3464 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
or ferric. In the previous research, it was well demonstrated
that TA can be complex with ferric ions and PEO poly-
mer to develop associative complexes. Herein, those com-
plexations may help form flocs with specific properties that
were beneficial to filtration. It is noted when TA was dosed
before ferric/PEO, it achieved the fastest filtration rate with
more than 110 grams of filtrate coming out, which was sig-
nificantly higher than other chemical conditions. It hints
that TA played an important role in pressure filtration.
Figure 3 indicates the weight percentage of solids in
the “filter cake” after the filtration operation. In fact, there
was no cake formed with inefficient chemical conditioning
because the filtered materials still possessed high moisture
and took on a viscous slurry state. Corresponding to the
filtration curves in Figure 2, it can be seen that all the fil-
ter cakes had a solid content below 50 wt% except for the
tailing slurry conditioned with TA followed by ferric/PEO.
The cake shown on the right of Figure 3 had a solid content
of 53 wt%, which will be higher if prolongs the filtration
time or optimizes the concentrations of chemicals.
Specific Resistance to Filtration
In Figure 4, the specific resistance to filtration (SRF) was
developed to quantitatively characterize the filterability of
oil sands tailings in filtration. Herein, we only considered
the resistance from filter cake and neglected the resistance
from filter media. The SRF of bare oil sands tailings was
significantly high at 9.48×1013 m/kg, which made water dif-
ficult to escape from the cake upon pressure and explained
why filtration was challenging. PEO flocculation only
decreased the SRF slightly and ferric coagulation decreased
the SRF more. Consistent with the filtration results, the
combination of ferric and PEO reduced the filtration
resistance more effectively and the SRF was decreased to
5.71×1013 m/kg. Preconditioning with TA followed by fer-
ric/PEO aggregation was found the most effective in reduc-
ing SRF, obtaining the lowest filtration resistance among all
the chemical conditioning. It is assumed that the TA could
connect the ferric and PEO during the tailings aggregation,
which may change the mechanical resistance of flocs or
microstructure between particles bonding so that the water
was easier to be removed in filtration.
Floc Size Distribution Measurement and
Sedimentation Test
We used FBRM to measure the floc size distribution
when the tailing slurry was subjected to different chemi-
cals. Herein, both unweighted and square-weighted chord
length distributions (CLD) were provided as shown in
Figure 5, with the former better reflecting the raw parti-
cle size distribution in slurry and the latter taking a cube
weighting to reflect particle size distribution in floccula-
tion. From the CLD of raw tailings, we can observe that
most particles in the slurry were very fine since the peak was
0 200 400 600 800 1000 1200 1400 1600 1800 2000
0
20
40
60
80
100
120
Tailngs only
Ferric
PEO
Ferric+PEO
TA+PEO
TA+Ferric
TA+Ferric/PEO
Filtration time (s)
Figure 2. Cumulative filtrate weight along with filtration time under different chemical
conditioning, [TA] =2kg/t, [Ferric] =5kg/t, [PEO] =1kg/t
Filtrate
wei
gh(g)
t
or ferric. In the previous research, it was well demonstrated
that TA can be complex with ferric ions and PEO poly-
mer to develop associative complexes. Herein, those com-
plexations may help form flocs with specific properties that
were beneficial to filtration. It is noted when TA was dosed
before ferric/PEO, it achieved the fastest filtration rate with
more than 110 grams of filtrate coming out, which was sig-
nificantly higher than other chemical conditions. It hints
that TA played an important role in pressure filtration.
Figure 3 indicates the weight percentage of solids in
the “filter cake” after the filtration operation. In fact, there
was no cake formed with inefficient chemical conditioning
because the filtered materials still possessed high moisture
and took on a viscous slurry state. Corresponding to the
filtration curves in Figure 2, it can be seen that all the fil-
ter cakes had a solid content below 50 wt% except for the
tailing slurry conditioned with TA followed by ferric/PEO.
The cake shown on the right of Figure 3 had a solid content
of 53 wt%, which will be higher if prolongs the filtration
time or optimizes the concentrations of chemicals.
Specific Resistance to Filtration
In Figure 4, the specific resistance to filtration (SRF) was
developed to quantitatively characterize the filterability of
oil sands tailings in filtration. Herein, we only considered
the resistance from filter cake and neglected the resistance
from filter media. The SRF of bare oil sands tailings was
significantly high at 9.48×1013 m/kg, which made water dif-
ficult to escape from the cake upon pressure and explained
why filtration was challenging. PEO flocculation only
decreased the SRF slightly and ferric coagulation decreased
the SRF more. Consistent with the filtration results, the
combination of ferric and PEO reduced the filtration
resistance more effectively and the SRF was decreased to
5.71×1013 m/kg. Preconditioning with TA followed by fer-
ric/PEO aggregation was found the most effective in reduc-
ing SRF, obtaining the lowest filtration resistance among all
the chemical conditioning. It is assumed that the TA could
connect the ferric and PEO during the tailings aggregation,
which may change the mechanical resistance of flocs or
microstructure between particles bonding so that the water
was easier to be removed in filtration.
Floc Size Distribution Measurement and
Sedimentation Test
We used FBRM to measure the floc size distribution
when the tailing slurry was subjected to different chemi-
cals. Herein, both unweighted and square-weighted chord
length distributions (CLD) were provided as shown in
Figure 5, with the former better reflecting the raw parti-
cle size distribution in slurry and the latter taking a cube
weighting to reflect particle size distribution in floccula-
tion. From the CLD of raw tailings, we can observe that
most particles in the slurry were very fine since the peak was
0 200 400 600 800 1000 1200 1400 1600 1800 2000
0
20
40
60
80
100
120
Tailngs only
Ferric
PEO
Ferric+PEO
TA+PEO
TA+Ferric
TA+Ferric/PEO
Filtration time (s)
Figure 2. Cumulative filtrate weight along with filtration time under different chemical
conditioning, [TA] =2kg/t, [Ferric] =5kg/t, [PEO] =1kg/t
Filtrate
wei
gh(g)
t