Calculation of cathode current density (cross post from Corrosion Engineering)

[001anuradha]

Dear All,

[Cross posting from Corrosion Engineering section as I didn't get any replies there]

I would like to verify my calculation of cathode current density in an electro-refining cell.
It is refining cast copper anodes from scrap copper in a CuSO4/H2SO4 bath.
Each tank has a set of impure anodes and copper cathodes forming cells in parallel.

The current passing into a cell is 134A, surface area of one side of cathode is 0.54m^2

My current density calculation is below:
*Each cathode receives copper from anodes on both sides, so according to my understanding the current passing through one side of cathode is I = 134A/2 = 67A
*As this current passes through a single side of cathode, the area,A = 0.54m^2
From this I get the current density, J=I/A = 67/0.54 = 124 A/m

This value I get is roughly half the typical industry values which are in the range of 250 - 280 A/m^2
Am I doing the calculation wrong, is there a industry specific calculation for "cathode current density"

Thank you all in advance!