XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 1979
slurry concentration is around 33%. Stirring for 5 minutes
ensures the thorough dispersion of mineral particles. Then,
adjust the stirring speed to 500 r/min, add NaOH to adjust
the slurry pH to 10.0, and stir for 3 min. Add a certain
amount of starch flocculant and stir for 5 min to agglomer-
ate fine-grained minerals. Adjust the high-intensity mag-
netic separator (SSS-II-80*90) with fixed strong magnetic
separation conditions: background magnetic field intensity
of 0.8 T, stroke of 11.40 mm, pulse frequency of 170 times/
min, slurry flow rate of 120 mL/s, and magnetic medium
parameters of 2 mm diameter, filling rate of 13.32% for
cylindrical rod medium. Uniformly feed the pre-treated
slurry for separation, and dry and sample the obtained
magnetic concentrate and tailings for assay. For the screen-
ing test of starch agents, the concentrate yield is used as the
evaluation indicator for strong magnetic separation, and
the yield is calculated as equation (1). For the selectivity
test of starch agents, the iron grade, iron recovery, and ben-
eficiation efficiency of the magnetic separation concentrate
of the specularite-quartz binary mixed ore are taken as the
beneficiation test indexes of the binary mixed ore. The ben-
eficiation efficiency is calculated as equation (2).
M
m 100 #c =(1)
where: γ is concentrate yield, m is the mass of concentrate,
and M is the total mass.
/b E 1
m a
f c =-
-(2)
where: E is beneficiation efficiency, ε is iron recovery, γ is
concentrate yield, α is the iron grade of ore, and βm is the
highest theoretical iron grade of specularite.
Analytical Tests
Microscopic Observation
After the interaction between the starch agents and min-
erals, the microscopic morphology of the aggregates was
observed using a polarizing microscope (ZEISS Axiolab 5).
Aggregated samples were dropped onto glass slides, and
their morphological features were observed at 200 times
magnification.
Zeta Potential Test
The surface potential changes of specularite and quartz
were analyzed using Zeta potential analysis under different
pH value conditions to investigate the interaction mecha-
nisms between the starch agents and specularite or quartz.
Minerals and agents were added to a beaker, and the slurry
pH value was adjusted using hydrochloric acid and sodium
hydroxide. The slurry was stirred with a magnetic stirrer for
3 min, followed by a 10-minute settling period. The upper
clear liquid was then taken for potential analysis. Each sam-
ple group was repeated three times, and the average values
were calculated.
FTIR Analysis
The interaction mechanisms between the starch agents,
specularite, and quartz were explored using an infrared
spectrometer (Nicolet FTIR-740). The samples, dried at
low temperature, were ground with KBr in an agate mortar
at a ratio of 1:100. During the grinding process, a heat-
ing lamp was used to prevent sample moisture and ensure
accurate detection results. The ground samples were then
pressed into pellets using a pelletizer, and the infrared spec-
tra were measured. The measurements were conducted with
a scanning resolution of 4 cm–1 and 32 scans.
RESULTS AND DISCUSSION
Effect of Reagents on Agglomeration-Magnetic
Separation of Specularite
The strong magnetic separation test was conducted under
a slurry pH value of 9 and stirring speed of 500 r/min,
and the experimental results are shown in Figs. 5a-b. As
shown in Figure 5a, it can be observed that when the dos-
age of CM-CS-1 is 50 mg/L, the magnetic separation yield
is 91.51% when the dosage of CM-CS-2 is 44 mg/L, the
magnetic separation yield is 92.42%, and when the dosage
of CM-CS-3 is 26 mg/L, the magnetic separation yield is
92.55%. Overall, CM-CS-3 exhibits the best aggregation
Figure 4. Agglomeration-magnetic separation test process
slurry concentration is around 33%. Stirring for 5 minutes
ensures the thorough dispersion of mineral particles. Then,
adjust the stirring speed to 500 r/min, add NaOH to adjust
the slurry pH to 10.0, and stir for 3 min. Add a certain
amount of starch flocculant and stir for 5 min to agglomer-
ate fine-grained minerals. Adjust the high-intensity mag-
netic separator (SSS-II-80*90) with fixed strong magnetic
separation conditions: background magnetic field intensity
of 0.8 T, stroke of 11.40 mm, pulse frequency of 170 times/
min, slurry flow rate of 120 mL/s, and magnetic medium
parameters of 2 mm diameter, filling rate of 13.32% for
cylindrical rod medium. Uniformly feed the pre-treated
slurry for separation, and dry and sample the obtained
magnetic concentrate and tailings for assay. For the screen-
ing test of starch agents, the concentrate yield is used as the
evaluation indicator for strong magnetic separation, and
the yield is calculated as equation (1). For the selectivity
test of starch agents, the iron grade, iron recovery, and ben-
eficiation efficiency of the magnetic separation concentrate
of the specularite-quartz binary mixed ore are taken as the
beneficiation test indexes of the binary mixed ore. The ben-
eficiation efficiency is calculated as equation (2).
M
m 100 #c =(1)
where: γ is concentrate yield, m is the mass of concentrate,
and M is the total mass.
/b E 1
m a
f c =-
-(2)
where: E is beneficiation efficiency, ε is iron recovery, γ is
concentrate yield, α is the iron grade of ore, and βm is the
highest theoretical iron grade of specularite.
Analytical Tests
Microscopic Observation
After the interaction between the starch agents and min-
erals, the microscopic morphology of the aggregates was
observed using a polarizing microscope (ZEISS Axiolab 5).
Aggregated samples were dropped onto glass slides, and
their morphological features were observed at 200 times
magnification.
Zeta Potential Test
The surface potential changes of specularite and quartz
were analyzed using Zeta potential analysis under different
pH value conditions to investigate the interaction mecha-
nisms between the starch agents and specularite or quartz.
Minerals and agents were added to a beaker, and the slurry
pH value was adjusted using hydrochloric acid and sodium
hydroxide. The slurry was stirred with a magnetic stirrer for
3 min, followed by a 10-minute settling period. The upper
clear liquid was then taken for potential analysis. Each sam-
ple group was repeated three times, and the average values
were calculated.
FTIR Analysis
The interaction mechanisms between the starch agents,
specularite, and quartz were explored using an infrared
spectrometer (Nicolet FTIR-740). The samples, dried at
low temperature, were ground with KBr in an agate mortar
at a ratio of 1:100. During the grinding process, a heat-
ing lamp was used to prevent sample moisture and ensure
accurate detection results. The ground samples were then
pressed into pellets using a pelletizer, and the infrared spec-
tra were measured. The measurements were conducted with
a scanning resolution of 4 cm–1 and 32 scans.
RESULTS AND DISCUSSION
Effect of Reagents on Agglomeration-Magnetic
Separation of Specularite
The strong magnetic separation test was conducted under
a slurry pH value of 9 and stirring speed of 500 r/min,
and the experimental results are shown in Figs. 5a-b. As
shown in Figure 5a, it can be observed that when the dos-
age of CM-CS-1 is 50 mg/L, the magnetic separation yield
is 91.51% when the dosage of CM-CS-2 is 44 mg/L, the
magnetic separation yield is 92.42%, and when the dosage
of CM-CS-3 is 26 mg/L, the magnetic separation yield is
92.55%. Overall, CM-CS-3 exhibits the best aggregation
Figure 4. Agglomeration-magnetic separation test process