C. Arslan et Pf. Duby, THE ANODIC-OXIDATION OF CR(III) TO CR(VI) IN A LABORATORY-SCALE CHROMIUM ELECTROWINNING CELL, Hydrometallurgy, 46(3), 1997, pp. 337-348
The factors affecting the anodic processes in the electrowinning of ch
romium were investigated by carrying out electrolysis experiments with
a chromium ammonium sulfate solution in a laboratory-scale cell of ap
proximately 90 mi equipped with a diaphragm. The current density (838-
1077 A m(-2)), temperature (50-70 degrees C), and rate of electrolyte
flow (5-18 ml/h) from catholyte to anolyte were varied to determine th
eir effects on the anodic oxidation of Cr(m) to Cr(VI). There was no a
ttempt to optimize the cathodic deposition process. The behavior of th
e traditional lead-silver anode with an effective surface area of 10 c
m(2) was compared with that of two commercially available dimensionall
y stable anodes. The current efficiency for the anodic oxidation of th
e chromic ion varied from about 75 to 100% with the lead-silver anode
while it was only about 10 to 20% with the dimensionally stable anodes
. The other variables had a much less significant effect. (C) 1997 Els
evier Science B.V.