The aim of this work is to evaluate, by electrodialysis, the influence of Ca2+ and Mg2+ on the rheology of bentonite clay dispersions from Boa Vista, PB. Dispersions were prepared with 4.86 wt.% and submitted to electrodialysis process by using a cationic polymeric membrane in the batch reactor. The electrodialysis was set up according to 2² + 3 factorial design by using 7, 10 and 13 V and 40, 80 and 120 min. After electrodialysis, the dispersions were treated with Na2CO3 and after curing, the apparent and plastic viscosities were measured using a viscosimeter and water loss with a filter-press. Moreover, exchanged cations were determinated before and after the electrodialysis process. The results show that the electrodialysis can be a valuable tool to identify the factors that dictate the rheological behavior of bentonite clay dispersions, as well as that the partially eliminated Ca2+ and Mg2+ do not influence on the rheology of the dispersions.
bentonite clays; Ca2+ and Mg2+; electrodialysis; rheological properties
