Figure 3 depicts the differences amongst slurry, paste, and
filter cake. The concentrations (weight) and strength (i.e.,
actual rheological yield stress) are displayed below. For
filler product, paste effluent
might have yield stress
variations ranging from 10-1000 Pa. The alumina production
is subjected to a yield stress of 40 Pa. Because yield stress
distribution curves can vary greatly even within the similar
industry, it is concluded that concentration is not a distinct
parameter, but yield stress is.
Figure 3: Strength vs concentration curve for slurry (Boger
2013)
For similar yield stress of 20 Pa, the concentration is found
to change from roughly 36 per cent weight. to 53 per cent
weight. Figure 4. Figure 5 displays yield stress as the factor
of concentration for eleven distinct minerals. This variance
happens within the similar industry
and it differs widely
from one industry to the other industry. The concentration
ranges from roughly 0.24 (mass fraction)
for coal mine
tailings to almost 0.68 for copper tailings to 0.8 for mine
slope fill material at a yield stress of 200 Pa. Therefore, for
same yield stress different
tailing have different
concentration.
Figure 4: yield stress vs concentration for red mud for different alumina
samples. (Boger 2013
Figure 5: shear yield stress vs solid mass fraction for different minerals.
(Boger 2013)
Mineral Tailings Rheology
The study conducted (Wang et. al)
considered samples of
gold, copper and iron tailings. Tailings are classified as tail
silty soil, tail finer sand and tail silty sand as per the
standards of particle size distribution. The influence of type
of ore,
size of particle, plasma concentration and rate of
shear on rheological properties is studied.
Type of ore
It can be seen in fig 6 that as the time increasing viscosity
decreases rapidly to a certain
limit and then becomes
constant. The reason is as the rotor started plasma was at rest
thus there is some initial viscosity. In fig 7 it can be shown
that yield stress increases up to certain limit and then
becomes constant. It has initial value almost zero because as
rotor started tailing also rotated with it. It was seen that iron
ore has maximum impact and copper ore minimum because
of difference in internal composition.
Figure 6: viscosity vs time Wang et.al
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