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盐酸酸溶对蒙脱石结构的影响

盐酸酸溶对蒙脱石结构的影响

硅酸盐学报

· 1 ·2006年

盐酸酸溶对蒙脱石结构的影响

钟山,孙世群,陈天虎,彭书传

(合肥工业大学资源与环境工程学院, 合肥 230009)

摘要:通过X射线衍射分析、Brunauer–Eammett–Teller法、透射电镜分析研究了盐酸酸溶对蒙脱石结构的影响。结果表明:随着蒙脱石酸溶程度增加,层间可交换阳离子与八面体中Al3+逐渐溶出,蒙脱石晶体逐渐被破坏,四面体片残留逐渐转变为无定型SiO2。酸溶产物比表面积先增加到144 m2/g,然后减小,酸溶过程中没有大孔产生。H+置换晶层间阳离子和八面体中部分Al3+,使微孔表面积增大,酸溶程度过高则使晶体骨架崩塌,微孔大幅度减少。中孔是蒙脱石颗粒堆垛形成,蒙脱石酸溶在某种程度上强化了蒙脱石晶片的剥片作用,增加了中孔表面积。

关键词:蒙脱石;比表面积;孔径分布

中图分类号:TU52 文献标识码:A 文章编号:0454–5648(2006)09–1162–05

INFLUENCE OF HYDROCHLORIC ACID-DISSOLUTION ON THE STRUCTURE OF

MONTMORILLONITE

ZHONG Shan, SUN Shiqun, CHEN Tianhu, PENG Shuchuan

(School of Natural Resources and Environment Engineering, Hefei University of Technology, Hefei 230009, China) Abstract: The influences of hydrochloric acid-dissolution on the structure of montmorillonite were investigated with X-ray diffrac-tion, Brunauer–Emmett–Teller method and transmission electron microscopy. The results indicate that as the reaction time increases, the interbedded cations and octahedral cations first are dissolved, montmorillonite crystals are destroyed, tetrahedron remains and the products becomes amorphous fiber-like silica. The specific surface area of the acid-dissolved products increases to 144 m2/g and then decreases. Few macropores are formed in the whole process. The substitution of the interbedded cations and octahedral cations with H+ causes an increase in the micropore surface area; however, intensive acid dissolution can destroy the crystals, resulting in the de-crease of the micropore surface area. Mesopores are formed by the piling of montmorillonite slices. Acid dissolution intensifies the rupture of montmorillonite slices and leads to an increase in the mesopore surface area.

Key words: montmorillonite; specific surface area; pore size distribution

蒙脱石是由2个硅氧四面体夹1个铝氧八面体构

成的层状硅酸盐矿物[1]。我国蒙脱石矿资源丰富[2],

蒙脱石在国民经济的许多部门中有着广泛的应用,

是许多工业的重要原料[3-4]。盐酸酸溶是对蒙脱石进

行活化处理的主要方法之一[5],对蒙脱石酸溶可改

变其物化性能,并引起蒙脱石结构变化。

对蒙脱石酸溶产物一般是借助X射线衍射分析

(X-ray diffraction, XRD)、差热分析(differential

thermal analysis, DTA)、红外分析(Fourier transform

infrared spectroscopy, FTIR)等手段研究其宏观结构

特征[6],微观结构方面多用扫描电镜与核磁共振进

行观察[7–8]。实验中以双气路氮吸附Brunauer–

Emmett–Teller(BET)比表面积测试分析,Barrett–

Joyner–Halenda(BJH)孔径分布测试分析以及透射电

镜(transmission electron microscope, TEM)测试分析

为主,结合XRD和水化学分析对盐酸处理后的蒙脱

石结构变化进行了研究。

1 实验

实验所用蒙脱石黏土取自宣城水东镇,属钙基

收稿日期:2006–03–07。修改稿收到日期:2006–05–15。

基金项目:国家自然科学基金(40472026)资助项目。

第一作者:钟山(1980~),男,硕士研究生。

通讯作者:陈天虎(1962~), 男, 教授。

Received date: 2006–03–07. Approved date: 2006–05–15.

First author: ZHONG Shan(1980–), male, graduate student for mater degree.

Correspondent author: CHEN Tianhu(1962–), male, professor.

E-mail: chentianhu168@http://www.wendangku.net/doc/54dbe4d350e2524de5187ecb.html

第34卷第9期

2006年9月

硅酸盐学报

JOURNAL OF THE CHINESE CERAMIC SOCIETY

Vol. 34,No. 9

September, 2006