Fe-Al-Mg-MMH/溪膨润土分散体系触变性研究

The Thixotropy of Ferric Aluminum Magnesium Hydroxide/Montmorillonite Suspension

研究了Fe-Al-Mg-混合金属氧化物(简称MMH)/金溪膨润土(简称MT)分散体系的触变性。实验表明,在不同的MMH/MT质量比(R)条件下,分散体系可分别呈现正触变性和负触变性。考察了pH值对纯金溪膨润土和Fe-Al-Mg-MMH/金溪膨润土分散体系触变性的影响。发现pH值能影响体系的触变性类型。当R值较小时(0～0.051),随着pH值增加,体系的触变性发生负触变性-复合触变性-正触变性的转化;而R较大的体系(0.091),在所研究的pH范围内(7.28～12.00),随着pH值增加,体系由复合触变性向负触变性转化。并对影响机理进行了初步探讨。

In this paper, the thixotropy of aqueous dispersion consisting of ferric aluminum magnesium Hydroxide （Fe-Al-Mg-MMH） possessing permanent positive charges and Na-montmorillonite （MT） possessing permanent nagative charges is studied. It was found that the suspension studied may display positive thixotropy, nagative thixotropy or complex thixotropy depending on the Fe-Al-Mg-MMH/MT mass ratio （R）. The effects of pH on the thixotropy of pure montmorillonite and MMH/MT suspension are examined, and it was found that pH could affect the type of thixotropy. When the mass ratio （R） is relatively low （0 - 0.051 ）, with pH rising slowly, the thixotro- py changed from nagative thixotropy to complex thixotropy then finally to positive thixotropy, When m （ MMH）/m （MT） was relatively high （0. 091 ）,with pH rising gradually, the thixotropy changed from complex thixotropy to nagative thixotropy. The mechanism of thixotropy is also discussied.