A new method is developed for removing the nickel coating on ITER superconducting cables by mechanical polishing.The obvious advantage of the mechanical method,which uses a nylon brush,is that there is no chemical res...A new method is developed for removing the nickel coating on ITER superconducting cables by mechanical polishing.The obvious advantage of the mechanical method,which uses a nylon brush,is that there is no chemical residual left in the cable,which would otherwise result in passive effects on the joint resistance.The coating resistance test results of this newly developed method are compared with those of the two other methods that can meet the requirements of ITER.An automatic polishing machine is designed and manufactured for the procedure to provide quality under precise control.This new technique can replace the conventional manual method due to its improved efficiency.展开更多
Filtration efficiency of Ni(II) from aqueous solution using pristine and modified MWCNTs filters was investigated as a function of Ni(II) ion concentration, p H, and filter mass. MWCNTs were synthesized by CVD method ...Filtration efficiency of Ni(II) from aqueous solution using pristine and modified MWCNTs filters was investigated as a function of Ni(II) ion concentration, p H, and filter mass. MWCNTs were synthesized by CVD method and modified using two complementary treatments, purification(using a mixture of hydrochloric acid and hydrogen peroxide) and functionalization(using nitric acid). The effect and mechanism of each treatment on the structural integrity of pristine MWCNTs has been studied. Morphology of the pristine and modified filters was investigated by Raman Spectrometry(RS), Scanning Electron Microscopy(SEM), Energy Dispersive X-ray Spectroscopy(EDS),Fourier Transform Infrared(FTIR) spectrometry and Thermogravimetric analysis. It was found from Raman spectra that the ratio of the intensity of D-band to that of G-band decreased by purification process, and increased by functionalization process. The adsorption mechanism of Ni(II) onto the surface functional groups of modified MWCNTs was confirmed by FTIR spectrum. The filtration results showed that the removal efficiency of Ni(II) is strongly dependent on pH and could reach 85% at pH = 8. Also, modified MWCNT filters can be reused through many cycles of regeneration with high performance. Functionalized MWCNTs filters may be a promising adsorbent candidate for heavy metal removal from wastewater.展开更多
Effective recovery of high-value heavy metals from electroplating wastewater is of great significance,but recovering nickel ions from real electroplating wastewater as nickel sheet has not been reported.In this study,...Effective recovery of high-value heavy metals from electroplating wastewater is of great significance,but recovering nickel ions from real electroplating wastewater as nickel sheet has not been reported.In this study,the pilot-scale fixed-bed resin adsorption was conducted to recover Ni(Ⅱ)ions from real nickel plating wastewater,and then the concentrated Ni(Ⅱ)ions in the regenerated solution were reduced to nickel sheet via electrodeposition.A commercial cation-exchange resin was selected and the optimal resin adsorption and regeneration conditions were investigated.The resin exhibited an adsorption capacity of 63 mg/g for Ni(Ⅱ)ions,and the average amount of treated water was 84.6 bed volumes(BV)in the pilot-scale experiments.After the adsorption by two ion-exchange resin columns in series and one chelating resin column,the concentrations of Ni(Ⅱ)in the treated wastewater were below 0.1 mg/L.After the regeneration of the spent resin using 3 BVof 4%(w/w)HC1 solution,1.5 BV of concentrated neutral nickel solution(>30 g/L)was obtained and used in the subsequent electrodeposition process.Using the aeration method,alkali and water required in resin activation process were greatly reduced to 2 BV and 3 BV,respectively.Under the optimal electrodeposition conditions,95.6%of Ni(Ⅱ)in desorption eluent could be recovered as the elemental nickel on the cathode,llie total treatment cost for the resin adsorption and regeneration as well as the electrodeposition was calculated.展开更多
Copper enrichment behavior in continuously cast slab induced by scale formation during continuous cooling was experimentally investigated,and the effects of initial slab surface temperature and oxygen potential in atm...Copper enrichment behavior in continuously cast slab induced by scale formation during continuous cooling was experimentally investigated,and the effects of initial slab surface temperature and oxygen potential in atmosphere were discussed.The results showed that a loose scale adhered to the substrate was formed in H2O-N2 atmosphere at higher slab surface temperature compared to a gap formed between the scale and the steel substrate after continuous cooling in H2O-O2-N2 atmosphere.Under the condition of continuous cooling in H2O-N2 atmosphere,the copper enrichment occurred both within the loose scale and at the scale/steel interface with simultaneous Ni enrichment near the interface at higher slab surface temperature.The combined effects of the loose scale and nickel enrichment were thought to promote the back-migration of Cu-rich phase from the interface and occlusion within the scale layer.While in H2O-O2-N2 atmosphere,the Cu enrichment was found on the steel side and the formed gap prevented the migration of Cu to the scale.展开更多
基金supported by ITER Research Project of China Matched Program(No.2008GB102000)
文摘A new method is developed for removing the nickel coating on ITER superconducting cables by mechanical polishing.The obvious advantage of the mechanical method,which uses a nylon brush,is that there is no chemical residual left in the cable,which would otherwise result in passive effects on the joint resistance.The coating resistance test results of this newly developed method are compared with those of the two other methods that can meet the requirements of ITER.An automatic polishing machine is designed and manufactured for the procedure to provide quality under precise control.This new technique can replace the conventional manual method due to its improved efficiency.
基金Supported by the Program of MSU Development and Russian Foundation for Basic Research(RFBR)(No.14-02-01230a and No.14-02-31147 mol_a)
文摘Filtration efficiency of Ni(II) from aqueous solution using pristine and modified MWCNTs filters was investigated as a function of Ni(II) ion concentration, p H, and filter mass. MWCNTs were synthesized by CVD method and modified using two complementary treatments, purification(using a mixture of hydrochloric acid and hydrogen peroxide) and functionalization(using nitric acid). The effect and mechanism of each treatment on the structural integrity of pristine MWCNTs has been studied. Morphology of the pristine and modified filters was investigated by Raman Spectrometry(RS), Scanning Electron Microscopy(SEM), Energy Dispersive X-ray Spectroscopy(EDS),Fourier Transform Infrared(FTIR) spectrometry and Thermogravimetric analysis. It was found from Raman spectra that the ratio of the intensity of D-band to that of G-band decreased by purification process, and increased by functionalization process. The adsorption mechanism of Ni(II) onto the surface functional groups of modified MWCNTs was confirmed by FTIR spectrum. The filtration results showed that the removal efficiency of Ni(II) is strongly dependent on pH and could reach 85% at pH = 8. Also, modified MWCNT filters can be reused through many cycles of regeneration with high performance. Functionalized MWCNTs filters may be a promising adsorbent candidate for heavy metal removal from wastewater.
文摘Effective recovery of high-value heavy metals from electroplating wastewater is of great significance,but recovering nickel ions from real electroplating wastewater as nickel sheet has not been reported.In this study,the pilot-scale fixed-bed resin adsorption was conducted to recover Ni(Ⅱ)ions from real nickel plating wastewater,and then the concentrated Ni(Ⅱ)ions in the regenerated solution were reduced to nickel sheet via electrodeposition.A commercial cation-exchange resin was selected and the optimal resin adsorption and regeneration conditions were investigated.The resin exhibited an adsorption capacity of 63 mg/g for Ni(Ⅱ)ions,and the average amount of treated water was 84.6 bed volumes(BV)in the pilot-scale experiments.After the adsorption by two ion-exchange resin columns in series and one chelating resin column,the concentrations of Ni(Ⅱ)in the treated wastewater were below 0.1 mg/L.After the regeneration of the spent resin using 3 BVof 4%(w/w)HC1 solution,1.5 BV of concentrated neutral nickel solution(>30 g/L)was obtained and used in the subsequent electrodeposition process.Using the aeration method,alkali and water required in resin activation process were greatly reduced to 2 BV and 3 BV,respectively.Under the optimal electrodeposition conditions,95.6%of Ni(Ⅱ)in desorption eluent could be recovered as the elemental nickel on the cathode,llie total treatment cost for the resin adsorption and regeneration as well as the electrodeposition was calculated.
基金Item Sponsored by National Natural Science Foundation of China(51174052,51374062,51574065,51574066)
文摘Copper enrichment behavior in continuously cast slab induced by scale formation during continuous cooling was experimentally investigated,and the effects of initial slab surface temperature and oxygen potential in atmosphere were discussed.The results showed that a loose scale adhered to the substrate was formed in H2O-N2 atmosphere at higher slab surface temperature compared to a gap formed between the scale and the steel substrate after continuous cooling in H2O-O2-N2 atmosphere.Under the condition of continuous cooling in H2O-N2 atmosphere,the copper enrichment occurred both within the loose scale and at the scale/steel interface with simultaneous Ni enrichment near the interface at higher slab surface temperature.The combined effects of the loose scale and nickel enrichment were thought to promote the back-migration of Cu-rich phase from the interface and occlusion within the scale layer.While in H2O-O2-N2 atmosphere,the Cu enrichment was found on the steel side and the formed gap prevented the migration of Cu to the scale.
