Search Results (17)

A slurry’s rheological properties significantly affect flotation performance. Flotation variables—including mineral composition, slurry concentration, and ore particle size—influence these properties by altering the interaction forces between mineral particles and the slurry’s microstructure, thereby impacting flotation outcomes. This study investigated the effects of flotation variables on the rheological properties and flotation performance of lead–zinc sulfide ores in two ternary systems comprising galena or sphalerite + kaolinite and quartz. Cryo-scanning electron microscopy and atomic force microscopy were used to analyze the slurries’ interaction forces and microstructure. The results show that finer ore particle sizes increase the formation of particle agglomerates, leading to larger structures and higher slurry apparent viscosity. This improves the metal mineral recovery rate during flotation but simultaneously increases gangue mineral entrainment, reducing concentrate grade. As the slurry concentration increases, the ternary system with kaolinite as the main gangue mineral forms a denser and more rigid honeycomb network structure. This results in higher yield stress and apparent viscosity, which negatively impacts lead and zinc sulfide separation during flotation. In contrast, the quartz-dominated system forms a slightly denser, stacked structure that lacks a solid network and thus maintains lower yield stress and apparent viscosity, which favors mineral separation. Adding sodium hexametaphosphate enhances particle dispersion by increasing repulsive forces between mineral particles. This thins or disrupts the kaolinite network structure, reducing the slurry’s apparent viscosity and yield stress, thereby improving its rheological properties and facilitating the flotation separation of lead and zinc sulfide minerals. Full article

The increasing demand for zinc resources and the declining availability of sulfide zinc ore reserves have made the efficient utilization of zinc oxide a topic of considerable interest. In this study, a ternary composite collector ABN (Al-BHA-NaOL system) was applied to the direct flotation of smithsonite. Micro-flotation studies showed that at pH 9, ABN exhibited better adsorption on smithsonite, achieving a recovery rate of 80.62%. Visual MINTEQ 3.1 and zeta potential analysis confirmed that ABN predominantly reacted with Zn(OH)₂(aq) on the surface of smithsonite. Furthermore, X-ray photoelectron spectroscopy (XPS) analysis results elucidated the formation of Al-O bonds through chemical adsorption on the smithsonite surface. Additionally, powder contact angle measurements indicated that ABN enhances the surface contact angle of smithsonite. These results illuminate that ABN is adsorbed by reacting with O sites on hydroxylated metal ions on the smithsonite surface, with Al serving as the adsorption center, thereby achieving separation and purification. Due to ABN’s adsorption characteristics, smithsonite can achieve efficient and clean direct flotation recovery without sulfidization. Full article

Metal–organic frameworks (MOFs) are hybrid inorganic–organic 3D coordination polymers with metal sites and organic linkers, which are a “hot” topic in the research of sorption, separations, catalysis, sensing, and environmental remediation. In this study, we explore the molecular mechanism and kinetics of interaction of the new copper porphyrin aluminum metal–organic framework (actAl-MOF-TCPPCu) compound 4 with a vapor of the volatile organic sulfur compound (VOSC) diethyl sulfide (DES). First, compound 4 was synthesized by post-synthetic modification (PSM) of Al-MOF-TCPPH₂ compound 2 by inserting Cu²⁺ ions into the porphyrin ring and characterized by complementary qualitative and quantitative chemical, structural, and spectroscopic analysis. Second, the interaction of compound 4 with DES vapor was analyzed dynamically by the novel method of in situ time-dependent attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy at controlled humidity levels. The sorbent–adsorbate interactions, as analyzed by the shifts in IR peaks, indicate that the bonding includes the hydroxy O-H, carboxylate COO⁻, and phenyl groups. The kinetics of sorption obeys the Langmuir pseudo-first-order rate law. The pre-adsorption of water vapor by compound 4 at the controlled relative humidity under static (equilibrium) conditions yields the binary stoichiometric adsorption complex (Al-MOF-TCPPCu)_1.0(H₂O)_8.0. The pre-adsorption of water vapor makes the subsequent sorption of DES slower, while the kinetics obey the same rate law. Then, static pre-adsorption of water vapor was followed by static sorption of DES vapor, and the ternary adsorption complex (Al-MOF-TCPPCu)_1.0(H₂O)_8.0(DES)₃.₈ was obtained. Despite the pre-adsorption of significant amounts of water, the binary complex adsorbs a large amount of DES: ca. 36.6 wt. % (per compound 4). Finally, the ternary complex is facilely regenerated by gentle heating under vacuum. Compound 4 and related MOFs are promising for adsorptive removal of vapor of DES and related VOSCs from dry and humid air. Full article

Copper sulfide ores frequently co-occur with pyrite, presenting a significant challenge for their selective separation during beneficiation processes. Despite advancements in flotation technology, there remains a critical need for efficient methods to enhance copper recovery while suppressing pyrite interference, particularly without compromising the associated precious metals such as gold and silver. Current practices often struggle with achieving high selectivity and recovery while maintaining environmental sustainability. Here, we investigate the efficacy of a ternary collector mixture consisting of ammonium dibutyl dithiophosphate (ADD), butyl xanthate (BX), and ethyl xanthate (EX) for the selective flotation of copper sulfide from a complex ore containing 0.79% Cu and associated precious metals (0.233 g/t Au and 5.83 g/t Ag). A combination of lime and hydrogen peroxide as inhibitors was employed to suppress pyrite effectively under alkaline conditions (pH = 11.33). The results demonstrate that the optimized ternary collector system (ADD:BX:EX at a ratio of 1:0.5:0.5) significantly improves the copper grade and recovery at an ultra-low dosage of 10 g/t. The optimized flotation method using the combined collectors and inhibitors effectively separated chalcopyrite from pyrite, achieving a copper concentrate with 20.08% Cu content and a recovery of 87.73%. Additionally, the process yielded notable recoveries of gold (9.22%) and silver (26.66%). These findings advance the field by providing a viable and environmentally conscious approach to the beneficiation of sulfide ores, potentially serving as a blueprint for processing similar mineral deposits while minimizing reagent usage and costs. Full article

In this study, we synthesized a transition metal sulfide (TMS) with a spinel structure, i.e., MnIn₂S₄ (MIS), using a two-step hydrothermal and sintering process. In the context of lithium-ion battery (LIB) applications, ternary TMSs are being considered as interesting options for anode materials. This consideration arises from their notable attributes, including high theoretical capacity, excellent cycle stability, and cost-effectiveness. However, dramatic volume changes result in the electrochemical performance being severely limited, so we introduced single-walled carbon nanotubes (SWCNTs) and prepared an MIS/SWCNT composite to enhance the structural stability and electronic conductivity. The synthesized MIS/SWCNT composite exhibits better cycle performance than bare MIS. Undergoing 100 cycles, MIS only yields a reversible capacity of 117 mAh/g at 0.1 A/g. However, the MIS/SWCNT composite exhibits a reversible capacity as high as 536 mAh/g after 100 cycles. Moreover, the MIS/SWCNT composite shows a better rate capability. The current density increases with cycling, and the SWCNT composite exhibits high reversible capacities of 232 and 102 mAh/g at 2 A/g and 5 A/g, respectively. Under the same conditions, pristine MIS can only deliver reversible capacities of 21 and 4 mAh/g. The results indicate that MIS/SWCNT composites are promising anode materials for LIBs. Full article

One of the most challenging problems for people around the world is the lack of clean water. In the past few decades, the massive discharge of emerging organic pollutants (EOPs) into natural water bodies has exacerbated this crisis. Considerable research efforts have been devoted to removing these EOPs due to their biotoxicity at low concentrations. Heterogeneous photocatalysis via coupling clay minerals with nanostructured semiconductors has proven to be an economical, efficient, and environmentally friendly technology for the elimination of EOPs in drinking water and watershed water. Natural zeolite minerals (especially clinoptilolites) are regarded as appropriate supports for semiconductor-based photocatalysts due to their characteristics of having a low cost, environmental friendliness, easy availability, co-catalysis, etc. This review summarizes the latest research on clinoptilolites used as supports to prepare binary and ternary metal oxide or sulfide semiconductor-based hybrid photocatalysts. Various preparation methods of the composite photocatalysts and their degradation efficiencies for the target contaminants are introduced. It is found that the good catalytic activity of the composite photocatalyst could be attributed to the synergistic effect of combining the clinoptilolite adsorbent with the semiconductor catalyst in the heterogeneous system, which could endow the composites with an excellent adsorption capacity and produce more e⁻/h⁺ pairs under suitable light irradiation. Finally, we highlight the serious threat of EOPs to the ecological environment and propose the current challenges and limitations, before putting the zeolite mineral composite photocatalysts into practice. The present work would provide a theoretical basis and scientific support for the application of zeolite-based photocatalysts for degrading EOPs. Full article

The greenstone belts of the Crixás-Goiás Domain are economically important due to significant epigenetic gold deposits and the potential for under-researched syngenetic deposits. The gold occurrences associated with the volcanogenic massive sulfide (VMS) deposits in the region are documented only in the volcanoclastic rocks of the Digo-Digo Formation, Serra de Santa Rita greenstone belt. The objective of this work is to discuss the efficiency of the induced polarization methods in the time and frequency domains for differentiating and identifying potentially mineralized zones in the exhalites associated with the VMS-type gold of the Digo-Digo Formation. Data were acquired using a multielectrode resistivity meter with the dipole–dipole array and 10 m spacing between electrodes, as well as different current injection times (250, 1000, and 2000 ms). After the electrical data processing and inversion, the sections were integrated into ternary red-green-blue and cyan-magenta-yellow models to highlight areas of high chargeability, low resistivity, and high metal factor (frequency domain) and, thus, map the higher potential zones to host polarizable metallic minerals. The geological–geophysical model elaborated from the correlation of electrical and surface geological data allowed us to identify four anomalous areas related to potential mineralized zones. The geological data confirm that two targets are associated with the geological contacts between metamafic and intermediate metavolcanic units and the exhalative horizon. One of the targets coincides with a sulfide-rich exhalative horizon (VMS), while the last target occurs in the occurrence area of metaultramafic rocks, where gold mineralization occurrences have not been previously described, being a promising target for future investigations. Full article

In this study, we synthesized a ternary transition metal sulfide, Zn_0.76Co_0.24S (ZCS-CE), using a one-step solvothermal method and explored its potential as a Pt-free counter electrode for dye-sensitized solar cells (DSSCs). Comprehensive investigations were conducted to characterize the structural, morphological, compositional, and electronic properties of the ZCS-CE electrode. These analyses utilized a range of techniques, including X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. The electrocatalytic performance of ZCS-CE for the reduction of I₃⁻ species in a symmetrical cell configuration was evaluated through electrochemical impedance spectroscopy and cyclic voltammetry. Our findings reveal that ZCS-CE displayed superior electrocatalytic activity and stability when compared to platinum in I⁻/I₃⁻ electrolyte systems. Furthermore, ZCS-CE-based DSSCs achieved power conversion efficiencies on par with their Pt-based counterparts. Additionally, we expanded the applicability of this material by successfully powering an electrochromic cell with ZCS-CE-based DSSCs. This work underscores the versatility of ZCS-CE and establishes it as an economically viable and environmentally friendly alternative to Pt-based counter electrodes in DSSCs and other applications requiring outstanding electrocatalytic performance. Full article

Photocatalytic degradation plays a crucial role in wastewater treatment, and the key to achieving high efficiency is to develop photocatalytic systems that possess excellent light absorption, carrier separation efficiency, and surface-active sites. Among various photocatalytic systems, S-type heterojunctions have shown remarkable potential for efficient degradation. This work delves into the construction of S-type heterojunctions of ternary indium metal sulfide and bismuth ferrite nanofibers with the introduction of sulfur vacancy defects and morphology modifications to enhance the photocatalytic degradation performance. Through the impregnation method, BiFeO₃/ZnIn₂S₄ heterojunction materials were synthesized and optimized. The 30% BiFeO₃/ZnIn₂S₄ heterojunction exhibited superior photocatalytic performance with higher sulfur vacancy concentration than ZnIn₂S₄. The in-situ XPS results demonstrate that the electrons between ZnIn₂S₄ and BFO are transferred via the S-Scheme, and after modification, ZnIn₂S₄ has a more favorable surface morphology for electron transport, and its flower-like structure interacts with the nanofibers of BFO, which has a further enhancement of the reaction efficiency for degrading pollutants. This exceptional material demonstrated a remarkable 99% degradation of Evans blue within 45 min and a significant 68% degradation of ciprofloxacin within 90 min. This work provides a feasible idea for developing photocatalysts to deal with the problem of polluted water resources under practical conditions. Full article

Electrolytes are one of the most influential aspects determining the efficiency of electrochemical supercapacitors. Therefore, in this paper, we investigate the effect of introducing co-solvents of ester into ethylene carbonate (EC). The use of ester co-solvents in ethylene carbonate (EC) as an electrolyte for supercapacitors improves conductivity, electrochemical properties, and stability, allowing greater energy storage capacity and increased device durability. We synthesized extremely thin nanosheets of niobium silver sulfide using a hydrothermal process and mixed them with magnesium sulfate in different wt% ratios to produce Mg(NbAgS)_x)(SO₄)_y. The synergistic effect of MgSO₄ and NbS₂ increased the storage capacity and energy density of the supercapattery. Multivalent ion storage in Mg(NbAgS)_x(SO₄)_y enables the storage of a number of ions. The Mg(NbAgS)_x)(SO₄)_y was directly deposited on a nickel foam substrate using a simple and innovative electrodeposition approach. The synthesized silver Mg(NbAgS)_x)(SO₄)_y provided a maximum specific capacity of 2087 C/g at 2.0 A/g current density because of its substantial electrochemically active surface area and linked nanosheet channels which aid in ion transportation. The supercapattery was designed with Mg(NbAgS)_x)(SO₄)_y and activated carbon (AC) achieved a high energy density of 79 Wh/kg in addition to its high power density of 420 W/kg. The supercapattery (Mg(NbAgS)_x)(SO₄)_y//AC) was subjected to 15,000 consecutive cycles. The Coulombic efficiency of the device was 81% after 15,000 consecutive cycles while retaining a 78% capacity retention. This study reveals that the use of this novel electrode material (Mg(NbAgS)_x(SO₄)_y) in ester-based electrolytes has great potential in supercapattery applications. Full article

Photocatalytic overall water splitting in solar–chemical energy conversion can effectively mitigate environmental pollution and resource depletion. Stable ternary metal indium zinc sulfide (ZnIn₂S₄) is considered one of the ideal materials for photocatalytic overall water splitting due to its unique electronic and optical properties, as well as suitable conduction and valence band positions for suitable photocatalytic overall water splitting, and it has attracted widespread researcher interest. Herein, we first briefly describe the mechanism of photocatalytic overall water splitting, and then introduce the properties of ZnIn₂S₄ including crystal structure, energy band structure, as well as the main synthetic methods and morphology. Subsequently, we systematically summarize the research progress of ZnIn₂S₄-based photocatalysts to achieve overall water splitting through modification methods such as defect engineering, heterostructure construction, and co-catalyst loading. Finally, we provide insights into the prospects and challenges for the overall water splitting of ZnIn₂S₄-based photocatalysts. Full article

The ternary metal sulfide CdIn₂S₄ (CIS) has great application potential in solar-to-hydrogen conversion due to its suitable band gap, good stability and low cost. However, the photocatalytic hydrogen (H₂) evolution performance of CIS is severely limited by the rapid electron–hole recombination originating from the slow photogenerated hole transfer kinetics. Herein, by simply depositing cobalt phosphate (CoH_xPO_y, noted as Co-Pi), a non-precious co-catalyst, an efficient pathway for accelerating the hole transfer process and subsequently promoting the H₂ evolution reaction (HER) activity of CIS nanosheets is developed. X-ray photoelectron spectroscopy (XPS) reveals that the Co atoms of Co-Pi preferentially combine with the unsaturated S atoms of CIS to form Co-S bonds, which act as channels for fast hole extraction from CIS to Co-Pi. Electron paramagnetic resonance (EPR) and time-resolved photoluminescence (TRPL) showed that the introduction of Co-Pi on ultrathin CIS surface not only increases the probability of photogenerated holes arriving the catalyst surface, but also prolongs the charge carrier’s lifetime by reducing the recombination of electrons and holes. Therefore, Co-Pi/CIS exhibits a satisfactory photocatalytic H₂ evolution rate of 7.28 mmol g⁻¹ h⁻¹ under visible light, which is superior to the pristine CIS (2.62 mmol g⁻¹ h⁻¹) and Pt modified CIS (3.73 mmol g⁻¹ h⁻¹). Full article

With the rapid development of modern industries, water pollution has become an urgent problem that endangers the health of human and wild animals. The photocatalysis technique is considered an environmentally friendly strategy for removing organic pollutants in wastewater. As an important member of Bi-series semiconductors, Bi₂WO₆ is widely used for fabricating high-performance photocatalysts. In this review, the recent advances of Bi₂WO₆-based photocatalysts are summarized. First, the controllable synthesis, surface modification and heteroatom doping of Bi₂WO₆ are introduced. In the respect of Bi₂WO₆-based composites, existing Bi₂WO₆-containing binary composites are classified into six types, including Bi₂WO₆/carbon or MOF composite, Bi₂WO₆/g-C₃N₄ composite, Bi₂WO₆/metal oxides composite, Bi₂WO₆/metal sulfides composite, Bi₂WO₆/Bi-series composite, and Bi₂WO₆/metal tungstates composite. Bi₂WO₆-based ternary composites are classified into four types, including Bi₂WO₆/g-C₃N₄/X, Bi₂WO₆/carbon/X, Bi₂WO₆/Au or Ag-based materials/X, and Bi₂WO₆/Bi-series semiconductors/X. The design, microstructure, and photocatalytic performance of Bi₂WO₆-based binary and ternary composites are highlighted. Finally, aimed at the existing problems in Bi₂WO₆-based photocatalysts, some solutions and promising research trends are proposed that would provide theoretical and practical guidelines for developing high-performance Bi₂WO₆-based photocatalysts. Full article

Ternary metal sulfides are projected as advanced lithium-ion battery (LIB) anodes due to their superior electronic conductivity and specific capacity compared to their respective oxide counterparts. Herein, a porous composite of cuboidal FeNi₂S₄ (FNS) with 2D reduced graphene oxide (rGO) and 1D multi-walled carbon nanotubes (MWCNTs) (composite name: FNS@GC) synthesised by an in-situ single-step hydrothermal process. The 1D/2D combined thin carbon coatings on the FeNi₂S₄ prevent aggregation during battery performance by increasing conductivity and resisting the volume changes at lithiation/de-lithiation processes. Consequently, the FNS@GC composite exhibits a commending electrochemical performance with a charge capacity of 797 mAh g⁻¹ and a first cycle coulombic efficiency of ~67% with reversible capacity restoration property and excellent long-term cycling stability. Furthermore, FNS@GC//LiFePO₄ full cell reveals its practical applicability as a LIB anode with a reversible capacity of 77 mAh g⁻¹ at 50 mA g⁻¹ current density. Full article

In this paper, we report the successful synthesis of cobalt ruthenium sulfides by a facile hydrothermal method. The structural aspects of the as-prepared cobalt ruthenium sulfides were characterized using X-ray diffraction, X-ray photoelectron spectroscopy, and Raman spectroscopy. All the prepared materials exhibited nanocrystal morphology. The electrochemical performance of the ternary metal sulfides was investigated by cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy techniques. Noticeably, the optimized ternary metal sulfide electrode exhibited good specific capacitances of 95 F g⁻¹ at 5 mV s⁻¹ and 75 F g⁻¹ at 1 A g⁻¹, excellent rate capability (48 F g⁻¹ at 5 A g⁻¹), and superior cycling stability (81% capacitance retention after 1000 cycles). Moreover, this electrode demonstrated energy densities of 10.5 and 6.7 Wh kg⁻¹ at power densities of 600 and 3001.5 W kg⁻¹, respectively. These attractive properties endow proposed electrodes with significant potential for high-performance energy storage devices. Full article