XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 2233
• Conditioning with collector for 5 min (or the recom-
mended by the owner company) at recommended
dosage (targeting baseline collector dosage)
• Conditioning with MIBC (5 g/t) or frother/pro-
moter recommended by the owner company for
3–5 min
• Scrubbing with 2 second cycles. with the flotation
cell rotor (60 mm) at 1200 rpm
• When doing kinetics tests, samples of overflow
are taken under fixed time intervals, which can be
adjusted due to observation of mass pull
• Overflow products are collected and dried at 100 °C
• The bottom product is dewatered by filtration and
dried at 100 °C
RESULTS AND ANALYSES
The results of screening tests led to a list of collectors from
all companies, to be tested at LKAB laboratory in Kiruna,
with fresh flotation feed. The purpose was to test the col-
lectors under true process water conditions, to minimize
experimental variance.
During the tests, certain collectors were subjected to
dilution due to their enhanced solubility. Conversely, oth-
ers required saponification, as for by the standard anionic
collector utilized in the process. Process data has shown
that during the sampling for the tests, the addition of water
glass in the pulp has remained constant, at 350 g/t.
It is important to highlight the distinction between
nominal dosage and real dosage, which necessitates adjust-
ment based on the accurate %solids by weight, recalcu-
lated after obtaining the correct dry mass of the material.
Nominal dosage is determined using the estimated %solids
in the sample. However, upon receiving the dry mass results
from the analysis. the actual solids percentage in the sam-
ple often varies. When the variation in solids %by mass is
notably significant, it may result in either under or overdos-
ing of the pulp. Despite observing discrepancies between
estimated and real percent solids in the samples, these varia-
tions were not deemed substantial enough to impact the
results or require a recalculation of the reagent dosage. All
the collectors used in this test trial have REACH, meaning
that they are regulated to be used in Europe, thus could be
used in the current process.
The best results from all potential collectors were com-
pared, and can be seen in Figure 2, Figure 3 and Figure 4.
When considering tests with similar concentrations
than standard (10 g/t), collector 1708 (T1) had better per-
formance with highest P cumulative recovery (24%) and
faster kinetics compared to the other collectors tested. It is
recommended further tests to confirm the reproducibility
of this result. The suggestion is to use a slightly longer flota-
tion time (8 minutes to 10 minutes, instead of 3 minutes).
A longer flotation time is also recommended for 1709 tests
presented in Figure 2. The same observation can be made
for 0755 collector when using both 0845 and 0070 as
frother. For those, kinetics should also be evaluated. It is
not possible, from the tests in which only one tailing (OF)
was taken after 5 minutes, to see if recovery could still occur
with longer flotation time. However, after 5 min flotation,
0755 collectors had slower recovery over time than others.
Collectors 0214, 8912 and 8915 show improved perfor-
mance when considering 10 minutes flotation time and
using one of the samples. When a second sample was used,
0
20
40
60
80
100
120
0 1 10 100 1,000
Size (μm)
Figure 1. Particle size distribution for the feed samples
Cummulag415ve
passing
(%)
• Conditioning with collector for 5 min (or the recom-
mended by the owner company) at recommended
dosage (targeting baseline collector dosage)
• Conditioning with MIBC (5 g/t) or frother/pro-
moter recommended by the owner company for
3–5 min
• Scrubbing with 2 second cycles. with the flotation
cell rotor (60 mm) at 1200 rpm
• When doing kinetics tests, samples of overflow
are taken under fixed time intervals, which can be
adjusted due to observation of mass pull
• Overflow products are collected and dried at 100 °C
• The bottom product is dewatered by filtration and
dried at 100 °C
RESULTS AND ANALYSES
The results of screening tests led to a list of collectors from
all companies, to be tested at LKAB laboratory in Kiruna,
with fresh flotation feed. The purpose was to test the col-
lectors under true process water conditions, to minimize
experimental variance.
During the tests, certain collectors were subjected to
dilution due to their enhanced solubility. Conversely, oth-
ers required saponification, as for by the standard anionic
collector utilized in the process. Process data has shown
that during the sampling for the tests, the addition of water
glass in the pulp has remained constant, at 350 g/t.
It is important to highlight the distinction between
nominal dosage and real dosage, which necessitates adjust-
ment based on the accurate %solids by weight, recalcu-
lated after obtaining the correct dry mass of the material.
Nominal dosage is determined using the estimated %solids
in the sample. However, upon receiving the dry mass results
from the analysis. the actual solids percentage in the sam-
ple often varies. When the variation in solids %by mass is
notably significant, it may result in either under or overdos-
ing of the pulp. Despite observing discrepancies between
estimated and real percent solids in the samples, these varia-
tions were not deemed substantial enough to impact the
results or require a recalculation of the reagent dosage. All
the collectors used in this test trial have REACH, meaning
that they are regulated to be used in Europe, thus could be
used in the current process.
The best results from all potential collectors were com-
pared, and can be seen in Figure 2, Figure 3 and Figure 4.
When considering tests with similar concentrations
than standard (10 g/t), collector 1708 (T1) had better per-
formance with highest P cumulative recovery (24%) and
faster kinetics compared to the other collectors tested. It is
recommended further tests to confirm the reproducibility
of this result. The suggestion is to use a slightly longer flota-
tion time (8 minutes to 10 minutes, instead of 3 minutes).
A longer flotation time is also recommended for 1709 tests
presented in Figure 2. The same observation can be made
for 0755 collector when using both 0845 and 0070 as
frother. For those, kinetics should also be evaluated. It is
not possible, from the tests in which only one tailing (OF)
was taken after 5 minutes, to see if recovery could still occur
with longer flotation time. However, after 5 min flotation,
0755 collectors had slower recovery over time than others.
Collectors 0214, 8912 and 8915 show improved perfor-
mance when considering 10 minutes flotation time and
using one of the samples. When a second sample was used,
0
20
40
60
80
100
120
0 1 10 100 1,000
Size (μm)
Figure 1. Particle size distribution for the feed samples
Cummulag415ve
passing
(%)