Minerals Engineering最新文献

Mechanism of quartz flotation separation from gypsum using tetradecyl trimethyl ammonium chloride: Guiding the improvement of phosphogypsum quality

IF 4.9 2区工程技术 Q1 ENGINEERING, CHEMICAL

Minerals Engineering

Pub Date : 2025-02-18 DOI: 10.1016/j.mineng.2025.109218

Haodong Shi , Liuyi Ren , Shenxu Bao , Yimin Zhang , Anh V. Nguyen , Bo Chen , Weifeng Li , Rui Huang , Yanqi Zeng , Sidi Lou

Phosphogypsum (PG), a by-product of wet-process phosphoric acid production, holds significant potential for use in construction and other industrial applications. However, impurities such as quartz, while not posing direct environmental hazards, negatively impact critical properties like whiteness, limiting PG’s practical utility. Addressing these impurities is therefore essential to enhance PG’s performance and expand its applicability. In this study, the selective separation of quartz from gypsum (CaSO₄·2H₂O) was investigated using tetradecyl trimethyl ammonium chloride (TTAC) as a novel cationic collector. Microflotation experiments were conducted over a broad pH range (2.5–9.5) to evaluate the separation efficiency. TTAC demonstrated excellent selectivity for quartz, achieving its peak performance at neutral pH. The peak recovery of 96 % (vs. 21.5 % for gypsum) at neutral pH (7.0 ± 0.1) with a low TTAC concentration of 100 mg/L. Adsorption tests revealed a maximum adsorption capacity of 12.8 mg/g on quartz, while contact angle measurements showed a 143 % increase in hydrophobicity (from 28.4° to 69.1°). Mechanistic analyses via zeta potential, FT-IR, and XPS confirmed electrostatic interactions and hydrogen bonding as dominant adsorption mechanisms. These analyses revealed that TTAC selectively interacts with quartz through electrostatic interactions and hydrogen bonding, while its weaker interaction with gypsum is driven primarily by minimal electrostatic forces. The findings establish TTAC as an effective reagent for improving the purity of PG. This enhanced purity not only increases PG’s suitability for large-scale industrial applications but also addresses significant environmental challenges with PG waste, paving the way for its sustainable utilization.

{"title":"Mechanism of quartz flotation separation from gypsum using tetradecyl trimethyl ammonium chloride: Guiding the improvement of phosphogypsum quality","authors":"Haodong Shi , Liuyi Ren , Shenxu Bao , Yimin Zhang , Anh V. Nguyen , Bo Chen , Weifeng Li , Rui Huang , Yanqi Zeng , Sidi Lou","doi":"10.1016/j.mineng.2025.109218","DOIUrl":"10.1016/j.mineng.2025.109218","url":null,"abstract":"<div><div>Phosphogypsum (PG), a by-product of wet-process phosphoric acid production, holds significant potential for use in construction and other industrial applications. However, impurities such as quartz, while not posing direct environmental hazards, negatively impact critical properties like whiteness, limiting PG’s practical utility. Addressing these impurities is therefore essential to enhance PG’s performance and expand its applicability. In this study, the selective separation of quartz from gypsum (CaSO<sub>4</sub>·2H<sub>2</sub>O) was investigated using tetradecyl trimethyl ammonium chloride (TTAC) as a novel cationic collector. Microflotation experiments were conducted over a broad pH range (2.5–9.5) to evaluate the separation efficiency. TTAC demonstrated excellent selectivity for quartz,achieving its peak performance at neutral pH. The peak recovery of96 %(vs.21.5 % for gypsum) at neutral pH (7.0 ± 0.1) with a low TTAC concentration of100 mg/L. Adsorption tests revealed a maximum adsorption capacity of12.8 mg/gon quartz, while contact angle measurements showed a143 % increasein hydrophobicity (from 28.4° to 69.1°). Mechanistic analyses via zeta potential, FT-IR, and XPS confirmedelectrostatic interactionsandhydrogen bondingas dominant adsorption mechanisms. These analyses revealed that TTAC selectively interacts with quartz through electrostatic interactions and hydrogen bonding, while its weaker interaction with gypsum is driven primarily by minimal electrostatic forces. The findings establish TTAC as an effective reagent for improving the purity of PG. This enhanced purity not only increases PG’s suitability for large-scale industrial applications but also addresses significant environmental challenges with PG waste, paving the way for its sustainable utilization.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"225 ","pages":"Article 109218"},"PeriodicalIF":4.9,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143427684","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Mitigating contaminated mine drainage through mine waste rock decontamination: A strategy for promoting cleaner and sustainable management

IF 4.9 2区工程技术 Q1 ENGINEERING, CHEMICAL

Minerals Engineering

Pub Date : 2025-02-17 DOI: 10.1016/j.mineng.2025.109217

Yassine Ait-khouia , Mostafa Benzaazoua , Yassine Taha , Isabelle Demers

This study investigates the potential of reprocessing mine waste rock (WR) to mitigate acid generation, remove contaminants, and recover valuable resources. The WR, with a wide particle size distribution, was separated into a reactive fine fraction and an inert coarse fraction based on the diameter of physical locking of sulphides (DPLS). Through mineralogical characterization and geochemical analysis, the DPLS was determined to be 2.5 mm for the studied material. The primary objectives of the research were to evaluate the acid- and contamination-generating potential of the reactive fraction (<DPLS), assess the feasibility of reprocessing through various desulphurization/decontamination processes, and analyze the geochemical behavior of the desulphurized materials. Chemical and mineralogical analysis revealed that the feed sample was enriched in contaminant-bearing sulphides (e.g., pyrite, gersdorffite, pyrrhotite) and carbonates (e.g., calcite). Various decontamination processes, such as centrifugal dense medium separation (DMS), spiral/shaking table, and combined gravity-flotation techniques, were investigated. Results indicated that these processes reduced contamination risk due to WR oxidation (e.g., As leaching). Particularly, DMS and combined gravity-flotation processes proved effective, producing desulphurized material with low sulphur (0.28 wt%) and arsenic (0.026 wt%) contents alongside a high sulphur-bearing mineral recovery (88 wt%). Geochemical properties were evaluated using kinetic weathering cells, which showed that desulphurized materials from DMS and the combined gravity-flotation approach had the lowest leachate arsenic concentrations. However, leachates from material desulphurized using the spiral/shaking table slightly exceeded environmental limits for arsenic concentration (D019, Quebec, Canada). This study underscores the effectiveness of upstream environmental desulphurization in managing and valorizing WR, reducing its environmental impact, and recovering valuable resources.

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引用次数: 0

A review of the research progress in the enrichment of rare earth resources by biosorbents 生物吸附剂富集稀土资源研究进展综述

IF 4.9 2区工程技术 Q1 ENGINEERING, CHEMICAL

Minerals Engineering

Pub Date : 2025-02-16 DOI: 10.1016/j.mineng.2025.109215

Shiyu Shao , Junjun Wang , Hao Zhou , Xinyi Yu , Jue Kang , Min Huang , Zhu Chen , Hongbo Zhao , Guanzhou Qiu , Li Shen

Rare earth elements are valuable resources on Earth and indispensable for many contemporary advanced technologies. Efficient and clean development and the use of rare earth resources are essential for sustainable development. However, the current development or recovery of rare earth resources incurs high economic and environmental costs, and there is an urgent need to develop low-cost and environmentally friendly technologies to extract rare earth elements. Biosorption is a green method that has been widely used for the treatment of heavy metals and other pollutants in wastewater. In recent years, researchers have found that it has promising applications in rare earth element adsorption. This review summarises the published work related to the biosorption of rare earth elements, describes the types of biosorbents that can be used for the enrichment of rare earth elements and its means of modification, describes the mechanism of action between biosorbents and rare earth elements, summarises the factors that affect the enrichment of rare earth elements by biosorbents, and highlights the adsorption, desorption, and regeneration properties of biosorbents in real samples. Furthermore, the application of biosorbents in rare earth adsorption prospects is discussed, and the authors propose future research directions for rare earth biosorption.

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引用次数: 0

Fourth generation gravity separation using the Reflux Classifier 利用回流分级机进行第四代重力分选

IF 4.9 2区工程技术 Q1 ENGINEERING, CHEMICAL

Minerals Engineering

Pub Date : 2025-02-16 DOI: 10.1016/j.mineng.2025.109216

M.E. Amosah, J. Zhou, K.P. Galvin

The Reflux Classifier achieves powerful synergy between an upper system of inclined channels and lower fluidised bed arrangement, delivering gravity separation in a single stage of separation. This paper is concerned with the step-change improvement in gravity separation utilising the latest in a series of improvements. The laminar-shear separation mechanism led to the introduction of closely-spaced inclined channels, nominally 6 mm, solving a previously intractable problem in concentrating metallurgical coal. The more recent shift to a spacing of 3 mm, and even 1.8 mm has delivered a further step change in the separation of gangue minerals from dense minerals. In this new work, we have introduced changes to the lower fluidised bed, removing the fluidisation distributor and installing a slow-moving rake with water addition. This change produced a much more robust fluidisation boundary condition, removing the vagaries of the minimum fluidisation condition, producing a stronger dense medium effect, hence significant step change in gravity separation performance well beyond anything that was previously possible. This step change in performance reveals a direct pathway from a feed grade of 0.32 wt% tin to a significant recovery of the tin at a grade higher than 40 wt%.

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引用次数: 0

Activation flotation and activating mechanism of cyanide-depressed pyrite using sodium persulfate and ferrous sulfate

IF 4.9 2区工程技术 Q1 ENGINEERING, CHEMICAL

Minerals Engineering

Pub Date : 2025-02-14 DOI: 10.1016/j.mineng.2025.109206

Qinzhi Yuan , Mengyu Wang , Changliang Shi , Ji Fang , Xianhui Qiu , Tingsheng Qiu

Cyanide tailings were produced by cyanidation gold extraction and normally contained a large amount of unrecovered valuable metals. At present, there are few pieces of research on the activation flotation recovery of useful minerals in cyanidation tailings. In this paper, the activation flotation of cyanide-depressed pyrite using sodium persulfate (PDS) and ferrous sulfate (Fe(II)) was systematically studied by microflotation tests. The activating mechanism was analyzed by FTIR spectroscopy, zeta potential measurement and electron paramagnetic resonance (EPR) analysis. The microflotation tests showed that pyrite flotation was deeply depressed in the presence of sodium cyanide (NaCN). The flotation of cyanide-depressed pyrite could be largely improved by the addition of individual PDS or combined PDS and Fe(II). The dosage of combined PDS and Fe(II) was lower and their activating effect was better than using PDS alone. Zeta potential measurements and FTIR analysis revealed that NaCN was adsorbed on the pyrite surface to generate the hydrophilic ferricyanide, which can reduce the pyrite floatability. The individual PDS or combined PDS and Fe(II) could react with ferricyanide to destroy the hydrophilic adsorption layer and restore the hydrophobicity of pyrite surface. EPR analysis indicated that the oxidation system of pyrite with combined PDS and Fe(II) could produce more powerful SO₄⁻• and HO• than individual PDS. The radical scavenging experiments further confirmed that the generating free radicals were the active species for the destruction of ferricyanide and reduction of the activator dosage.

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引用次数: 0

The role of grinding media and water composition on the chemical characteristics in a laboratory ball mill

IF 4.9 2区工程技术 Q1 ENGINEERING, CHEMICAL

Minerals Engineering

Pub Date : 2025-02-12 DOI: 10.1016/j.mineng.2025.109214

S.N. Nyoni, C.T. O’Connor, K.C. Corin

Milling processes have been predominantly studied in relation to their primary function of particle size reduction and liberation, with little attention paid to the underlying chemical changes induced by this process. Furthermore, most studies have been conducted in the presence of ore, making it difficult to establish a clear reference point for understanding the different effects of the milling conditions on the slurry chemistry as opposed to those imparted by the ore on the chemical environment. In this study, the effects of milling in the absence of ore have been investigated, considering variables such as process water and grinding media composition at different pH conditions. The effect of using a stainless-steel mill shell was also investigated using inert ceramic grinding media. It has been shown that the type of Fe ion present affects the mixed potential (Eh) and pH of the system. This, in turn, significantly impacts the availability of a collector such as SIBX in the slurry phase. Furthermore, the presence of ions in the process water, typical of those produced during recycling, was found to buffer pH and Eh changes when Fe(III) is the dominant Fe species. Compared to milling under natural conditions, pH control could reduce the effects of both media and water type on Eh. The relative amount of dissolved Fe present correlated the most with the observed Eh trends when milling with different media types at natural pH. Dissolution of Fe attributable to the mill shell was also observed when using ceramic media. Therefore, the composition of the mill shell may have a significant impact on the reactions occurring in the slurry phase. It is proposed that the results of this investigation may lead to a better understanding of the relative effects of grinding media, ore type, and the nature of the mill shell on the slurry chemistry and, thus, on the ultimate downstream processes such as flotation.

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引用次数: 0

Understanding the effect of particle shapes on particle motions in Reflux Flotation Cell’s downcomer through fluid dynamic modelling

IF 4.9 2区工程技术 Q1 ENGINEERING, CHEMICAL

Minerals Engineering

Pub Date : 2025-02-12 DOI: 10.1016/j.mineng.2025.109208

Jiarui Chen , Wonder Chimonyo , Yongjun Peng

The Reflux Flotation Cell (RFC) developed in recent years has proven to be able to process a wide size range of particles and enhance the throughput in coal flotation. Our previous research has shown that the recovery of graphite particles with an aspect ratio of 0.2 is significantly lower than the recovery of coal particles with an aspect ratio of 0.8, attributed to the higher drag on graphite particles resulting in stronger repulsion between particles and bubbles in the RFC’s downcomer. In this study, a three-phase CFD simulation was performed to expand the understanding of the effect of particle shapes on particle flotation. From the simulation result, it was found that compared to the particles with an aspect ratio of 0.8, the flow of the particles with an aspect ratio of 0.2 became more concentrated at the middle of the stream when entering the gas inlet region due to the higher drag force. The higher drag force also created a stronger downward push on the particles, resulting in a lower solid volumetric fraction in the gas inlet and the high turbulence region directly below it in the downcomer. A smaller gas–solid relative velocity was observed for the particles with an aspect ratio of 0.2 in the high turbulence region as well. Those factors could result in a lower particle-bubble collision efficiency and a lower particle floatation recovery. The simulation result also indicated that the reduction of the gas flux reduced the high drag force on the particles with an aspect ratio of 0.2, which provided a smoother compression of the particle phase in the gas inlet, raised the solid volumetric fraction in the gas inlet and the high turbulence region and increased the gas–solid relative velocity in the high turbulence region. As a result, the reduction of the gas flux could benefit the particle-bubble collision and particle flotation for the particles with an aspect ratio of 0.2.

{"title":"Understanding the effect of particle shapes on particle motions in Reflux Flotation Cell’s downcomer through fluid dynamic modelling","authors":"Jiarui Chen , Wonder Chimonyo , Yongjun Peng","doi":"10.1016/j.mineng.2025.109208","DOIUrl":"10.1016/j.mineng.2025.109208","url":null,"abstract":"<div><div>The Reflux Flotation Cell (RFC) developed in recent years has proven to be able to process a wide size range of particles and enhance the throughput in coal flotation. Our previous research has shown that the recovery of graphite particles with an aspect ratio of 0.2 is significantly lower than the recovery of coal particles with an aspect ratio of 0.8, attributed to the higher drag on graphite particles resulting in stronger repulsion between particles and bubbles in the RFC’s downcomer. In this study, a three-phase CFD simulation was performed to expand the understanding of the effect of particle shapes on particle flotation. From the simulation result, it was found that compared to the particles with an aspect ratio of 0.8, the flow of the particles with an aspect ratio of 0.2 became more concentrated at the middle of the stream when entering the gas inlet region due to the higher drag force. The higher drag force also created a stronger downward push on the particles, resulting in a lower solid volumetric fraction in the gas inlet and the high turbulence region directly below it in the downcomer. A smaller gas–solid relative velocity was observed for the particles with an aspect ratio of 0.2 in the high turbulence region as well. Those factors could result in a lower particle-bubble collision efficiency and a lower particle floatation recovery. The simulation result also indicated that the reduction of the gas flux reduced the high drag force on the particles with an aspect ratio of 0.2, which provided a smoother compression of the particle phase in the gas inlet, raised the solid volumetric fraction in the gas inlet and the high turbulence region and increased the gas–solid relative velocity in the high turbulence region. As a result, the reduction of the gas flux could benefit the particle-bubble collision and particle flotation for the particles with an aspect ratio of 0.2.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"224 ","pages":"Article 109208"},"PeriodicalIF":4.9,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143395255","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Improving the flotation performance of fine molybdenite using superhydrophobic magnetic carriers

IF 4.9 2区工程技术 Q1 ENGINEERING, CHEMICAL

Minerals Engineering

Pub Date : 2025-02-12 DOI: 10.1016/j.mineng.2025.109212

He Wan , Juanping Qu , Linfeng Zhao , Xianzhong Bu

Effective flotation recovery of fine molybdenite is a significant challenge. This study investigated the role of superhydrophobic magnetic carriers (SMC) in improving the flotation recovery of fine molybdenite. Flotation tests of actual molybdenum ore showed that the addition of SMC can significantly improve the recovery of −38 μm molybdenite, especially −19 μm molybdenite, with a 14 % increase in recovery. Pure molybdenite flotation tests showed that the flotation speed of fine molybdenite in the early stage of flotation (0–1 min) was significantly faster in the presence of SMC than in the absence of SMC, and its flotation recovery (52.9 %) in 1 min is even slightly higher than that (51.3 %) in 3 min in the absence of SMC. Optical microscopy analysis confirmed that SMC adsorbed fine molybdenite particles, forming SMC-molybdenite agglomerates that facilitated carrier flotation. Calculations based on the EDLVO theory indicated that hydrophobic agglomeration was predominantly driven by hydrophobic potential energy, which was two to three orders of magnitude greater than electrostatic and van der Waals interaction potentials at interaction distances of 30 nm and 20 nm, respectively. The hydrophobic potential energy between SMC and fine molybdenite was more than 40 % higher than that between fine molybdenite particles, enabling more efficient adsorption of fine molybdenite onto the SMC surface and the formation of hydrophobic agglomerates. These agglomerates were more easily captured by bubbles during flotation, enhancing the recovery of fine molybdenite. The findings of this study demonstrate that carrier flotation technology using SMC provides an effective approach for the recovery of fine molybdenite. Furthermore, this approach offers technical and theoretical insights into minimizing the loss of fine target minerals in refractory ores that are low-grade, complex, and highly disseminated, contributing to the economic, efficient, and environmentally sustainable recovery of valuable elements from tailings.

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引用次数: 0

A new method for assessing coarse particle flotation performance Part 2: Assessment of reproducibility using data from a mechanical cell

IF 4.9 2区工程技术 Q1 ENGINEERING, CHEMICAL

Minerals Engineering

Pub Date : 2025-02-11 DOI: 10.1016/j.mineng.2025.109210

Luke J. Crompton, Md.Tariqul Islam, Emma Gibbs, Kevin P. Galvin

In Part I, we introduced distributed rate constants into the algorithm of Crompton et al (2023) used for describing the partitioning of hydrophobic particles in coarse particle flotation. The Part I paper applied the new algorithm to a previous data set generated using the CoarseAIR^TM fluidised bed separator. This Part II paper investigated the uncertainty in the new algorithm. A mechanical cell was used to simulate the coarse particle flotation process, providing a means for preparing pseudo steady state feed, product, and reject samples. A comprehensive protocol for preparing the samples was established. The overall methodology was then repeated multiple times, providing a basis for quantifying the reproducibility and reliability of the methodology, confirming its robustness.

引用次数: 0

Thickening mechanism under high compression stress based on double yield stress: Comparison between compression and compression-shear coupling

IF 4.9 2区工程技术 Q1 ENGINEERING, CHEMICAL

Minerals Engineering

Pub Date : 2025-02-10 DOI: 10.1016/j.mineng.2025.109205

Zhenqi Wang , Aixiang Wu , Zhuen Ruan , Raimund Bürger , Yi Mo

Tailings thickening is the primary link and key technology of cemented paste backfill (CPB) systems. However, the thickened tailings solids concentration is often substandard because the thickening mechanism under high compression stress (up to 30 kPa) is poorly understood, and is therefore investigated based on the rheological properties of tailings. A self-developed high-compression stress experimental device was used to test the double yield stress (compressive and shear yield stresses) and concentration evolution under compression and compression-shear coupling, respectively. Furthermore, the evolution of floc structure and drainage channels was observed in both scenarios. The results indicate that concentration can be approximated by a power function of the double yield stress, and shear yield stress can be approximated by a linear function of the compressive yield stress. It is found that the linear fitting proportionality coefficients under compression are smaller than those under compression-shear coupling and that the proportionality coefficients in the low-compression stress range are smaller than in the high-compression stress range under compression, but the opposite result is obtained under compression-shear coupling. It turns out that the introduction of rake-shearing action (RSA) by compression-shear coupling mainly improves the thickening rate and the thickening effect in the low-compression stress range. Moreover, by introducing the RSA, the concentration growth ratio also confirms that the compression-shear coupling improves the thickening effect in the low-compression stress range, mainly because the shear action improves the floc arrangement, the drainage channels are more developed, and the drainage rate increases. This study reveals the thickening mechanism under high compression stress from the relationship between double yield stress. Also, it obtains the mechanism by which the RSA increases the dewatering rate in low compression stress.

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引用次数: 0