XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 3631
circuit was chosen as the best option for Mont Reed case.
This circuit was able to remove 32.3% of the feed mass,
discarding 47% of the total silica contained in the original
material without big losses of recoverable iron, as illustrated
in Figure 7. In addition, the Fe grade of the main concen-
tration circuit increases from 32.11% to 39.55% with the
addition of the pre-concentraton.
This circuit strikes a good balance between gangue
removal and iron loss, allowing the pre-concentrate to be
ground and concentrated in subsequent stages, while main-
taining a reasonable iron recovery in the process. Aiming at
investigating the efficiency of the pre-concentration stage,
the mineralogy and the liberation degree of the minerals in
the products were analysed. The mineral composition of
the products is presented in Table 8.
In general terms, the process succeeded in keep most
part of the Fe oxides in the concentrate and to divert the
quartz to the tailings. This is well illustrated in Figure 8,
where the recoveries of different minerals are presented.
Despite this, approximately 25% of magnetite and
15% of the hematite originally in the feed were lost to the
tailings. Aiming at analysing if this material was liberated
(and consequently recoverable) a complete liberation study
was performed with the products and the results are pre-
sented in Table 9 and Figure 9.
The data shows that most part of iron oxide particles
contained in the tailings are not liberated, being approxi-
mately 50% classified as “locked” (Figure 10). This indi-
cates that they are not recoverable due to the necessity of
extremely fine grinding to release them, which would be
unfeasible. Furthermore, the results reinforce the effectiv-
ity of the pre-concentration stage in Mont-Reed flowsheet.
Considering the planned production for the plant
-15Mtpa (50Mtpa of ROM), the average energy costs
at Canada (0.01 USD/kWh) and the specific energy for
grinding the material up to 75µm (11kWh/t), an economy
of 1.8M USD per year related to energy savings is expected
with the addition of the proposed pre-concentration stage
(Mesquita et al, 2023).
Figure 7. Pre-concentration circuit mass balance
circuit was chosen as the best option for Mont Reed case.
This circuit was able to remove 32.3% of the feed mass,
discarding 47% of the total silica contained in the original
material without big losses of recoverable iron, as illustrated
in Figure 7. In addition, the Fe grade of the main concen-
tration circuit increases from 32.11% to 39.55% with the
addition of the pre-concentraton.
This circuit strikes a good balance between gangue
removal and iron loss, allowing the pre-concentrate to be
ground and concentrated in subsequent stages, while main-
taining a reasonable iron recovery in the process. Aiming at
investigating the efficiency of the pre-concentration stage,
the mineralogy and the liberation degree of the minerals in
the products were analysed. The mineral composition of
the products is presented in Table 8.
In general terms, the process succeeded in keep most
part of the Fe oxides in the concentrate and to divert the
quartz to the tailings. This is well illustrated in Figure 8,
where the recoveries of different minerals are presented.
Despite this, approximately 25% of magnetite and
15% of the hematite originally in the feed were lost to the
tailings. Aiming at analysing if this material was liberated
(and consequently recoverable) a complete liberation study
was performed with the products and the results are pre-
sented in Table 9 and Figure 9.
The data shows that most part of iron oxide particles
contained in the tailings are not liberated, being approxi-
mately 50% classified as “locked” (Figure 10). This indi-
cates that they are not recoverable due to the necessity of
extremely fine grinding to release them, which would be
unfeasible. Furthermore, the results reinforce the effectiv-
ity of the pre-concentration stage in Mont-Reed flowsheet.
Considering the planned production for the plant
-15Mtpa (50Mtpa of ROM), the average energy costs
at Canada (0.01 USD/kWh) and the specific energy for
grinding the material up to 75µm (11kWh/t), an economy
of 1.8M USD per year related to energy savings is expected
with the addition of the proposed pre-concentration stage
(Mesquita et al, 2023).
Figure 7. Pre-concentration circuit mass balance