3066 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
Table 1 delineates process flows, indicating automated
and manual sampling requirements. Additional samples
collected during the campaign were also subject to mineral
characterization in this study.
Table 1. Flotation streams and sampler information
No Flotation Products
Manual
Sampler
Onstream XRF
Autosampler
1 Cyclone overflow x
2 Total feed x
3 Rougher concentrate x
4 Rougher tail No Sampling
5 Scavenger conc return x
6 Final tail x
7 Cleaner tail return x
8 Final concentrate x
Note: “x” indicates the sampling method used for each flotation
stream
Characterization
The flotation streams from the plant underwent preparation
at Boliden’s process laboratory. Half of each sample was set
aside for mineralogical characterization, categorized into
different size ranges. Polished resin mounts with a diam-
eter of 30 mm were created for size fractions of –20 μm,
+20 and –45 μm, and +45 μm. Prior to QEMSCAN ®
(Quantitative Evaluation of Minerals by Scanning Electron
Microscope) analysis, a carbon sputter coating was applied.
These samples were utilized for optical microscopy and
examined using QEMSCAN ® 650 analysis FEI with W fila-
ment, 2 EDS. Quantitative modal analyses were conducted
at Boliden’s laboratory, employing the QEMSCAN ® 650
automated mineralogy system.
RESULTS
This section summarizes the primary findings from the ini-
tial laboratory and plant tests at the Boliden Area concen-
trator for the evaluated collectors. The correlation between
tellurium and gold is demonstrated through results from
the chemical laboratory and online analyzer. It also includes
the mineral characterization results based on samples col-
lected during the plant test period.
Laboratory Flotation Test
Tests 1 and 2 demonstrate an increase in tellurium recovery
for the concentrate ranging from 4% to 15% with the com-
plete replacement of the xanthate collector with Aerophine.
Additionally, a higher enrichment is observed, showing
an enhancement of 3× to 4× in relation to the tellurium
content for the final concentrate, Figure 5. Therefore,
for ores of different intervals, the substitution of xan-
thate with a more selective collector was beneficial for the
Åkulla Kankberg ore treatment, enhancing both recovery
and selectivity, with an anticipated improvement in gold
and silver results. The increased selectivity for these tests is
depicted in Figure 6, where sulphur recovery is significantly
reduced with Aerophine. As a result, the mass in the final
concentrate is reduced by 60% to 70% with greater selec-
tivity (Table 2).
Results at lower pH align with previously obtained
results in terms of tellurium recovery in the rougher
stage but show a higher enrichment ratio with the use of
Aerophine, as seen in Figure 7. Additionally, favorable
Figure 4. Plant flotation scheme
Table 1 delineates process flows, indicating automated
and manual sampling requirements. Additional samples
collected during the campaign were also subject to mineral
characterization in this study.
Table 1. Flotation streams and sampler information
No Flotation Products
Manual
Sampler
Onstream XRF
Autosampler
1 Cyclone overflow x
2 Total feed x
3 Rougher concentrate x
4 Rougher tail No Sampling
5 Scavenger conc return x
6 Final tail x
7 Cleaner tail return x
8 Final concentrate x
Note: “x” indicates the sampling method used for each flotation
stream
Characterization
The flotation streams from the plant underwent preparation
at Boliden’s process laboratory. Half of each sample was set
aside for mineralogical characterization, categorized into
different size ranges. Polished resin mounts with a diam-
eter of 30 mm were created for size fractions of –20 μm,
+20 and –45 μm, and +45 μm. Prior to QEMSCAN ®
(Quantitative Evaluation of Minerals by Scanning Electron
Microscope) analysis, a carbon sputter coating was applied.
These samples were utilized for optical microscopy and
examined using QEMSCAN ® 650 analysis FEI with W fila-
ment, 2 EDS. Quantitative modal analyses were conducted
at Boliden’s laboratory, employing the QEMSCAN ® 650
automated mineralogy system.
RESULTS
This section summarizes the primary findings from the ini-
tial laboratory and plant tests at the Boliden Area concen-
trator for the evaluated collectors. The correlation between
tellurium and gold is demonstrated through results from
the chemical laboratory and online analyzer. It also includes
the mineral characterization results based on samples col-
lected during the plant test period.
Laboratory Flotation Test
Tests 1 and 2 demonstrate an increase in tellurium recovery
for the concentrate ranging from 4% to 15% with the com-
plete replacement of the xanthate collector with Aerophine.
Additionally, a higher enrichment is observed, showing
an enhancement of 3× to 4× in relation to the tellurium
content for the final concentrate, Figure 5. Therefore,
for ores of different intervals, the substitution of xan-
thate with a more selective collector was beneficial for the
Åkulla Kankberg ore treatment, enhancing both recovery
and selectivity, with an anticipated improvement in gold
and silver results. The increased selectivity for these tests is
depicted in Figure 6, where sulphur recovery is significantly
reduced with Aerophine. As a result, the mass in the final
concentrate is reduced by 60% to 70% with greater selec-
tivity (Table 2).
Results at lower pH align with previously obtained
results in terms of tellurium recovery in the rougher
stage but show a higher enrichment ratio with the use of
Aerophine, as seen in Figure 7. Additionally, favorable
Figure 4. Plant flotation scheme