2750 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
mineral surface (Yehia et al., 2021). Under the appropriate
depressant system, the development of new collectors sig-
nificantly impacts the efficiency of impurity removal in the
reverse flotation process. In recent years, many influential
collectors have been designed based on the types and con-
centrations of metal ions in gangue minerals and the char-
acteristics of the fractured exposed surface. Northeastern
University has successfully developed modified fatty acid
collectors by introducing atoms or group such as Cl, Br,
or amine into the α-position carbon atoms of fatty acid.
Modified fatty acid collectors have been successfully devel-
oped and achieved good commercial application(Zhu et
al., 2015 Zhu et al., 2016). At the same time, TD-2, CY
series anion collectors, and GE series cation collectors also
showed good application effects (Jiang et al., 2018 Mei et
al., 2016 Xiong et al., 2012 Zhou et al., 2020).
Although the development of flotation reagents has
significantly improved the efficiency of iron ore reverse
flotation. However, it is a difficult problem for hematite
ore with fine particles and complex associated components
to obtain high iron grade and recovery. This type of ore
required fine grinding to dissociate the mineral monomers
(Xu et al., 2020). And the fine-grained silicate minerals
were produces, which can reduce the flotation efficiency. As
the particle size decreased, the probability of collision with
conventional bubbles was diminished. Simultaneously, the
flotation effect of the target mineral would also deteriorate
due to the coverage on the surface (Lima et al., 2020 Yu
et al., 2017). Research results showed that strengthening
the wettability difference at the mineral interface through
reagents was the prerequisite for solving the problem (Koh
et al., 2009). To enhance the separation efficiency, it is still
necessary to appropriately increase the apparent particle size
of minerals or reduce the bubble size (Wang et al., 2021).
The preferential enrichment of micro-nanobubbles on the
surface of hydrophobic particles enables the interface nano-
bubbles to agglomerate fine-grained minerals selectively
(Cheng et al., 2023). Moreover, the flotation effect and
recovery could be enhanced through increasing the prob-
ability of collision and attachment between agglomerated
particles and conventional bubbles (Zhang et al., 2021a).
At the same time, A.H. Englert et al. used dissolved air
flotation to compare the effects of two different flotation
devices on fine-grained quartz flotation. The recovery of
fine-grained quartz was increased from 6% to 53% when
using amine collectors for interface control and introduc-
ing micro-nano bubbles (Englert et al., 2009). This result
verifies that flotation recovery can be effectively improved
by reducing bubble size and increasing the collision prob-
ability between bubbles and fine-grained minerals (Tao,
2022 Tao et al., 2021).
This study focuses on refractory hematite ores contain-
ing silicate minerals, which is easy to muddied and consider
chlorite and hematite as the research objects. The effect of
introducing micro-nano bubbles on its flotation separation
effect was investigated. Strengthened mechanism analysis
was carried out through mineral flotation experiments,
combined with analysis of reagent adsorption characteris-
tics and visual observation of particles and bubbles.
MATERIALS AND METHODS
Materials and Reagents
Chlorite and hematite samples were taken from Hebei and
Liaoning provinces, respectively. High-purity ore blocks
were selected for grinding. The products were screened to
obtain mineral samples with particle sizes of 38–74 μm for
experiments. Samples were subjected to chemical multi-ele-
ment and physical phase detection to analyze their purity.
The results are shown in Table 1 and Figure 1, indicate that
the purity of the sample meets the test requirements. The
reagents used in the experiment were α-Bromolauric acid
(α-BLA), starch, calcium chloride, methyl amyl alcohol
(MIBC), hydrochloric acid, and sodium hydroxide. α-BLA
is a laboratory-made anionic collector. The starch is food-
grade corn starch purchased from Tianjin Comeo, which
depresses the floatability of hematite. Calcium chloride was
used to activate chlorite and was purchased from Sinopharm
Chemical Group. MIBC, hydrochloric acid, and sodium
hydroxide were purchased from Tianjin Comeo Company.
They were used to prepare micro-nano bubble water and
adjust the pH of the slurry, respectively.
Experiment and Analysis Methods
Flotation experiments are divided into single mineral
and artificial mixed mineral experiments. The sample was
stirred in a 35 ml flotation tank for 2 min and the slurry
pH during this process was adjusted. Then, the depressant,
activator, and collector were added in sequence, with each
reagent having an action time of 3 minutes. A control group
experiment was set up to observe the impact of micro-nano
Table 1. Chemical composition analysis results of samples
Composition TFe S P FeO MgO CaO SiO2 Al2O3
Hematite 69.42 0.016 0.026 0.74 — 0.096 0.35 0.15
Chlorite 8.17 0.047 0.041 — 11.39 0.99 51.29 15.32
mineral surface (Yehia et al., 2021). Under the appropriate
depressant system, the development of new collectors sig-
nificantly impacts the efficiency of impurity removal in the
reverse flotation process. In recent years, many influential
collectors have been designed based on the types and con-
centrations of metal ions in gangue minerals and the char-
acteristics of the fractured exposed surface. Northeastern
University has successfully developed modified fatty acid
collectors by introducing atoms or group such as Cl, Br,
or amine into the α-position carbon atoms of fatty acid.
Modified fatty acid collectors have been successfully devel-
oped and achieved good commercial application(Zhu et
al., 2015 Zhu et al., 2016). At the same time, TD-2, CY
series anion collectors, and GE series cation collectors also
showed good application effects (Jiang et al., 2018 Mei et
al., 2016 Xiong et al., 2012 Zhou et al., 2020).
Although the development of flotation reagents has
significantly improved the efficiency of iron ore reverse
flotation. However, it is a difficult problem for hematite
ore with fine particles and complex associated components
to obtain high iron grade and recovery. This type of ore
required fine grinding to dissociate the mineral monomers
(Xu et al., 2020). And the fine-grained silicate minerals
were produces, which can reduce the flotation efficiency. As
the particle size decreased, the probability of collision with
conventional bubbles was diminished. Simultaneously, the
flotation effect of the target mineral would also deteriorate
due to the coverage on the surface (Lima et al., 2020 Yu
et al., 2017). Research results showed that strengthening
the wettability difference at the mineral interface through
reagents was the prerequisite for solving the problem (Koh
et al., 2009). To enhance the separation efficiency, it is still
necessary to appropriately increase the apparent particle size
of minerals or reduce the bubble size (Wang et al., 2021).
The preferential enrichment of micro-nanobubbles on the
surface of hydrophobic particles enables the interface nano-
bubbles to agglomerate fine-grained minerals selectively
(Cheng et al., 2023). Moreover, the flotation effect and
recovery could be enhanced through increasing the prob-
ability of collision and attachment between agglomerated
particles and conventional bubbles (Zhang et al., 2021a).
At the same time, A.H. Englert et al. used dissolved air
flotation to compare the effects of two different flotation
devices on fine-grained quartz flotation. The recovery of
fine-grained quartz was increased from 6% to 53% when
using amine collectors for interface control and introduc-
ing micro-nano bubbles (Englert et al., 2009). This result
verifies that flotation recovery can be effectively improved
by reducing bubble size and increasing the collision prob-
ability between bubbles and fine-grained minerals (Tao,
2022 Tao et al., 2021).
This study focuses on refractory hematite ores contain-
ing silicate minerals, which is easy to muddied and consider
chlorite and hematite as the research objects. The effect of
introducing micro-nano bubbles on its flotation separation
effect was investigated. Strengthened mechanism analysis
was carried out through mineral flotation experiments,
combined with analysis of reagent adsorption characteris-
tics and visual observation of particles and bubbles.
MATERIALS AND METHODS
Materials and Reagents
Chlorite and hematite samples were taken from Hebei and
Liaoning provinces, respectively. High-purity ore blocks
were selected for grinding. The products were screened to
obtain mineral samples with particle sizes of 38–74 μm for
experiments. Samples were subjected to chemical multi-ele-
ment and physical phase detection to analyze their purity.
The results are shown in Table 1 and Figure 1, indicate that
the purity of the sample meets the test requirements. The
reagents used in the experiment were α-Bromolauric acid
(α-BLA), starch, calcium chloride, methyl amyl alcohol
(MIBC), hydrochloric acid, and sodium hydroxide. α-BLA
is a laboratory-made anionic collector. The starch is food-
grade corn starch purchased from Tianjin Comeo, which
depresses the floatability of hematite. Calcium chloride was
used to activate chlorite and was purchased from Sinopharm
Chemical Group. MIBC, hydrochloric acid, and sodium
hydroxide were purchased from Tianjin Comeo Company.
They were used to prepare micro-nano bubble water and
adjust the pH of the slurry, respectively.
Experiment and Analysis Methods
Flotation experiments are divided into single mineral
and artificial mixed mineral experiments. The sample was
stirred in a 35 ml flotation tank for 2 min and the slurry
pH during this process was adjusted. Then, the depressant,
activator, and collector were added in sequence, with each
reagent having an action time of 3 minutes. A control group
experiment was set up to observe the impact of micro-nano
Table 1. Chemical composition analysis results of samples
Composition TFe S P FeO MgO CaO SiO2 Al2O3
Hematite 69.42 0.016 0.026 0.74 — 0.096 0.35 0.15
Chlorite 8.17 0.047 0.041 — 11.39 0.99 51.29 15.32