Achieving efficient flotation separation of chalcopyrite and galena while maintaining environmental friendliness poses a challenge.This study utilized the environmentally friendly copolymer acrylic acid-2-acrylamide-2...Achieving efficient flotation separation of chalcopyrite and galena while maintaining environmental friendliness poses a challenge.This study utilized the environmentally friendly copolymer acrylic acid-2-acrylamide-2-methylpropanesulfonic acid(AA/AMPS)as a depressant to separate chalcopyrite and galena.Flotation tests revealed a significant reduction in galena recovery when AA/AMPS was employed,with minimal impact observed on chalcopyrite.In artificial mixed ore flotation,AA/AMPS was found to enhance the efficiency of copper and lead separation,surpassing K_(2)Cr_(2)O_(7).Furthermore,the effectiveness of AA/AMPS in facilitating copper-lead separation has been validated in practical ore flotation.The presence of AA/AMPS inhibited the adsorption of SBX onto galena,as confirmed by zeta potential and contact angle measurements.However,the adsorption on chalcopyrite remained unaffected.Through analyses using Atomic Force Microscope,X-ray photoelectron spectroscopy,and Density Functional Theory,a robust chemical interaction between the reactive groups in AA/AMPS and Pb sites on galena was uncovered,resulting in the formation of a hydrophilic polymer layer.This layer impedes SBX adsorption and reduces galena's floatability.In contrast,no significant chemical adsorption was observed between AA/AMPS and Cu and Fe sites on chalcopyrite,preserving its SBX affinity.Overall,AA/AMPS shows promise in replacing traditional depressants for Cu-Pb sulfide ore separation,enhancing environmental sustainability.展开更多
Hierarchical layered structures,whether in a compact form like nacre or a porous manner like bone,are well known for their combined features of high stiffness,strength,and lightweight,inspiring many man-made materials...Hierarchical layered structures,whether in a compact form like nacre or a porous manner like bone,are well known for their combined features of high stiffness,strength,and lightweight,inspiring many man-made materials and structures for high performance applications.The use of nacre/bone like hierarchical structures in polymer nanocomposites can achieve excellent mechanical and functional properties with high filler volume fractions after carefully aligning functional nanofillers,although the fabrication and processing remain a great challenge.In this work,a bio-inspired lightweight nano-cellular epoxy/graphene-Fe_(3)O_(4) nanocomposite with high nanofiller loading of 75 wt.%was successfully fabricated by combining features from both nacre and bone structures,via a simple compression molding process together with an eco-friendly supercritical CO_(2) foaming process to achieve robust mechanical strength and excellent electromagnetic interference(EMI)shielding effectiveness(SE)simultaneously.Highly aligned graphene-Fe_(3)O_(4) nanoplatelets with well controlled nanoscale porous structures(52.6 nm)enabled both low density(1.26 g/cm^(3))and high specific EMI SE>5200 dB/cm^(2)/g,as well as preserved tensile strength of 67 MPa.This study provides a sustainable route to fabricate nature mimicked structures with high performance and high flexibility for a wide range of applications,from portable electronics to healthcare devices.展开更多
基金supported by the Cultivation plan of National Science and Technology Award reserve Project of Jiangxi Science and Technology Department(No.20192AEI91003)the Major science and technology projects of Qinghai Province(No.2018GX-A7)。
文摘Achieving efficient flotation separation of chalcopyrite and galena while maintaining environmental friendliness poses a challenge.This study utilized the environmentally friendly copolymer acrylic acid-2-acrylamide-2-methylpropanesulfonic acid(AA/AMPS)as a depressant to separate chalcopyrite and galena.Flotation tests revealed a significant reduction in galena recovery when AA/AMPS was employed,with minimal impact observed on chalcopyrite.In artificial mixed ore flotation,AA/AMPS was found to enhance the efficiency of copper and lead separation,surpassing K_(2)Cr_(2)O_(7).Furthermore,the effectiveness of AA/AMPS in facilitating copper-lead separation has been validated in practical ore flotation.The presence of AA/AMPS inhibited the adsorption of SBX onto galena,as confirmed by zeta potential and contact angle measurements.However,the adsorption on chalcopyrite remained unaffected.Through analyses using Atomic Force Microscope,X-ray photoelectron spectroscopy,and Density Functional Theory,a robust chemical interaction between the reactive groups in AA/AMPS and Pb sites on galena was uncovered,resulting in the formation of a hydrophilic polymer layer.This layer impedes SBX adsorption and reduces galena's floatability.In contrast,no significant chemical adsorption was observed between AA/AMPS and Cu and Fe sites on chalcopyrite,preserving its SBX affinity.Overall,AA/AMPS shows promise in replacing traditional depressants for Cu-Pb sulfide ore separation,enhancing environmental sustainability.
基金the National Natural Science Foundation of China(Grant No.51773170)the Shaanxi Coal Joint Fund(Grant 2019JLM-24)+3 种基金funded by the International Science&Technology Cooperation Plan of Shaanxi Province(2021KW-52)Fund of Natural Science Foundation of Shaanxi Provincial(2021JQ-111)Fund of Basic and Applied Fundamental Research of Guangdong Provincial(2020A1515110861)sponsored by Innovation Foundation for Doctor Dissertation of Northwestern Polytechnical University(No.CX202051)。
文摘Hierarchical layered structures,whether in a compact form like nacre or a porous manner like bone,are well known for their combined features of high stiffness,strength,and lightweight,inspiring many man-made materials and structures for high performance applications.The use of nacre/bone like hierarchical structures in polymer nanocomposites can achieve excellent mechanical and functional properties with high filler volume fractions after carefully aligning functional nanofillers,although the fabrication and processing remain a great challenge.In this work,a bio-inspired lightweight nano-cellular epoxy/graphene-Fe_(3)O_(4) nanocomposite with high nanofiller loading of 75 wt.%was successfully fabricated by combining features from both nacre and bone structures,via a simple compression molding process together with an eco-friendly supercritical CO_(2) foaming process to achieve robust mechanical strength and excellent electromagnetic interference(EMI)shielding effectiveness(SE)simultaneously.Highly aligned graphene-Fe_(3)O_(4) nanoplatelets with well controlled nanoscale porous structures(52.6 nm)enabled both low density(1.26 g/cm^(3))and high specific EMI SE>5200 dB/cm^(2)/g,as well as preserved tensile strength of 67 MPa.This study provides a sustainable route to fabricate nature mimicked structures with high performance and high flexibility for a wide range of applications,from portable electronics to healthcare devices.
