5
determined by TIMA, showed that the largest Au abun-
dance of 69.8% corresponded to native gold, followed by
30.2% Au abundance in petzite.
Mineral liberation analysis of CT using TIMA indi-
cated that Te minerals (using tetradymite as a Te representa-
tive) and Au-Ag minerals were very fine-grained sized, with
100% of the grains less than 20 μm. The PSD of tetrady-
mite and Au-Ag grains showed that P80 was 14 μm and
16 μm, respectively. The PSD for tetradymite and Au-Ag
minerals as a function of increasing size (log10-scale) and
cumulative passing in Figure 2.
Furthermore, liberation analysis of CT using TIMA
indicated that tetradymite and Au-Ag minerals were pri-
marily locked in pyrite, as less than 20 μm inclusions.
Tables 5 and Figure 3 show that pyrite hosted both tetrady-
mite and Au-Ag minerals at least 93%, with at least 3% of
both reporting as free surface minerals.
TIMA of CT suggested that Te, Au, and Ag minerals
were primarily hosted in pyrite as less than 20 μm inclu-
sions. Therefore, this research investigated whether repro-
cessing of CT using a bulk pyrite flotation process could be
a feasible strategy to increase Te recovery from the existing
copper porphyry supply chain [26,31,32].
Bench-Scale Flotation Experiments
The flotation efficiency of Te, Au, and Ag minerals (pre-
sented as Te, Au, and Ag concentrations in concentrate
products) was investigated using EXP300422 and SIPX col-
lectors and OREPREP X237, MIBC, and terpineol froth-
ers. The results from the baseline experiments showed that
the most efficient reagent combination for recovering Te
was 150 g/t SIPX with 50 g/t OREPREP X-237, achieving
a 92.18% recovery at 1.4 ppm. The most efficient reagent
combination for recovering Au was 30 g/t SIPX with 50 g/t
MIBC, achieving a 79.37% recovery at 121 ppb. Lastly, the
most efficient reagent combination for recovering Ag was
150 g/t SIPX with 50 g/t terpineol, achieving a 91.15 %
recovery at 0.99 ppm.
Notably, from the reagent combinations mentioned
before, the reagent combination that achieved the highest
overall efficiency was 150 g/t SIPX with 50 g/t OREPREP
X-237. For this reagent combination, Te, Au, and Ag
recovery were 92.18%, 74.55 and 76.97%, respectively.
Tellurium, Au, and Ag grades were also 1.4 ppm, 160 ppb,
and 1.23 ppm, respectively. Figure 4 summarizes the base-
line test results, highlighting the most efficient collector
and frother combinations for Te, Au, and Ag.
Results showed in Table 6 that the collector and frother
combinations positively impacted the flotation recovery
of Te in the following order: SIPX EXP300422 and
OREPREP terpineol MIBC. Collector and frother
combination positively impacted Au recovery in the follow-
ing order: SIPX EXP 300422 and MIBC OREPREP
X-237 terpineol. Lastly, Ag recovery was positively affected
by the collector frother combination in the following order:
Figure 2. Particle size distribution of tetradymite and Au-Ag
minerals showing P
80 with a straight black line and P
50 or
median as a dashed black line.
Figure 3. False-color SEM-EDS of a 120 μm pyrite (Py) grain
in CT Mozley concentrates. The pyrite grain locked at least 7
inclusions less than 30 μm, of which 5 were galena (Gn), and
the remaining were tetradymite and hessite/argentite
Table 5. Liberation analysis of Te, Ag, and Au minerals in
CT
Mineral
Tetradymite
Locking (wt.%)
Au-Ag mineral
Locking (wt.%)
Pyrite 94.7 93.3
Apatite 0.1 0
Hematite/agnetite 1.5 0.9
Calcite 0.2 0
Free surface 3.3 5.7
determined by TIMA, showed that the largest Au abun-
dance of 69.8% corresponded to native gold, followed by
30.2% Au abundance in petzite.
Mineral liberation analysis of CT using TIMA indi-
cated that Te minerals (using tetradymite as a Te representa-
tive) and Au-Ag minerals were very fine-grained sized, with
100% of the grains less than 20 μm. The PSD of tetrady-
mite and Au-Ag grains showed that P80 was 14 μm and
16 μm, respectively. The PSD for tetradymite and Au-Ag
minerals as a function of increasing size (log10-scale) and
cumulative passing in Figure 2.
Furthermore, liberation analysis of CT using TIMA
indicated that tetradymite and Au-Ag minerals were pri-
marily locked in pyrite, as less than 20 μm inclusions.
Tables 5 and Figure 3 show that pyrite hosted both tetrady-
mite and Au-Ag minerals at least 93%, with at least 3% of
both reporting as free surface minerals.
TIMA of CT suggested that Te, Au, and Ag minerals
were primarily hosted in pyrite as less than 20 μm inclu-
sions. Therefore, this research investigated whether repro-
cessing of CT using a bulk pyrite flotation process could be
a feasible strategy to increase Te recovery from the existing
copper porphyry supply chain [26,31,32].
Bench-Scale Flotation Experiments
The flotation efficiency of Te, Au, and Ag minerals (pre-
sented as Te, Au, and Ag concentrations in concentrate
products) was investigated using EXP300422 and SIPX col-
lectors and OREPREP X237, MIBC, and terpineol froth-
ers. The results from the baseline experiments showed that
the most efficient reagent combination for recovering Te
was 150 g/t SIPX with 50 g/t OREPREP X-237, achieving
a 92.18% recovery at 1.4 ppm. The most efficient reagent
combination for recovering Au was 30 g/t SIPX with 50 g/t
MIBC, achieving a 79.37% recovery at 121 ppb. Lastly, the
most efficient reagent combination for recovering Ag was
150 g/t SIPX with 50 g/t terpineol, achieving a 91.15 %
recovery at 0.99 ppm.
Notably, from the reagent combinations mentioned
before, the reagent combination that achieved the highest
overall efficiency was 150 g/t SIPX with 50 g/t OREPREP
X-237. For this reagent combination, Te, Au, and Ag
recovery were 92.18%, 74.55 and 76.97%, respectively.
Tellurium, Au, and Ag grades were also 1.4 ppm, 160 ppb,
and 1.23 ppm, respectively. Figure 4 summarizes the base-
line test results, highlighting the most efficient collector
and frother combinations for Te, Au, and Ag.
Results showed in Table 6 that the collector and frother
combinations positively impacted the flotation recovery
of Te in the following order: SIPX EXP300422 and
OREPREP terpineol MIBC. Collector and frother
combination positively impacted Au recovery in the follow-
ing order: SIPX EXP 300422 and MIBC OREPREP
X-237 terpineol. Lastly, Ag recovery was positively affected
by the collector frother combination in the following order:
Figure 2. Particle size distribution of tetradymite and Au-Ag
minerals showing P
80 with a straight black line and P
50 or
median as a dashed black line.
Figure 3. False-color SEM-EDS of a 120 μm pyrite (Py) grain
in CT Mozley concentrates. The pyrite grain locked at least 7
inclusions less than 30 μm, of which 5 were galena (Gn), and
the remaining were tetradymite and hessite/argentite
Table 5. Liberation analysis of Te, Ag, and Au minerals in
CT
Mineral
Tetradymite
Locking (wt.%)
Au-Ag mineral
Locking (wt.%)
Pyrite 94.7 93.3
Apatite 0.1 0
Hematite/agnetite 1.5 0.9
Calcite 0.2 0
Free surface 3.3 5.7