The relationship between the efficiency of NiO/Fe2O3 wet grinding and noisy-power dissipation was studied. The optimal grinding parameters were found as: a slurry water content of 64.10%-85.47%, ball number ratio of 3...The relationship between the efficiency of NiO/Fe2O3 wet grinding and noisy-power dissipation was studied. The optimal grinding parameters were found as: a slurry water content of 64.10%-85.47%, ball number ratio of 360/20, revolution speed of 300.9 r/min, powder-filling ratio of 10.88%, ball-filling ratio of 20.53%-23.88%, and grinding time of approximately 6 h. The discrete element method(DEM) was employed to analyze relationship between the noisy-power dissipation and the grinding efficiency, and equations describing the relationship were derived. The mean particle size of the ground powder decreased with a decrease in the degree of noisy-power dissipation, while the grinding efficiency and the amount of specific impact power used decreased with an increase in the degree of noisy-power dissipation.展开更多
The non-isothermal reduction kinetics and mechanism of Fe2O3-NiO composites with different Fe2O3-NiO compacts using carbon monoxide as reductant were investigated. The results show that the reduction degree increases ...The non-isothermal reduction kinetics and mechanism of Fe2O3-NiO composites with different Fe2O3-NiO compacts using carbon monoxide as reductant were investigated. The results show that the reduction degree increases rapidly with increasing the content of NiO, and the presence of NiO also improves the reduction rate of iron oxides. It is found that NiO is preferentially reduced at the beginning of the reactions, and then the metallic Ni acts as a catalyst promoting the reduction rate of iron oxides. It is also observed that the increase of the Ni O content enhances the formation of awaruite(FeNi3) but decreases the percentage of kamacite(Fe,Ni) and taenite(Fe,Ni). The particle size of the materials tends to be uniform during the reduction process due to the presence of metallic nickel, metallic iron and the formation of Fe-Ni alloy. The concentration of CO in the product gas is greater than that of CO2 at the beginning of the reaction and then slows down. The fastest reduction rate of Fe2O3-NiO composites with CO appears at 400-500 °C, and nucleation growth model can be used to elucidate the reduction mechanism. Nucleation growth process is found to be the rate controlling step when the temperature is lower than 1000 °C.展开更多
高性能复合镀层具有优良的耐磨、耐蚀性能,能满足工业生产对材料性能的要求。研究了脉冲电沉积RE Ni W B PTFE Al2O3 复合镀层的成分、形貌及性能。结果表明:脉冲电流及Al2O3 固体颗粒能明显提高RE Ni W B PTFE Al2O3 复合镀层中W和B的...高性能复合镀层具有优良的耐磨、耐蚀性能,能满足工业生产对材料性能的要求。研究了脉冲电沉积RE Ni W B PTFE Al2O3 复合镀层的成分、形貌及性能。结果表明:脉冲电流及Al2O3 固体颗粒能明显提高RE Ni W B PTFE Al2O3 复合镀层中W和B的含量;与直流电沉积相比,脉冲电沉积RE Ni W B复合镀层的表面裂纹已明显减小,但裂纹仍存在,当Al2O3 耐磨颗粒及PTFE减摩微粒嵌入RE Ni W B复合镀层中以后,在SEM 400倍下观察,RE Ni W B PTFE Al2O3镀层已不存在裂纹, 而且镀液中Al2O3 颗粒含量越多,晶粒就越细;此外,研究表明,镀液中Al2O3 颗粒含量增加, RE Ni W B PTFE Al2O3 复合镀层镀态硬度增加,磨损率降低。展开更多
A 60%Fe/Al_2O_3 catalyst was prepared by the co-precipitation method.It was reduced by H_2 to produce metallic Fe,which was then sulfided by CS_2 to Fe_(0.96) S and Fe_3S_4 or phosphided by triphenylphosphine(PPh3) in...A 60%Fe/Al_2O_3 catalyst was prepared by the co-precipitation method.It was reduced by H_2 to produce metallic Fe,which was then sulfided by CS_2 to Fe_(0.96) S and Fe_3S_4 or phosphided by triphenylphosphine(PPh3) in liquid phases to Fe2 P and Fe P.It was found that the iron sulfides(Fe0.96 S and Fe_3S_4) exhibited the low activity for the hydrodesulfurization(HDS) reactions.The HDS activity was also low on the Fe(metal)/Al_2O_3 and Fe_2 P/Al_2O_3 catalysts since they were converted into Fe0.96 S and Fe_3S_4 during the HDS reactions.In contrast,the FeP/Al_2O_3 was found to be stable and active for the HDS reactions.In particular,Fe P/Al_2O_3 possessed significantly smaller Fe P particles than Fe P/C,leading to the significant higher HDS activity of FeP/Al_2O_3 than Fe P/C.展开更多
基金supported by the Inert Anode Material Production and Application in Electrolytic Production of Aluminium program of the Yunnan Aluminium Yonxin Aluminium Co. Ltd
文摘The relationship between the efficiency of NiO/Fe2O3 wet grinding and noisy-power dissipation was studied. The optimal grinding parameters were found as: a slurry water content of 64.10%-85.47%, ball number ratio of 360/20, revolution speed of 300.9 r/min, powder-filling ratio of 10.88%, ball-filling ratio of 20.53%-23.88%, and grinding time of approximately 6 h. The discrete element method(DEM) was employed to analyze relationship between the noisy-power dissipation and the grinding efficiency, and equations describing the relationship were derived. The mean particle size of the ground powder decreased with a decrease in the degree of noisy-power dissipation, while the grinding efficiency and the amount of specific impact power used decreased with an increase in the degree of noisy-power dissipation.
基金Projects(51304091,U1302274)supported by the National Natural Science Foundation of ChinaProjects(2013FD009,2013FZ007)supported by Applied Basic Research Program of Yunnan Province,ChinaProject(2012HB009)supported by the Candidate Talents Training Fund of Yunnan Province,China
文摘The non-isothermal reduction kinetics and mechanism of Fe2O3-NiO composites with different Fe2O3-NiO compacts using carbon monoxide as reductant were investigated. The results show that the reduction degree increases rapidly with increasing the content of NiO, and the presence of NiO also improves the reduction rate of iron oxides. It is found that NiO is preferentially reduced at the beginning of the reactions, and then the metallic Ni acts as a catalyst promoting the reduction rate of iron oxides. It is also observed that the increase of the Ni O content enhances the formation of awaruite(FeNi3) but decreases the percentage of kamacite(Fe,Ni) and taenite(Fe,Ni). The particle size of the materials tends to be uniform during the reduction process due to the presence of metallic nickel, metallic iron and the formation of Fe-Ni alloy. The concentration of CO in the product gas is greater than that of CO2 at the beginning of the reaction and then slows down. The fastest reduction rate of Fe2O3-NiO composites with CO appears at 400-500 °C, and nucleation growth model can be used to elucidate the reduction mechanism. Nucleation growth process is found to be the rate controlling step when the temperature is lower than 1000 °C.
文摘高性能复合镀层具有优良的耐磨、耐蚀性能,能满足工业生产对材料性能的要求。研究了脉冲电沉积RE Ni W B PTFE Al2O3 复合镀层的成分、形貌及性能。结果表明:脉冲电流及Al2O3 固体颗粒能明显提高RE Ni W B PTFE Al2O3 复合镀层中W和B的含量;与直流电沉积相比,脉冲电沉积RE Ni W B复合镀层的表面裂纹已明显减小,但裂纹仍存在,当Al2O3 耐磨颗粒及PTFE减摩微粒嵌入RE Ni W B复合镀层中以后,在SEM 400倍下观察,RE Ni W B PTFE Al2O3镀层已不存在裂纹, 而且镀液中Al2O3 颗粒含量越多,晶粒就越细;此外,研究表明,镀液中Al2O3 颗粒含量增加, RE Ni W B PTFE Al2O3 复合镀层镀态硬度增加,磨损率降低。
基金Financial supports from the NSFC-DFG (21761132006),NSFC (21773108)fundamental research funds for central universities are acknowledged
文摘A 60%Fe/Al_2O_3 catalyst was prepared by the co-precipitation method.It was reduced by H_2 to produce metallic Fe,which was then sulfided by CS_2 to Fe_(0.96) S and Fe_3S_4 or phosphided by triphenylphosphine(PPh3) in liquid phases to Fe2 P and Fe P.It was found that the iron sulfides(Fe0.96 S and Fe_3S_4) exhibited the low activity for the hydrodesulfurization(HDS) reactions.The HDS activity was also low on the Fe(metal)/Al_2O_3 and Fe_2 P/Al_2O_3 catalysts since they were converted into Fe0.96 S and Fe_3S_4 during the HDS reactions.In contrast,the FeP/Al_2O_3 was found to be stable and active for the HDS reactions.In particular,Fe P/Al_2O_3 possessed significantly smaller Fe P particles than Fe P/C,leading to the significant higher HDS activity of FeP/Al_2O_3 than Fe P/C.
