我国制备氧化铁黄的原料大多以硫铁矿烧渣、钛白副产品硫酸亚铁、硫酸亚铁等分析纯试剂为主,存在杂质多、原料成本高、原料来源复杂等问题。试验采用超级铁精矿作为初始原料,通过酸溶-过滤-还原法制备硫酸亚铁,利用碳酸氢铵为沉淀剂,通...我国制备氧化铁黄的原料大多以硫铁矿烧渣、钛白副产品硫酸亚铁、硫酸亚铁等分析纯试剂为主,存在杂质多、原料成本高、原料来源复杂等问题。试验采用超级铁精矿作为初始原料,通过酸溶-过滤-还原法制备硫酸亚铁,利用碳酸氢铵为沉淀剂,通过氧化沉淀法制备氧化铁黄。试验表明在超级铁精矿(TFe:71.81%)、400 m L 4°Bé硫酸亚铁、初始pH为3.5、水浴温度为100℃、搅拌速度为500 r·min^(-1)、反应时间11 h等条件下,与GB/T 1863—2008各项指标数值作对比,铁含量高于国家标准1.07%,筛余物低于国家标准0.005%,105℃挥发物低于国家标准0.15%,总钙量低于国家标准0.248%。具有原料来源广、节能环保等优点,为制备高纯氧化铁黄提供新思路。展开更多
CeO2–TiO2composite supports with different Ce/Ti molar ratios were prepared by a homogeneous precipitation method, and V2O5–WO3/CeO2–TiO2catalysts for the selective catalytic reduction（SCR） of NOx with NH3 were p...CeO2–TiO2composite supports with different Ce/Ti molar ratios were prepared by a homogeneous precipitation method, and V2O5–WO3/CeO2–TiO2catalysts for the selective catalytic reduction（SCR） of NOx with NH3 were prepared by an incipient-wetness impregnation method. These catalysts were characterized by means of BET, XRD, UV–Vis,Raman and XPS techniques. The results showed that the catalytic activity of V2O5–WO3/TiO2 was greatly enhanced by Ce doping（molar ratio of Ce/Ti = 1/10） in the TiO2 support.The catalysts that were predominantly anatase TiO2 showed better catalytic performance than the catalysts that were predominantly fluorite CeO2. The Ce additive could enhance the surface adsorbed oxygen and accelerate the SCR reaction. The effects of O2 concentration, ratio of NH3/NO, space velocity and SO2 on the catalytic activity were also investigated. The presence of oxygen played an important role in NO reduction. The optimal ratio of NH3/NO was 1/1 and the catalyst had good resistance to SO2 poisoning.展开更多
文摘我国制备氧化铁黄的原料大多以硫铁矿烧渣、钛白副产品硫酸亚铁、硫酸亚铁等分析纯试剂为主,存在杂质多、原料成本高、原料来源复杂等问题。试验采用超级铁精矿作为初始原料,通过酸溶-过滤-还原法制备硫酸亚铁,利用碳酸氢铵为沉淀剂,通过氧化沉淀法制备氧化铁黄。试验表明在超级铁精矿(TFe:71.81%)、400 m L 4°Bé硫酸亚铁、初始pH为3.5、水浴温度为100℃、搅拌速度为500 r·min^(-1)、反应时间11 h等条件下,与GB/T 1863—2008各项指标数值作对比,铁含量高于国家标准1.07%,筛余物低于国家标准0.005%,105℃挥发物低于国家标准0.15%,总钙量低于国家标准0.248%。具有原料来源广、节能环保等优点,为制备高纯氧化铁黄提供新思路。
基金financially supported by the National Natural Science Foundation of China (Nos. 21376261, 21173270, 21177160)the National Hi-Tech Research and Development Program (863) of China (No. 2013AA065302)+2 种基金the Beijing Natural Science Foundation (2142027)the Doctoral Selection Fund (No. 20130007110007)the China University of Petroleum Fund (No. KYJJ2012-06-31)
文摘CeO2–TiO2composite supports with different Ce/Ti molar ratios were prepared by a homogeneous precipitation method, and V2O5–WO3/CeO2–TiO2catalysts for the selective catalytic reduction（SCR） of NOx with NH3 were prepared by an incipient-wetness impregnation method. These catalysts were characterized by means of BET, XRD, UV–Vis,Raman and XPS techniques. The results showed that the catalytic activity of V2O5–WO3/TiO2 was greatly enhanced by Ce doping（molar ratio of Ce/Ti = 1/10） in the TiO2 support.The catalysts that were predominantly anatase TiO2 showed better catalytic performance than the catalysts that were predominantly fluorite CeO2. The Ce additive could enhance the surface adsorbed oxygen and accelerate the SCR reaction. The effects of O2 concentration, ratio of NH3/NO, space velocity and SO2 on the catalytic activity were also investigated. The presence of oxygen played an important role in NO reduction. The optimal ratio of NH3/NO was 1/1 and the catalyst had good resistance to SO2 poisoning.
