凹凸棒石粘土的提纯、活化和性能表征

Purification of attapulgite clay and its activition and characterization

摘要:

对凹凸棒石粘土(ATP)进行了湿法提纯，对提纯后的ATP进行了NaOH处理和浓度分别为1 mol/L、2 mol/L和3 mol/L的HCl处理。用透射电子显微镜(TEM)和X射线衍射(XRD)对经不同方式处理的样品进行形貌和物相分析，并测定样品的比表面、孔结构和Zeta电位。结果表明：湿法提纯可以除去SiO2、Al2O3杂质，提纯过程未对ATP的纤维结构和物相造成改变。3 mol/L的酸处理溶出ATP结构中物质SiO2， ATP的纤维结构被破坏，使其断裂形成碎片并形成SiO2。研究了原土、提纯土、碱处理土、1 mol/L HCl处理、2 mol/L HCl处理和3 mol/L HCl处理的ATP对浓度为0.01 mol/L Fe3 、Ni2 和Cr2O72-的吸附效果，分析了不同处理方法对离子吸附率的影响。结果表明：ATP对阳离子的吸附率大于阴离子，吸附率的大小与ATP表面Zeta电位密切相关。

Abstract:

Attapulgite clay(ATP) from Xuyi was purified by a wet method then treated with NaOH and 1 mol/L，2 mol/L and 3 mol/L solutions of HCl. Transmission electron microscope(TEM) and X-ray diffraction (XRD) were used to characterize the ATPs of different treated methods, and then specific surface, pore volume and Zeta potential were deteremined as well. Results showed that wet purification could remove most of impurities without destroy composition and fiber structure of ATP. Treatment of 3 mol/L hydrochloric acid could dissolve some element of ATP so much as form SiO2 and destroy fiber structure to clips. Adsorption experiments of 0.01 mol/L Fe3 , Ni2 and Cr2O72- on ATP removed from aqueous solutions were done. Absorbents were original ATP, purified ATP or ATP treated with sodium hydroxide, 1 mol/L，2 mol/L and 3 mol/L solutions of hydrochloric acid. Influences of treatment methods and kinds of ion on adsorptive ratio were studied. The results showed that Fe3 and Ni2 had higher adsorptive ratio on ATP than Cr2O72- , and adsorptive ratios had close relationship to Zeta potenial of ATP.