Abstract:

The effect of pH on the rheological properties of Mg-Al-Hydrotalcite-like compound／kaolinite suspensions are investigated. For pure kaolinite suspension, both of the yield stress τy obtained in the controlled rate mode and critical shear stress τc obtained in the controlled stress mode increased first and then decreased with the increase of the pH, showing a maximum at about pH=7. But for Mg-Al-hydrotalcite-like compound／kaolinite suspensions with R=0.25, it is showed a maximum at about pH=11. Experimental results are discussed on the basis of the interactions between the HTlc and kaolinite particles.

Key words:  hydrotalcitelike compound;kaolinite;shear stress;suspension; rheology