Special Issue "Flotation Chemistry, Volume II"

A special issue of Minerals (ISSN 2075-163X). This special issue belongs to the section "Mineral Processing and Extractive Metallurgy".

Deadline for manuscript submissions: 20 September 2021.

Special Issue Editors

Prof. Dr. Zhiyong Gao
E-Mail Website1 Website2
Guest Editor
School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
Interests: flotation of oxide minerals; mineral crystal chemistry; flotation reagent molecular design; mineral/reagent/water interfacial science; waste treatment in minerals processing
Special Issues and Collections in MDPI journals
Dr. Wenjihao Hu
E-Mail Website
Co-Guest Editor
Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB T6G 2R3, Canada
Interests: interfacial science and engineering for selective separation; membrane technology; oil/water separation; desalination; wastewater treatment; mineral surface science; conductive AFM; synthesis of 2D materials; AFM force measurement; material characterization
Dr. Peipei Wang
E-Mail Website
Co-Guest Editor
ARC Centre of Excellence for Enabling Eco-Efficient Beneficiation of Minerals, Newcastle Institute for Energy and Resources, University of Newcastle, Shortland NSW 2307, Australia
Interests: mineral processing; particle/bubble motion and dynamics in fluid; chemical adsorption; foams; solution chemistry; colloids and interface
Dr. Kirsten Claire Corin
E-Mail Website
Co-Guest Editor
Centre for Minerals Research, University of Cape Town, Cape Town, South Africa
Interests: water within flotation; flotation chemistry; flotation reagents; electrochemistry of flotation; grinding chemistry
Special Issues and Collections in MDPI journals
Dr. Ljudmilla Bokányi
E-Mail Website
Co-Guest Editor
Department of Bioprocessing and Reaction Techniques, Institute of Raw Materials Preparation and Environmental Processing University of Miskolc, 3515 Miskolc, Hungary
Interests: interfacial phenomena; flotation chemistry; modelling and technology

Special Issue Information

Dear Colleagues,

We invite contributions to this Special Issue on aspects listed in the keywords, covering recent advances and innovations in flotation chemistry, which will be of direct interest to researchers and practitioners in the mineral processing field. Contributions reporting on mineral surface chemistry, the development and design of novel reagents, and mechanism exploration of mineral/reagent interactions using advanced tools and instruments are especially welcome.

Keywords

  • Minerals (sulfide oxides, silicates, sparingly soluble minerals, iron minerals, rare earth minerals, etc.)
  • Mineral chemistry (surface reactivity, surface broken bonds, surface energy, wettability, surface hydration, surface charge, etc.)
  • Reagents (collectors, depressants, dispersants, etc.)
  • Reagent chemistry (QSAR, molecular design, assembly, etc.)
  • Mineral/reagent interaction (molecular dynamics simulation, quantum chemistry simulation, AFM, XPS, QCM-D, SFG, etc.)
  • Flotation

This Special Issue is dedicated to Prof. Yuehua Hu, who is currently Professor at the school of minerals processing and bioengineering, Central South University, on the occasion of his 60th birthday (to be celebrated on 1 January, 2022), and in honor of his many achievements in flotation chemistry.

Brief Introduction about Prof. Hu

Professor Yuehua Hu is now the executive vice-president of Central South University (CSU), and the academic leader of mineral engineering discipline of CSU. He also serves as the vice president of Nonferrous Metals Society of China, and vice president of China Mineral Processing Congress. Since 1991, he has been awarded over RMB120M in competitive grant funding from the National natural science foundation of China, Ministry of Science and Technology, Ministry of Education, and national and private industry. He has received numerous awards and honours over the years. These include the National Science Fund for Distinguished Young Scholars in 1999, Chang Jiang Scholars Program in 2000, National University Distinguished Teacher Award in 2009. As a supervisor or cosupervisor, he has trained 40 PhDs, 42 masters and 11 postdoctoral fellows, 18 of whom are full professors in universities/institutes and half of whom are senior managers in mining companies. He authored and co-authored over 300 papers with 8 highly cited papers, h-index reaching 46. He had more than 70 authorized Chinese patents and most of them has been transfered and/or applied in industry.

Dr. Zhiyong Gao
Dr. Wenjihao Hu
Dr. Peipei Wang
Dr. Kirsten Claire Corin
Dr. Ljudmilla Bokányi
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Minerals is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1800 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Related Special Issue

Published Papers (8 papers)

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Research

Open AccessArticle
Adsorption Behaviors of Straight-Chain Alkanes on a Molybdenite [001]/[100] Surface: A Molecular Dynamics Study
Minerals 2021, 11(5), 489; https://doi.org/10.3390/min11050489 - 04 May 2021
Viewed by 202
Abstract
Straight-chain alkanes (SCA) as collectors can effectively enhance the floatability of molybdenite. In a previous study, SCA were found to have an excellent adsorption effect on the molybdenite [001] surface (MS001), but they exhibited no adsorption behavior on the molybdenite [100] surface (MS100). [...] Read more.
Straight-chain alkanes (SCA) as collectors can effectively enhance the floatability of molybdenite. In a previous study, SCA were found to have an excellent adsorption effect on the molybdenite [001] surface (MS001), but they exhibited no adsorption behavior on the molybdenite [100] surface (MS100). However, other studies have shown that SCA could adsorb on MS100. In this paper, the underlying cause of this contradictory conclusion was identified by molecular dynamics simulation. The results show that SCA could adsorb both MS001 and MS100. However, at low SCA dosages, SCA have a strong interaction with MS001 but desorb quickly on MS100. This leads to the selective adsorption of SCA on MS001. As SCA’s concentration gradually increases, the selective adsorption behavior of SCA on MS001 will be disrupted. Excessive SCA concentration will lead to its adsorption at MS100. Full article
(This article belongs to the Special Issue Flotation Chemistry, Volume II)
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Open AccessArticle
Activation of Peroxymonosulfate by Chrysotile to Degrade Dyes in Water: Performance Enhancement and Activation Mechanism
Minerals 2021, 11(4), 400; https://doi.org/10.3390/min11040400 - 10 Apr 2021
Viewed by 352
Abstract
An environmentally friendly activation method of peroxymonosulfate (PMS) provides a promising advanced oxidation processes for the degradation of organic wastewater. In this article, chrysotile, extracted from asbestos tailings, was found to be a kind of one-off catalyst relying on hydroxyl groups to activate [...] Read more.
An environmentally friendly activation method of peroxymonosulfate (PMS) provides a promising advanced oxidation processes for the degradation of organic wastewater. In this article, chrysotile, extracted from asbestos tailings, was found to be a kind of one-off catalyst relying on hydroxyl groups to activate PMS. Furthermore, the activation performance of the chrysotile had been greatly improved by the mean of calcining at 850 °C (850CC). It is worth mentioning that 850CC could not only realize three effective cycles, but also the mineralization ratio of Rhodamine B (RhB) could be impressively higher than 60%. According to characterization results, it was discovered that the chrysotile had transformed into forsterite with a fibrous morphology after calcination at 850 °C due to the loss of hydroxyl groups and the recombination of silicon, oxygen and magnesium atoms. Besides, the main active species produced by 850CC activating PMS were singlet oxygen and sulfate radicals. Further studies uncovered that PMS was successfully activated by a large number of unsaturated coordination oxygen on 850CC surface, and the activation mechanism was further elucidated. This study provides a new route for the comprehensive utilization of chrysotile and a valuable strategy for the degradation of hazardous organic pollutants in wastewater by PMS activation. Full article
(This article belongs to the Special Issue Flotation Chemistry, Volume II)
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Open AccessArticle
Probing the Effect of Water Recycling on Flotation through Anion Spiking Using a Low-Grade Cu–Ni–PGM Ore: The Effect of NO3, SO42− and S2O32−
Minerals 2021, 11(4), 340; https://doi.org/10.3390/min11040340 - 25 Mar 2021
Viewed by 359
Abstract
Water scarcity necessitates the recycling of process water within mineral processing practices. This may however come with its disadvantages for unit operations such as froth flotation as this process is water intensive and sensitive to water chemistry. It is therefore important to monitor [...] Read more.
Water scarcity necessitates the recycling of process water within mineral processing practices. This may however come with its disadvantages for unit operations such as froth flotation as this process is water intensive and sensitive to water chemistry. It is therefore important to monitor the water chemistry of the recycle stream of process water and any other water source to flotation. Monitoring the concentrations of the anions in recycled process water is therefore important to consider as these are speculated to impact flotation performance. Batch flotation tests were conducted using synthetically prepared plant water (3 SPW) with a TDS of 3069 mg/L as the baseline experiment. 3 SPW contained 528 mg/LNO3 and 720 mg/L SO42−, other anions and cations, and no S2O32−. Upon spiking 3 SPW with selected anions, viz, NO3, SO42− and S2O32−, it was noted that NO3 and SO42− exhibited threshold concentrations while S2O32− did not show a threshold concentration for both copper and nickel grade. Spiking 3 SPW with 352 mg/L more of NO3 to a total 880 mg/L NO3 concentration resulted in the highest copper and nickel grade compared to 3 SPW while increasing the S2O32− from 60 to 78 mg/L increased nickel and copper grade. 720 to 1200 mg/L SO42− and 528 to 880 mg/L NO3 were deemed the concentration boundaries within which lies the threshold concentration above which flotation performance declines with respect to metal grades, while for S2O32− the threshold concentration lies outside the range considered for this study. Anion distribution between the pulp and the froth did not seem to impact the recovery of copper or nickel. Notably, the correlation between the concentrate grades and anion distribution between the froth and the pulp seemed to be ion dependent. Full article
(This article belongs to the Special Issue Flotation Chemistry, Volume II)
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Open AccessArticle
Effect of Ferric Ions on Sulfidization Flotation of Oxidize Digenite Fine Particles and Their Significance
Minerals 2021, 11(3), 305; https://doi.org/10.3390/min11030305 - 16 Mar 2021
Viewed by 316
Abstract
Digenite fine particles are easily oxidized and ferric ions (Fe3+) commonly exist in the flotation pulp of digenite. This study investigated the effect of Fe3+ on the sulfidization flotation of oxidized digenite fine particles using sodium butyl xanthate (SBX) as [...] Read more.
Digenite fine particles are easily oxidized and ferric ions (Fe3+) commonly exist in the flotation pulp of digenite. This study investigated the effect of Fe3+ on the sulfidization flotation of oxidized digenite fine particles using sodium butyl xanthate (SBX) as a collector. The results of microflotation experiments show that the flotation rate and recovery of oxidized digenite fine particles can be improved by adding Na2S and SBX, whereas the existence of large amounts of Fe3+ is not beneficial for the sulfidization flotation of digenite. The results of Fe3+ adsorption, zeta potential, and contact angle measurements indicate that Fe3+ can be adsorbed on the digenite surface mainly in the form of Fe(OH)3, which hinders the adsorption of SBX and significantly reduces the surface hydrophobicity of digenite. X-ray photoelectron spectroscopy analysis further suggests that the poor surface hydrophobicity of digenite in the presence of Fe3+ is due to the production of large amounts of hydrophilic iron and copper oxides/hydroxides on the surface. Furthermore, optical microscopy analysis shows that these hydrophilic species effectively disperse digenite fine particles in the pulp, which eventually leads to the poor floatability of digenite. Therefore, it is necessary to reduce the amount of Fe3+ present in the pulp and adsorbed on digenite surface before sulfidization to realize effective separation of oxidized digenite fine particles and iron sulfide minerals. Full article
(This article belongs to the Special Issue Flotation Chemistry, Volume II)
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Open AccessArticle
Effect of Dodecane-Oleic Acid Collector Mixture on the Evolution of Wetting Film between Air Bubble and Low-Rank Coal
Minerals 2021, 11(1), 58; https://doi.org/10.3390/min11010058 - 10 Jan 2021
Cited by 1 | Viewed by 509
Abstract
The wetting film evolution process is essential for flotation, especially in bubble–particle attachment. A mixed collector has been proved effective in promoting flotation. In this paper, the effect of a mixed collector (MC) composed by n-dodecane (D) and oleic acid (OA) on wetting [...] Read more.
The wetting film evolution process is essential for flotation, especially in bubble–particle attachment. A mixed collector has been proved effective in promoting flotation. In this paper, the effect of a mixed collector (MC) composed by n-dodecane (D) and oleic acid (OA) on wetting film evolution was investigated using the extended Derjagin–Landau–Verwey–Overbeek (EDLVO) theory, the Stefan–Reynolds model, induction time, and zeta potential measurement. The hydrophobic force constant between bubble and coal treated by different collectors was analyzed. The results showed that MC was superior in reducing the induction time and increasing the zeta potential. When bubbles interacted with coal treated by MC, they had relatively low interaction energy, high critical film thickness, and high drainage rate. The order of hydrophobic force constant was no reagent < D < OA < MC. It indicated that the hydrophobic interaction between bubbles and coal particles treated by MC was the strongest because of the synergistic effect of D and OA. Full article
(This article belongs to the Special Issue Flotation Chemistry, Volume II)
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Open AccessArticle
Comparative Studies on Flotation Performance of Saturated Fatty Acids and Unsaturated Fatty Acids Separated from Hogwash Oil
Minerals 2021, 11(1), 50; https://doi.org/10.3390/min11010050 - 06 Jan 2021
Viewed by 487
Abstract
Low flotation recovery, high pulp temperature, and large dosage of reagents are the typical disadvantages when using mixed fatty acids (MFA) prepared from hogwash oil for flotation directly. To determine the type of fatty acid that yields poor flotation performance, flotation performance and [...] Read more.
Low flotation recovery, high pulp temperature, and large dosage of reagents are the typical disadvantages when using mixed fatty acids (MFA) prepared from hogwash oil for flotation directly. To determine the type of fatty acid that yields poor flotation performance, flotation performance and adsorption characteristics of saturated fatty acids (SFA) and unsaturated fatty acids (UFA) separated from the MFA were studied in our work. GC-MS, FT-IR, iodine value detection and melting point measurement showed that UFA contained –(CH=CH–CH2)n- groups and had much lower melting point. Quartz flotation tests were used to compare the flotation performance of UFA and SFA, which showed that UFA had excellent low-temperature floatability, and the flotation recovery of UFA was 35 percentage points higher than that of SFA at 20 °C and pH = 11.5. Zeta potential, FT-IR and XPS analysis indicated that UFA and SFA could adsorb onto the surface of activated quartz through chemisorption and hydrogen bonding. However, the adsorption of UFA was much stronger and more favorable; thus, the reason MFA have poor flotation performance was the presence of SFA. Full article
(This article belongs to the Special Issue Flotation Chemistry, Volume II)
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Open AccessArticle
The Influence Mechanism of Magnesium Ions on the Morphology and Crystal Structure of Magnetized Anti-Scaling Products
Minerals 2020, 10(11), 997; https://doi.org/10.3390/min10110997 - 10 Nov 2020
Cited by 1 | Viewed by 461
Abstract
Magnetization technology has been widely used in various transportation pipeline anti-scaling and descaling processes due to its simple equipment, low operating cost and low secondary pollution. To resolve structural pipeline issues in concentrations, the effects of magnesium salt concentration on conductivity, pH value [...] Read more.
Magnetization technology has been widely used in various transportation pipeline anti-scaling and descaling processes due to its simple equipment, low operating cost and low secondary pollution. To resolve structural pipeline issues in concentrations, the effects of magnesium salt concentration on conductivity, pH value and calcium ion concentration of a magnetized calcium chloride sodium bicarbonate mixed solution were studied. The results indicated that 4.0% MgSO4 had the greatest anti-scaling effect under dynamic water conditions, which increased the calcium concentration of the mixed solution by 5.93%. Furthermore, the synergistic effects of 5.0% magnesium carbonate on the scaling of calcium carbonate were the largest, which reduced the calcium concentration of the mixed solution by 22.19%. Scanning electron microscope (SEM) and Raman spectra showed that magnesium carbonate reduced the effects of magnetization because it inhibited the formation of vaterite-type calcium carbonate and promoted the formation of calcite-type calcium carbonate. Magnesium sulfate can improve the anti-scaling effects of magnetization because it promotes the formation of vaterite calcium carbonate with high solubility. The results of this study can provide a theoretical basis for the scaling process and dissolution behavior regulation of calcium carbonate and have an important reference significance for scale prevention and scale removal in concentrator pipelines. Full article
(This article belongs to the Special Issue Flotation Chemistry, Volume II)
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Open AccessArticle
Adsorption Behavior and Wettability of Rhodochrosite Surface: Effect of C18 Fatty Acid Unsaturation
Minerals 2020, 10(10), 905; https://doi.org/10.3390/min10100905 - 12 Oct 2020
Viewed by 569
Abstract
Mineral surface wettability and its regulation by the adsorption of collectors have an important influence on the flotation performance. The adsorption behavior of C18 fatty acid with different unsaturation and its effect on rhodochrosite wettability was investigated with surface tension, contact angle, [...] Read more.
Mineral surface wettability and its regulation by the adsorption of collectors have an important influence on the flotation performance. The adsorption behavior of C18 fatty acid with different unsaturation and its effect on rhodochrosite wettability was investigated with surface tension, contact angle, and atomic force microscopy (AFM) measurements. The results indicated that rhodochrosite hydrophobicity increased with the increasing concentration of fatty acid, along with the maximum contact angle (θmax) between hemimicelle concentration (HMC) and critical micelle concentration (CMC). Oleic acid (OA), linoleic acid (LA), and α-linolenic acid (ALA) had a higher θmax than stearic acid (SA), but the value decreased with the increase of C=C bond number. Besides, preferential adsorption of unsaturated fatty acids on the liquid-air interface can be attributed to the molecule’s steric hindrance resulting from C=C double bond, and the θ kept almost invariant with a higher value of ΓLG than ΓSL until HMC. The oriented monolayer and bilayer structure of fatty acids formed gradually on rhodochrosite surface with increasing concentration. However, the θmax may not necessarily correspond to the beginning of bilayer formation. Cylindrical monolayer and bilayer micelles of SA molecules were observed on rhodochrosite surface at HMC and CMC, respectively. While bilayer structures of unsaturated fatty acids formed before complete coverage of monolayer on rhodochrosite surface because of surface heterogeneity. This work provided a good understanding on the adsorption mechanism of fatty acid on rhodochrosite for flotation. Full article
(This article belongs to the Special Issue Flotation Chemistry, Volume II)
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