2232 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
In light of continuous research and development efforts
focused on chemical reagent formulations, benchmarking
for alternative suppliers has been initiated to address this
issue. Hence, collectors from several suppliers were selected
for the tests. The initial phase involved conducting the first
round of tests for reagent screening at the chemical compa-
nies’ laboratories, followed by a subsequent round of test-
ing in the LKAB internal laboratory. The primary objective
of the second round was to assess the collectors using the
actual flotation feed, obtained in slurry form from one of
the Kiruna concentrating plants. The slurry was comprised
of process water and conditioned with a depressant.
MATERIAL AND METHODS
Feed Material
Samples used in the validation tests at LKAB were obtained
in slurry form in one of Kiruna’s processing plants after the
depressant conditioning tank. Experiments utilizing the
standard anionic collector were conducted at every stage to
facilitate performance comparisons. A stock solution of 1%
was prepared, and the dosage used for the baseline tests was
10 g/t. In response to challenges and concerns regarding
low %P and excessively low mass pull, a decision was made
to scale up the cell size for several tests from 4 litre to 8 litre.
The objective was to acquire samples of a size adequate
for x-ray fluorescence (XRF) analysis. Chemical composi-
tion of the feed samples used in all tests are presented in
Table 1, and particle size distribution (PSD) curves in
Figure 1. Flotation feed is characterised by a P80 of 45 µm.
Reagents
The reagents employed in the baseline tests mimicked
those utilized in the flotation test work, originating from
the established reverse flotation process of magnetite in
the Kiruna concentrator plant. Gangue depressant and
pH adjustment were achieved using water glass (sodium
silicate). Methyl Isobutyl Carbinol (MIBC) served as the
frother in the apatite flotation. All tests were conducted
using process water.
During the comparative tests, 14 potential alternative
collectors were evaluated, and their names were assigned
randomly as part of a confidentiality agreement. The condi-
tions pertaining to pH, depressant, and frother were main-
tained in alignment with the current process. If the supplier
recommended omitting frother due to the unique chemis-
try of the provided collector, it was excluded accordingly.
Method
All flotation trials for the second campaign were also car-
ried out in Kiruna using the Outotech GTK LabCell. The
fabricant recommended setup was used. Air and rotation
speed were adjusted to maintain the same flotation condi-
tions aiming to keep the air per active cell volume ratio
constant. The procedure is described as follows:
• 8 liters of flotation cell
• 7000 to 8000 grams of magnetite concentrate slurry
at 45–55% solids by weigh, contained 350 g/t of
depressant
• Mixing 8–10 minutes (until full dispersion) before
conditioning
Table 1. Chemical composition (in wt.%) of the feed samples
Chemical
Analysis Sample 1 Sample 2 Sample 3 Sample 4
Fe 71.05 71.17 71.13 71.13
P 0.05 0.04 0.03 0.03
SiO2 0.61 0.54 0.64 0.64
K
2 O 0.04 0.03 0.04 0.04
Al
2 O
3 0.12 0.12 0.14 0.14
CaO 0.28 0.23 0.23 0.23
MgO 0.18 0.19 0.15 0.15
MnO 0.07 0.06 0.07 0.07
TiO
2 0.20 0.17 0.18 0.18
V2O5 0.20 0.22 0.21 0.21
Na2O 0.100 0.100 0.100 0.100
S 0.1000 0.1000 0.1000 0.1000
CaO/SiO
2 0.41 0.40 0.35 0.35
MgO/SiO2 0.30 0.35 0.24 0.24
MgO+SiO2 0.79 0.73 0.79 0.79
P
2 O
5 0.11 0.09 0.06 0.06
In light of continuous research and development efforts
focused on chemical reagent formulations, benchmarking
for alternative suppliers has been initiated to address this
issue. Hence, collectors from several suppliers were selected
for the tests. The initial phase involved conducting the first
round of tests for reagent screening at the chemical compa-
nies’ laboratories, followed by a subsequent round of test-
ing in the LKAB internal laboratory. The primary objective
of the second round was to assess the collectors using the
actual flotation feed, obtained in slurry form from one of
the Kiruna concentrating plants. The slurry was comprised
of process water and conditioned with a depressant.
MATERIAL AND METHODS
Feed Material
Samples used in the validation tests at LKAB were obtained
in slurry form in one of Kiruna’s processing plants after the
depressant conditioning tank. Experiments utilizing the
standard anionic collector were conducted at every stage to
facilitate performance comparisons. A stock solution of 1%
was prepared, and the dosage used for the baseline tests was
10 g/t. In response to challenges and concerns regarding
low %P and excessively low mass pull, a decision was made
to scale up the cell size for several tests from 4 litre to 8 litre.
The objective was to acquire samples of a size adequate
for x-ray fluorescence (XRF) analysis. Chemical composi-
tion of the feed samples used in all tests are presented in
Table 1, and particle size distribution (PSD) curves in
Figure 1. Flotation feed is characterised by a P80 of 45 µm.
Reagents
The reagents employed in the baseline tests mimicked
those utilized in the flotation test work, originating from
the established reverse flotation process of magnetite in
the Kiruna concentrator plant. Gangue depressant and
pH adjustment were achieved using water glass (sodium
silicate). Methyl Isobutyl Carbinol (MIBC) served as the
frother in the apatite flotation. All tests were conducted
using process water.
During the comparative tests, 14 potential alternative
collectors were evaluated, and their names were assigned
randomly as part of a confidentiality agreement. The condi-
tions pertaining to pH, depressant, and frother were main-
tained in alignment with the current process. If the supplier
recommended omitting frother due to the unique chemis-
try of the provided collector, it was excluded accordingly.
Method
All flotation trials for the second campaign were also car-
ried out in Kiruna using the Outotech GTK LabCell. The
fabricant recommended setup was used. Air and rotation
speed were adjusted to maintain the same flotation condi-
tions aiming to keep the air per active cell volume ratio
constant. The procedure is described as follows:
• 8 liters of flotation cell
• 7000 to 8000 grams of magnetite concentrate slurry
at 45–55% solids by weigh, contained 350 g/t of
depressant
• Mixing 8–10 minutes (until full dispersion) before
conditioning
Table 1. Chemical composition (in wt.%) of the feed samples
Chemical
Analysis Sample 1 Sample 2 Sample 3 Sample 4
Fe 71.05 71.17 71.13 71.13
P 0.05 0.04 0.03 0.03
SiO2 0.61 0.54 0.64 0.64
K
2 O 0.04 0.03 0.04 0.04
Al
2 O
3 0.12 0.12 0.14 0.14
CaO 0.28 0.23 0.23 0.23
MgO 0.18 0.19 0.15 0.15
MnO 0.07 0.06 0.07 0.07
TiO
2 0.20 0.17 0.18 0.18
V2O5 0.20 0.22 0.21 0.21
Na2O 0.100 0.100 0.100 0.100
S 0.1000 0.1000 0.1000 0.1000
CaO/SiO
2 0.41 0.40 0.35 0.35
MgO/SiO2 0.30 0.35 0.24 0.24
MgO+SiO2 0.79 0.73 0.79 0.79
P
2 O
5 0.11 0.09 0.06 0.06