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location: >Simulations >Table of filtration resistances
Look Up Table for specific
resistance and cake concentration
Look Up Table for specific resistance
and cake concentration of common materials and how they are influenced by the
filtration pressure (D
Pc).
The equation for average specific
resistance (alpha) is:
and, likewise, for cake concentration
by volume fraction:
where a
o ,C0, n and u are
empirically derived constants.
Published values for constants used
in above equations
|
Material |
Resistance
at 1 bar
(m
kg-1) |
a
o
(m kg-1
Pa-n) |
n |
Co
(Pa-u) |
u |
|
100 m m glass beads* |
0.064
x109 |
0.064
x109 |
0 |
0.60 |
0 |
|
10 m
m glass beads* |
6.4
x109 |
6.4
x109 |
0 |
0.60 |
0 |
|
Alumina |
5.2x109 |
2.37x108 |
0.3 |
0.07 |
0.066 |
|
Calcium
carbonate
in salt
solution |
18.2
x109 |
46.9
x108 |
0.13 |
0.22 |
0.03 |
|
Fine calcium
carbonate
in water |
71
x109 |
89.3
x108 |
0.2 |
0.09 |
0.1 |
|
…end of vacuum filtration
range |
|
|
|
|
|
|
Coarse grade
kaolin |
71
x109 |
4.5
x108 |
0.5 |
0.15 |
0.08 |
|
Talc in salt
solution |
112
x109 |
7.1
x108 |
0.5 |
0.008 |
0.29 |
|
Talc in water |
112
x109 |
7.1
x108 |
0.5 |
0.088 |
0.144 |
|
Titanium
dioxide |
344
x109 |
127
x108 |
0.32 |
0.06 |
0.13 |
|
1 m
m glass beads* |
640
x109 |
640
x109 |
0 |
0.60 |
0 |
|
Cement |
491
x109 |
222
x108 |
0.3 |
0.33 |
0.05 |
|
Kaolin (Hong Kong
pink) |
1025
x109 |
64.8
x108 |
0.5 |
0.17 |
0.08 |
|
zinc sulphide pH
3 |
1300
x109 |
1000
x108 |
0.25 |
0.19 |
0.06 |
|
…end of pressure
filtration range |
|
|
|
|
|
|
Magnesium
hydroxide |
1600
x109 |
135
x108 |
0.47 |
|
|
|
Aluminium
hydroxide |
11000
x109 |
3320
x108 |
0.34 |
|
|
|
Stable zinc
sulphide |
47000
x109 |
148
x108 |
0.92 |
0.002 |
0.39 |
|
Colloidal clay |
63000
x109 |
1440
x108 |
0.61 |
|
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* assuming a random close packing and
using the Kozeny-Carman equation
If you would like to calculate a value for specific
resistance at your filtration pressure then enter values in the following
boxes, using the table values or practical data, and press the calculate
button:
postscript
If you want
to know how the average mass of dry cake per unit volume filtrate is obtained
from the average cake concentration and the mass fraction of solids in the feed
slurry then the following formula is useful. Hence, the filter cake forming
pressure influences the volumetric cake concentration and the dry cake mass in
a way given by the equations on this page.
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