硫铁矿烧渣水热法合成形貌可控的氧化铁  

Morphology controllable iron oxide synthesized from pyrite cinders by hydrothermal method

作　　者：刘昭成[1] 郑雅杰[1] 

机构地区：[1]中南大学冶金科学与工程学院,湖南长沙410083

出　　处：《中南大学学报（自然科学版）》2011年第9期2563-2570,共8页Journal of Central South University:Science and Technology

基　　金：广东省重大科技资助专项(2008A090300016);中南大学贵重仪器开放共享基金资助项目(ZKL2010022)

摘　　要：以硫铁矿烧渣硫酸浸出液与氨水反应制备的Fe(OH)3胶体为前驱体,采用水热法合成不同形貌的氧化铁粒子。在中性介质中考察反应温度、物质的量比(n(Fe2+)/n(Fe3+))、水热体系总Fe浓度及晶种量对水热法氧化铁物相、形貌和粒径的影响。采用X线衍射仪、扫描电镜、透射电镜及选择区域电子衍射对水热产物物相和形貌进行研究。研究结果表明:反应温度为230℃,n(Fe2+)/n(Fe3+)为0.1以及水热体系总Fe浓度为1.25 mol/L和晶种量为2 g时,水热产物为片状α-Fe2O3粒子;控制上述其他条件不变,当温度在140～260℃时,随着温度的升高,水热法产物由α-FeOOH相向α-Fe2O3相转变,α-Fe2O3粒子形貌由球形向小圆饼状和片状依次转变;当n(Fe2+)/n(Fe3+)在0～0.12时,随着n(Fe2+)/n(Fe3+)的增加,水热产物由α-Fe2O3相向α-Fe2O3和Fe3O4相转变,α-Fe2O3粒子形貌由球形逐渐向片状转变,其粒径由小变大;当水热体系中总Fe浓度为0.625 mol/L和1.875 mol/L时,水热法氧化铁分别为不均一形貌和球形;当没有加入晶种及晶种量为6 g时,水热法氧化铁分别为椭球状和不均一形貌。Iron oxide particles with different morphologies were synthesized by hydrothermal treatment using ferric hydroxide gel as precursor,prepared by adding ammonia to sulfuric acid leaching solution of pyrite cinders.In addition,the effects of reaction temperature,n（Fe2＋）/n（Fe3＋）,total iron concentration and seed crystals adding amount on the phase,shape and size of the prepared iron oxide in the neutral medium were investigated.The phase and shape of the synthesized iron oxide particles were characterized by X-ray diffraction（XRD）,scanning electron microscope（SEM）,transmission electron microscopy（TEM） and selected area electron diffraction（SAED）.The results show that platelet-type α-Fe2O3 particles are prepared via hydrothermal route when the temperature is 230 ℃,n（Fe2＋）/n（Fe3＋） is 0.1,total iron concentration is 1.25 mol/L and seed crystal adding amount is 2 g.With the increase of temperature,when it is in the range of 140？260 ℃,the hydrothermal products transfer from α-FeOOH to α-Fe2O3 and their shapes change from sphere to round pie and then to platelet.With the increase of n（Fe2＋）/n（Fe3＋）,in the range of 0？0.12,the hydrothermal products are transferred from α-Fe2O3 to α-Fe2O3 and Fe3O4,and the shapes of α-Fe2O3 particles gradually change to platelet from sphere.Furthermore,the particle size also increases with the increase of n（Fe2＋）/n（Fe3＋）.The obtained iron oxide particles become heterogeneous when the total Fe concentration is 0.625 mol/L,while it becomes sphere when the total Fe concentration is 1.875 mol/L.The products are elliptical without adding any seed crystal,while it becomes heterogeneous when the crystal seed adding amount is 6 g.

关 键 词：硫铁矿烧渣 氧化铁 Α-FE2O3 水热法 形貌可控 

分 类 号：TQ138.1[化学工程—无机化工]