XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 1381
Various concentrates and tailings samples from flota-
tion circuits were investigated along with feed and discharge
samples from pressure oxidation circuits and carbon-in-
leach (CIL) residues from gold processing circuits.
Key objectives of this investigation were to identify and
quantify visible and invisible gold along with better under-
standing of the morphology and liberation of gold associ-
ated with various sulphides, iron-oxides and non-sulphide
gangue species. In addition, the aim of this study was also
to leverage the mineralogical and gold deportment infor-
mation to allow metallurgy diagnostics for optimization of
process performance.
METHODOLOGY
The methodology for an integrated gold deportment tech-
nique has been presented elsewhere (Chattopadhyay &
Gorain, 2014). A snap shot of the various steps involved is
shown in Figure 1. The key to this methodology is a detailed
and rigorous mass balance of precious metals in every step
of the sample preparation, pre-concentration and various
mineral analytical techniques to provide a high confidence
quantified deportment in various mineral species.
RESULTS AND DISCUSSION
This section presents and discusses results for the composi-
tion, quantitative mineralogy and gold deportment for three
different ore types and various process streams samples.
Three Different Ore Types
Tables 1a and 1b show the composition of various ore types
used in this study. Compositionally, these three ores are
mainly composed of calcium aluminium silicates (quartz,
feldspar and mica). Moderate amounts of carbonates (dolo-
mite and calcite) and minor amounts of carbonaceous mat-
ters (organic carbon) were noted in the double and triple
refractory ores. High arsenic was noted in the triple refrac-
tory ore. Compositions of various process streams presented
in this study are shown in Tables 2a to 2f. Graphitic C was
identified from optical microscope.
Table 1a. Whole rock analysis data (weight %)for three different ore types used in this study
Sample ID SiO2 AI2O3 Fe2O3 CaO MgO Na2O K2O P2O5 MnO Cr2O3 TiO2 V2O5 LOI
Copper-gold ore 55.6 5.1 2.9 10.7 5.2 0.01 1.1 0.16 0.04 0.02 0.3 0.03 15.5
Double refractory ore 57.5 5.9 2.6 9.5 5 0.06 0.75 0.21 0.04 0.02 0.29 0.05 15
Triple refractory ore 55.4 12.5 5.6 8.4 1.8 0.17 2.3 0.2 0.04 0.04 0.66 0.02 8.1
Table 1b. Gold, copper, sulphur, arsenic and carbon analysis data from these three ore types
Sample ID
Au Ag Cu S–2 C (Org) CO
3 C (graphitic) As
g/t %
Copper-gold ore 0.23 136 0.51% 1.72 — 0.12 — 30g/t
Double refractory ore 8.34 10 35 1.08 1.5 12.5 0.2 0.05
Triple refractory ore 18.5 15 35 2.25 0.45 8.15 0.13 0.92
Table 2a. Whole rock analysis data (weight %)for process stream samples from a copper-gold-ore
Sample ID SiO
2 Al
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
Rougher Tails 61.9 13.1 3.6 4.5 2.1 2.1 2.9 0.21 0.02 0.02 0.46 0.02
Cleaner Tails 42.5 13.8 16.3 3.6 2.2 1.4 3.2 0.22 0.02 0.09 0.48 0.02
Final Conc 1.5 0.6 43.3 0.05 0.17 0.04 0.12 0.04 0.008 0.01 0.1 0.02
Table 2b. Gold, Cu, S, As and C-analysis data for process stream samples from a copper-gold-ore
Sample ID
Au Ag Cu S–2 C (Org) CO
3 C (graphitic) As
g/t %
Rougher tails 0.04 8 0.02 0.32 — 0.15 — 30g/t
Cleaner tails 0.39 29 0.19 10.3 — 0.1 — 30g/t
Final Conc 7.11 330 33.2 30.8 — 0.1 — 440g/t
Various concentrates and tailings samples from flota-
tion circuits were investigated along with feed and discharge
samples from pressure oxidation circuits and carbon-in-
leach (CIL) residues from gold processing circuits.
Key objectives of this investigation were to identify and
quantify visible and invisible gold along with better under-
standing of the morphology and liberation of gold associ-
ated with various sulphides, iron-oxides and non-sulphide
gangue species. In addition, the aim of this study was also
to leverage the mineralogical and gold deportment infor-
mation to allow metallurgy diagnostics for optimization of
process performance.
METHODOLOGY
The methodology for an integrated gold deportment tech-
nique has been presented elsewhere (Chattopadhyay &
Gorain, 2014). A snap shot of the various steps involved is
shown in Figure 1. The key to this methodology is a detailed
and rigorous mass balance of precious metals in every step
of the sample preparation, pre-concentration and various
mineral analytical techniques to provide a high confidence
quantified deportment in various mineral species.
RESULTS AND DISCUSSION
This section presents and discusses results for the composi-
tion, quantitative mineralogy and gold deportment for three
different ore types and various process streams samples.
Three Different Ore Types
Tables 1a and 1b show the composition of various ore types
used in this study. Compositionally, these three ores are
mainly composed of calcium aluminium silicates (quartz,
feldspar and mica). Moderate amounts of carbonates (dolo-
mite and calcite) and minor amounts of carbonaceous mat-
ters (organic carbon) were noted in the double and triple
refractory ores. High arsenic was noted in the triple refrac-
tory ore. Compositions of various process streams presented
in this study are shown in Tables 2a to 2f. Graphitic C was
identified from optical microscope.
Table 1a. Whole rock analysis data (weight %)for three different ore types used in this study
Sample ID SiO2 AI2O3 Fe2O3 CaO MgO Na2O K2O P2O5 MnO Cr2O3 TiO2 V2O5 LOI
Copper-gold ore 55.6 5.1 2.9 10.7 5.2 0.01 1.1 0.16 0.04 0.02 0.3 0.03 15.5
Double refractory ore 57.5 5.9 2.6 9.5 5 0.06 0.75 0.21 0.04 0.02 0.29 0.05 15
Triple refractory ore 55.4 12.5 5.6 8.4 1.8 0.17 2.3 0.2 0.04 0.04 0.66 0.02 8.1
Table 1b. Gold, copper, sulphur, arsenic and carbon analysis data from these three ore types
Sample ID
Au Ag Cu S–2 C (Org) CO
3 C (graphitic) As
g/t %
Copper-gold ore 0.23 136 0.51% 1.72 — 0.12 — 30g/t
Double refractory ore 8.34 10 35 1.08 1.5 12.5 0.2 0.05
Triple refractory ore 18.5 15 35 2.25 0.45 8.15 0.13 0.92
Table 2a. Whole rock analysis data (weight %)for process stream samples from a copper-gold-ore
Sample ID SiO
2 Al
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
Rougher Tails 61.9 13.1 3.6 4.5 2.1 2.1 2.9 0.21 0.02 0.02 0.46 0.02
Cleaner Tails 42.5 13.8 16.3 3.6 2.2 1.4 3.2 0.22 0.02 0.09 0.48 0.02
Final Conc 1.5 0.6 43.3 0.05 0.17 0.04 0.12 0.04 0.008 0.01 0.1 0.02
Table 2b. Gold, Cu, S, As and C-analysis data for process stream samples from a copper-gold-ore
Sample ID
Au Ag Cu S–2 C (Org) CO
3 C (graphitic) As
g/t %
Rougher tails 0.04 8 0.02 0.32 — 0.15 — 30g/t
Cleaner tails 0.39 29 0.19 10.3 — 0.1 — 30g/t
Final Conc 7.11 330 33.2 30.8 — 0.1 — 440g/t