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FLORICA IMRE-LUCACI, SORIN-AUREL DORNEANU, PETRU ILEA
The influence of volume flow rate
In order to evaluate the positive effect of the mass transport intensification,
several measurements were accomplished at different volume flow rates. In
this context, the results concerning the influence of VF on RCu are presented
in Table 3. The evolutions in time of the copper concentration at different VF
values are also presented in Figure 1.
Table 3. Global electrolysis parameters at different volume flow rate
(t = 90 min, CNaCl = 10 mM, εW.E. = –200 mV/ER).
VF [mL/min] EC [V] WS [kWh/m 3 ] CE [%] CR [ppm]
25 1.97 0.35 5.56 0.682
50 1.79 0.18 9.18 0.060
75 1.90 0.29 6.05 0.069
100 1.97 0.49 4.37 0.053
Log ([Cu] / ppm)
1.0
0.5
0.0
-0.5
-1.0
V F , mL/min
25
50
75
100
0 10 20 30 40 50 60 70 80 90
Time / min.
Figure 1. The evolution in time of the copper concentrations for different volume
flow rates (εW.E. = –200 mV/RE; CNaCl = 10 mM).
At very low VF values, the rate of RCu is also low and the Cu deposit is
insufficient to inhibit RRO.
The increase of the volume flow rate intensifies Cu nucleation and a
fast grows of the deposit, which inhibits RRO.
Anyway, the implicit increase of de oxygen quantity developed at
the anode and its faster transport to the cathode produces a decrease of
the CE and an increase of WS.