摘要
以活化坡缕石作为吸附剂的应用已经十分广泛。活化方法一般有酸活化和焙烧活化。本文用X射线衍射和红外光谱分析,研究了纤维状坡缕石和土状坡缕石经HCl活化和焙烧活化后晶体结构的变化。结果表明,HCl活化对纤维状坡缕石结构没有影响。而土状坡缕石则不然:当HCl浓度为1.0 mol／L时,呈八面体配位的阳离子部分被H+取代或溶出,导致晶胞参数减小;当HCl浓度为1.5 mol／L时,出现八面体片坍塌,游离出SiO2,结构出现较大破坏,对进一步提高活性没有贡献。在350℃及以上温度焙烧活化会使坡缕石晶体结构产生明显破坏,分解氧化形成的Fe2O3使其脱色率明显下降。
The activated palygorskite has been widely used as sorption agent. Normally, there are two activating methods including the acid activating and the heat activating. The crystal structural variations of fibrous and earthy palygorskite, which were activated by HCl and heat, have been studied in this paper by using X-ray diffraction (XRD) and infrared spectrometry (FT-IR). The analyses show that no variation has occurred for the structure of the HCl activated fibrous palygorskite in comparison with that of the original fibrous palygorskite. However, the structure of the HCl activated earthy palygorskite is different to that of the original earthy palygorskite. For the earthy palygorskite activated by 1. 0mol/L HCl acid, a part of positive ions coordinated in its octahedron would be substituted by H+ or be dissolved out, and thus resulted in the decrease of its cell parameter. For the earthy palygorskile activated by 1. 5mol/L HCl acid, its octahedron sheet would be collapsed, its SiO2 would be extricated, and its crystal structure would be destructed obviously. Therefore, the increase of acid concentration would not increase the activity of the palygorskite. For the earthy palygorskite activated by over 350℃ heating, its crystal structure would be obviously damaged and its decolorized rate would be obviously decreased by the Fe2O3 derived from decomposition and oxidation of the earthy palygorskite.
出处
《矿物岩石地球化学通报》
CAS
CSCD
2005年第1期62-66,共5页
Bulletin of Mineralogy, Petrology and Geochemistry
