INFLUENCE OF ANODE MATERIAL ON CURRENT YIELD DURING FERRATE(VI) PRODUCTION BY ANODIC IRON DISSOLUTION .3. CURRENT EFFICIENCY DURING ANODIC-DISSOLUTION OF PURE IRON TO FERRATE(VI) IN CONCENTRATED ALKALI HYDROXIDE SOLUTIONS
K. Bouzek et I. Rousar, INFLUENCE OF ANODE MATERIAL ON CURRENT YIELD DURING FERRATE(VI) PRODUCTION BY ANODIC IRON DISSOLUTION .3. CURRENT EFFICIENCY DURING ANODIC-DISSOLUTION OF PURE IRON TO FERRATE(VI) IN CONCENTRATED ALKALI HYDROXIDE SOLUTIONS, Journal of Applied Electrochemistry, 27(6), 1997, pp. 679-684
The dependence of the current efficiency for the oxidation of a pure i
ron (99.95%) anode to ferrate(VI) ions in 14M NaOH was measured in the
region of bubble induced convection for the temperature range 20 to 5
0 degrees C. The highest current yield obtained after 180 min electrol
ysis was 60% at a current density of 2.3 mA cm(-2) and a temperature o
f 30 degrees C. The same current yield was found at a current density
of 4.5 mA cm(-2) and a temperature of 40 degrees C. The dependence of
the ferrate(VI) current yields on the NaOH concentration in the electr
olyte solution was studied in the range 12 to 17M. The optimum concent
ration was found to be 16M. The quasistationary anodic polarization cu
rve of pure iron in the transpassive potential region was measured. Ap
parent oxygen evolution starts at a potential 110 mV higher than for w
hite and grey cast iron anodes.