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Current flotation practices using lime or cyanide as depressants in chalcopyrite and pyrite separation have significant disadvantages, such as substantial reagent consumption, high slurry pH, and environmental hazards. This work aimed to explore the utilization and mechanisms of tannic acid (TA) as an eco-friendly alternative to lime or cyanide in chalcopyrite-pyrite separation. Flotation results showed that TA selectively depressed pyrite yet allowed chalcopyrite to float at neutral or alkaline pH. Adsorption density and zeta potential results indicated that TA adsorbed intensely on pyrite but minorly on chalcopyrite. Besides, potassium ethyl xanthate was still largely adsorbed on chalcopyrite but not on pyrite after TA adsorption. Surface analysis by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy further showed that the oxidation species of FeOOH and Fe (SO), particularly FeOOH were the main active sites for TA chemical adsorption. Owing to the greater and faster oxidation of pyrite, more FeOOH and Fe (SO) were generated on the pyrite surface, and the chemical adsorption of TA was more pronounced on the pyrite surface than on the chalcopyrite surface.
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http://dx.doi.org/10.1021/acsomega.3c03663 | DOI Listing |
Langmuir
July 2025
State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Yunnan Key Laboratory of Green Separation and Enrichment of Strategic Metal Resources, Faculty of Land Resources Engineering, Kunming University of Science and Technology, Kunming, Yunnan 650093, PR China.
The efficient flotation separation between chalcopyrite and pyrite is considered challenging under weak alkaline conditions due to their similar floatability characteristics. In this work, based on the differences in the chemical valence states of Fe atoms on chalcopyrite and pyrite, an innovative depressant system combining sodium sulfide (NaS) and proanthocyanidins (PC) was proposed. In artificial mixed ore tests, compared with a single PC, a higher separation efficiency between chalcopyrite and pyrite is achieved when the combined depressants 20 mg/L NaS and 40 mg/L PC are employed.
View Article and Find Full Text PDFFront Microbiol
May 2025
Institute for Biological and Medical Engineering, Schools of Engineering, Medicine & Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile.
Biomining is a sustainable alternative to conventional mineral processing that uses acidophilic microorganisms to catalyze the extraction of valuable metals from sulfide minerals. Mixed microbial consortia composed of moderate thermophiles such as and some species improve metal extraction efficiency at higher temperatures compared to pure cultures of mesophiles. However, quorum sensing (QS), which regulates microbial interactions and likely influences bioleaching performance, has not been studied in these species.
View Article and Find Full Text PDFBiology (Basel)
April 2025
State Key Laboratory of Submarine Geoscience, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou 310012, China.
The weathering of seafloor hydrothermal sulfides is facilitated by microbial activities, yet the specific mechanisms of different sulfide types are not well understood. Previous studies have primarily been carried out under laboratory conditions, making it difficult to accurately replicate the complex in situ conditions of deep-sea hydrothermal fields. Herein, we deployed two well-characterized pyrite (Py)-dominated and chalcopyrite (Ccp)-dominated sulfide slices, which were placed 300 m from an active venting site in the Wocan-1 hydrothermal field (Carlsberg Ridge, Northwest Indian Ocean) for an 18-month in situ incubation experiment.
View Article and Find Full Text PDFChemistryOpen
May 2025
Sustainable and Innovative Minerals and Metals Extraction Technology (SIMMET) Group, School of Chemical and Metallurgical Engineering, University of the Witwatersrand, Private Bag X3, Wits, 2050, South Africa.
Understanding the oxidation of sulfidic minerals, especially those of pyrite and chalcopyrite, under acidic conditions has important outcomes, such as exposing any encapsulated gold not recovered by traditional cyanidation processes. This study focused on the electrochemical oxidation of pyrite and chalcopyrite in a 0.5 M nitric acid solution.
View Article and Find Full Text PDFWorld J Microbiol Biotechnol
April 2025
Laboratory of Applied and Basic Microbiology, Department of Biology, Faculty of Chemistry and Biology, University of Santiago of Chile (USACH), Av. Libertador Bernardo O'Higgins 3363, Santiago, Chile.
Acidithiobacillus ferrooxidans is a chemolithoautotrophic acidophilic bacterium belonging to microbial communities involved in sulfide ore bioleaching. This microorganism possesses redundancy of genes encoding ATP-independent chaperone holdases like Hsp20 (hps20.1, hsp20.
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