A novel and environmentally friendly route to directly prepare metallic vanadium from NaV03 by molten salt electrolysis is proposed. The feasibility about the direct electro-reduction of NaV03 to metallic vanadi- um i...A novel and environmentally friendly route to directly prepare metallic vanadium from NaV03 by molten salt electrolysis is proposed. The feasibility about the direct electro-reduction of NaV03 to metallic vanadi- um is analyzed based on the thermodynamic calculations and experimental verifications. The theoretical decomposition voltage of NaV03 to metallic vanadium is only 0.47 V at 800 ℃ and much lower than that of the alkali and alkali earth metal chloride salts. The value is slightly higher than that of low-valence vanadium oxides such as V203, V305 and VO. However, the low-valence vanadium oxides can he further electro-reduced to metallic vanadium thermodynamically. The thermodynamic analysis is verified by the experimental results. The direct preparation of metallic vanadium from NaV03 by molten salt electrolysis is feasible.展开更多
Hardwoods are important raw material for making pulp and paper products. Eucalyptus camaldulensis is a fast-growing hardwood species with a wide distribution in Iran and can be introduced as appropriatematerial to com...Hardwoods are important raw material for making pulp and paper products. Eucalyptus camaldulensis is a fast-growing hardwood species with a wide distribution in Iran and can be introduced as appropriatematerial to compensate the wood shortages of the natural forest. Kraft pulping was performed under different cooking conditions and, based on the relations of pulp yield and kappa number, bleachable kraft pulp at screened yield of 43.3% and kappa number of 31.3 was selected for DED （Chlorine Dioxide-Alkaline Extraction-Chlorine Dioxide） bleaching and its bleachability was studied at different kappa factor in D~ stage. The results indicated that the bleachable kraft pulp from this species has high kappa number at acceptable screened yield and to complete the delignification in the bleaching process, higher kappa factor may be needed in DED bleaching sequence. The main reduction in final kappa number and yield loss were observed at kappa factor level of 0.2 but by further increase in kappa factor up to 0.4, more development were observed in optical properties but at lower opacity.展开更多
基金Supported by the National Basic Research Program of China(2013CB632606)the National Natural Science Foundation of China(51474200)+1 种基金the Youth Innovation Promotion AssociationCAS(2015036)
文摘A novel and environmentally friendly route to directly prepare metallic vanadium from NaV03 by molten salt electrolysis is proposed. The feasibility about the direct electro-reduction of NaV03 to metallic vanadi- um is analyzed based on the thermodynamic calculations and experimental verifications. The theoretical decomposition voltage of NaV03 to metallic vanadium is only 0.47 V at 800 ℃ and much lower than that of the alkali and alkali earth metal chloride salts. The value is slightly higher than that of low-valence vanadium oxides such as V203, V305 and VO. However, the low-valence vanadium oxides can he further electro-reduced to metallic vanadium thermodynamically. The thermodynamic analysis is verified by the experimental results. The direct preparation of metallic vanadium from NaV03 by molten salt electrolysis is feasible.
文摘Hardwoods are important raw material for making pulp and paper products. Eucalyptus camaldulensis is a fast-growing hardwood species with a wide distribution in Iran and can be introduced as appropriatematerial to compensate the wood shortages of the natural forest. Kraft pulping was performed under different cooking conditions and, based on the relations of pulp yield and kappa number, bleachable kraft pulp at screened yield of 43.3% and kappa number of 31.3 was selected for DED （Chlorine Dioxide-Alkaline Extraction-Chlorine Dioxide） bleaching and its bleachability was studied at different kappa factor in D~ stage. The results indicated that the bleachable kraft pulp from this species has high kappa number at acceptable screened yield and to complete the delignification in the bleaching process, higher kappa factor may be needed in DED bleaching sequence. The main reduction in final kappa number and yield loss were observed at kappa factor level of 0.2 but by further increase in kappa factor up to 0.4, more development were observed in optical properties but at lower opacity.
