Nylon 10 T and Nylon 10T/1010 samples were synthesized by direct melt polymerization. The non-isothermal crystallization kinetics of Nylon 10 T and Nylon 10T/1010 was investigated by means of differential scanning cal...Nylon 10 T and Nylon 10T/1010 samples were synthesized by direct melt polymerization. The non-isothermal crystallization kinetics of Nylon 10 T and Nylon 10T/1010 was investigated by means of differential scanning calorimetry(DSC). Jeziorny equation and Mo equation were applied to describe the non-isothermal crystallization kinetics of the Nylon 10 T and the Nylon 10T/1010. The activation energies for non-isothermal crystallization were obtained by Vyazovkin's method and Friedman's method, respectively. These results showed that Jeziorny equation and Mo equation well described the non-isothermal crystallization kinetics of the Nylon 10 T and the Nylon 10T/1010. It was found that the values of the activation energy for non-isothermal crystallization of the Nylon 10T/1010 were lower than those of the Nylon 10 T at a given temperature or relative crystallinity degree,which revealed that crystallization ability of the Nylon 10T/1010 was higher. The crystal morphology was observed by means of a polarized optical microscope(POM) and X-ray diffraction(XRD). It was found that the addition of sebacic acid comonomer not only did not change the crystal form of the Nylon 10 T, but also significantly increased the number and decreased the size of spherulites. Comparing with the Nylon 10 T, the crystallization rate was increased with the addition of the sebacic acid comonomer.展开更多
The oxygen-enriched direct smelting of jamesonite concentrate was carried out at 1250℃by changing the slag composition.The effects of Fe/SiO2 and Ca O/SiO2 mass ratios on the metal recovery rate as well as metal cont...The oxygen-enriched direct smelting of jamesonite concentrate was carried out at 1250℃by changing the slag composition.The effects of Fe/SiO2 and Ca O/SiO2 mass ratios on the metal recovery rate as well as metal content in slag were investigated.Experimental results indicated that the metal(Pb+Sb)recovery rate was up to 88.30%,and metal(Pb+Sb)content in slag was below 1 wt.%under the condition of slag composition of 21-22 wt.%Fe,19-20 wt.%SiO2 and 17-18 wt.%Ca O with Fe/SiO2 mass ratio of 1.1:1 and Ca O/SiO2 mass ratio of 0.9:1.The microanalysis of the alloy and slag demonstrated that the main phases in the alloy contained metallic Pb,metallic Sb and a small amount of Cu2 Sb and Fe Sb2 intermetallic compounds.The slag was mainly composed of kirschsteinite and fayalite.Zinc in the raw material was mainly oxidized into the slag phase in the form of zinc oxide.展开更多
The billets of AM60 alloy, prepared with self-inoculation method, were partially remelted into semisolid state. Effects of process parameters on remelting microstructure of semisolid billet were investigated. Experime...The billets of AM60 alloy, prepared with self-inoculation method, were partially remelted into semisolid state. Effects of process parameters on remelting microstructure of semisolid billet were investigated. Experimental results show that the solid particles obtained with self-inoculation method are in smaller grain size and globular shape after partial remelting, compared with those prepared with other casting methods. In the optimized process conditions, the average size of solid particles of partially remelted billet is 65 μm, and the shape factor is 1.12. The process parameters, i.e. pouting temperature, addition amount of self-inoculants, and the slope angle of multi-stream mixing cooling chalmel have influence on the microstructure of partially remelted billet. The optimized temperature is from 680 ℃ to 700 ℃, addition amount of self-inoculants is between 5% and 7% （mass fraction）, slope angle of multi-stream mixing cooling channel is between 30° and 45°, with which the dendritic microstructure of as-cast billet can be avoided, and the size of solid particles ofremelted billet is reduced.展开更多
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
基金Supported by the National Science and Technology Support Program of China(No.2013BAE02B01)the Special Project on the Integration of Industry,Education and Research of Guangdong Province(No.2013B090500003)the Commissioner Workstation Project of Guangdong Province(No.2014A090906002)
文摘Nylon 10 T and Nylon 10T/1010 samples were synthesized by direct melt polymerization. The non-isothermal crystallization kinetics of Nylon 10 T and Nylon 10T/1010 was investigated by means of differential scanning calorimetry(DSC). Jeziorny equation and Mo equation were applied to describe the non-isothermal crystallization kinetics of the Nylon 10 T and the Nylon 10T/1010. The activation energies for non-isothermal crystallization were obtained by Vyazovkin's method and Friedman's method, respectively. These results showed that Jeziorny equation and Mo equation well described the non-isothermal crystallization kinetics of the Nylon 10 T and the Nylon 10T/1010. It was found that the values of the activation energy for non-isothermal crystallization of the Nylon 10T/1010 were lower than those of the Nylon 10 T at a given temperature or relative crystallinity degree,which revealed that crystallization ability of the Nylon 10T/1010 was higher. The crystal morphology was observed by means of a polarized optical microscope(POM) and X-ray diffraction(XRD). It was found that the addition of sebacic acid comonomer not only did not change the crystal form of the Nylon 10 T, but also significantly increased the number and decreased the size of spherulites. Comparing with the Nylon 10 T, the crystallization rate was increased with the addition of the sebacic acid comonomer.
基金Project(51474248)supported by the National Natural Science Foundation of China
文摘The oxygen-enriched direct smelting of jamesonite concentrate was carried out at 1250℃by changing the slag composition.The effects of Fe/SiO2 and Ca O/SiO2 mass ratios on the metal recovery rate as well as metal content in slag were investigated.Experimental results indicated that the metal(Pb+Sb)recovery rate was up to 88.30%,and metal(Pb+Sb)content in slag was below 1 wt.%under the condition of slag composition of 21-22 wt.%Fe,19-20 wt.%SiO2 and 17-18 wt.%Ca O with Fe/SiO2 mass ratio of 1.1:1 and Ca O/SiO2 mass ratio of 0.9:1.The microanalysis of the alloy and slag demonstrated that the main phases in the alloy contained metallic Pb,metallic Sb and a small amount of Cu2 Sb and Fe Sb2 intermetallic compounds.The slag was mainly composed of kirschsteinite and fayalite.Zinc in the raw material was mainly oxidized into the slag phase in the form of zinc oxide.
基金Project(2007CB613700) supported by the National Basic Research Program of ChinaProject(50964010) supported by the National Natural Science Foundation of ChinaProject(090WCGA894) supported by the International S&T Cooperation Program of Gansu Province,China
文摘The billets of AM60 alloy, prepared with self-inoculation method, were partially remelted into semisolid state. Effects of process parameters on remelting microstructure of semisolid billet were investigated. Experimental results show that the solid particles obtained with self-inoculation method are in smaller grain size and globular shape after partial remelting, compared with those prepared with other casting methods. In the optimized process conditions, the average size of solid particles of partially remelted billet is 65 μm, and the shape factor is 1.12. The process parameters, i.e. pouting temperature, addition amount of self-inoculants, and the slope angle of multi-stream mixing cooling chalmel have influence on the microstructure of partially remelted billet. The optimized temperature is from 680 ℃ to 700 ℃, addition amount of self-inoculants is between 5% and 7% （mass fraction）, slope angle of multi-stream mixing cooling channel is between 30° and 45°, with which the dendritic microstructure of as-cast billet can be avoided, and the size of solid particles ofremelted billet is reduced.
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.
