The recovery of vanadium from a black shale from Guizhou Province of China was performed using a three-step process, which consists of a leaching step in the H2SO4-HF-NaClO system under atmospheric pressure,the vanadi...The recovery of vanadium from a black shale from Guizhou Province of China was performed using a three-step process, which consists of a leaching step in the H2SO4-HF-NaClO system under atmospheric pressure,the vanadium separation from leachate by solvent extraction and stripping,followed by precipitation of ammonium vanadate and thermal decomposition.Under the optimum leaching conditions of 100 g/L sulfuric,15 g/L hydrofluoric acid,1.5 g/L NaClO,6 h leaching at 90℃and oxygen partial pressure of 1 200 kPa,and the liquid-to-solid ratio of 2,about 91%vanadium extraction is achieved.The vanadium extraction yields of solvent and stripping are 99.83%and 97.66%when using 10%(volume fraction)P204,5%TBP and 85%sulfonated berosene as organic phase and 15%(mass fraction)sulphuric acid as stripping agent.After thermal decomposition the purity of powder vanadium pentoxide products is 99.18%and the overall vanadium recovery is over 81%in the whole process.展开更多
The hot deformation behavior of a Nb microalloyed anti-seismic rebar was investigated at deformation temperatures of 950-1 100 ℃ and strain rates of 0. 01-0. 1 s- 1 on a Gleeble-3800 thermo-mechnical simulator. The f...The hot deformation behavior of a Nb microalloyed anti-seismic rebar was investigated at deformation temperatures of 950-1 100 ℃ and strain rates of 0. 01-0. 1 s- 1 on a Gleeble-3800 thermo-mechnical simulator. The flow stress-strain curves show the typical dynamic recrystallization with a peak,before reaching the steady state flow at higher deformation temperatures and lower strain rates. The constitutive equation governing the dynamic recrystallization( DRX) was obtained and the average activation energy of deformation was calculated as Q = 389. 5 kJ / mol by the regression analysis. The DRX grain size was also found to decrease with the increasing strain rate and the decreasing deformation temperature. The austenite grain size was refined from 118. 0 μm to 15. 07-40. 01 μm by DRX. The DRX grain size under diverse deformation conditions predicted by mathematical model agrees well with experimental results.展开更多
Lithium-sulfur batteries are a promising candidate for next-generation energy storage due to their high theoretical energy density.However,S insulation and the lithium polysulfide intermediate’s shuttle effect greatl...Lithium-sulfur batteries are a promising candidate for next-generation energy storage due to their high theoretical energy density.However,S insulation and the lithium polysulfide intermediate’s shuttle effect greatly hinder its practical application.In this paper,a three-dimensional porous graphene oxide(GO)/MXene(Ti_(3)C_(2)T_(x))(GM)aerogel is designed and applied to a lithium-sulfur battery to settle the problem mentioned.In this strategy,two-dimensional(2D)GO sheets and highly conductive MXene nanosheets are integrated to form a 3D porous aerogel structure,creating a 3D conductive network and large polar surfaces,which can simultaneously achieve fast Li-ion/electron transport,strong chemical anchoring sulfur,and promot redox reactions between poly sulfides.Therefore,the cathode shows excellent sulfur utilization and cycle stability.The prepared GM electrode battery has been tested for nearly nine months at 0.1C,providing the high initial capacity of 1255.62 mAh·g^(-1)and maintaining615.7 mAh·g^(-1)after 450 cycles.展开更多
基金Project(50874053)supported by the National Natural Science Foundation of ChinaProject(2007GA010)supported by the Science and Technology Bureau of Yunnan Province,China
文摘The recovery of vanadium from a black shale from Guizhou Province of China was performed using a three-step process, which consists of a leaching step in the H2SO4-HF-NaClO system under atmospheric pressure,the vanadium separation from leachate by solvent extraction and stripping,followed by precipitation of ammonium vanadate and thermal decomposition.Under the optimum leaching conditions of 100 g/L sulfuric,15 g/L hydrofluoric acid,1.5 g/L NaClO,6 h leaching at 90℃and oxygen partial pressure of 1 200 kPa,and the liquid-to-solid ratio of 2,about 91%vanadium extraction is achieved.The vanadium extraction yields of solvent and stripping are 99.83%and 97.66%when using 10%(volume fraction)P204,5%TBP and 85%sulfonated berosene as organic phase and 15%(mass fraction)sulphuric acid as stripping agent.After thermal decomposition the purity of powder vanadium pentoxide products is 99.18%and the overall vanadium recovery is over 81%in the whole process.
基金National Natural Science Foundation of China(No.51261009)
文摘The hot deformation behavior of a Nb microalloyed anti-seismic rebar was investigated at deformation temperatures of 950-1 100 ℃ and strain rates of 0. 01-0. 1 s- 1 on a Gleeble-3800 thermo-mechnical simulator. The flow stress-strain curves show the typical dynamic recrystallization with a peak,before reaching the steady state flow at higher deformation temperatures and lower strain rates. The constitutive equation governing the dynamic recrystallization( DRX) was obtained and the average activation energy of deformation was calculated as Q = 389. 5 kJ / mol by the regression analysis. The DRX grain size was also found to decrease with the increasing strain rate and the decreasing deformation temperature. The austenite grain size was refined from 118. 0 μm to 15. 07-40. 01 μm by DRX. The DRX grain size under diverse deformation conditions predicted by mathematical model agrees well with experimental results.
基金financially supported by the National Natural Science Foundation of Yunnan Province(Nos.202101AW070006 and 202001AU070079)。
文摘Lithium-sulfur batteries are a promising candidate for next-generation energy storage due to their high theoretical energy density.However,S insulation and the lithium polysulfide intermediate’s shuttle effect greatly hinder its practical application.In this paper,a three-dimensional porous graphene oxide(GO)/MXene(Ti_(3)C_(2)T_(x))(GM)aerogel is designed and applied to a lithium-sulfur battery to settle the problem mentioned.In this strategy,two-dimensional(2D)GO sheets and highly conductive MXene nanosheets are integrated to form a 3D porous aerogel structure,creating a 3D conductive network and large polar surfaces,which can simultaneously achieve fast Li-ion/electron transport,strong chemical anchoring sulfur,and promot redox reactions between poly sulfides.Therefore,the cathode shows excellent sulfur utilization and cycle stability.The prepared GM electrode battery has been tested for nearly nine months at 0.1C,providing the high initial capacity of 1255.62 mAh·g^(-1)and maintaining615.7 mAh·g^(-1)after 450 cycles.
