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13 pages, 1471 KB

Open AccessArticle

Effect of Frother Type on Surface Properties and Flotation Performance of Galena: A Comparative Study of EH, PPG250, and MIBC

by Yunus Emre Cavdar, Ilayda Asil, Saleban Mohamed Muse, Feridun Boylu and Orhan Ozdemir

Minerals 2025, 15(10), 1044; https://doi.org/10.3390/min15101044 - 1 Oct 2025

Abstract

The selection of suitable frothers in flotation processes plays a crucial role in controlling bubble formation, foam stability, and ultimately mineral recovery. Therefore, understanding the interfacial behavior of frothers is important to optimize flotation efficiency, especially for valuable sulfide minerals such as galena [...] Read more.

The selection of suitable frothers in flotation processes plays a crucial role in controlling bubble formation, foam stability, and ultimately mineral recovery. Therefore, understanding the interfacial behavior of frothers is important to optimize flotation efficiency, especially for valuable sulfide minerals such as galena (PbS). In this study, the interfacial behavior and flotation performance of different frothers in PbS flotation were investigated with a particular focus on surface tension, bubble coalescence, foam stability, and flotation recovery. A high-purity crystalline PbS sample (≈96.65% PbS) obtained from Trabzon, Türkiye, was subjected to systematic experimental analyses including surface tension measurements, critical coalescence concentration (CCC) determination, dynamic foam stability (DFS) tests using the DFA100 analyzer, and micro-flotation experiments. 2-ethylhexanol (EH), polypropylene glycol 250 (PPG250), and methyl isobutyl carbinol (MIBC) were used as frothers, while potassium ethyl xanthate (PEX) was employed as a collector. The results revealed that EH had the highest surface activity (42.67 mN/m at 1000 ppm), and the lowest CCC value (~2 ppm) compared to PPG250 (~3 ppm) and MIBC (~8 ppm). According to the micro-flotation results, the flotation recovery gradually increased with increasing frother dosage; the highest recoveries were obtained with PPG250 (99.45%), EH (98.31%), and MIBC (95.17%). PPG250 and EH achieved higher flotation performance at lower dosages compared to MIBC. These findings highlight the critical role of molecular structure and interfacial properties in the effective selection of frothers for galena flotation. Full article

(This article belongs to the Special Issue Surface Chemistry and Reagents in Flotation)

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16 pages, 2834 KB

Open AccessArticle

The Effect of Particle Size and Dodecylamine Concentration on the Flotation of Lepidolite in Alkaline Medium

by Martín Reyes Pérez, Francisco Patiño Cardona, Hernan Islas Vázquez, Iván Alejandro Reyes Domínguez, Mizraim Uriel Flores Guerrero, Miguel Pérez Labra, Julio Cesar Juárez Tapia, Dayli Yamileth Tolentino Mendoza and Miroslava Mishelle Sánchez Acosta

Minerals 2025, 15(9), 954; https://doi.org/10.3390/min15090954 - 6 Sep 2025

Viewed by 524

Abstract

Currently, lepidolite is considered an important natural alternative for obtaining lithium, given the difficulty in processing other species containing this metal. However, its mechanical preparation and beneficiation present considerable challenges and play a critical role in its efficient separation by flotation. This study [...] Read more.

Currently, lepidolite is considered an important natural alternative for obtaining lithium, given the difficulty in processing other species containing this metal. However, its mechanical preparation and beneficiation present considerable challenges and play a critical role in its efficient separation by flotation. This study explores the effect of particle size and dodecylamine concentration during flotation in a laboratory Denver cell. The results indicate that particle size significantly affects the finding in which the optimum was −90 + 75 μm, with a separation efficiency of 94%, and with only 2.067 × 10⁻⁵ M of dodecylamine (DDA) (5 g/t) at pH 11.0. The hydrophobicity of lepidolite was generated by the effect of the chemisorption of the cationic collector and the FTIR results indicate detection of the characteristic bands of the adsorption of DDA to the surface of lepidolite. Full article

(This article belongs to the Special Issue Surface Chemistry and Reagents in Flotation)

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15 pages, 1229 KB

Open AccessArticle

Effect of Gas Holdup on the Performance of Column Flotation of a Low-Grade Apatite Ore

by Larissa R. Demuner, Angelica S. Reis and Marcos A. S. Barrozo

Minerals 2025, 15(9), 901; https://doi.org/10.3390/min15090901 - 25 Aug 2025

Viewed by 493

Abstract

As a consequence of the gradual exhaustion of apatite ore reserves, intensive comminution has been implemented in mineral processing operations to enhance phosphorus liberation. Consequently, improving the flotation efficiency of fine particles has remained a persistent challenge within the phosphate industry. The performance [...] Read more.

As a consequence of the gradual exhaustion of apatite ore reserves, intensive comminution has been implemented in mineral processing operations to enhance phosphorus liberation. Consequently, improving the flotation efficiency of fine particles has remained a persistent challenge within the phosphate industry. The performance of flotation columns is strongly affected by the interaction between gas (bubble) and particle. The present research was designed to evaluate how certain process variables and chemical dosages influence gas holdup and its correlation with the column flotation performance of fine particles derived from a low-grade apatite ore. Column flotation experiments were conducted employing a factorial experimental approach to evaluate the effects of air flow rate, surfactant concentration, collector dosage, and depressant dosage on gas holdup, P₂O₅ grade, and recovery. The results made it possible to identify the levels of gas holdup that lead to appropriate values of P₂O₅ grade and recovery simultaneously, and their relation with the operating variables and reagent dosage. Gas holdup values higher than 23.5% led to the desired values of P₂O₅ grade (>30%) and recovery (>60%) simultaneously. Statistical models were developed with high correlation coefficients (R² > 0.98) to predict P₂O₅ grade and recovery as functions of the operating variables. This research provides a comprehensive framework of the gas holdup effect on column flotation systems, offering significant potential for improving the economic viability of low-grade phosphate ore processing. Full article

(This article belongs to the Special Issue Surface Chemistry and Reagents in Flotation)

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16 pages, 1212 KB

Open AccessArticle

Harnessing Mixed Fatty Acid Synergy for Selective Flotation of Apatite from Calcite and Quartz with Sodium Alginate

by Imane Aarab, Khalid El Amari, Abdelrani Yaacoubi, Abdelaziz Baçaoui and Abderahman Etahiri

Minerals 2025, 15(8), 822; https://doi.org/10.3390/min15080822 - 1 Aug 2025

Viewed by 448

Abstract

Maximizing the efficient utilization of critical apatite resources through flotation necessitates the exploration of effective and innovative collectors. This study investigates the potential of a fatty acid mixture (FAM) synthesized from saturated palmitic and stearic acids, monounsaturated oleic and palmitoleic acids, and polyunsaturated [...] Read more.

Maximizing the efficient utilization of critical apatite resources through flotation necessitates the exploration of effective and innovative collectors. This study investigates the potential of a fatty acid mixture (FAM) synthesized from saturated palmitic and stearic acids, monounsaturated oleic and palmitoleic acids, and polyunsaturated linoleic acid. The saponified collector FAM and the depressant sodium alginate (NaAl) achieved a direct flotation of apatite from calcite and quartz (97% apatite, 10% calcite, and 7% quartz). The flotation performance with the tested combination exhibited a highly effective enrichment of apatite, mainly from calcite, which aligns with the surface chemistry assessments. Adsorption tests and zeta potential measurements confirmed the micro-flotation results. They provided compelling evidence of a chemisorption interaction between Ca²⁺ sites on calcite and the carboxyl and hydroxyl groups of NaAl. FTIR analyses suggested a reaction between the apatite surface and the carboxyl groups of saturated and unsaturated acid groups in FAM, even those conditioned with NaAl before, facilitating the complex formation. Remarkably, the synergistic effect of the functional groups demonstrates dual functionality, serving as both a hydrophilic entity for calcite and a hydrophobic entity for apatite flotation. The universal mechanism unveils substantial potential for the extensive application of FAM within apatite flotation. Full article

(This article belongs to the Special Issue Surface Chemistry and Reagents in Flotation)

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9 pages, 1401 KB

Open AccessArticle

Pyrite–Coal Depressants Interactions During Coal Reverse Flotation

by You Zhou, Zijuan Xie, Boris Albijanic, Arturo A. García-Figueroa, Sheila Devasahayam, Bogale Tadesse and Rensheng Li

Minerals 2025, 15(2), 130; https://doi.org/10.3390/min15020130 - 29 Jan 2025

Viewed by 1022

Abstract

This work investigates coal desulfurization by using reverse flotation. In this method, pyrite (the only source of sulfur in the studied coal) was separated from the meta-bituminous coal by using three different coal depressants (starch, dextrin and humic acid). A novel variable elimination [...] Read more.

This work investigates coal desulfurization by using reverse flotation. In this method, pyrite (the only source of sulfur in the studied coal) was separated from the meta-bituminous coal by using three different coal depressants (starch, dextrin and humic acid). A novel variable elimination approach was used to determine the contribution of the depressant type and the depressant concentration on the desulfurization performance. The results showed that the pyrite recoveries are influenced by the depressant type while the highest pyrite recovery was achieved in the presence of humic acid. Therefore, humic acid should be used in flotation rougher and scavenger cells in which the aim is to achieve high pyrite recovery. By contrast, the pyrite grades are affected significantly by the depressant concentration. Considering that the aim in flotation cleaner cells is to achieve high pyrite grade, any of the studied coal depressants can be successfully used but at high concentrations. This work demonstrated that the selection of flotation depressants depends on the type of flotation cells used in coal desulfurization. Full article

(This article belongs to the Special Issue Surface Chemistry and Reagents in Flotation)

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12 pages, 1645 KB

Open AccessArticle

Insights on the Flotation Separation of Hematite from Quartz with a 4-Tert-butyl-catechol Collector

by Chenglong Du, Jiang Yu and Guangyi Liu

Minerals 2024, 14(12), 1255; https://doi.org/10.3390/min14121255 - 10 Dec 2024

Viewed by 1688

Abstract

Iron ore is the main raw material of the iron and steel metallurgy industry, but quartz in iron ore reduces metallurgical efficiency and increases metallurgical costs. Therefore, iron ore desiliconization by flotation plays an important role in the iron and steel metallurgy industry. [...] Read more.

Iron ore is the main raw material of the iron and steel metallurgy industry, but quartz in iron ore reduces metallurgical efficiency and increases metallurgical costs. Therefore, iron ore desiliconization by flotation plays an important role in the iron and steel metallurgy industry. In this study, 4-tert-butyl-catechol (TBC) was designed as a collector to directly float out hematite from quartz. The micro-flotation tests demonstrated that under pH ~9.0, 1 × 10⁻⁵ mol·L⁻¹ TBC recovered 98% hematite from its mixture with quartz, while the recovery of quartz was only about 17%. Zeta potential and contact angle results inferred that the adsorption affinity of TBC toward hematite was greater than that to quartz. The results of FTIR and XPS inferred that TBC adsorbed on the Fe³⁺ sites of hematite interfaced via the O atom of its two adjacent hydroxyl groups to form a stable five-membered chelating ring at pH 9.0. This study offered new research insight on the development of novel collectors for hematite flotation through bionics technology. Full article

(This article belongs to the Special Issue Surface Chemistry and Reagents in Flotation)

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14 pages, 3015 KB

Open AccessArticle

Surface Chemistry and Flotation of Gold-Bearing Pyrite

by Seda Özçelik and Zafir Ekmekçi

Minerals 2024, 14(9), 914; https://doi.org/10.3390/min14090914 - 6 Sep 2024

Cited by 4 | Viewed by 2423

Abstract

Gold grains are observed in a variety of forms, such as coarse-liberated native gold grains, and ultra-fine grains associated with sulfide or non-sulfide mineral particles, in the form of solid solution in sulfide minerals, mainly pyrite. In the flotation of gold ores, bulk [...] Read more.

Gold grains are observed in a variety of forms, such as coarse-liberated native gold grains, and ultra-fine grains associated with sulfide or non-sulfide mineral particles, in the form of solid solution in sulfide minerals, mainly pyrite. In the flotation of gold ores, bulk sulfide mineral flotation is generally applied to maximize gold recovery. This approach gives high gold recoveries, but it also causes the recovery of barren sulfide minerals (i.e., sulfide mineral particles with no gold content), which increases concentrate tonnage and transportation costs and reduces the grade sometimes to below the saleable limit (approx. 10 g/t Au). This study addresses the differences between gold-bearing and barren pyrite particles taken from various ore deposits and utilizes these differences for the selective flotation of gold-bearing pyrite. The laboratory scale flotation tests conducted on three pyrite samples having different cyanide soluble gold contents show that a selective separation between gold-bearing pyrite and barren pyrite particles could be achieved under specific flotation conditions. Gold recovery is correlated directly with the cyanide-soluble gold in the ore samples. Electrochemical experiments were conducted to elucidate the differences in surface properties of the two types of pyrite. The barren pyrite particles were more cathodic and prone to cathodic reduction of OH⁻ and depressant ions on the surface, and they could be depressed effectively without significantly affecting the gold-bearing particles. Full article

(This article belongs to the Special Issue Surface Chemistry and Reagents in Flotation)

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15 pages, 3441 KB

Open AccessArticle

Analysis of the Effect of Surfactants on the Performance of Apatite Column Flotation

by Thessa F. Mendes, Angelica S. Reis, André C. Silva and Marcos A. S. Barrozo

Minerals 2024, 14(8), 840; https://doi.org/10.3390/min14080840 - 20 Aug 2024

Cited by 4 | Viewed by 1568

Abstract

Given that particle and bubble size, as well as their surface properties, are pivotal in froth flotation, surfactants have been extensively employed due to their impact on bubble size and froth stabilization. This study aimed to investigate the influence of surfactants on the [...] Read more.

Given that particle and bubble size, as well as their surface properties, are pivotal in froth flotation, surfactants have been extensively employed due to their impact on bubble size and froth stabilization. This study aimed to investigate the influence of surfactants on the performance of apatite flotation in column. Three different categories of surfactants were examined: anionic, amphoteric, and nonionic, specifically Lupromin, Genagen, and Triton X-100, respectively. The critical coalescence concentration (CCC) and surface tension of each surfactant were determined. The impact of these surfactants on reducing bubble size was quantified, and their subsequent effects on apatite flotation in a column were assessed. The most favorable flotation response for Genagen was achieved at CCC and pH 11, resulting in the highest apatite recovery and the smallest bubble size. For Triton X-100, the best condition was attained at ¼ CCC and pH 11. However, overall, Lupromin was the surfactant that yielded the best flotation results (at ¼ CCC and pH 11). The superior performance of this anionic surfactant was corroborated by chemical adsorption results, as demonstrated by FTIR analyses. Full article

(This article belongs to the Special Issue Surface Chemistry and Reagents in Flotation)

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13 pages, 4244 KB

Open AccessArticle

First Principle Study of the Relationship between Electronic Properties and Adsorption Energy: Xanthate Adsorption on Pyrite and Arsenopyrite

by Qiang Cui, Chongjun Liu, Zehui Gao, Tong Lu, Zhiqiang Zhao, Yangge Zhu and Guiye Wu

Minerals 2024, 14(8), 749; https://doi.org/10.3390/min14080749 - 25 Jul 2024

Cited by 2 | Viewed by 1175

Abstract

This study investigates the correlation between the electronic structure of the active sites on mineral surfaces and their adsorption capacity. Density functional theory (DFT) and flotation experiments are employed to examine the bonding behavior and adsorption enthalpy of ethylxanthate on pyrite (1 0 [...] Read more.

This study investigates the correlation between the electronic structure of the active sites on mineral surfaces and their adsorption capacity. Density functional theory (DFT) and flotation experiments are employed to examine the bonding behavior and adsorption enthalpy of ethylxanthate on pyrite (1 0 0) and arsenopyrite (0 0 1) surfaces. The results indicate that ethylxanthate adsorbs more significantly on pyrite than on arsenopyrite. The adsorption is chemical, primarily occurring through the orbitals of sulfur in the ethylxanthate and iron on the mineral surface. Compared to arsenopyrite, the d-band center of the iron atoms on the surface of pyrite is closer to the Fermi level; thus, the adsorption strength of ethylxanthate on the pyrite surface is greater than on arsenopyrite. The d-band centers of pyrite and arsenopyrite exhibit a direct relationship with their adsorption capacity. Full article

(This article belongs to the Special Issue Surface Chemistry and Reagents in Flotation)

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