The low-grade vanadium-containing stone coal used in this experiment was collected from Wuxi Country, Chongqing City, China. The experiment focused on the vanadium recovery from roasted residue through optimizing the ...The low-grade vanadium-containing stone coal used in this experiment was collected from Wuxi Country, Chongqing City, China. The experiment focused on the vanadium recovery from roasted residue through optimizing the process conditions of an effective and environmentally-friendly technology, named calcified roasting-sulfuric acid leaching technology. By single-factor experiments and orthogonal experiments, the effects of roasting temperature, roasting time, sulfuric acid concentration and leaching time on the leaching ratio of vanadium were analyzed. The results showed that the leaching ratio of vanadium reached 85.5% under the proper technological conditions of roasting temperature=950℃, roasting time=4 h, 40% concentration of sulfuric acid and leaching time=6 h.展开更多
Near-fault ground motions, potentially with large amplitude and typical velocity pulses, may significantly impact the performance of a wide range of structures. The current study is aimed at evaluating the safety impl...Near-fault ground motions, potentially with large amplitude and typical velocity pulses, may significantly impact the performance of a wide range of structures. The current study is aimed at evaluating the safety implications of the near-fault effect on nuclear power plant facilities designed according to the Chinese code. To this end, a set of near- fault ground motions at rock sites with typical forward-directivity effect is examined with special emphasis on several key parameters and response spectra. Spectral comparison of the selected records with the Chinese and other code design spectra was conducted. The bi-normalized response spectra in terms of different comer periods are utilized to derive nuclear design spectra. It is concluded that nuclear design spectra on rock sites derived from typical rupture directivity records are significantly influenced both by the earthquake magnitude and the rupture distance. The nuclear design spectra specified in the code needs to be adjusted to reflect the near-fault directivity effect of large earthquakes.展开更多
Manganese was extracted from leaching low-grade manganese ore in sulfuric acid medium. The effects of granule diameter, leaching time, liquid/solid ratio (V/W) and the concentration of sulfuric acid were investigated ...Manganese was extracted from leaching low-grade manganese ore in sulfuric acid medium. The effects of granule diameter, leaching time, liquid/solid ratio (V/W) and the concentration of sulfuric acid were investigated through orthogonal and single factor experiments. The experimental results showed that the optimal leaching conditions are, size of 0.054mm, 120 minutes of reaction time, 3(V/W) of liquid/solid ratio and 30% of the concentration of sulfuric acid (g/g). Under those conditions, the leaching efficiency is 96.73%. The kinetics of the leaching process is in accordance with the characteristics of fractal reaction.展开更多
The adsorption kinetics of Pb2+ in rocks has been studied using ion selective electrodes and atomic absorption spectrophotometer. The results showed that the adsorption process is a fractal-like reaction. The adsorpti...The adsorption kinetics of Pb2+ in rocks has been studied using ion selective electrodes and atomic absorption spectrophotometer. The results showed that the adsorption process is a fractal-like reaction. The adsorption rate was relatively high before 30 minutes, and then dropped. The saturated adsorption capacity (a) of Pb2+ and kinetic parameters (b, α , D and k) increased with increasing initial concentrations of Pb2+. These parameters (except a) decreased while Na+ was present in the solution. Furthermore, the smaller the rocks were in grain size, the bigger these kinetic parameters would be, though the parameter a was almost constant.展开更多
The pore structural characteristics of strontium residue were studied with the N2 adsorption method(ASAP2010).The kinetic properties concerning dissolving and leaching strontium waste were described by determining the...The pore structural characteristics of strontium residue were studied with the N2 adsorption method(ASAP2010).The kinetic properties concerning dissolving and leaching strontium waste were described by determining the concentrations of Sr2+,Ba2+ and soluble sulphides in solutions.The results showed that the specific surface area and pore volume increased with decreasing granule diameter,and the micropore surface of the residue was fractal.In the dissolving and leaching processes of strontium residue,soluble ion concentrations increased with decreasing granule diameter of the residue,and the reaction dimension was lower than the fractal dimension of pore surface.Sr2+ and soluble sulphide concentrations significantly exceeded the defined standard values,while Ba2+ concentrations did not,either in the dissolving or leaching solutions.In addition,dissolving and leaching reactions selectively occurred on the micropore surface of strontium residue.展开更多
基金the Scientific Research Foundation of State Key Lab.of Coal Mine Disaster Dynamics and Control(2011AD105827-MS201206)Scientific&Technologic Program for the Bureau of Land Resources and Housing Management of Chongqing
文摘The low-grade vanadium-containing stone coal used in this experiment was collected from Wuxi Country, Chongqing City, China. The experiment focused on the vanadium recovery from roasted residue through optimizing the process conditions of an effective and environmentally-friendly technology, named calcified roasting-sulfuric acid leaching technology. By single-factor experiments and orthogonal experiments, the effects of roasting temperature, roasting time, sulfuric acid concentration and leaching time on the leaching ratio of vanadium were analyzed. The results showed that the leaching ratio of vanadium reached 85.5% under the proper technological conditions of roasting temperature=950℃, roasting time=4 h, 40% concentration of sulfuric acid and leaching time=6 h.
基金National Natural Science Foundation of China Under Grant No.50808168Ministry of Science and Technology of Weihai Under Grant No.2008087Beijing Natural Science Foundation Under Grant No.8092029
文摘Near-fault ground motions, potentially with large amplitude and typical velocity pulses, may significantly impact the performance of a wide range of structures. The current study is aimed at evaluating the safety implications of the near-fault effect on nuclear power plant facilities designed according to the Chinese code. To this end, a set of near- fault ground motions at rock sites with typical forward-directivity effect is examined with special emphasis on several key parameters and response spectra. Spectral comparison of the selected records with the Chinese and other code design spectra was conducted. The bi-normalized response spectra in terms of different comer periods are utilized to derive nuclear design spectra. It is concluded that nuclear design spectra on rock sites derived from typical rupture directivity records are significantly influenced both by the earthquake magnitude and the rupture distance. The nuclear design spectra specified in the code needs to be adjusted to reflect the near-fault directivity effect of large earthquakes.
基金financially supported jointly by the Bureau of Land Resources and Housing Management of Chongqing (Scientific &Technologic Program in 2011)Post graduates’Science & Innovation Fund of Chongqing University (Project No. CDJXS10240007)
文摘Manganese was extracted from leaching low-grade manganese ore in sulfuric acid medium. The effects of granule diameter, leaching time, liquid/solid ratio (V/W) and the concentration of sulfuric acid were investigated through orthogonal and single factor experiments. The experimental results showed that the optimal leaching conditions are, size of 0.054mm, 120 minutes of reaction time, 3(V/W) of liquid/solid ratio and 30% of the concentration of sulfuric acid (g/g). Under those conditions, the leaching efficiency is 96.73%. The kinetics of the leaching process is in accordance with the characteristics of fractal reaction.
文摘The adsorption kinetics of Pb2+ in rocks has been studied using ion selective electrodes and atomic absorption spectrophotometer. The results showed that the adsorption process is a fractal-like reaction. The adsorption rate was relatively high before 30 minutes, and then dropped. The saturated adsorption capacity (a) of Pb2+ and kinetic parameters (b, α , D and k) increased with increasing initial concentrations of Pb2+. These parameters (except a) decreased while Na+ was present in the solution. Furthermore, the smaller the rocks were in grain size, the bigger these kinetic parameters would be, though the parameter a was almost constant.
文摘The pore structural characteristics of strontium residue were studied with the N2 adsorption method(ASAP2010).The kinetic properties concerning dissolving and leaching strontium waste were described by determining the concentrations of Sr2+,Ba2+ and soluble sulphides in solutions.The results showed that the specific surface area and pore volume increased with decreasing granule diameter,and the micropore surface of the residue was fractal.In the dissolving and leaching processes of strontium residue,soluble ion concentrations increased with decreasing granule diameter of the residue,and the reaction dimension was lower than the fractal dimension of pore surface.Sr2+ and soluble sulphide concentrations significantly exceeded the defined standard values,while Ba2+ concentrations did not,either in the dissolving or leaching solutions.In addition,dissolving and leaching reactions selectively occurred on the micropore surface of strontium residue.
