2140 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
phases in approximately 50 grams of material. The concen-
trates obtained from the gravity separation were analyzed
using TIMA bright phase analysis. The minerals of inter-
est were identified as native gold, electrum, petzite, hessite/
argentite, goldfieldite, and tetradymite. The major miner-
alogical composition of the CT Mozley concentrates was
found to be 84.75% pyrite, 2.06% hematite/magnetite,
and 1.67% galena.
Table 4 presents the mineralogical distribution of the
Mozley concentrates of CT using TIMA bright-phase
analysis. Table 4 excludes gangue minerals such as silicates,
phosphates, and carbonates.
According to TIMA analysis, Te distribution among
mineral phases in CT showed that Te was 75% in the
tetradymite, 15% in petzite, 9.2% in hessite, and 0.5% in
other minerals like goldfildite. TIMA analysis also showed
that native gold had the highest Au abundance at 69.8%,
followed by 30.2% Au abundance in petzite.
Furthermore, mineral liberation analysis of CT using
TIMA revealed that Te minerals (represented by tetrady-
mite) and Au-Ag minerals were very fine-grained, with all
grains being less than 20 μm. The particle size distribution
(PSD) of tetradymite and Au-Ag minerals were found to be
P80 at 14 μm and 16 μm, respectively. Figure 3 shows the
PSD for tetradymite and Au-Ag minerals as a function of
increasing size (log10-scale) and cumulative passing.
Liberation analysis of CT using TIMA indicated that
tetradymite and Au-Ag minerals were mainly present as
inclusions in pyrite, and their size was less than 20 μm.
As per the data presented in Table 5 and Figure 4, it was
observed that at least 93% of tetradymite and Au-Ag min-
erals were hosted in pyrite, while a minimum of 3% of
them were found as free surface minerals.
It was observed that Te, Au, and Ag minerals were
found mainly in pyrite as inclusions less than 20 μm in size.
Findings from the mineralogy studies indicated that Te min-
erals in CT can be enriched if efficient flotation procedures
were applied to enrich their hosted sulfide minerals (e.g.,
pyrite). Additionally, a significant presence of fine particles
was shown by TIMA. Around 80% of these fine particles
(less than 38 µm) were silicates, primarily quartz (36.2%),
K-feldspar (20.3%), biotite (18%), and albite (4.85%).
Studies have shown that fine silicate particles can have a
detrimental impact on concentration processes, particu-
larly froth flotation, due to the creation of slime coatings,
increased slurry viscosity, and higher reagent consumption
resulting from their large surface area (C. Wang et al. 2014
Molatlhegi and Alagha 2016 Hayat, Alagha, and Sannan
2017 Khodakarami and Alagha 2017 Alsafasfeh et al.
2018 Khodakarami, Alagha, and Burnett 2019 Nykänen
et al. 2020 K.C. Monyake and Alagha 2021 Keitumetse
Cathrine Monyake and Alagha 2022a 2022b K. Monyake
et al. 2023).
Table 3. Elemental analysis of CT samples determined by ICP-MS
Valuable Elements Tailings 1* Tailings 2† Tailings Average‡ Units
Te 0.7 0.2 0.45 ppm
Au 88 59 73.5 ppb
Ag 0.77 0.42 0.6 ppm
Cu 377 452 415 ppm
Mo 24.8 30 27.4 ppm
Pb 34.8 18.7 26.8 ppm
Ni 0.5 39.7 39.7 ppm
Zn 48.3 28.1 38.2 ppm
S 1.81 0.69 1.25 %
As 14.8 5.4 10.1 ppm
Bi 1.3 0.3 0.8 ppm
Co 22.9 15.5 19.2 ppm
Fe 5.01 2.5 3.8 %
Ga 17.9 16.8 17.4 ppm
Ge 0.1 0.1 0.1 ppm
Se 2.3 2 2.2 ppm
*Tailings 1 is a batch sample of June 2021 from the rougher flotation tailings of a CP mine.
† Tailings 2 is a batch sample of May 2022 from the rougher flotation tailings of a CP mine.
‡ Values represent averages of the 2 tailings batches received.
phases in approximately 50 grams of material. The concen-
trates obtained from the gravity separation were analyzed
using TIMA bright phase analysis. The minerals of inter-
est were identified as native gold, electrum, petzite, hessite/
argentite, goldfieldite, and tetradymite. The major miner-
alogical composition of the CT Mozley concentrates was
found to be 84.75% pyrite, 2.06% hematite/magnetite,
and 1.67% galena.
Table 4 presents the mineralogical distribution of the
Mozley concentrates of CT using TIMA bright-phase
analysis. Table 4 excludes gangue minerals such as silicates,
phosphates, and carbonates.
According to TIMA analysis, Te distribution among
mineral phases in CT showed that Te was 75% in the
tetradymite, 15% in petzite, 9.2% in hessite, and 0.5% in
other minerals like goldfildite. TIMA analysis also showed
that native gold had the highest Au abundance at 69.8%,
followed by 30.2% Au abundance in petzite.
Furthermore, mineral liberation analysis of CT using
TIMA revealed that Te minerals (represented by tetrady-
mite) and Au-Ag minerals were very fine-grained, with all
grains being less than 20 μm. The particle size distribution
(PSD) of tetradymite and Au-Ag minerals were found to be
P80 at 14 μm and 16 μm, respectively. Figure 3 shows the
PSD for tetradymite and Au-Ag minerals as a function of
increasing size (log10-scale) and cumulative passing.
Liberation analysis of CT using TIMA indicated that
tetradymite and Au-Ag minerals were mainly present as
inclusions in pyrite, and their size was less than 20 μm.
As per the data presented in Table 5 and Figure 4, it was
observed that at least 93% of tetradymite and Au-Ag min-
erals were hosted in pyrite, while a minimum of 3% of
them were found as free surface minerals.
It was observed that Te, Au, and Ag minerals were
found mainly in pyrite as inclusions less than 20 μm in size.
Findings from the mineralogy studies indicated that Te min-
erals in CT can be enriched if efficient flotation procedures
were applied to enrich their hosted sulfide minerals (e.g.,
pyrite). Additionally, a significant presence of fine particles
was shown by TIMA. Around 80% of these fine particles
(less than 38 µm) were silicates, primarily quartz (36.2%),
K-feldspar (20.3%), biotite (18%), and albite (4.85%).
Studies have shown that fine silicate particles can have a
detrimental impact on concentration processes, particu-
larly froth flotation, due to the creation of slime coatings,
increased slurry viscosity, and higher reagent consumption
resulting from their large surface area (C. Wang et al. 2014
Molatlhegi and Alagha 2016 Hayat, Alagha, and Sannan
2017 Khodakarami and Alagha 2017 Alsafasfeh et al.
2018 Khodakarami, Alagha, and Burnett 2019 Nykänen
et al. 2020 K.C. Monyake and Alagha 2021 Keitumetse
Cathrine Monyake and Alagha 2022a 2022b K. Monyake
et al. 2023).
Table 3. Elemental analysis of CT samples determined by ICP-MS
Valuable Elements Tailings 1* Tailings 2† Tailings Average‡ Units
Te 0.7 0.2 0.45 ppm
Au 88 59 73.5 ppb
Ag 0.77 0.42 0.6 ppm
Cu 377 452 415 ppm
Mo 24.8 30 27.4 ppm
Pb 34.8 18.7 26.8 ppm
Ni 0.5 39.7 39.7 ppm
Zn 48.3 28.1 38.2 ppm
S 1.81 0.69 1.25 %
As 14.8 5.4 10.1 ppm
Bi 1.3 0.3 0.8 ppm
Co 22.9 15.5 19.2 ppm
Fe 5.01 2.5 3.8 %
Ga 17.9 16.8 17.4 ppm
Ge 0.1 0.1 0.1 ppm
Se 2.3 2 2.2 ppm
*Tailings 1 is a batch sample of June 2021 from the rougher flotation tailings of a CP mine.
† Tailings 2 is a batch sample of May 2022 from the rougher flotation tailings of a CP mine.
‡ Values represent averages of the 2 tailings batches received.