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Gold Recovery in Heap Leaching of Old Mine Tailings Using Chloride Solution

JOM 2025年 1-10页

作者： Mahamba, Kupakwashe Masamvu, John Malbenia Mabwe, Nancy Mabikire, Tinashe Chiwandika, Edson Kugara Department of Mining Chemical and Metallurgical Engineering Faculty of Engineering and Built Environment University of Zimbabwe Harare Zimbabwe Department of Metallurgical Engineering Faculty of Engineering and Environment Gwanda State University Gwanda Zimbabwe Polymer and Materials Science Institute Scientific and Industrial Research and Development Centre Harare Zimbabwe

The closure of hydrometallurgical plants due to mineral reserve depletion prompts exploration into alternative solutions, such as processing gold tailing ores. Despite challenges posed by minerals like hydronium jarosite and sulfides, which hinder gold dissolution in conventional cyanide leaching, preliminary investigations of utilizing chloride oxidation on an old mine tailing dump showed some promising results. This study aims to assess the efficacy of this technique on refractory gold tailings, employing acid leaching with sodium hypochlorite, sodium chloride, and hydrochloric acid. Various factors affecting gold extraction from heap leaching, such as agglomeration blending ratios, pellet size, leaching pH, bed height, and spraying rate, were evaluated. Results indicate a > 40% increase in gold extraction with chloride-based heap leaching. This innovative approach offers a promising alternative for liberating gold from sulfide ores within tailings, potentially mitigating the challenges associated with conventional methods and revitalizing hydrometallurgical operations.

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Innovations in Packaging to Monitor and Maintain the Quality of the Food Products

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Journal of Packaging Technology and Research 2024年第1期8卷 15-50页

作者： Yadav, Neelam Kaur, Raminder Department of Applied Sciences and Humanities ABES Engineering College Ghaziabad India Department of Polymer Science and Chemical Technology Delhi Technological University New Delhi India

Packaging is a technology and art that has been developed to enclose and protect a variety of objects for use in trade, storage, and circulation. Creating concepts for active and intelligent packaging has improved the superiority of food products and produced a wealth of new outcomes for postponing the deterioration of packaged food. Unquestionably, one of the best advancements in packaging technology is active packaging. Active packaging, such as modified active packaging (MAP) systems, improves appearance and delays ripening while also extending the shelf life of fresh items, providing a high-quality food product and lowering economic losses. To maintain the freshness of packed food products like fresh fruits, vegetables, dairy, and meat products, there are several different packaging solutions available. By incorporating components like antimicrobial agents, antioxidants, carbon dioxide absorbers, etc. in the built-in packaging systems, such as the packaging films, sachets, or an absorbent pad, that either release or absorb active chemicals into the packaged goods or adjoining environment, aids in extending the stability of packed food products and improves the performance of the packaging. These elements can surround the food, preventing food deterioration and extending the shelf life of the product. This extensive analysis examines the cutting-edge active food packaging technologies that have recently been developed with the aim of preserving or extending the shelf life and quality of food products.

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面向高性能柔性电子的强韧、可修复和优异抗穿刺的氟化弹性体

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science Bulletin 2024年第12期69卷 1875-1886页

作者：贾宇杰管清宝储成臻张璐之 Rasoul Esmaeely Neisiany 顾士甲孙俊芬游正伟 State Key Laboratory for Modification of Chemical Fibers and Polymer Materials Institute of Functional MaterialsCollege of Materials Science and EngineeringResearch Base of Textile Materials for Flexible Electronics and Biomedical Applications(China Textile Engineering Society)Shanghai Engineering Research Center of Nano-Biomaterials and Regenerative MedicineDonghua UniversityShanghai 201620China Biotechnology Centre Silesian University of TechnologyGliwice 44-100Poland Department of Polymer Engineering Hakim Sabzevari UniversitySabzevar ***Iran

There is usually a trade-off between high mechanical strength and dynamic self-healing because the mechanisms of these properties are mutually ***,we design and fabricate a fluorinated phenolic polyurethane(FPPU)elastomer based on octafluoro-4,4'-biphenol to overcome this *** fluorine-based motif not only tunes interchain interactions throughπ-πstacking between aromatic rings and free-volume among polymer chains but also improves the reversibility of phenol-carbamate bonds via electron-withdrawing effect of fluorine *** developed FPPU elastomer shows the highest recorded puncture energy(648.0 m J),high tensile strength(27.0 MPa),as well as excellent selfhealing efficiency(92.3%),along with low surface energy(50.9 MJ m^(-2)),notch-insensitivity,and reprocessability compared with non-fluorinated counterpart biphenolic polyurethane(BPPU)*** advantage of the above-mentioned merits of FPPU elastomer,we prepare an anti-fouling triboelectric nanogenerator(TENG)with a self-healable,and reprocessable elastic *** from stronger electron affinity of fluorine atoms than hydrogen atoms,this electronic device exhibits ultrahigh peak open-circuit voltage of 302.3 V compared to the TENG fabricated from BPPU ***,a healable and stretchable conductive composite is *** research provides a distinct and general pathway toward constructing high-performance elastomers and will enable a series of new applications.

关键词： Fluorinated elastomer Polyurethane Phenol-carbamate bonds Self-healing Reprocessable

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Edge atomic Fe sites decorated porous graphitic carbon as an efficient bifunctional oxygen catalyst for Zinc-air batteries

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Journal of Energy Chemistry 2023年第8期83卷 602-611,I0014页

作者： Ruihui Gan Yali Wang Xiangwu Zhang Yan Song Jingli Shi Chang Ma Tianjin Municipal Key Lab of Advanced Fiber and Energy Storage Technology Tiangong UniversityTianjin 300387China Fiber and Polymer Science Program Department of Textile EngineeringChemistry and ScienceWilson College of TextilesNorth Carolina State UniversityRaleighNC 27695-8301uNITED sTATES CAS Key Laboratory of Carbon Materials Institute of Coal ChemistryChinese Academy of SciencesTaiyuan 030001ShanxiChina

The development of advanced bifunctional oxygen electrocatalysts for oxygen reduction and evolution reactions(ORR and OER) is critical to the practical application of zinc-air batteries(ZABs). Herein, a silica-assisted method is reported to integrate numerous accessible edge Fe-Nx sites into porous graphitic carbon(named Fe-N-G) for achieving highly active and robust oxygen electrocatalysis. Silica facilitates the formation of edge Fe-Nx sites and dense graphitic domains in carbon by inhibiting iron *** purification process creates a well-developed mass transfer channel for Fe-N-G. Consequently,Fe-N-G delivers a half-wave potential of 0.859 V in ORR and an overpotential of 344 m V at10 m A cm^(-2)in OER. During long-term operation, the graphitic layers protect edge Fe-Nx sites from demetallation in ORR and synergize with Fe OOH species endowing Fe-N-G with enhanced OER *** functional theory calculations reveal that the edge Fe-Nx site is superior to the in-plane Fe-Nx site in terms of OH* dissociation in ORR and OOH* formation in OER. The constructed ZAB based on Fe-N-G cathode shows a higher peak power density of 133 m W cm^(-2)and more stable cycling performance than Pt/C + RuO2counterparts. This work provides a novel strategy to obtain high-efficiency bifunctional oxygen electrocatalysts through space mediation.

关键词： Bifunctionality EdgeFe-Nxsites Oxygen catalysis Graphitic domains Zinc-air batteries

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Continuous Lithium-Ion Extraction From Seawater and Mine Water With a Fuel Cell System and Ceramic Membranes

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Energy & Environmental Materials 2024年第6期7卷 254-261页

作者： Cansu Kök Lei Wang Jean Gustavo A.Ruthes Antje Quade Matthew E.Suss Volker Presser INM–Leibniz Institute for New Materials Campus D2266123Saarbr¨uckenGermany Department of Materials Science&Engineering Saarland UniversityCampus D2266123Saarbr¨uckenGermany Leibniz Institute for Plasma Science and Technology Felix-Hausdorff-Straße 217489GreifswaldGermany Faculty of Mechanical Engineering Technion–Israel Institute of TechnologyHaifa3200003Israel Wolfson Department of Chemical Engineering Technion–Israel Institute of TechnologyHaifa3200003Israel Grand Technion Energy Program Technion–Israel Institute of TechnologyHaifa3200003Israel Saarene–Saarland Center for Energy Materials and Sustainability Campus C4266123Saarbr¨uckenGermany

The demand for electronic devices that utilize lithium is steadily increasing in this rapidly advancing technological *** high-purity lithium in an environmentally friendly way is challenging by using commercialized ***,we propose the first fuel cell system for continuous lithium-ion extraction using a lithium superionic conductor membrane and advanced *** fuel cell system for extracting lithium-ion has demonstrated a twofold increase in the selectivity of Li^(+)/Na^(+)while producing *** data show that the fuel cell with a titania-coated electrode achieves 95%lithium-ion purity while generating 10.23 Wh of energy per gram of *** investigation revealed that using atomic layer deposition improved the electrode's uniformity,stability,and electrocatalytic *** 2000 cycles determined by cyclic voltammetry,the electrode preserved its stability.

关键词： atomic layer deposition cation selectivity electrochemical lithium-ion extraction fuel cell

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Interfacial Diffusion Manipulation by Amphiphilic Cellulose Nanocrystal Having Antibacterial Property for Asymmetric Polyamide Layer

SSRN

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SSRN 2023年

作者： Seo, Huiran Shin, Huiseob Kong, Saerom Jung, Kyung Hwa Kim, Mun Hyeon Kim, Jae Jun Suh, Dongwoo Baek, Youngbin Lee, Changha Kim, Hee Joong Lee, Jong-Chan Department of Chemical and Biological Engineering Institute of Chemical Processes Seoul National University Seoul08826 Korea Republic of Department of Biological Engineering Inha University Incheon22212 Korea Republic of Department of Polymer Science and Engineering Program in Environmental and Polymer Engineering Inha University Incheon22212 Korea Republic of

Polyamide (PA) thin-film composite (TFC) membranes, fabricated by interfacial polymerization (IP) process, have been widely used for the desalination process due to high water permeability with high water/salt selectivity. A number of advanced PA TFC membranes have been developed as more efficient alternatives to further improve separation performance and address the surface contamination problem of commercial membranes. Here, we utilized amphiphilic functionalized cellulose nanocrystal (f-CNC) having antibacterial property as a nanofiller material for the preparation of an advanced PA membrane system, featuring improved water permeability with high salt rejection ability. This strategy is inexpensive, scalable, environmentally friendly, and practically relevant, given that typical IP process with a renewable nanofiller was employed. The amphiphilic f-CNC manipulates interfacial diffusion of monomers upon IP process, thereby decreasing the effective PA layer thickness by 30% (from ~377 nm to ~268 nm) and increasing water permeability by 44% (from 1.26 Lm-2h-1bar-1 to 1.82 Lm-2h-1bar-1). In addition, the PA membrane with f-CNC showed improved antibacterial (~90%) and antifouling properties (~84%, FRR) due to the specific nature of f-CNC. This study provides insights for the development of thin, effective, and antibacterial, yet more green and scalable PA membrane alternatives to the conventional desalination membranes. © 2023, The Authors. All rights reserved.

关键词： Cellulose

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THE EFFECTS OF PRE-COATING LAYERS ON BARRIER LAYER PERFORMANCE

THE EFFECTS OF PRE-COATING LAYERS ON BARRIER LAYER PERFORMAN...

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TAPPICon 2023 - Rock the Roll: Unleashing the Harmonies of the Paper Industry

作者： Pokharel, Kritee Wang, Jinwu Bousfield, Douglas Paper Surface Science Program Department of Chemical and Biomedical Engineering University of Maine OronoME04469 United States Forest Products Laboratory MadisonWI United States

CNF (cellulose nanofibrils) layers on paper are an effective barrier against oxygen and grease and improve dispersion-based barrier coatings. The potential to produce paper grades with good oxygen, grease, and moisture barrier properties is clear, but synergies between CNF, other coating layers, and water-borne barrier coatings (WBBC) are not. Different WBBC weights were applied to papers with different CNF films that varied in quality and amounts. WBBC were also applied to pigmented coating layers with different pigment types and pigment to volume concentrations (PVC). Samples are tested for oil and grease resistance (OGR), water vapor transmission rate (WVTR), and oxygen transmission rate (OTR). WVTR reduces by more than ten times when WBBC is applied to a CNF film compared to no layer at the same coat weight. WVTR is reduced when WBBC is applied to pigment coating layers as well. The folding of the samples reduces moisture barrier performance to some degree but not grease resistance when a CNF film is used. WBBC coatings on CNF film have good oxygen barrier properties. © 2023 TAPPICon 2023 - "Rock the Roll: Unleashing the Harmonies of the Paper Industry". All rights reserved.

关键词： Oxygen

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Cascaded-Type Band Alignment of a WBG Perovskite/NBG Perovskite For Heterostructure Solar Cells

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ACS Applied Energy Materials 2024年第8期7卷 3039-3048页

作者： Thakran, Anjali Mohapatra, Anisha Verma, Hemant Hofmann, Mario Ansari, Zeeshan Alam Hanmandlu, Chintam Lu, Chung Hsin Chu, Chih Wei Department of Physics National Taiwan University Taipei106 Taiwan Research Center for Applied Sciences Academia Sinica 128 Academia Road Section 2 Nangang Taipei11529 Taiwan Nano-Science and Technology Program Taiwan International Graduate Program Academia Sinica Taipei106 Taiwan Department of Chemical Engineering National Taiwan University Taipei106 Taiwan Department of Photonics National Yang Ming Chiao Tung University Hsinchu City30010 Taiwan College of Engineering Center for Green Technology Chang Gung University Taoyuan City333002 Taiwan

The performance of single-junction mixed-halide perovskite-based solar cells is limited by thermalization and spectral losses. With advanced device architectures, the perovskite/perovskite heterostructure, where two or more photoactive layers are stacked together, can help to minimize these losses. In this work, we conformally transfer printed a narrow-band-gap perovskite over a spin-coated wide-band-gap perovskite layer to form a perovskite/perovskite heterostructure. This heterostructure results in broader spectral coverage and the higher position of the lowest unoccupied molecular orbital (LUMO) level of MAPbBrxI3-x compared to MA0.7FA0.3Pb0.5Sn0.5I3, forming a cascaded energy level alignment between photoactive layers. Additionally, direct evidence of improved morphology has been observed with the transfer-printing technique in heterostructure formation. The bottom layer provides favorable assistance for the growth of the top perovskite near the interface with good coverage and maintains the quality of the film. Thus, the increased crystallinity and reduced grain boundaries lead to less defects. This reduction played a key role in suppressing recombination losses at the interfaces, ultimately leading to improved device performance. These inherent properties have a positive impact on the photovoltaic response of the device, resulting in broader spectral response and power conversion efficiencies (PCEs) of 14.76% in the heterostructure device. A notable improvement is achieved compared to control single-junction devices, which typically have a PCE of nearly 10% with printed-Sn and 12% with spin-Br-based devices. Moreover, the heterostructure-based device exhibits high stability, retaining almost 80% of its initial PCE value for almost 1000 h with proper encapsulation. Our technique can be utilized for designing low-temperature and solution-processed stacked layers, applicable for optoelectronic devices, including light-emitting diodes (LEDs), sensors, and transist

关键词： Perovskite

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Oxygen/Sulfur Atom Exchange Copolymerization of Carbon Disulfide and Propylene Oxide by a Highly Effective Heterogeneous Berlin Green Catalyst

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chemical Research in Chinese Universities 2023年第5期39卷 790-796页

作者： Munir Ullah KHAN Safir Ullah KHAN CAO Xiaohan Muhammad USMAN Muhammad Naeem SHAH Abdul GHAFFAR Muhammad HASSAN ZHANG Chengjian ZHANG Xinghong State Key Laboratory of Motor Vehicle Biofuel Technology International Research Center for X PolymersDepartment of Polymer Science and EngineeringZhejiang UniversityHangzhou 310027P.R.China Shanxi-Zheda Institute of Advanced Materials and Chemical Engineering Shanxi 030013P.R.China Hefei National Laboratory for Physical Science at the Microscale School of Life SciencesUniversity of Science and Technology of ChinaHefei 230027P.R.China Key Laboratory of Macromolecular Synthesis and Functionalization(Ministry of Education) International Research Center for X PolymersDepartment of Polymer Science and EngineeringZhejiang UniversityHangzhou 310027P.R.China College of Information Science and Electronic Engineering Zhejiang UniversityHangzhou 310027P.R.China Advanced Materials Research Center Zhejiang University-University of Illinois at Urbana-Champaign Institute(ZJU-UIUC)Haining 314400P.R.China

In this study,we report that Berlin Green(FeFe-BG)framework exhibits superior performance in the catalytic coupling of carbon disulfide(CS_(2))and propylene oxide(PO)to generate a random copolymer containing thioether,propylene monothiocarbonate and ether *** and sulfur atom exchange was detected in polymeric and cyclic thiocarbonate byproducts and utilized to modulate the copolymerization of CS_(2)and propylene *** coupling of PO and CS_(2)was selective for copolymer formation under various reaction conditions.^(1)H and^(13)C NMR spectroscopy determined two distinct polymer linkages and two cyclic *** number average molecular weights ranged from 6.4 kg/mol to 10.5 kg/mol,with a comparatively low polydispersity of *** CS_(2)/PO molar feed ratio had a significant impact on the O/S exchange process;the ratio of cyclic thiocarbonate byproducts could be efficiently regulated by tuning the CS_(2)molar feed ratio.

关键词： Carbon disulfide Copolymerization Prussian Blue analogue Heterogeneous catalysis Berlin Green

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Low-cost Free-standing ferroelectric polymer films with high polarization produced via pressing-and-folding

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Journal of Materiomics 2022年第3期8卷 640-648页

作者： Nan Meng Xintong Ren Jiyue Wu Emiliano Bilotti Michael J.Reece Haixue Yan State Key Laboratory for Modification of Chemical Fibers and Polymer Materials College of Materials Science and EngineeringDonghua UniversityShanghai201620China School of Engineering and Materials Science Queen Mary University of LondonMile End RoadLondonE14NSUK Department of Materials Science and State Key Laboratory of Molecular Engineering of Polymers Fudan UniversityShanghai200433China

Ferroelectric polymer poly(vinylidene fluoride)(PVDF)shows excellent electro-activity and is promising for flexible electronic ***,the processing of PVDF into the favourable ferroelectric structure(β-phase)presents difficulties,while its copolymer with trifluoroethylene(PVDF-TrFE)can directly crystallize into β-phase,but shows limited thermal stability and high-cost *** a result,an easily implementable method,pressing-and-folding(P&F),was used to produce highly compatible blended films of PVDF and PVDF-TrFE without using any hazardous solvent or complex polymer processing ***-pressed PVDF(molecular weight:530 kg/mol)and PVDF-TrFE(molar ratio:51/49)films were firstly stacked before undergoing P&F *** to extrusion-blended films before and after P&F,the P&F stacked films showed isotropic crystalline structure of b-phase,as confirmed using X-ray diffraction and infrared *** ferroelectric remnant polarization of the P&F stacked films is 0.068 C/m^(2),surpassing pure PVDF-TrFE(0.062 C/m^(2))and the simulated value of remnant polarization of pure PVDF(~0.065 C/m^(2)).The above findings promise to provide inspirations for new processing strategy on PVDF-based functional polymers.

关键词： polymer blends PVDF PVDF-TrFE Ferroelectric Polarization

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