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Article

Efficient and Green Flotation Separation of Molybdenite from Chalcopyrite Using 1-Thioglycerol as Depressant

by
Feng Jiang
1,2,
Shuai He
1,2,
Wei Sun
1,2,
Yuanjia Luo
1,2 and
Honghu Tang
1,2,*
1
School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
2
Engineering Research Center of Ministry of Education for Carbon Emission Reduction in Metal Resource Exploitation and Utilization, Central South University, Changsha 410083, China
*
Author to whom correspondence should be addressed.
Metals 2025, 15(3), 299; https://doi.org/10.3390/met15030299
Submission received: 18 February 2025 / Revised: 7 March 2025 / Accepted: 7 March 2025 / Published: 9 March 2025
(This article belongs to the Special Issue Advances in Flotation Separation and Mineral Processing)
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Abstract

The effective and environmental separation of chalcopyrite and molybdenite has long presented a challenge in mineral processing due to their similar floatability and close association at room temperature. This study explores the non-toxic 1-thioglycerol (1-TG) as a selective depressant for chalcopyrite–molybdenite flotation separation. An impressive separation effect was realized through single-mineral and mixed-mineral flotation experiments when using 1-TG as a depressant and kerosene as a collector. Contact angle measurements, zeta potential tests, and Fourier transform infrared spectroscopy (FT-IR) confirm the selective adsorption of 1-TG on the chalcopyrite surface, leading to enhanced surface hydrophilicity and the inhibition of collector adsorption. The depression mechanism is further elucidated through X-ray photoelectron spectroscopy (XPS), which demonstrates that it occurs via chemosorption between the thiol group in 1-TG and active iron sites on the chalcopyrite surface. These findings provide a potential efficient depressant for chalcopyrite–molybdenite flotation separation with low dosage, environmental friendliness, and human harmlessness.

Graphical Abstract

1. Introduction

Copper and molybdenum, as essential non-ferrous metals and strategic resources, play an irreplaceable role in economic development. Copper, prized for its excellent electrical conductivity, thermal conductivity, and ductility, is extensively used in construction, power generation, machinery manufacturing, and defense industries [1,2]. Molybdenum, renowned for its exceptional thermal expansion properties, high-temperature strength, and wear resistance, is predominantly utilized in steelmaking, aerospace, electronics, and pharmaceuticals [3]. Chalcopyrite and molybdenite are the principal mineral sources of copper and molybdenum, respectively. Approximately 70% of the world’s copper resources are derived from chalcopyrite [4], while molybdenite, with its distinctive layered crystal structure and strong hydrophobicity, is the primary target for molybdenum extraction [5,6]. Chalcopyrite and molybdenite are often found together in porphyry sulfide deposits [7], and a two-stage flotation process is typically employed to separate chalcopyrite and molybdenite. In the first stage, both minerals are floated together to produce a mixed copper–molybdenum concentrate. During the second stage, selective depressants are introduced to realize chalcopyrite and molybdenite separation [8,9,10].
The main depressants used in the copper–molybdenum separation process can be broadly classified into two categories: inorganic and organic depressants. Their primary role is to weaken the interaction between minerals and collectors, reducing the hydrophobicity of the mineral surfaces and facilitating effective separation [11]. Inorganic depressants typically include substances such as sodium sulfide, sodium hydrosulfide, cyanide, Nokes’ reagent, sodium thiosulfate, ferrate, and sodium metabisulfite [12,13,14,15,16]. During the separation of copper–molybdenum mixed concentrates, inorganic depressants like sodium sulfide, sodium hydrosulfide, cyanide, and Nokes’ reagent decompose to generate SH− and CN− ions. These ions can replace the xanthate adsorbed on the surface of chalcopyrite, thereby increasing its hydrophilicity. Meanwhile, depressants like sodium thiosulfate, ferrate, and sodium metabisulfite form hydrophilic sulfate layers on the chalcopyrite surface, removing residual collectors from earlier separation stages and making the chalcopyrite surface more hydrophilic. This allows for the effective separation of copper and molybdenum, as collectors are less likely to adsorb onto the now hydrophilic chalcopyrite surface. Although inorganic depressants such as sodium sulfide, sodium hydrosulfide, sodium thiosulfate, and sodium metabisulfite are cost-effective and exhibit strong inhibition, their corrosive and toxic properties pose significant environmental hazards when used in large quantities in mineral processing plants. This has highlighted the need for the development of efficient, low-cost, and environmentally friendly organic depressants [17].
In recent years, various novel organic depressants have been developed for the separation of chalcopyrite from molybdenite, including thioglycolic acid, amidinothiourea, modified copolymerized polyacrylamide, 3-amino-5-mercapto-1,2,4-triazole, and 3-mercaptopropionic acid [18,19,20,21,22]. Most of these organic depressants possess hydrophilic carboxyl or hydroxyl groups, as well as thiol groups that exhibit strong adsorption to minerals. During the separation of copper–molybdenum concentrates, the thiol groups selectively adsorb onto Cu and Fe sites on the chalcopyrite surface, while the hydrophilic groups of the depressant help suppress chalcopyrite flotation. Due to the complex pre-treatment modification required for high-molecular-weight organic depressants, such as polyacrylamide (PAM), their application is currently limited to laboratory research [23]. However, with increasing environmental regulations and awareness in the mining industry, the development of efficient and biodegradable small-molecule organic depressants remains a key focus in copper–molybdenum separation research. Sodium thioglycolate, a commonly used small-molecule organic depressant in copper–molybdenum separation, selectively inhibits the surface of chalcopyrite, reducing the co-flotation of chalcopyrite and molybdenite. While it effectively suppresses chalcopyrite, sodium thioglycolate has little impact on molybdenite, preserving its floatability and enabling the effective separation of the two minerals. However, the required dosage of sodium thioglycolate is relatively high (3 × 10−3 mol/L) [20], and the certain toxicity of sodium thioglycolate is also a threat to human health [24]. In this regard, searching for a candidate with no toxicity and dual or multiple hydrophilic groups may address the above-mentioned problem. 1-Thioglycerol (1-TG), as a non-toxic small-molecule organic, is widely used as a stabilizer and modifier for nanoparticles due to its strong association with metal ions [25,26]. Benefiting from the dual hydroxyl groups in 1-TG, it has great potential to be adopted as a high-efficiency, green, and safe depressant for copper–molybdenum flotation separation.
In this study, a detailed examination was conducted to assess the effect of 1-TG on enhancing the flotation separation of chalcopyrite and molybdenite. Systematic micro-flotation experiments were performed to investigate the selective adsorption characteristics and depression efficiency of 1-TG on chalcopyrite. Additionally, techniques such as Fourier transform infrared spectroscopy (FTIR), contact angle measurements, zeta potential analysis, and X-ray photoelectron spectroscopy (XPS) were employed to thoroughly investigate the depression mechanism of 1-TG on chalcopyrite.

2. Experimental Materials and Methods

2.1. Materials and Reagents

Natural chalcopyrite was obtained from Dongchuan City, Yunnan Province, China, while natural molybdenite was sourced from Jiangxi Province, China. Initially, the chalcopyrite and molybdenite lumps were crushed and hand-selected to obtain high-purity samples. The purified samples were then dry-ground in ceramic jars and sieved. Samples with particle sizes in the range of 38–75 μm were used for flotation experiments, whereas those smaller than 38 μm were subjected to XRD, FT-IR, zeta potential, and XPS testing. The samples were stored in vacuum-sealed plastic bags to prevent oxidative deterioration [18]. XRD (Figure 1) results confirmed the high purity of the chalcopyrite and molybdenite samples, as evidenced by the absence of impurity peaks.
In this study, deionized water with a resistivity of 18 MΩ·cm was used to prepare all solutions and slurries. Kerosene served as a collector, while 1-thioglycerol was employed as a depressant, and terpinol was selected as a frother. The pH of the slurry was adjusted using HCl and NaOH. All reagents—kerosene, 1-thioglycerol, terpinol, HCl, and NaOH—were analytically pure and sourced from Shanghai Aladdin Biochemical Science and Technology Co., China (Shanghai, China).

2.2. Micro-Flotation Experiments

Micro-flotation experiments were conducted in a 40 mL plexiglas cell using an XFG flotation machine (Jilin Mining Machinery Manufacturing Co., Ltd., Jilin, China). For the single-mineral flotation test, 2.0 g of natural chalcopyrite or natural molybdenite was weighed and placed into the flotation cell. Then, 40 mL of deionized water was added, and agitation was commenced at 1800 r/min. Upon starting agitation, the pH of the slurry was adjusted using HCl and NaOH to maintain stability in the pH range of 2 to 12 for 3 min. Next, 1-TG was added as a depressant and agitated for 2 min, followed by the addition of kerosene as a collector and further agitation for 2 min, and then terpinol as a frother with 1 min of agitation. The mineral particles, along with rising froth, were manually collected as concentrate for 3 min. The suspension was then filtered, and the remaining mineral particles in the flotation cell were recovered from the filter paper as flotation tailings. For the artificial mixed ore flotation test, 1.0 g of natural chalcopyrite and an equal amount of natural molybdenite were added to the flotation cell. The pH was adjusted to the optimal value of 6, and flotation was conducted following the same steps used for the single-mineral flotation.

2.3. Zeta Potential Measurements

A ZEN3600/nano ZS analyzer (Malvern Zetasizer, UK) was used to investigate changes in the electrical potential of 1-TG adsorbed onto chalcopyrite and molybdenite surfaces. The natural samples smaller than 38 μm were ground to a particle size of less than 5 μm. In total, 0.04 g of the sample was added to 40 mL of 10−3 mol/L KCl electrolyte solution. After adjusting the flotation slurry to the desired pH using HCl and NaOH, 1-TG was added. The mixture was then stirred for 5 min and allowed to stand for 10 min. After settling, the supernatant was carefully drawn with a syringe and transferred to a Malvern potential cuvette for zeta potential measurements. Each test was performed three times, and the mean and variance of the results were recorded.

2.4. FT-IR Measurements

In this experiment, FT-IR spectra reagents and minerals were measured using an IRAffinity-1 FT-IR spectrometer (Shimadzu Instrument Co., Ltd., Kyoto, Japan). A 40 mL volume of deionized water, along with the sample and reagent, was added to the flotation cell and stirred for 20 min. The pulp was filtered and washed three times with deionized water, and then dried in an oven at 45 °C for 24 h. Infrared spectra were acquired in transmission mode using the KBr pellet method [27].

2.5. Contact Angle Measurements

The contact angle test is a fundamental method for directly evaluating the wettability and floatability of mineral surfaces at the macroscopic level, typically expressed as the angle between the solid and liquid on the mineral surface. A larger contact angle indicates a more hydrophobic and floatable mineral surface, while a smaller contact angle suggests reduced hydrophobicity and floatability [28,29,30]. The contact angle of molybdenite and chalcopyrite samples was measured using a JC2000C device (Zhongchen, Shanghai, China). The mineral blocks were first polished with 5000 mesh sandpaper, thoroughly cleaned with deionized water, and then immersed in prepared 1-TG and kerosene solutions sequentially. After stirring for 10 min, the samples were dried under a nitrogen flow, and the contact angle was measured. For each sample, three measurements were taken at different locations on the mineral surface, and the average value was recorded.

2.6. XPS Analysis

X-ray photoelectron spectroscopy (XPS) analysis was conducted using a Thermo Fisher Scientific Nexsa spectrometer, equipped with a monochromatic Al Kα light source operating at 15 kV and 10 mA, and a pressure of 5 × 10−10 Pa in the analysis chamber. A pass energy of 50 eV was used for the survey scans. The XPS sampling procedure was consistent with that of the FT-IR method.

3. Results and Discussion

3.1. Flotation Experiments

The effect of 1-TG concentration on the flotation of chalcopyrite and molybdenite was initially investigated using 2.5 × 10−4 mol/L kerosene and 4.5 × 10−4 mol/L terpinol as a collector and frother, respectively, under a natural pH value of about 5. As shown in Figure 2a, 1-TG exhibited a significant depression effect on chalcopyrite flotation, with flotation recovery gradually decreasing as the concentration of 1-TG increased. In contrast, the molybdenite recovery stayed above 90% until the 1-TG concentration exceeded 2.8 × 10−4 mol/L. At this concentration, the difference in flotation recovery between chalcopyrite and molybdenite was maximized. Specifically, chalcopyrite recovery was 24.21%, while molybdenite recovery was 91.96%.
Figure 2b shows the impact of the pH value on the flotation of chalcopyrite and molybdenite when using 2.8 × 10−4 mol/L 1-TG as a depressant, 2.5 × 10−4 mol/L kerosene as a collector, and 4.5 × 10−4 mol/L terpinol as a frother. The flotation recovery of molybdenite exhibited a slight decrease with the increasing pH value. However, the recovery trend of chalcopyrite varied significantly with pH, reaching its lowest point within the pH range of 4 to 6. To align with the neutral pH conditions commonly used in actual copper–molybdenum separation processes at concentrator plants, this study selected pH 6 as the optimal condition for separating chalcopyrite and molybdenite. Under this condition, flotation experiments were conducted using artificially mixed ore, with the mass ratio of molybdenite to chalcopyrite maintained at 1:1.
Figure 3 illustrates the results of flotation tests on an artificial mixture of chalcopyrite and molybdenite in a 1:1 mass ratio. The recovery rates of molybdenum and copper were 97.05% and 24.34%, respectively. The flotation concentrate contained 45.03% molybdenum and 10.45% copper. The approximately 70% difference in recovery between the two minerals underscores the excellent selective inhibition of 1-TG for the separation of chalcopyrite and molybdenite.

3.2. Contact Angle Test

Figure 4 illustrates the effects of 1-TG (2.8 × 10−4 mol/L) and kerosene (2.5 × 10−4 mol/L) on the surface contact angles of chalcopyrite and molybdenite. The contact angles of untreated chalcopyrite and molybdenite were 74° and 89°, respectively. After treatment with 1-TG, the contact angles decreased to 40° for chalcopyrite and 86° for molybdenite. Treatment with kerosene increased the contact angles to 93° for chalcopyrite and 108° for molybdenite. When treated first with 1-TG and then with kerosene, the contact angles were 68° for chalcopyrite and 106° for molybdenite. The decrease in the contact angle of chalcopyrite from 74° to 40° after treatment with 1-TG, indicating the strong reaction between the chalcopyrite surface and 1-TG. Additionally, 1-TG significantly inhibited the kerosene adsorption on chalcopyrite surface, maintaining a relatively low contact angle. For molybdenite, the contact angle on its surface showed only slight variation after treatment with 1-TG, retaining strong hydrophobicity even after subsequent kerosene treatment. These results demonstrate that 1-TG has a highly selective impact on the wettability of chalcopyrite, consistent with the flotation test results.

3.3. Zeta Potential Characterizations

To better understand the interaction mechanism of 1-TG with chalcopyrite and molybdenite, the zeta potential of both minerals was measured in the presence and absence of 1-TG (2.8 × 10−4 mol/L), as shown in Figure 5. The relationship between zeta potential changes and the adsorption of flotation reagents on mineral surfaces is well established, with larger shifts in zeta potential indicating greater adsorption of flotation chemicals [31]. As depicted in Figure 5, the points of zero charge (PZCs) for chalcopyrite and molybdenite are approximately 4.1 and 1.2, respectively, consistent with values reported in the literature [32,33]. The zeta potential of both minerals decreases significantly with increasing pH. The addition of 1-TG resulted in a more pronounced negative shift in the zeta potential of chalcopyrite, while molybdenite showed little change. Notably, at pH 6, the zeta potential of chalcopyrite shifted by −9.63 mV, compared to only −1.80 mV for molybdenite. This suggests that 1-TG adsorbed more readily on the surface of chalcopyrite, leading to better selective inhibition of chalcopyrite particles compared to molybdenite in the flotation process.

3.4. FT-IR Analysis

Given 1-thioglycerol’s strong selective inhibition of chalcopyrite, its adsorption mechanism on mineral surfaces was extensively investigated through infrared spectroscopy, with the results presented in Figure 6. Figure 6a illustrates the FT-IR spectra of kerosene and 1-TG. For kerosene, the peaks at 2957, 2925, and 2852 cm−1 correspond to the C-H stretching vibrations of the -CH, -CH3, and -CH2 groups, respectively. Additionally, the peaks at 1460 and 1380 cm−1 are attributed to the symmetric bending vibration of -CH3, while the peak at 725 cm−1 is linked to the deformation vibration of -(CH2)n- [34,35]. In the case of 1-TG, the peak at 2553 cm−1 corresponds to the S-H stretching vibration, the peak at 2930 cm−1 to the antisymmetric stretching of C-H in the -CH2 group, the peak at 3335 cm−1 to the -OH stretching vibration, the peak at 1417 cm−1 to the -CH2 shear vibration, and the peak at 1025 cm−1 to the C-O stretching absorption [36,37].
Figure 6b shows the FT-IR spectral changes in chalcopyrite following different reagent treatments. After 1-TG treatment, a stretching vibrational peak for the sulfhydryl group emerged at 2555 cm−1, confirming 1-TG adsorption on the chalcopyrite surface. When chalcopyrite was treated with kerosene, new C-H stretching peaks at 2925 cm−1 and 2854 cm−1, corresponding to methyl and methylene groups, appeared—indicating kerosene adsorption on chalcopyrite. Notably, when chalcopyrite was first treated with 1-TG followed by kerosene, the characteristic peak of 1-TG at 2557 cm−1 remained visible, and the kerosene peaks vanished. This suggests that the adsorption of kerosene is significantly depressed by the 1-TG on the chalcopyrite surface.
For molybdenite (Figure 6c), treatment with 1-TG showed no change compared to the untreated sample, indicating the absence of 1-TG adsorption on molybdenite. However, kerosene treatment led to the appearance of strong C-H stretching peaks at 2962 cm−1, 2919 cm−1, and 2852 cm−1, along with the symmetric bending vibration of -CH3 at 1459 cm−1, indicating robust adsorption of kerosene on the molybdenite surface, stronger than that of chalcopyrite. When molybdenite was treated with both 1-TG and kerosene, the intensity of kerosene peaks remained strong, suggesting no influence of 1-TG on the interaction between kerosene and molybdenite.

3.5. XPS Analysis

To further investigate the adsorption mechanism of 1-TG on the mineral surface, the bonding state of elements was analyzed using X-ray photoelectron spectroscopy (XPS) to explore surface changes [31]. Figure 7a presents the high-resolution Cu 2p XPS spectra of the chalcopyrite surface before and after treatment with 1-TG. The Cu 2p3/2 XPS spectrum of untreated chalcopyrite reveals four peaks: The peak at 932.14 eV corresponds to CuFeS2 in the chalcopyrite lattice, while those at 933.75 eV and 934.26 eV are attributed to CuO and Cu(OH)2, respectively [38]. Additionally, the peak at 931.61 eV represents Cu2S [39]. Following treatment with 1-TG, the position of the CuFeS2 peak in the Cu 2p3/2 XPS spectra remained essentially unchanged, indicating that the adsorption sites on the chalcopyrite surface are not located on Cu atoms.
The Fe 2p3/2 XPS spectra for both untreated and 1-TG-treated chalcopyrite are shown in Figure 7b. Peaks at 707.40 eV and 708.25 eV are associated with FeS and Fe(III)-S, respectively, while the peak at 710.89 eV corresponds to the oxidation of chalcopyrite, leading to the formation of Fe oxides/hydroxides. The higher binding energy peak at 713.25 eV indicates the presence of iron sulfate on the chalcopyrite surface [40]. After treatment with 1-TG, significant changes were observed in the Fe 2p3/2 spectra: the Fe(III)-S peak shifted from 708.25 eV to 708.52 eV. These shifts suggest interactions between the -SH group of 1-TG and Fe sites on the chalcopyrite surface [20].
Figure 7c presents the S 2p spectrum of untreated chalcopyrite, where peaks at 161.33 eV, 162.47 eV, 163.03 eV, and 164.99 eV correspond to S2−, S22−, Sn2−, and energy loss, respectively [40]. After the addition of 1-TG, the peaks appeared at 161.13 eV, 162.33 eV, 163.66 eV, and 164.94 eV, corresponding to the same species (S2−, S22−, Sn2−, and energy loss). Additionally, a new peak at 162.80 eV, attributed to the interaction between mercaptans and metal atoms [19], appeared. It is reasonable to speculate that the new peak near 162.76 eV originates from the coordination between the sulfhydryl group of 1-TG and Fe atoms in chalcopyrite. This peak indicates a strong chemosorption interaction between 1-TG and Fe sites on the chalcopyrite surface.
Figure 8a,b display the Mo 3d and S 2p spectra of molybdenite before and after treatment with 1-TG. No significant changes were observed, indicating that 1-TG does not react with molybdenite.

3.6. Possible Adsorption Mechanism

Based on all the previous results, Figure 9 illustrates the probable adsorption mechanism of 1-TG on the chalcopyrite surface. Infrared spectroscopy and XPS analyses revealed that the S-H group in 1-TG chemisorbs to the active iron sites on the chalcopyrite surface, forming a stable bond. This chemosorption remains intact when the mineral interacts with subsequent collectors, resulting in the formation of a complex between 1-TG and chalcopyrite, which enhances the hydrophilicity of the chalcopyrite surface. Conversely, 1-TG shows minimal reactivity with molybdenite and does not interfere with the adsorption of kerosene on molybdenite, aiding in the separation of chalcopyrite and molybdenite during flotation.

4. Conclusions

This study systematically investigated the feasibility of employing 1-thioglycerol (1-TG) as a selective depressant for the flotation separation of chalcopyrite and molybdenite and demonstrated the depression mechanism of the 1-TG on the chalcopyrite surface. Based on the results and subsequent analysis, the following key conclusions can be drawn:
(1)
1-TG demonstrated a strong depression effect on chalcopyrite flotation, with minimal impact on molybdenite when kerosene was used as the collector at pH 6.
(2)
Robust adsorption was realized between 1-TG and the chalcopyrite surface, which realized the selectively enhanced hydrophilicity of the chalcopyrite surface and the inhibition of subsequent collector adsorption.
(3)
The interaction between 1-TG and chalcopyrite was driven by the chemosorption of the S-H group with active iron sites on the chalcopyrite surface.

Author Contributions

Conceptualization, F.J.; methodology, F.J. and Y.L.; formal analysis, Y.L.; Investigation, F.J., S.H. and W.S.; resources, W.S.; data curation, S.H.; writing—original draft, F.J.; writing—review and editing, S.H., Y.L. and H.T.; supervision, H.T.; project administration, H.T.; funding acquisition, F.J. All authors have read and agreed to the published version of the manuscript.

Funding

This research was funded by the [National Key R&D Program of China] grant number [2022YFC2904502, 2022YFC2904501] and the [National Natural Science Foundation of China] grant number [52204298].

Data Availability Statement

The original contributions presented in this study are included in the article. Further inquiries can be directed to the corresponding author.

Conflicts of Interest

The authors declare no conflict of interest.

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Figure 1. XRD patterns of (a) chalcopyrite and (b) molybdenite samples.
Figure 1. XRD patterns of (a) chalcopyrite and (b) molybdenite samples.
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Figure 2. Flotation recovery rates of chalcopyrite and molybdenite vary with the (a) concentration of 1-TG and (b) pH value (2.8 × 10−4 mol/L 1-TG, 2.5 × 10−4 mol/L kerosene, and 4.5 × 10−4 mol/L terpineol).
Figure 2. Flotation recovery rates of chalcopyrite and molybdenite vary with the (a) concentration of 1-TG and (b) pH value (2.8 × 10−4 mol/L 1-TG, 2.5 × 10−4 mol/L kerosene, and 4.5 × 10−4 mol/L terpineol).
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Figure 3. Recovery rate and grade of flotation concentrate for artificially mixed ore were measured at room temperature.
Figure 3. Recovery rate and grade of flotation concentrate for artificially mixed ore were measured at room temperature.
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Figure 4. Contact angles of chalcopyrite and molybdenite before and after treatment with various reagents.
Figure 4. Contact angles of chalcopyrite and molybdenite before and after treatment with various reagents.
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Figure 5. Zeta potentials of (a) chalcopyrite and (b) molybdenite versus pH value.
Figure 5. Zeta potentials of (a) chalcopyrite and (b) molybdenite versus pH value.
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Figure 6. FT-IR spectra of (a) kerosine and 1-TG; (b) chalcopyrite and (c) molybdenite treated with different reagents.
Figure 6. FT-IR spectra of (a) kerosine and 1-TG; (b) chalcopyrite and (c) molybdenite treated with different reagents.
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Figure 7. (a) Cu 2p3/2, (b) Fe 2p3/2, and (c) S 2p high-resolution XPS spectra of chalcopyrite.
Figure 7. (a) Cu 2p3/2, (b) Fe 2p3/2, and (c) S 2p high-resolution XPS spectra of chalcopyrite.
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Figure 8. (a) Mo 3d and (b) S 2p high-resolution XPS spectra of molybdenite.
Figure 8. (a) Mo 3d and (b) S 2p high-resolution XPS spectra of molybdenite.
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Figure 9. Illustration of the probable adsorption mechanism of 1-TG on chalcopyrite surface.
Figure 9. Illustration of the probable adsorption mechanism of 1-TG on chalcopyrite surface.
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MDPI and ACS Style

Jiang, F.; He, S.; Sun, W.; Luo, Y.; Tang, H. Efficient and Green Flotation Separation of Molybdenite from Chalcopyrite Using 1-Thioglycerol as Depressant. Metals 2025, 15, 299. https://doi.org/10.3390/met15030299

AMA Style

Jiang F, He S, Sun W, Luo Y, Tang H. Efficient and Green Flotation Separation of Molybdenite from Chalcopyrite Using 1-Thioglycerol as Depressant. Metals. 2025; 15(3):299. https://doi.org/10.3390/met15030299

Chicago/Turabian Style

Jiang, Feng, Shuai He, Wei Sun, Yuanjia Luo, and Honghu Tang. 2025. "Efficient and Green Flotation Separation of Molybdenite from Chalcopyrite Using 1-Thioglycerol as Depressant" Metals 15, no. 3: 299. https://doi.org/10.3390/met15030299

APA Style

Jiang, F., He, S., Sun, W., Luo, Y., & Tang, H. (2025). Efficient and Green Flotation Separation of Molybdenite from Chalcopyrite Using 1-Thioglycerol as Depressant. Metals, 15(3), 299. https://doi.org/10.3390/met15030299

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