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Journal of Applied Electrochemistry

, Volume 15, Issue 6, pp 807–824 | Cite as

Enhanced mass transfer at the rotating cylinder electrode: III. Pilot and production plant experience

  • D. R. Gabe
  • F. C. Walsh
Papers

Abstract

Enhanced mass transfer at a rotating cylinder electrode, due to the development of surface roughness of a metal deposit, has been studied in a range of commercial and pilot scale reactors known as ECO-CELLS. The data obtained for relatively restricted ranges of process parameters show reasonable agreement with the more definitive data obtained under laboratory conditions. With scale-up factors of approximately six times in terms of the rotating cylinder diameter, enhanced mass transfer factors of up to 30 times are reported (in comparison with hydrodynamically smooth electrodes) due to the development of roughened deposits during the process of metal extraction from aqueous solution.

Keywords

Surface Roughness Laboratory Condition Production Plant Reasonable Agreement Metal Deposit 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Nomenclature

a, b, c

constants in Equation 15

A

active area of rotating cylinder (cm2)

C

(bulk) concentration of metal (mol cm−3 or mg dm−3)

Δc

concentration change over reactor (mol cm−3 or mg dm−3)

CIN,COUT,CCELL

inlet, outlet and reactor concentrations of metal (mol cm−3 or mgdm−3)

d

diameter of rotating cylinder (cm)

D

diffusion coefficient (cm2 s−1)

fR

fractional conversion

F

Faraday constant=96 500 A s (mo1−1)

I

current (A)

IL

limiting current (A)

Io

useful current (A)

jD'

mass transport factor (=St Scc)

K

constant in Equation 27

KL

mass transport coefficient (cm s−1)

m

slope of Fig. 8 (s−1)

M

molar mass of copper = 63.54 g mol−1

n

number of elements in the cascade

N

volumetric flow rate (cm3−1)

P

Reynolds number exponent for powder formation (Equation 28)

R

total cell resistance (Q)

t

time (s)

U

peripheral velocity of cylinder (cm s−1)

Vcell

cell voltage (V)

VR,VT

effective cell, reservoir volume (cm3)

W

electrolytic power consumption (W)

x

velocity index in Equation 27

z

number of electrons

Re

Reynolds number=Ud/v

Sc

Schmidt number=v/D

St

Stanton number=KL/U

gu

kinematic viscosity (cm2 s−1)

φ

cathode current efficiency

ω

rotational speed (revolutions min−1)

ɛ

peak to valley roughness (cm)

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References

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Copyright information

© Chapman and Hall Ltd 1985

Authors and Affiliations

  • D. R. Gabe
    • 1
  • F. C. Walsh
    • 1
  1. 1.Department of Materials Engineering and DesignThe University of TechnologyLoughboroughUK

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