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102
FLORICA IMRE-LUCACI, SORIN-AUREL DORNEANU, PETRU ILEA
in the 7.5 mM Na2SO4 solution, the CR decrease under 0.1 ppm and Ws is low,
we decide to use this concentration for further experiments.
Table 5. Global electrolysis parameters at different CNa2SO4 values
(t = 90 min; εW.E. = –200 mV/RE; VF = 50 mL/min)
CNa2SO4 [mM] EC [V] WS [kWh/m 3 ] CE [%] CR [ppm]
1.0 5.20 2.04 2.14 0.365
2.5 1.88 0.19 8.35 0.164
5.0 1.74 0.35 5.19 0.350
7.5 1,69 0.18 7.85 0.093
10.0 1.69 0.21 6.66 0.133
The influence of volume flow rate
In order to evaluate influence of electrolyte volume flow rate on RCu,
measurements were accomplished at VF values of 25, 50, 75, 100 mL/min,
the obtained results being presented in Table 6. The evolutions in time of the
copper concentration at different VF values are also presented in Figure 2.
Table 6. Global electrolysis parameters at different volume flow rate
(t = 90 min, εW.E. = –200 mV/ER; 7.5 mM Na2SO4).
VF [mL/min] EC [V] WS [kWh/m 3 ] CE [%] CR [ppm]
25 1.42 0.11 11.78 0.727
50 1.69 0.19 7.85 0.093
75 1.72 0.19 7.82 0.264
100 1.87 0.29 5.79 0.062
Log ([Cu] / ppm)
1.2
0.8
0.4
0.0
-0.4
-0.8
-1.2
V F , mL/min
25
50
75
100
0 10 20 30 40 50 60 70 80 90
Time / min.
Figure 2. The evolution in time of the copper concentration for different volume
flow rate (εW.E. = –200 mV/RE; 7.5 mM Na2SO4)