XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 1977
to obtain fine-grained quartz single mineral. The chemi-
cal composition analysis and XRD analysis results of the
prepared quartz single mineral are presented in Table 1 and
Figure 1b. According to the chemical composition analysis,
the SiO2 content in the quartz single mineral is 99.11%.
The XRD pattern shows no impurity peaks, indicating high
purity of quartz, meeting the experimental requirements.
After grinding, a quartz single mineral was prepared with
–12.5 μm particle size by hydraulic analysis method, and its
particle size characteristic is shown in Figure 2b. As can be
seen from Figure 2b, the average particle size of the quartz
single mineral is 8.29 μm, and the particle size distribution
of each particle grade is uniform, meeting the experimental
requirements.
Modification of Starch Agents
Starch agents can be modified through chemical modifica-
tion to introduce iron-friendly functional groups into the
polymer matrix. This modification enhances the floccula-
tion performance of the modified agents for fine-grained
iron minerals, aiming to improve the iron grade and recov-
ery of fine-grained iron minerals. Chemical modification
methods for starch agents mainly include carboxymethyl-
ation, sulfation, phosphorylation, acylation, etc [10, 12].
In this study, carboxymethylated starch agents with differ-
ent degrees of substitution were prepared, and their degrees
of substitution were determined using improved copper
complexometric titration [13]. The molecular weights of
the starch agents were determined using gel permeation
chromatography (GPC).
Preparation of Carboxymethyl Starch Agents with
Different Degrees of Substitution
The following methods are used to prepare carboxymethyl
starch agents with varying degrees of substitution. First,
heat the water bath to 40 °C. Add 10.0 g of corn or cas-
sava starch in a 350 mL beaker and 40 mL of 95% ethanol.
Place the beaker in the water bath and stir and emulsify
for 10 min. Add sodium hydroxide to the reaction system
(sodium hydroxide: chloroacetic acid molar ratio of 1)
for an alkaline reaction for 4 h. Then, add 7.0, 8.5, 10.0,
11.5, and 13.0 g of chloroacetic acid to the reaction sys-
tem. During this process, a small amount of 95% ethanol
solution is added to adjust the concentration of the reac-
tion system. Add sodium hydroxide (sodium hydroxide:
chloroacetic acid molar ratio of 2.25). Seal the reaction sys-
tem and continue the etherification reaction for 8 h. After
the reaction, adjust the solution pH to around 7.0 with a
10% mass fraction of acetic acid. Filter the product, and
immerse, wash, and filter the filter residue repeatedly with
anhydrous ethanol at least three times. Dry the product at
45 °C for 4 h for five degrees of carboxymethylated corn
and cassava starch substitution.
Degree of Substitution for Starch Reagents
Five different degrees of substitution carboxymethyl starch
were prepared using a solvent method. The degrees of sub-
stitution for the carboxymethyl starches derived from corn
starch (CM-CS) and cassava starch (CM-TS) were deter-
mined using an improved copper complexometric titra-
tion method, and the results are presented in Figure 3.
Experimental data indicate that the best substitution effect
Figure 2. Particle size characteristics of specularite (–12.5 μm) (a) and quartz (–12.5 μm) (b)
to obtain fine-grained quartz single mineral. The chemi-
cal composition analysis and XRD analysis results of the
prepared quartz single mineral are presented in Table 1 and
Figure 1b. According to the chemical composition analysis,
the SiO2 content in the quartz single mineral is 99.11%.
The XRD pattern shows no impurity peaks, indicating high
purity of quartz, meeting the experimental requirements.
After grinding, a quartz single mineral was prepared with
–12.5 μm particle size by hydraulic analysis method, and its
particle size characteristic is shown in Figure 2b. As can be
seen from Figure 2b, the average particle size of the quartz
single mineral is 8.29 μm, and the particle size distribution
of each particle grade is uniform, meeting the experimental
requirements.
Modification of Starch Agents
Starch agents can be modified through chemical modifica-
tion to introduce iron-friendly functional groups into the
polymer matrix. This modification enhances the floccula-
tion performance of the modified agents for fine-grained
iron minerals, aiming to improve the iron grade and recov-
ery of fine-grained iron minerals. Chemical modification
methods for starch agents mainly include carboxymethyl-
ation, sulfation, phosphorylation, acylation, etc [10, 12].
In this study, carboxymethylated starch agents with differ-
ent degrees of substitution were prepared, and their degrees
of substitution were determined using improved copper
complexometric titration [13]. The molecular weights of
the starch agents were determined using gel permeation
chromatography (GPC).
Preparation of Carboxymethyl Starch Agents with
Different Degrees of Substitution
The following methods are used to prepare carboxymethyl
starch agents with varying degrees of substitution. First,
heat the water bath to 40 °C. Add 10.0 g of corn or cas-
sava starch in a 350 mL beaker and 40 mL of 95% ethanol.
Place the beaker in the water bath and stir and emulsify
for 10 min. Add sodium hydroxide to the reaction system
(sodium hydroxide: chloroacetic acid molar ratio of 1)
for an alkaline reaction for 4 h. Then, add 7.0, 8.5, 10.0,
11.5, and 13.0 g of chloroacetic acid to the reaction sys-
tem. During this process, a small amount of 95% ethanol
solution is added to adjust the concentration of the reac-
tion system. Add sodium hydroxide (sodium hydroxide:
chloroacetic acid molar ratio of 2.25). Seal the reaction sys-
tem and continue the etherification reaction for 8 h. After
the reaction, adjust the solution pH to around 7.0 with a
10% mass fraction of acetic acid. Filter the product, and
immerse, wash, and filter the filter residue repeatedly with
anhydrous ethanol at least three times. Dry the product at
45 °C for 4 h for five degrees of carboxymethylated corn
and cassava starch substitution.
Degree of Substitution for Starch Reagents
Five different degrees of substitution carboxymethyl starch
were prepared using a solvent method. The degrees of sub-
stitution for the carboxymethyl starches derived from corn
starch (CM-CS) and cassava starch (CM-TS) were deter-
mined using an improved copper complexometric titra-
tion method, and the results are presented in Figure 3.
Experimental data indicate that the best substitution effect
Figure 2. Particle size characteristics of specularite (–12.5 μm) (a) and quartz (–12.5 μm) (b)