XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 3487
essential. The development of new, more selective reagents
for ultrafine iron ore has been the subject of recent studies.
Research by (Silva et al., 2022, 2021) demonstrates that
amidoamine is a more selective collector than etheramine
in the flotation of ultrafine iron ore tailings without requir-
ing the use of a depressant. This advancement holds prom-
ise for improving the efficiency of iron ore processing and
resource utilization.
However, in the context of beneficiating hydrated
ores, additional tools are necessary to maximize metallur-
gical recovery. Dispersion represents another solution that
can enhance the selectivity of the concentration process.
Furthermore, ultrasound holds promise as an innovative
approach for definitively addressing the slime coating prob-
lem, particularly in the case of these complex ores. The use
of ultrasound to clean mineral surface and reduce slime
coating has expanded in the recent years for various types
of ore (Chu et al., 2022 Donskoi et al., 2012 Gungoren
et al., 2019 Malayoglu and Ozkan, 2019). However, lit-
tle is known about the effect of its variables on iron ore
concentration.
MATERIALS AND METHODS
Sample Characterization
The goethitic ore sample was collected from a beneficia-
tion plant located in Iron Quadrangle region of Brazil. The
sampling procedure was performed with a wet splitter,
which was repeated until the desired amount was attained.
All samples were kept in conditions to avoid drying, which
could lead to the alteration of the clay minerals’ surface
properties.
For particle size distribution, a laser diffraction particle
size analyzer was employed. Additionally, X-ray diffraction
was conducted to characterize the mineral composition and
identify the mineral phases. The chemical analysis was car-
ried out using the X-ray fluorescence method.
Physical Dispersion and Flotation Tests
For ultrasound treatment, the Sonopuls Ultrasonic
Homogenizers HD 3100 were employed. This system
includes an HF generator, an ultrasonic transducer, and a
probe. The HF generator converts mains energy into high-
frequency energy (20 kHz), which is transmitted via the
probe into liquid media (Bandelin, 2016). After the end of
the residence time, the probe was removed and the flotation
test started.
Flotation tests were conducted using 32.5g of ore in
a self-aerated flotation machine. The machine operated at
1,780 rpm, with a 1-minute collector conditioning time
followed by a 4-minute flotation time. As pH regulator
NaOH supplied by VWR Chemicals was used. The collec-
tor used was a new formulation development by Clariant
which commercial name is Flotinor 16939. The test param-
eters are described in Table 1. Flotation kinetics tests are
also carried out in order to evaluate the effect of ultrasound
on the flotation rate.
RESULTS AND DISCUSSIONS
Sample Characterization
The size distribution and chemical analysis are presented in
Table 2 and Table 3, respectively. The sample has 95% of
the material less than 0.045 mm and 63% less than
0.010 mm and presents high Fe and LOI content which
leads to a concentrate up to 60% Fe. The main iron mineral
is goethite and the mains gangue minerals are quartz and
kaolinite.
Physical Dispersion and Flotation Tests
The presence of ultrafines materials exhibits a range of
characteristics that contribute to the phenomenon of slime
coating (Farrokhpay et al., 2021). Chemical dispersion has
been extensively researched and is often considered the
Table 2. Particle size distribution
75 μm 45 μm 25 μm 10 μm 2.5 μm
98.8 95.1 87.4 63.3 15.1
Table 3. Chemical analysis
Fe SiO
2 P Al
2 O
3 Mn LOI
51,1 12,9 0,135 4,08 0,164 8,5
Table 1. Test parameters
Test Solids %
Collector
Dosage g/t
Sonication
Time (min)
Sonication
Intensity (%)Dispersant pH
1 10 300 0 0 — 10.5
2 10 300 0 0 SHMP and NaOH 10.5
3 10 300 5, 10, 15 25 — 10.5
4 10 300 10 10, 20, 25, 30, 50, 75, 100 — 10.5
5 10, 20, 30 300 10 25 — 10.5
essential. The development of new, more selective reagents
for ultrafine iron ore has been the subject of recent studies.
Research by (Silva et al., 2022, 2021) demonstrates that
amidoamine is a more selective collector than etheramine
in the flotation of ultrafine iron ore tailings without requir-
ing the use of a depressant. This advancement holds prom-
ise for improving the efficiency of iron ore processing and
resource utilization.
However, in the context of beneficiating hydrated
ores, additional tools are necessary to maximize metallur-
gical recovery. Dispersion represents another solution that
can enhance the selectivity of the concentration process.
Furthermore, ultrasound holds promise as an innovative
approach for definitively addressing the slime coating prob-
lem, particularly in the case of these complex ores. The use
of ultrasound to clean mineral surface and reduce slime
coating has expanded in the recent years for various types
of ore (Chu et al., 2022 Donskoi et al., 2012 Gungoren
et al., 2019 Malayoglu and Ozkan, 2019). However, lit-
tle is known about the effect of its variables on iron ore
concentration.
MATERIALS AND METHODS
Sample Characterization
The goethitic ore sample was collected from a beneficia-
tion plant located in Iron Quadrangle region of Brazil. The
sampling procedure was performed with a wet splitter,
which was repeated until the desired amount was attained.
All samples were kept in conditions to avoid drying, which
could lead to the alteration of the clay minerals’ surface
properties.
For particle size distribution, a laser diffraction particle
size analyzer was employed. Additionally, X-ray diffraction
was conducted to characterize the mineral composition and
identify the mineral phases. The chemical analysis was car-
ried out using the X-ray fluorescence method.
Physical Dispersion and Flotation Tests
For ultrasound treatment, the Sonopuls Ultrasonic
Homogenizers HD 3100 were employed. This system
includes an HF generator, an ultrasonic transducer, and a
probe. The HF generator converts mains energy into high-
frequency energy (20 kHz), which is transmitted via the
probe into liquid media (Bandelin, 2016). After the end of
the residence time, the probe was removed and the flotation
test started.
Flotation tests were conducted using 32.5g of ore in
a self-aerated flotation machine. The machine operated at
1,780 rpm, with a 1-minute collector conditioning time
followed by a 4-minute flotation time. As pH regulator
NaOH supplied by VWR Chemicals was used. The collec-
tor used was a new formulation development by Clariant
which commercial name is Flotinor 16939. The test param-
eters are described in Table 1. Flotation kinetics tests are
also carried out in order to evaluate the effect of ultrasound
on the flotation rate.
RESULTS AND DISCUSSIONS
Sample Characterization
The size distribution and chemical analysis are presented in
Table 2 and Table 3, respectively. The sample has 95% of
the material less than 0.045 mm and 63% less than
0.010 mm and presents high Fe and LOI content which
leads to a concentrate up to 60% Fe. The main iron mineral
is goethite and the mains gangue minerals are quartz and
kaolinite.
Physical Dispersion and Flotation Tests
The presence of ultrafines materials exhibits a range of
characteristics that contribute to the phenomenon of slime
coating (Farrokhpay et al., 2021). Chemical dispersion has
been extensively researched and is often considered the
Table 2. Particle size distribution
75 μm 45 μm 25 μm 10 μm 2.5 μm
98.8 95.1 87.4 63.3 15.1
Table 3. Chemical analysis
Fe SiO
2 P Al
2 O
3 Mn LOI
51,1 12,9 0,135 4,08 0,164 8,5
Table 1. Test parameters
Test Solids %
Collector
Dosage g/t
Sonication
Time (min)
Sonication
Intensity (%)Dispersant pH
1 10 300 0 0 — 10.5
2 10 300 0 0 SHMP and NaOH 10.5
3 10 300 5, 10, 15 25 — 10.5
4 10 300 10 10, 20, 25, 30, 50, 75, 100 — 10.5
5 10, 20, 30 300 10 25 — 10.5