XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 923
concentration Cmax. This pseudo-equilibrium depends on
dissolution parameters, recirculation ratio and plant resi-
dence time.
Impact of Recirculated Water on Performance and
Required Water Treatment
For the next simulations, Best fit DW-PW (Table 2) is con-
sidered for sulfates, and PW Mg and PW Ca fits are consid-
ered for calcium and magnesium (Table 3).
The selected case to assess the impact of water recircula-
tion is the one at highest S/L separation rate (85%).
The first simulation considers the simplest scenario,
without any water treatment. The semi-empiric law pro-
vides negative kinetic constant and the simulation is not reli-
able. This highlights from one hand that a real flotation law
might be more complex than a simple linear relationship,
and from another hand that this kind of law hardly extends
beyond the concentration range of the experimentation.
It was thus decided to tighten the range of simula-
tion around scenarios with water quality close to the one
of process water. Three scenarios were considered, with
target concentrations of sulfates, magnesium, and calcium
in recirculated water equal, higher (factor 1.25) and lower
(factor 0.75) than PW for scenarios PW, Concentrated PW
and Treated PW respectively. The first simulations enabled
to estimate the concentrations in Cu circuit tails and thus
the water treatment requirements (Table 4) as well as the
impact of recirculated water quality on plant performance
(Table 5). The scenario with PW water is considered as the
reference scenario and performances are considered relative
to it.
As expected by considering the setting of semi-empiric
flotation laws, better water quality improves plant perfor-
mances. The impact on grade is less pronounced, better
grade is obtained with Concentrated PW, which follows the
Figure 9. Influence of water recirculation ratio and dissolution parameters (Table 1) on SO4
concentrations of recycled water
Table 4. Water to treat in the different scenarios
Scenario
Target SO
4 ,
mg/L
Recirculated
SO
4 ,mg/L
Target Mg,
mg/L
Recirculated Mg,
mg/L
Target Ca,
mg/L
Recirculated Ca,
mg/L
PW 620.0 719.2 66.0 96.6 160.0 190.0
Concentrated PW
Treated PW
775.0
465.0
846.1
586.7
82.5
49.5
108.0
83.4
200.0
120.0
223.1
155.2
Table 5. Impact of recirculated water quality on plant
performances
Scenario Cu recovery, %Cu grade, %
PW — —
Concentrated PW
Treated PW
–4.54
+2.34
+0.04
+0.05
concentration Cmax. This pseudo-equilibrium depends on
dissolution parameters, recirculation ratio and plant resi-
dence time.
Impact of Recirculated Water on Performance and
Required Water Treatment
For the next simulations, Best fit DW-PW (Table 2) is con-
sidered for sulfates, and PW Mg and PW Ca fits are consid-
ered for calcium and magnesium (Table 3).
The selected case to assess the impact of water recircula-
tion is the one at highest S/L separation rate (85%).
The first simulation considers the simplest scenario,
without any water treatment. The semi-empiric law pro-
vides negative kinetic constant and the simulation is not reli-
able. This highlights from one hand that a real flotation law
might be more complex than a simple linear relationship,
and from another hand that this kind of law hardly extends
beyond the concentration range of the experimentation.
It was thus decided to tighten the range of simula-
tion around scenarios with water quality close to the one
of process water. Three scenarios were considered, with
target concentrations of sulfates, magnesium, and calcium
in recirculated water equal, higher (factor 1.25) and lower
(factor 0.75) than PW for scenarios PW, Concentrated PW
and Treated PW respectively. The first simulations enabled
to estimate the concentrations in Cu circuit tails and thus
the water treatment requirements (Table 4) as well as the
impact of recirculated water quality on plant performance
(Table 5). The scenario with PW water is considered as the
reference scenario and performances are considered relative
to it.
As expected by considering the setting of semi-empiric
flotation laws, better water quality improves plant perfor-
mances. The impact on grade is less pronounced, better
grade is obtained with Concentrated PW, which follows the
Figure 9. Influence of water recirculation ratio and dissolution parameters (Table 1) on SO4
concentrations of recycled water
Table 4. Water to treat in the different scenarios
Scenario
Target SO
4 ,
mg/L
Recirculated
SO
4 ,mg/L
Target Mg,
mg/L
Recirculated Mg,
mg/L
Target Ca,
mg/L
Recirculated Ca,
mg/L
PW 620.0 719.2 66.0 96.6 160.0 190.0
Concentrated PW
Treated PW
775.0
465.0
846.1
586.7
82.5
49.5
108.0
83.4
200.0
120.0
223.1
155.2
Table 5. Impact of recirculated water quality on plant
performances
Scenario Cu recovery, %Cu grade, %
PW — —
Concentrated PW
Treated PW
–4.54
+2.34
+0.04
+0.05