1382 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
Bulk and TCM Mineralogy
The mineralogical findings presented in this paper are based
on feed composite samples and processed products from
flotation and gold leaching circuits. The bulk mineralogy
of the rougher feed and tailings samples for the copper-gold
ore was similar, mainly composed of quartz, plagioclase and
mica with minor amounts of iron-oxides and a minor to
trace amounts of Cu-sulphide phases. Cleaner tails were
mainly composed of pyrite, mica and quartz while the final
concentrate was dominantly composed of chalcopyrite
with minor amounts of other copper-sulphides and pyrite
(Plate 1). The bulk mineralogy of three CIL leach stream
samples of double refractory ore was similar, mainly com-
posed of quartz with moderate amounts of dolomite, mica
and clay (kaolinite). Minor to trace amounts of pyrite/arse-
nian pyrite, sulphate, TCM (total carbonaceous matters),
calcite, iron-oxides, were noted (Plates 2 and 3). In case of
triple refractory ores, the bulk mineralogy of all these four
samples was similar, mainly composed of quartz, mica and
other silicates with minor to moderate amount of calcite
and minor to traces of arsenopyrite and realgar (Plate 4).
High pyrite, around 11%, in the pyrite scavenger rougher
concentrate and high arsenopyrite (3%) and realgar (5%)
in the TCM rougher concentrate was noted. The quantita-
tive mineral analysis data is presented in Tables 3a to 3c.
Visible Gold Mineralogy
A gold scan was carried out by optical microscopy and
MLA for different polished sections prepared from all these
samples after pre-concentration.
A number of gold grains were noted in the copper-gold
refractory ore and in the triple refractory ore. Morphology
of gold grains in both ores were similar, mostly occurred as
fine grained (average grain 3µm to 4µm) native gold (76 to
100% Au). In the copper-gold refractory ore, gold grains
were mostly liberated (60%) while the majority of gold
grains occurred as inclusions within arsenopyrite/pyrite in
triple refractory ore. No visible gold grains were noted in
the double refractory ore.
A number of gold grains were noted in flotation stream
samples from the Cu-Au refractory ore and triple refrac-
tory ore samples. Gold grains in the flotation stream sam-
ples from the copper-gold refractory ore were fine grained
(average grain size 2µm –7µm) gold grains, mostly liberated
(90%) in the concentrate and mostly locked (95%–100%)
in the tailings (Plate 5). Gold grains in the flotation stream
samples from the triple refractory ore occurred as fine
Table 2c. Whole rock analysis data (weight %)for process stream samples from a double refractory ore
Sample ID SiO
2 Ai
2 O
3 Fe
2 O
3 CaO MgO Na
2 O K
2 O P
2 O
5 MnO Cr
2 O
3 TiO
2 V
2 O
5 LOI
POX/CIL Residue 59.4 4.2 2 10.6 6.2 0.02 0.63 0.15 0.03 0.02 0.22 0.03 15.4
CIL Residue 55.8 6.1 2.6 11.3 5.6 0.07 0.7 0.17 0.04 0.01 0.26 0.04 16.1
Table 2d. Au, Cu, S, As &C-analysis data for process stream samples from a double refractory ore
Sample ID
Au Cu S–2 C (org) CO3 C (graphitic) As
g/t %
POX/CIL Residue 3.36 37 0.07 0.89 10.3 0.2 0.06
CIL Residue 1.9 29 0.09 0.23 9.6 0.3 0.05
Table 2e. Whole rock analysis data (weight %)for process stream samples from a triple refractory ore
Sample ID SiO2 Ai2O3 Fe2O3 MgO CaO Na2O K2O TiO2 P2O5 MnO Cr2O3 V2O5 LOI
Py Scav Ro Conc 55.7 13.5 8.92 1.54 4.73 0.12 2.41 0.65 0.22 0.02 0.03 0.02 9.88
TCM Ro Conc 46.1 13.6 4.62 2.36 4.55 0.02 2.36 0.92 0.41 0.02 0.03 0.02 22.1
Rougher Tail 56.5 11.1 3.08 1.88 12.1 0.27 2.1 0.64 0.18 0.05 0.03 0.02 11.4
Table 2f. Au, Cu, S, As &C-analysis data for process stream samples from a triple refractory ore
Sample ID
Au Cu S–2 C (org) CO
3 C (graphitic) As
g/t %
Pyrite Scav Ro Conc 34.4 153 5.04 0.48 4.5 0.08 0.72
TCM Rougher Conc 35.2 96 3.28 2.41 4.4 0.13 8.91
Rougher Tail 2.84 77 0.08 0.24 11.3 0.06 0.07
Bulk and TCM Mineralogy
The mineralogical findings presented in this paper are based
on feed composite samples and processed products from
flotation and gold leaching circuits. The bulk mineralogy
of the rougher feed and tailings samples for the copper-gold
ore was similar, mainly composed of quartz, plagioclase and
mica with minor amounts of iron-oxides and a minor to
trace amounts of Cu-sulphide phases. Cleaner tails were
mainly composed of pyrite, mica and quartz while the final
concentrate was dominantly composed of chalcopyrite
with minor amounts of other copper-sulphides and pyrite
(Plate 1). The bulk mineralogy of three CIL leach stream
samples of double refractory ore was similar, mainly com-
posed of quartz with moderate amounts of dolomite, mica
and clay (kaolinite). Minor to trace amounts of pyrite/arse-
nian pyrite, sulphate, TCM (total carbonaceous matters),
calcite, iron-oxides, were noted (Plates 2 and 3). In case of
triple refractory ores, the bulk mineralogy of all these four
samples was similar, mainly composed of quartz, mica and
other silicates with minor to moderate amount of calcite
and minor to traces of arsenopyrite and realgar (Plate 4).
High pyrite, around 11%, in the pyrite scavenger rougher
concentrate and high arsenopyrite (3%) and realgar (5%)
in the TCM rougher concentrate was noted. The quantita-
tive mineral analysis data is presented in Tables 3a to 3c.
Visible Gold Mineralogy
A gold scan was carried out by optical microscopy and
MLA for different polished sections prepared from all these
samples after pre-concentration.
A number of gold grains were noted in the copper-gold
refractory ore and in the triple refractory ore. Morphology
of gold grains in both ores were similar, mostly occurred as
fine grained (average grain 3µm to 4µm) native gold (76 to
100% Au). In the copper-gold refractory ore, gold grains
were mostly liberated (60%) while the majority of gold
grains occurred as inclusions within arsenopyrite/pyrite in
triple refractory ore. No visible gold grains were noted in
the double refractory ore.
A number of gold grains were noted in flotation stream
samples from the Cu-Au refractory ore and triple refrac-
tory ore samples. Gold grains in the flotation stream sam-
ples from the copper-gold refractory ore were fine grained
(average grain size 2µm –7µm) gold grains, mostly liberated
(90%) in the concentrate and mostly locked (95%–100%)
in the tailings (Plate 5). Gold grains in the flotation stream
samples from the triple refractory ore occurred as fine
Table 2c. Whole rock analysis data (weight %)for process stream samples from a double refractory ore
Sample ID SiO
2 Ai
2 O
3 Fe
2 O
3 CaO MgO Na
2 O K
2 O P
2 O
5 MnO Cr
2 O
3 TiO
2 V
2 O
5 LOI
POX/CIL Residue 59.4 4.2 2 10.6 6.2 0.02 0.63 0.15 0.03 0.02 0.22 0.03 15.4
CIL Residue 55.8 6.1 2.6 11.3 5.6 0.07 0.7 0.17 0.04 0.01 0.26 0.04 16.1
Table 2d. Au, Cu, S, As &C-analysis data for process stream samples from a double refractory ore
Sample ID
Au Cu S–2 C (org) CO3 C (graphitic) As
g/t %
POX/CIL Residue 3.36 37 0.07 0.89 10.3 0.2 0.06
CIL Residue 1.9 29 0.09 0.23 9.6 0.3 0.05
Table 2e. Whole rock analysis data (weight %)for process stream samples from a triple refractory ore
Sample ID SiO2 Ai2O3 Fe2O3 MgO CaO Na2O K2O TiO2 P2O5 MnO Cr2O3 V2O5 LOI
Py Scav Ro Conc 55.7 13.5 8.92 1.54 4.73 0.12 2.41 0.65 0.22 0.02 0.03 0.02 9.88
TCM Ro Conc 46.1 13.6 4.62 2.36 4.55 0.02 2.36 0.92 0.41 0.02 0.03 0.02 22.1
Rougher Tail 56.5 11.1 3.08 1.88 12.1 0.27 2.1 0.64 0.18 0.05 0.03 0.02 11.4
Table 2f. Au, Cu, S, As &C-analysis data for process stream samples from a triple refractory ore
Sample ID
Au Cu S–2 C (org) CO
3 C (graphitic) As
g/t %
Pyrite Scav Ro Conc 34.4 153 5.04 0.48 4.5 0.08 0.72
TCM Rougher Conc 35.2 96 3.28 2.41 4.4 0.13 8.91
Rougher Tail 2.84 77 0.08 0.24 11.3 0.06 0.07