy
image and can be easily distinguished from each other.
Table 3 shows several examples of the same analysis
conducted on locked minerals instead.
In these examples, the Chalcopyrite regions can be eas-
ily distinguished from other minerals as they exhibited the
characteristic green-ish black colour. Similarly, Sphalerite
is not as shiny as the other sulfides and exhibits a dark
purple to red colour. Pyrite can also be distinguished from
Table 2. Comparison of fully liberated mineral appearances under SEM, MinDet, and EDS (continued)
SEM Image MinDet Image
EDS Scan Normalised Mass (%)
Mineral O S Cu Fe Zn Pb Others
33.0 34.1 32.9
Chalcopyrite 2.6 32.7 32.2 32.5
32.3 36.2 31.5
43.8 16.6 1.1 38.5 Gangue
(non-sulfide)
40.8 1.3 49.4 8.5 Gangue
(iron oxide bearing)