Meisam Mirarab Razi - School of Chemical Engineering, Iran University of Science and Technology (IUST), Tehran,Iran
Majid Ghiass - Iran Polymer and Petrochemical Institute
Fatemeh Mirarab Razi - Mathematics and Computer Science Department, Amirkabir University of Technology, Hafez St., Tehran,Iran
Reyhane Alipoor - School of Chemical Engineering, Iran University of Science and Technology (IUST), Tehran,Iran

The effects of guar gum polymer and lime powder addition on the fluid loss and rheological properties of bentonite dispersions have been investigated. Elevendifferent formulations have been prepared according to the American Petroleum Institute procedures and their rheological characteristics have been determinedusing a rotational viscometer. Four rheological models have been used to describe the pseudoplastic behavior of the dispersions. It has been observedthat all rheological properties increase with pH and show a maximum at pH value of about 11.5. The effect of addition of lime also extremely increases the fluid loss of bentonite dispersions.

Bentonite dispersions; Guar gum; Lime; Rheological properties;Fluid loss