XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 3629
The rougher spiral test was performed using a spiral
concentrator model HC33L and cleaner /recleaner ones
with a spiral concentrator model WW6FL, both sup-
plied by Mineral technologies. The operational parameters
adopted in each test are presented in Table 4.
RESULTS &DISCUSSION
The mineralogical composition of the head sample is pre-
sented in Table 5.
The sample is mainly composed by quartz, magnetite,
hematite and ferrosilite, with small amounts of dolomite,
diopside and calcite. Traces of hornblende and talc are also
observed. The data presented in the table shows that there
is a big difference between the densities of quartz (main
gangue) and the Fe oxides, which explains the decision of
using gravity separation for the pre-concentration stage.
Regarding the liberation of the material, the characteriza-
tion results are presented in Table 6.
Results confirms the high liberation achieved for quartz
particles when grinding Mont Reed ore up to 1mm. The
mineral presents the highest liberation among the gangues
with a very small quantity of locked particles. This is an
important indication for the effectiveness of a pre-concen-
tration stage aiming at removing this gangue previously
to the next grinding/concentration processes. The results
obtained with the material in the spiral tests are presented
in Figure 6.
A summary of the results is presented in Table 7. It
is worth to remember that the primary aim of the pre-
concentration stage is to eliminate the liberated gangue
particles before the downstream processes. Therefore, the
silica removal numbers are crucial for evaluating the data.
Additionally, the iron losses to the tailings is also a signifi-
cant factor that must be considered when deciding which
pre-concentration circuit to select.
In general, the tailings qualities were quite stable
among all circuits and the biggest differences were observed
in both concentrates recoveries and qualities. In this sense,
despite presenting higher silica removal numbers (80.9 and
90.8%, respectively) and better concentrates in terms of
quality (50.31 and 57.79%, respectively), the circuits with
more than one stage led to higher losses of iron to the tail-
ings (32.7 and 37.0%, respectively). In Mont Reed case this
parameter is extremely important given the low grade of
the ore.
As that the primary goal of the pre-concentration stage
is to eliminate gangue while minimizing iron losses, the first
Table 5. Grinding feed sample mineralogical composition
Mineral Mineral Class Chemical Formula Density (g/cm3) Proportion (%)
Quartz Tectosilicate SiO2 2.65 43.5
Magnetite Oxides Fe3O4 5.18 28.4
Hematite Oxides Fe
2 O
3 5.26 9.0
Ferrosilite Orthopyroxenes Fe
2 Si
2 O
6 3.52 9.1
Dolomite Carbonates CaMg(CO3)2 2.84 2.9
Diopside Clinopyroxenes CaMgSi2O6 3.26 3.7
Calcite Carbonates CaCO
3 2.71 2.1
Hornblende Carbonates Ca
2 Fe
5 Si
7 AlO
22 (OH)
2 3.15 0.7
Talc Phyllosilicate Mg3Si4O10(OH)2 2.70 0.6
Table 6. Head sample liberation study results
Mineral
Proportion (%)
Liberated Middlings Locked
Quartz 67 31 2
Iron oxide 70 16 14
Ferrosilite 32 56 12
Dolomite 62 26 12
Diopside 31 52 17
Table 4. Operational parameters
Parameter
Rougher
Stage
Cleaner
Stage
Recleaner
Stage
%of solids 26 42 42
Solid’s flowrate (kg/h) 3 272 2876 2576
Washing Water (l/h) 994 1761 1,764
The rougher spiral test was performed using a spiral
concentrator model HC33L and cleaner /recleaner ones
with a spiral concentrator model WW6FL, both sup-
plied by Mineral technologies. The operational parameters
adopted in each test are presented in Table 4.
RESULTS &DISCUSSION
The mineralogical composition of the head sample is pre-
sented in Table 5.
The sample is mainly composed by quartz, magnetite,
hematite and ferrosilite, with small amounts of dolomite,
diopside and calcite. Traces of hornblende and talc are also
observed. The data presented in the table shows that there
is a big difference between the densities of quartz (main
gangue) and the Fe oxides, which explains the decision of
using gravity separation for the pre-concentration stage.
Regarding the liberation of the material, the characteriza-
tion results are presented in Table 6.
Results confirms the high liberation achieved for quartz
particles when grinding Mont Reed ore up to 1mm. The
mineral presents the highest liberation among the gangues
with a very small quantity of locked particles. This is an
important indication for the effectiveness of a pre-concen-
tration stage aiming at removing this gangue previously
to the next grinding/concentration processes. The results
obtained with the material in the spiral tests are presented
in Figure 6.
A summary of the results is presented in Table 7. It
is worth to remember that the primary aim of the pre-
concentration stage is to eliminate the liberated gangue
particles before the downstream processes. Therefore, the
silica removal numbers are crucial for evaluating the data.
Additionally, the iron losses to the tailings is also a signifi-
cant factor that must be considered when deciding which
pre-concentration circuit to select.
In general, the tailings qualities were quite stable
among all circuits and the biggest differences were observed
in both concentrates recoveries and qualities. In this sense,
despite presenting higher silica removal numbers (80.9 and
90.8%, respectively) and better concentrates in terms of
quality (50.31 and 57.79%, respectively), the circuits with
more than one stage led to higher losses of iron to the tail-
ings (32.7 and 37.0%, respectively). In Mont Reed case this
parameter is extremely important given the low grade of
the ore.
As that the primary goal of the pre-concentration stage
is to eliminate gangue while minimizing iron losses, the first
Table 5. Grinding feed sample mineralogical composition
Mineral Mineral Class Chemical Formula Density (g/cm3) Proportion (%)
Quartz Tectosilicate SiO2 2.65 43.5
Magnetite Oxides Fe3O4 5.18 28.4
Hematite Oxides Fe
2 O
3 5.26 9.0
Ferrosilite Orthopyroxenes Fe
2 Si
2 O
6 3.52 9.1
Dolomite Carbonates CaMg(CO3)2 2.84 2.9
Diopside Clinopyroxenes CaMgSi2O6 3.26 3.7
Calcite Carbonates CaCO
3 2.71 2.1
Hornblende Carbonates Ca
2 Fe
5 Si
7 AlO
22 (OH)
2 3.15 0.7
Talc Phyllosilicate Mg3Si4O10(OH)2 2.70 0.6
Table 6. Head sample liberation study results
Mineral
Proportion (%)
Liberated Middlings Locked
Quartz 67 31 2
Iron oxide 70 16 14
Ferrosilite 32 56 12
Dolomite 62 26 12
Diopside 31 52 17
Table 4. Operational parameters
Parameter
Rougher
Stage
Cleaner
Stage
Recleaner
Stage
%of solids 26 42 42
Solid’s flowrate (kg/h) 3 272 2876 2576
Washing Water (l/h) 994 1761 1,764