Ultrafine copper tailings(UTCT) are a type of bulk solid waste containing heavy metals,discharged from copper refining industries.Large stockpiles of these tailings pose significant environmental risks and lead to the...Ultrafine copper tailings(UTCT) are a type of bulk solid waste containing heavy metals,discharged from copper refining industries.Large stockpiles of these tailings pose significant environmental risks and lead to the wastage of valuable mineral resources.To address this issue,this study has developed a backfill material(solidified ultrafine copper tailings,S-UTCT) for mine shaft rehabilitation.This material utilizes waste alkali exciters and UTCT as base components.The primary process involves thoroughly mixing the alkali exciter with UTCT,followed by injection into a mold or pit for curing.The optimized process parameters are as follows:UTCT solid content of 50wt%-60wt%,mixing duration of 6-8 min,alkali activator dosage of 30wt%-35wt%,water-to-solid weight ratio of 0.2,mixing speed of 400 r/min,and curing period of 28 d.Mechanistic analysis revealed that the alkali activator induces mineral phase reconstruction and morphological reconfiguration of UTCT,driven by mechanochemical activation during ball milling.This results in improved compressive strength and effective immobilization of heavy metals.This paper presents a novel cement-free and burn-free method for preparing cementitious materials for recycling resources in mines.展开更多
Electrospinning has drawn wide attention for its powerful capacity to produce ultrafne nanofbers(UNFs)from various materials.These UNFs demonstrated signifcantly enhanced performance,such as ultra-high surface area,mo...Electrospinning has drawn wide attention for its powerful capacity to produce ultrafne nanofbers(UNFs)from various materials.These UNFs demonstrated signifcantly enhanced performance,such as ultra-high surface area,more porosity and stronger mechanical properties.Here,we comprehensively review their basic principles,state-of-the-art methods and preponderant applications.We begin with a brief introduction to the refnement theory of polymer jets,followed by discussion of factors afecting fber refnement.We then discuss the refning strategies from the aspects of solution properties,spinning parameters,auxiliary force and post-treatment.Afterward,we highlight the most relevant and recent applications associated with the remarkable features of UNFs,including fltration materials,supercapacitors,biomedical materials and other applications.At the end,we ofer perspectives on the challenges,opportunities,and new directions for future development of electrospun UNFs.展开更多
基金financially supported by the Major Science and Technology Special Project of China Energy Construction Corporation(No.CEEC2021-ZDYF-03)the National Key Research and Development Program of China(No.2020YFC1806401)the Postdoc Matching Fund Scheme of The Hong Kong Polytechnic University(No.P0045785)
文摘Ultrafine copper tailings(UTCT) are a type of bulk solid waste containing heavy metals,discharged from copper refining industries.Large stockpiles of these tailings pose significant environmental risks and lead to the wastage of valuable mineral resources.To address this issue,this study has developed a backfill material(solidified ultrafine copper tailings,S-UTCT) for mine shaft rehabilitation.This material utilizes waste alkali exciters and UTCT as base components.The primary process involves thoroughly mixing the alkali exciter with UTCT,followed by injection into a mold or pit for curing.The optimized process parameters are as follows:UTCT solid content of 50wt%-60wt%,mixing duration of 6-8 min,alkali activator dosage of 30wt%-35wt%,water-to-solid weight ratio of 0.2,mixing speed of 400 r/min,and curing period of 28 d.Mechanistic analysis revealed that the alkali activator induces mineral phase reconstruction and morphological reconfiguration of UTCT,driven by mechanochemical activation during ball milling.This results in improved compressive strength and effective immobilization of heavy metals.This paper presents a novel cement-free and burn-free method for preparing cementitious materials for recycling resources in mines.
基金This work was partly supported by the Fundamental Research Funds for the Central Universities(2232020D-15,2232020A-08,2232020G-01,2232020D-14 and 2232019D3-11)grants(51773037,51973027,51803023,52003044 and 61771123)from the National Natural Science Foundation of China+3 种基金This work has also been supported by the Chang Jiang Scholars Program and the Innovation Program of Shanghai Municipal Education Commission(2019-01-07-00-03-E00023)to Prof.Xiaohong Qinthe Shanghai Sailing Program(19YF1400700)the Opening Project of State Key Laboratory of High Performance Ceramics and Superfne Microstructure(SKL201906SIC)Young Elite Scientists Sponsorship Program by CAST and DHU Distinguished Young Professor Program to Prof.Liming Wang.
文摘Electrospinning has drawn wide attention for its powerful capacity to produce ultrafne nanofbers(UNFs)from various materials.These UNFs demonstrated signifcantly enhanced performance,such as ultra-high surface area,more porosity and stronger mechanical properties.Here,we comprehensively review their basic principles,state-of-the-art methods and preponderant applications.We begin with a brief introduction to the refnement theory of polymer jets,followed by discussion of factors afecting fber refnement.We then discuss the refning strategies from the aspects of solution properties,spinning parameters,auxiliary force and post-treatment.Afterward,we highlight the most relevant and recent applications associated with the remarkable features of UNFs,including fltration materials,supercapacitors,biomedical materials and other applications.At the end,we ofer perspectives on the challenges,opportunities,and new directions for future development of electrospun UNFs.
