2116 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
Here, Uu represents the amount of material finer than the
aperture size in the fine product, and Ff is the amount of
feed material finer than a defined cut-point (or cut-size),
such as the screen aperture size.
METHODOLOGY
All ore samples were prepared, homogenized, and divided
in 16 samples for test works. All the samples were lumps
feed produced as direct shipping ore but out of commer-
cial specification, which means top size around 75 mm and
wide size distribution aggregating the fines to the product,
with approximately P80 =23 mm and P50 =12 mm.
SAP Kinetics Protocol for Water Absorption
A protocol has been established with the aim of delineating
the equation that governs the water absorption per gram
of SAP during a specified time. The procedure involves the
sampling of approximately 1g of polymer for each trial. A
quantity of 200 ml of water was measured out in this case,
the water chosen was aligned closely with on-site condi-
tions for this study.
Following this, the polymer is placed into a 400 ml
beaker, and the pre-measured water is carefully poured into
the beaker. The timer is initiated when the first drop of
water falls into the beaker. The presence of polymer lumps,
if any, should be promptly addressed by agitation to dis-
perse them. At a predefined time t the water-polymer mix-
ture is passed through a 50μm sieve, and the liquid that
passes through is collected in a tray. Any remaining water is
thoroughly drained.
Subsequently, the sieve-beaker-polymer assembly, the
tray-water assembly, and the water remaining on the bal-
ance after weighing the sieve-beaker-polymer assembly are
all subjected to weighing. It is crucial to take note of the
tare for each piece of equipment used. The entire procedure
is subsequently replicated at different absorption times to
ensure comprehensive testing. The results were then fine-
tuned to conform to the second-order kinetics equation,
employing statistical analysis to enhance precision.
SAP Kinetics Protocol for Screen Efficiency
To comprehend the behavior of SAP water absorption in the
context of moisture interaction, a protocol has been devised
that incorporates particle size distribution (PSD) analysis
after the integration of SAP over time. A blank sample was
characterized by its PSD under natural moisture conditions
for a duration of three minutes. Subsequently, the same
sample underwent a 24-hour drying process at 105°C, and
a PSD analysis was conducted on the resultant moisture-
free sample.
Subsequently, various periods of incorporation were
carried out at each SAP dosage using a laboratory shovel,
with mixing occurring for a specified duration, denoted as
time t. The incorporated sample was then subjected to siev-
ing for a duration of three minutes, adhering to the stan-
dard employed for the blank sample.
Dosage of 900g/t was the most explored dosage, once
the high amount of polymer entails the samples satura-
tion and reduces the environmental and procedures errors.
Times of incorporation for this dosage are: 0s 40s 2 min
4 min 10 min 18 min and 25 min. In the sample time 0,
SAP was spread and direct sieved during 3 min as the stan-
dard sieving procedure. At dosage 900g/t (natural moisture
basis) kinetic test into a longer incorporation time, as such
as 10 min and 18 min, previous incorporated samples were
used (samples time 0s and 2 min) with a second sieving after
the total time past. The method was used aiming to increase
the points population in the kinetic curves even with the
samples amount limitation. Results has shown a minimized
impact of incorporation methodology into a longer time.
Dosage of 600g/t was tested within 40s 2 min 4 min
10 min and 25 min, where samples 10 min and 25 min are
previous incorporated samples (40s and 2 min).
Dosage of 300g/t was tested under the same conditions
as the previous dosage, except for the test at 4 minutes of
incorporation.
The results analysis involves an apparent particle size
distribution (PDS) through examination the undersize
fraction of the sample, coupled with a comparison of screen
efficiency. This efficiency is calculated using a 10 mm cutoff
and normalized with the dried sample set as the reference as
100% efficiency. The selection of the 10 mm cutoff is based
on observed clogging during the sieving process through
aperture of this sieve in the series.
TEST RESULTS AND DISCUSSION
Each polymer showcases individual absorption kinet-
ics, while the trend of the curves remains comparable. As
expected, at a time t, water absorption no longer evolves,
and the maximum absorption is reached. To adjust the
curves, a first simple second-order kinetics model was tested
(Masaro, Zhu 1999). However, its adjustment with the
experimental data was not optimal (R2 0,90). In order to
enhance comprehension of the curve’s structure and equa-
tion, models were generated using both the Python pro-
gramming language and JMP software. The introduction
of an additional degree of freedom facilitated near-perfect
adjustment of the experimental data. The resulting empiri-
cal model takes the following form:
St =Se (1− e–[t(1/b)]/r)
Here, Uu represents the amount of material finer than the
aperture size in the fine product, and Ff is the amount of
feed material finer than a defined cut-point (or cut-size),
such as the screen aperture size.
METHODOLOGY
All ore samples were prepared, homogenized, and divided
in 16 samples for test works. All the samples were lumps
feed produced as direct shipping ore but out of commer-
cial specification, which means top size around 75 mm and
wide size distribution aggregating the fines to the product,
with approximately P80 =23 mm and P50 =12 mm.
SAP Kinetics Protocol for Water Absorption
A protocol has been established with the aim of delineating
the equation that governs the water absorption per gram
of SAP during a specified time. The procedure involves the
sampling of approximately 1g of polymer for each trial. A
quantity of 200 ml of water was measured out in this case,
the water chosen was aligned closely with on-site condi-
tions for this study.
Following this, the polymer is placed into a 400 ml
beaker, and the pre-measured water is carefully poured into
the beaker. The timer is initiated when the first drop of
water falls into the beaker. The presence of polymer lumps,
if any, should be promptly addressed by agitation to dis-
perse them. At a predefined time t the water-polymer mix-
ture is passed through a 50μm sieve, and the liquid that
passes through is collected in a tray. Any remaining water is
thoroughly drained.
Subsequently, the sieve-beaker-polymer assembly, the
tray-water assembly, and the water remaining on the bal-
ance after weighing the sieve-beaker-polymer assembly are
all subjected to weighing. It is crucial to take note of the
tare for each piece of equipment used. The entire procedure
is subsequently replicated at different absorption times to
ensure comprehensive testing. The results were then fine-
tuned to conform to the second-order kinetics equation,
employing statistical analysis to enhance precision.
SAP Kinetics Protocol for Screen Efficiency
To comprehend the behavior of SAP water absorption in the
context of moisture interaction, a protocol has been devised
that incorporates particle size distribution (PSD) analysis
after the integration of SAP over time. A blank sample was
characterized by its PSD under natural moisture conditions
for a duration of three minutes. Subsequently, the same
sample underwent a 24-hour drying process at 105°C, and
a PSD analysis was conducted on the resultant moisture-
free sample.
Subsequently, various periods of incorporation were
carried out at each SAP dosage using a laboratory shovel,
with mixing occurring for a specified duration, denoted as
time t. The incorporated sample was then subjected to siev-
ing for a duration of three minutes, adhering to the stan-
dard employed for the blank sample.
Dosage of 900g/t was the most explored dosage, once
the high amount of polymer entails the samples satura-
tion and reduces the environmental and procedures errors.
Times of incorporation for this dosage are: 0s 40s 2 min
4 min 10 min 18 min and 25 min. In the sample time 0,
SAP was spread and direct sieved during 3 min as the stan-
dard sieving procedure. At dosage 900g/t (natural moisture
basis) kinetic test into a longer incorporation time, as such
as 10 min and 18 min, previous incorporated samples were
used (samples time 0s and 2 min) with a second sieving after
the total time past. The method was used aiming to increase
the points population in the kinetic curves even with the
samples amount limitation. Results has shown a minimized
impact of incorporation methodology into a longer time.
Dosage of 600g/t was tested within 40s 2 min 4 min
10 min and 25 min, where samples 10 min and 25 min are
previous incorporated samples (40s and 2 min).
Dosage of 300g/t was tested under the same conditions
as the previous dosage, except for the test at 4 minutes of
incorporation.
The results analysis involves an apparent particle size
distribution (PDS) through examination the undersize
fraction of the sample, coupled with a comparison of screen
efficiency. This efficiency is calculated using a 10 mm cutoff
and normalized with the dried sample set as the reference as
100% efficiency. The selection of the 10 mm cutoff is based
on observed clogging during the sieving process through
aperture of this sieve in the series.
TEST RESULTS AND DISCUSSION
Each polymer showcases individual absorption kinet-
ics, while the trend of the curves remains comparable. As
expected, at a time t, water absorption no longer evolves,
and the maximum absorption is reached. To adjust the
curves, a first simple second-order kinetics model was tested
(Masaro, Zhu 1999). However, its adjustment with the
experimental data was not optimal (R2 0,90). In order to
enhance comprehension of the curve’s structure and equa-
tion, models were generated using both the Python pro-
gramming language and JMP software. The introduction
of an additional degree of freedom facilitated near-perfect
adjustment of the experimental data. The resulting empiri-
cal model takes the following form:
St =Se (1− e–[t(1/b)]/r)