698 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
performance decreased. At 20 mg/L, concentration of thio-
cyanate decreased to 5.31 mg/L in the first 10 minutes,
then it increased gradually and reached to 17.95 mg/L at
the end of treatment.
The number of ions between the electrodes was directly
proportional to the influent salt concentration and thus
affected the desalination performance. The results given
in Figure 7a showed that the total thiocyanate removal
increased from 2301 mg/m2 to 3689 mg/m2, whereas the
removal efficiency decreased from 85% to 68% for 5 mg/L
to 10 mg/L, respectively (Figure 7b). When the influent
concentration was 20 mg/L, the salt removal efficiency
decreased to 22% that could be due to the fouling on the
electrode surface.
Real Mine Process Water Tests
In real water systems, the desalination performance is
affected by the chemical composition of the water (Suss
et al., 2015). In this work, gold mining process water was
used to observe the effect of water constituents on thio-
cyanate removal efficiency. Sulfate (SO42–), thiocyanate
(SCN–), calcium (Ca2+), chloride (Cl–), and magnesium
(Mg2+) ions were determined as major components of the
mine process water as shown in Table 1.
The process water containing 77.7 mg/L SCN– was
pumped continuously for 120 minutes at a flow rate of 1.5
mL/min and a constant voltage of 5 V. The results shown
in Figure 8 indicated that the concentration of inorganic
ions did not change significantly during the treatment. The
0
20
40
60
80
100
5 10 20
Concentration (mg/L)
0
500
1000
1500
2000
2500
3000
3500
4000
5 10 20
Concentration (mg/L)
a) b)
Figure 7. Influence of influent concentration on desalination performance for the continuous flow test of
initial concentrations ranging from 5 mg/L, 10 mg/L and 20 mg/L. a) total thiocyanate removal during
180 minutes b) %removal efficiency of thiocyanate. All experiments were performed at a constant voltage
of 3 V and a constant flow rate of 1.5 mL/min
0
10
20
30
40
50
60
70
80
90
0
500
1000
1500
2000
2500
3000
3500
4000
4500
5000
0 5 10 15 30 60 90 120
Operation Time (min.)
SO4 Cl Ca Mg SCN
Figure 8. Concentration changes of ions in the mine process water. The experiment was performed in a
continuous flow, at a constant operating voltage of 5 V and a constant flow rate of 1.5 mL/min for 120
minutes
SCN
Removal
Efficiency
%
Total
SCNRemoval
(mg/m2)
[SCN]
(mg/L) Concentration
o f
I
(mg/L)
performance decreased. At 20 mg/L, concentration of thio-
cyanate decreased to 5.31 mg/L in the first 10 minutes,
then it increased gradually and reached to 17.95 mg/L at
the end of treatment.
The number of ions between the electrodes was directly
proportional to the influent salt concentration and thus
affected the desalination performance. The results given
in Figure 7a showed that the total thiocyanate removal
increased from 2301 mg/m2 to 3689 mg/m2, whereas the
removal efficiency decreased from 85% to 68% for 5 mg/L
to 10 mg/L, respectively (Figure 7b). When the influent
concentration was 20 mg/L, the salt removal efficiency
decreased to 22% that could be due to the fouling on the
electrode surface.
Real Mine Process Water Tests
In real water systems, the desalination performance is
affected by the chemical composition of the water (Suss
et al., 2015). In this work, gold mining process water was
used to observe the effect of water constituents on thio-
cyanate removal efficiency. Sulfate (SO42–), thiocyanate
(SCN–), calcium (Ca2+), chloride (Cl–), and magnesium
(Mg2+) ions were determined as major components of the
mine process water as shown in Table 1.
The process water containing 77.7 mg/L SCN– was
pumped continuously for 120 minutes at a flow rate of 1.5
mL/min and a constant voltage of 5 V. The results shown
in Figure 8 indicated that the concentration of inorganic
ions did not change significantly during the treatment. The
0
20
40
60
80
100
5 10 20
Concentration (mg/L)
0
500
1000
1500
2000
2500
3000
3500
4000
5 10 20
Concentration (mg/L)
a) b)
Figure 7. Influence of influent concentration on desalination performance for the continuous flow test of
initial concentrations ranging from 5 mg/L, 10 mg/L and 20 mg/L. a) total thiocyanate removal during
180 minutes b) %removal efficiency of thiocyanate. All experiments were performed at a constant voltage
of 3 V and a constant flow rate of 1.5 mL/min
0
10
20
30
40
50
60
70
80
90
0
500
1000
1500
2000
2500
3000
3500
4000
4500
5000
0 5 10 15 30 60 90 120
Operation Time (min.)
SO4 Cl Ca Mg SCN
Figure 8. Concentration changes of ions in the mine process water. The experiment was performed in a
continuous flow, at a constant operating voltage of 5 V and a constant flow rate of 1.5 mL/min for 120
minutes
SCN
Removal
Efficiency
%
Total
SCNRemoval
(mg/m2)
[SCN]
(mg/L) Concentration
o f
I
(mg/L)