磁性海泡石的制备及表征

PREPARATION AND CHARACTERIZATION OF MAGNETIC SEPIOLITE

先采用化学共沉淀法制备Fe3O4磁流体,再与海泡石复合制备一系列不同Fe3O4载量(质量分数)的磁性海泡石,并进行X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)、振动样品磁强计(VSM)等表征分析,测定了其磁分离回收率及Cu2+、Zn2+、Cd2+的饱和交换吸附量。结果表明,Fe3O4微粒相互聚集并附载于海泡石表面,并与海泡石形成团聚体。磁性海泡石具超顺磁性,其饱和磁化强度(Ms)、剩余磁化强度(Mr)及磁分离回收率随Fe3O4载量增加而升高,对Cu2+、Zn2+、Cd2+的饱和交换吸附量随Fe3O4载量增加而降低。磁性海泡石中Fe3O4载量以16%(质量分数)为宜,该磁性海泡石磁分离回收率为98.1%,对Cu2+、Zn2+、Cd2+饱和交换吸附量分别为18.4、16.1、13.6mg·g-1。

Magnetic ferrofluid of Fe3O4 was prepared by chemical coprecipitation method firstly,and then magnetic sepiolite with different Fe3O4 loading was prepared by sepiolite composited with magnetic ferrofluid.The as-prepared magnetic sepiolite was characterized by X-ray diffraction（XRD）,scanning electronic microscopy（SEM）,transmission electronic microscopy（TEM） and vibration sample magnetometer（VSM）,and the magnetic recovery rate and saturation exchange-adsorption capacity of Cu^2＋,Zn^2＋,Cd^2＋ were also measured.The results showed that Fe3O4 particles aggregate each other and coat on the surface of sepiolite particles,and further compose to agglomerates.Magnetic sepiolite has well superparamagnetism.The saturation magnetization（Ms）,remanence magnetization（Mr） and magnetic recovery rate increased with the Fe3O4 loading increasing,but the saturation exchange-adsorption capacityofCu^2＋,Zn^2＋,Cd^2＋ decrease regularly.In the magnetic sepiolite the fitting Fe3O4loading is 16%,the recoveryrate ofmagnetic sepiolite is 98.1%,and saturation exchange-adsorption capacityofCu^2＋,Zn^2＋,Cd^2＋ is 18.4,16.1,13.6 mg·g^-1respectively.