Niobium-promoted Fe/CNTs catalysts were prepared using a wet impregnation method.Samples were characterized by nitrogen adsorption,H2-TPR,TPD,XRD and TEM.The Fischer-Tropsch Synthesis(FTS) was carried out in a fixed-b...Niobium-promoted Fe/CNTs catalysts were prepared using a wet impregnation method.Samples were characterized by nitrogen adsorption,H2-TPR,TPD,XRD and TEM.The Fischer-Tropsch Synthesis(FTS) was carried out in a fixed-bed microreactor at 220 ℃,1 atm and H2/CO=2 for 5 h.Addition of niobium into Fe/CNTs increased the dispersion,decreased the average size of iron oxide nanoparticles and the catalyst reducibility.Niobium-promoted Fe catalyst resulted in appreciable increase in the selectivity of C5+ hydrocarbons and suppressed methane formation.These effects were more pronounced for the 0.04%Nb/Fe/CNTs catalyst,compared to those observed from other niobium compositions.The 0.04%Nb/Fe/CNTs catalyst enhanced the C5+ hydrocarbons selectivity by a factor of 67.5% and reduced the methane selectivity by a factor of 59.2%.展开更多
这是一篇工艺矿物学领域的论文。锂、铍、铌、钽等稀有金属作为国家战略性新兴资源,主要应用于国防、航空、航天等工业领域,近年来备受地质学家的关注。湖北某地铌钽铁矿为含铌粗面质火山岩及火山碎屑岩矿床,本文对该矿石进行了系统的...这是一篇工艺矿物学领域的论文。锂、铍、铌、钽等稀有金属作为国家战略性新兴资源,主要应用于国防、航空、航天等工业领域,近年来备受地质学家的关注。湖北某地铌钽铁矿为含铌粗面质火山岩及火山碎屑岩矿床,本文对该矿石进行了系统的工艺矿物学研究,查明矿石中主要含铌的矿物有铌铁矿,铌铁金红石、赤褐铁矿和钛铁矿、黄铁矿等,铌铁矿为该矿石选别铌精矿的主要回收矿物。大部分铌矿物嵌布粒度均小于0.04 mm,铌铁矿粒度微细,多为0.5~8μm,但在-0.037 mm 90%时单体解离度可达71.11%,可考虑用磁选方法分离铌铁矿和脉石矿物;矿石中脉石矿物以绢云母、斜长石为主,磨细后泥化严重,应注意泥级物质团聚对选矿实验的影响。展开更多
基金Ministry of Science,Technology and Innovation(E-Science Fund,03-02-02-SF0036)Ministry of Higher Education Malaysia(FRGS/2/2010/SG/UTP/02/3)Universiti Teknologi PETRONAS(31/09.10)
文摘Niobium-promoted Fe/CNTs catalysts were prepared using a wet impregnation method.Samples were characterized by nitrogen adsorption,H2-TPR,TPD,XRD and TEM.The Fischer-Tropsch Synthesis(FTS) was carried out in a fixed-bed microreactor at 220 ℃,1 atm and H2/CO=2 for 5 h.Addition of niobium into Fe/CNTs increased the dispersion,decreased the average size of iron oxide nanoparticles and the catalyst reducibility.Niobium-promoted Fe catalyst resulted in appreciable increase in the selectivity of C5+ hydrocarbons and suppressed methane formation.These effects were more pronounced for the 0.04%Nb/Fe/CNTs catalyst,compared to those observed from other niobium compositions.The 0.04%Nb/Fe/CNTs catalyst enhanced the C5+ hydrocarbons selectivity by a factor of 67.5% and reduced the methane selectivity by a factor of 59.2%.
文摘这是一篇工艺矿物学领域的论文。锂、铍、铌、钽等稀有金属作为国家战略性新兴资源,主要应用于国防、航空、航天等工业领域,近年来备受地质学家的关注。湖北某地铌钽铁矿为含铌粗面质火山岩及火山碎屑岩矿床,本文对该矿石进行了系统的工艺矿物学研究,查明矿石中主要含铌的矿物有铌铁矿,铌铁金红石、赤褐铁矿和钛铁矿、黄铁矿等,铌铁矿为该矿石选别铌精矿的主要回收矿物。大部分铌矿物嵌布粒度均小于0.04 mm,铌铁矿粒度微细,多为0.5~8μm,但在-0.037 mm 90%时单体解离度可达71.11%,可考虑用磁选方法分离铌铁矿和脉石矿物;矿石中脉石矿物以绢云母、斜长石为主,磨细后泥化严重,应注意泥级物质团聚对选矿实验的影响。
