A novel process was developed for the decomposition of vanadium slag using KOH sub-molten salt under ambient pressure, and the effects of reaction temperature, alkali-to-ore mass ratios, particle size, and stirring sp...A novel process was developed for the decomposition of vanadium slag using KOH sub-molten salt under ambient pressure, and the effects of reaction temperature, alkali-to-ore mass ratios, particle size, and stirring speed on vanadium and chromium extraction were studied. The results suggest that the reaction temperature and KOH-to-ore mass ratio are more influential factors for the extraction of vanadium and chromium. Under the optimal reaction conditions （temperature 180 °C, initial KOH-to-ore mass ratio 4：1, stirring speed 700 r/min, gas flow 1 L/min, and reaction time 300 min）, vanadium and chromium extraction rates can reach up to 95% and 90%, respectively. Kinetics analysis results show that the decomposing process of vanadium slag in KOH sub-molten salt can be well interpreted by the shrinking core model under internal diffusion control. The apparent activation energies for vanadium and chromium are 40.54 and 50.27 kJ/mol, respectively.展开更多
NiO nano-crystal powders with cubic structure were synthesized by molten salt method. The synthesized materials were characterized by XRD, TEM, N2 adsorption-desorption and TG, etc. Not only are the eminent characters...NiO nano-crystal powders with cubic structure were synthesized by molten salt method. The synthesized materials were characterized by XRD, TEM, N2 adsorption-desorption and TG, etc. Not only are the eminent characters of weak agglomeration, narrow distribution and fine crystalline configuration, but the average crystal sizes of synthesized NiO powders could be efficiently controlled from 10 nm to 100 nm by changing the calcination conditions, such as calcination temperature, calcination time, and proportion of molten salt KNO3. Molten salt method is technologically easy and cheap, for the production of NiO nano-crystal powders in industrial scale.展开更多
基金Project(2013CB632605)supported by the National Basic Research Development Program of ChinaProjects(51274178,51274179)supported by the National Natural Science Foundation of China
文摘A novel process was developed for the decomposition of vanadium slag using KOH sub-molten salt under ambient pressure, and the effects of reaction temperature, alkali-to-ore mass ratios, particle size, and stirring speed on vanadium and chromium extraction were studied. The results suggest that the reaction temperature and KOH-to-ore mass ratio are more influential factors for the extraction of vanadium and chromium. Under the optimal reaction conditions （temperature 180 °C, initial KOH-to-ore mass ratio 4：1, stirring speed 700 r/min, gas flow 1 L/min, and reaction time 300 min）, vanadium and chromium extraction rates can reach up to 95% and 90%, respectively. Kinetics analysis results show that the decomposing process of vanadium slag in KOH sub-molten salt can be well interpreted by the shrinking core model under internal diffusion control. The apparent activation energies for vanadium and chromium are 40.54 and 50.27 kJ/mol, respectively.
文摘NiO nano-crystal powders with cubic structure were synthesized by molten salt method. The synthesized materials were characterized by XRD, TEM, N2 adsorption-desorption and TG, etc. Not only are the eminent characters of weak agglomeration, narrow distribution and fine crystalline configuration, but the average crystal sizes of synthesized NiO powders could be efficiently controlled from 10 nm to 100 nm by changing the calcination conditions, such as calcination temperature, calcination time, and proportion of molten salt KNO3. Molten salt method is technologically easy and cheap, for the production of NiO nano-crystal powders in industrial scale.
