MINERALS ENGINEERING
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2024
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IF 4.9
Weilun Qian,Huibin Zhang,Jiankang Tan,Wenyu Feng,Huazhen Cao,Guoqu Zheng
The transformation of pyrite into ferrous sulfide (FeS) has a substantial significance in gold extraction from gold-bearing pyrite. This work proposed to treat pyrite by reactive diffusion with added elemental Fe for generating FeS. The diffusion kinetics and transformation mechanism during reactive synthesis were investigated via constructing Fe-FeS 2 powder diffusion couples. The results indicated that the formation of the pyrrhotite phase (Fe 1-x S, x = 0–0.5) firstly occurred at the interface of the diffusion couple. The interdiffusion coefficient ranged from 10 −16 m 2 s −1 ∼ 10 −12 m 2 s −1 at 723–873 K and the apparent activation energy of the product layer was about 147.59 kJ mol −1 . XRD and HRTEM results demonstrated that with the increase of sintering temperature, the diffusion of Fe played the pivotal role in the phase transformation of Fe 1-x S to FeS. Furthermore, the conversion rate of FeS can reach 95.82 % by optimizing sintering process. The synthesized FeS can be readily dissolved by sulfuric acid and the mass ratio of leaching residue is only 2.3 %, indicating that the precious metals in pyrite such as gold can be concentrated by nearly 43.5 times. This proposed method with the green economy characteristic would be a promising candidate for the pretreatment of gold-bearing pyrite.
研究领域:
化学工程
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材料科学
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冶金工程
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DOI
高影响因子
Cell Reports Physical Science
·
2021
·
IF 0
Lin Qiao,Qing Dai,Huamin Zhang,Xianfeng Li
Summary Turing patterns and reaction-diffusion models are of great significance in biological and chemical fields. However, Turing-shape materials together with their application are rarely investigated, since at present Turing patterns are typically formed by the reaction of small molecules in a viscous system. Herein, a facile route to fabricate membrane materials with macro-scale Turing patterns is proposed. Macromolecules, rather than small molecules, are chosen as reactants to generate chemical Turing patterns, which makes it easy to freeze and construct Turing-shape materials. The formation mechanism and influence factors of Turing patterns are discussed in detail via experimental investigation and numerical simulation. Turing-shape membranes are successfully applied to electrochemical energy storage and exhibit good performance benefiting from the rich surface area.
研究领域:
材料科学
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化学
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生物学
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DOI
CHEMICAL ENGINEERING JOURNAL
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2025
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IF 13.2
Zhiheng Wang,Jiali Huang,Guancong Jiang,Tuo Ji,Han Lin,Liwen Mu,Xiaohua Lu,Jiahua Zhu
In heterogeneous reactions, catalyst support plays an important role in tuning catalytic activity of metallic structures and regulating fluid transport during reaction, while it needs to be engineered to balance reaction and diffusion for optimized outcome. In this work, a combined delignification and activation strategy was used to prepare a series of carbon supports with varied porous structures and surface properties. Pd was then loaded on the carbon supports for direct synthesis of H 2 O 2 (DSHP) reaction. Results indicated that highly developed meso-macropore structures significantly promoted the dispersion of Pd and exposed more active sites for H 2 dissociation. However, the enrichment of pore structure brought excessive surface oxygen groups, leading to the transition of Pd from Pd 0 to PdO and thus inhibiting the hydrogenation activity. The optimized catalyst, with desirable porous structure and appropriate Pd 0 /PdO ratio, exhibited an extraordinarily high H 2 O 2 productivity of 37346.42 mmol g Pd −1 h −1 under atmospheric conditions. This work provided a case study on the regulation of reactivity and diffusion through catalyst support engineering, demonstrating the essential role of matched reaction–diffusion in heterogeneous DSHP reactions.
研究领域:
催化化学
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材料科学
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DOI
高影响因子
Polymers
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2024
·Vol. 16
·期 7
·873
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IF 4.7
Xiong Yi,Shengfang Li,Pin Wen,Shilin Yan
Traditional polymer curing techniques present challenges such as a slow processing speed, high energy consumption, and considerable initial investment. Frontal polymerization (FP), a novel approach, transforms monomers into fully cured polymers through a self-sustaining exothermic reaction, which enhances speed, efficiency, and safety. This study focuses on acrylamide hydrogels, synthesized via FP, which hold significant potential for biomedical applications and 3D printing. Heat conduction is critical in FP, particularly due to its influence on the temperature distribution and reaction rate mechanisms, which affect the final properties of polymers. Therefore, a comprehensive analysis of heat conduction and chemical reactions during FP is presented through the establishment of mathematical models and numerical methods. Existing research on FP hydrogel synthesis primarily explores chemical modifications, with limited studies on numerical modeling. By utilizing Differential Scanning Calorimetry (DSC) data on the curing kinetics of polymerizable deep eutectic solvents (DES), this paper employs Malek’s model selection method to establish an autocatalytic reaction model for FP synthesis. In addition, the finite element method is used to solve the reaction–diffusion model, examining the temperature evolution and curing degree during synthesis. The results affirm the nth-order autocatalytic model’s accuracy in studying acrylamide monomer curing kinetics. Additionally, factors such as trigger temperature and solution initial temperature were found to influence the FP reaction’s frontal propagation speed. The model’s predictions on acrylamide hydrogel synthesis align with experimental data, filling the gap in numerical modeling for hydrogel FP synthesis and offering insights for future research on numerical models and temperature control in the FP synthesis of high-performance hydrogels.
研究领域:
材料科学
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生物医学工程
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化学工程
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DOI
PubMed
高影响因子
MATERIALS CHARACTERIZATION
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2025
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IF 5.5
Dang Xu,Pengqi Chen,Kaichao Fu,Changcheng Sang,Ruizhi Chen,Tao Hong,Jigui Cheng,Kai Xu
The inherent metallurgical incompatibility between dissimilar metals such as tungsten (W) and copper (Cu) engenders weak chemical bonding, substantially constraining the attainment of high strength. This constitutes a critical limitation for nuclear fusion applications demanding robust interfacial integrity. To address these limitations, this study introduces a dual interface reinforcement strategy employing a CrCoNi medium entropy alloy (MEA) interlayer and achieving diffusion bonding of oxide diffusion-strengthened tungsten (ODS-W) and Cu through spark plasma sintering (SPS) technology. At the optimized bonding temperature of 1000 °C, the joint achieves a maximum tensile strength of 256.7 ± 8.2 MPa, corresponding to a 171 % enhancement over direct bonding (DB) joint (94.6 ± 5.1 MPa), accompanied by a fracture mode transition from brittle to ductile failure. Multi-scaled microstructure and interface element diffusion behavior analyses reveal that reactive diffusion at the W/MEA interface facilitates the formation of a solution-strengthened matrix associated with an amorphous diffusion layer. Whereas mutual diffusion at the Cu/MEA interface induces multiple phase structures, resulting concurrently in solid solution strengthening and precipitation strengthening, thereby reinforcing the interface bonding. This dual interface reinforcement methodology establishes an effective design strategy for enhancing mechanical properties in immiscible metal systems.
研究领域:
材料科学
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冶金学
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核工程
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机械工程
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连接技术
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产品关联
DOI
高影响因子
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