3098 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
and they were mainly associated with quartz, orthoclase,
iron oxides, and pyrrhotite. In a few particles, silver (50–
60%) associated with tellurium was also detected.
Flotation
Experimental Design
The flotation work was divided into two phases. The initial
screening tests aimed to select the best performing reagent.
During the second phase, the best performing promoters
were subjected to further optimization of dosage levels.
The initial screening encompassed eight secondary col-
lectors/promoters listed in Table 2. The performance of
each of them was benchmarked against the base case sce-
nario (PAX -Aero-238 ® being the current practice on site).
Figure 4 illustrates the base dosage level (starting point)
for each reagent and their dosage variation margins. These
dosages were selected based on data sheets and producers’
recommendations.
For the second phase of testing, a factorial experimen-
tal design focusing on 2 process variables (dosage of PAX
and promoter) was established. An additional point of high
promoter/low PAX dosage is added to evaluate whether
PAX could be entirely excluded and substituted by a sec-
ondary promoter.
RESULTS AND DISCUSSION
Initial Screening of Reagents
The eight reagents have been compared against the base-
case scenario (PAX-Aero-238) using a currently practiced
flotation protocol. A specific objective is to find which
combination will lead to a gold recovery higher than base
case gold recovery. Figure 5 summarizes the average figures
for gold recovery and concentrate mass yield obtained from
the duplicate tests. The error bars indicate the highest and
lowest points achieved with each reagent.
Review of the results undoubtedly ranks the Hostaflot
promoters (10093, LIB, 7650) as the best performing
ones—higher mass pull and recovery. The DP-OMC-1127
reached a recovery similar to the base-case scenario, however
at a marginally lower dosage level of 20 g/t. Tecflote-S11
and Armoflote-S100 gave the worst performance (Au recov-
ery of 81.2 and 81.7% respectively), a possible explana-
tion being their low solubility, eventually requiring longer
conditioning time. Therefore the four promoters selected
for the second phase study were the three Hostaflot’s and
DP-OMC-1127. It should be noted, that the back-calcu-
lated feed assays for the tests were consistent.
30
60
20 20 20
60 60 60
0
20
40
60
80
100
120
Promoter
Figure 4. Dose levels of tested promoters at initial screening
phase with range variations
Figure 5. Gold recovery—comparative results from initial screening
Dosage
[g/t]
and they were mainly associated with quartz, orthoclase,
iron oxides, and pyrrhotite. In a few particles, silver (50–
60%) associated with tellurium was also detected.
Flotation
Experimental Design
The flotation work was divided into two phases. The initial
screening tests aimed to select the best performing reagent.
During the second phase, the best performing promoters
were subjected to further optimization of dosage levels.
The initial screening encompassed eight secondary col-
lectors/promoters listed in Table 2. The performance of
each of them was benchmarked against the base case sce-
nario (PAX -Aero-238 ® being the current practice on site).
Figure 4 illustrates the base dosage level (starting point)
for each reagent and their dosage variation margins. These
dosages were selected based on data sheets and producers’
recommendations.
For the second phase of testing, a factorial experimen-
tal design focusing on 2 process variables (dosage of PAX
and promoter) was established. An additional point of high
promoter/low PAX dosage is added to evaluate whether
PAX could be entirely excluded and substituted by a sec-
ondary promoter.
RESULTS AND DISCUSSION
Initial Screening of Reagents
The eight reagents have been compared against the base-
case scenario (PAX-Aero-238) using a currently practiced
flotation protocol. A specific objective is to find which
combination will lead to a gold recovery higher than base
case gold recovery. Figure 5 summarizes the average figures
for gold recovery and concentrate mass yield obtained from
the duplicate tests. The error bars indicate the highest and
lowest points achieved with each reagent.
Review of the results undoubtedly ranks the Hostaflot
promoters (10093, LIB, 7650) as the best performing
ones—higher mass pull and recovery. The DP-OMC-1127
reached a recovery similar to the base-case scenario, however
at a marginally lower dosage level of 20 g/t. Tecflote-S11
and Armoflote-S100 gave the worst performance (Au recov-
ery of 81.2 and 81.7% respectively), a possible explana-
tion being their low solubility, eventually requiring longer
conditioning time. Therefore the four promoters selected
for the second phase study were the three Hostaflot’s and
DP-OMC-1127. It should be noted, that the back-calcu-
lated feed assays for the tests were consistent.
30
60
20 20 20
60 60 60
0
20
40
60
80
100
120
Promoter
Figure 4. Dose levels of tested promoters at initial screening
phase with range variations
Figure 5. Gold recovery—comparative results from initial screening
Dosage
[g/t]