SUSPENSION PROPERTY OF ALUMINA IN LAPPING MEDIA

ABSTRACT

In order to understand the suspension properties of alumina grit in lapping liquids, with particular interest on their flocculation behavior both electro kinetic and sedimentation experiments were carried out on three different alumina powders, that were either wet or air classified in two commercial additives ( Mon - 60 and Rust Lick - 900 ). The results suggest that all three alumina powders have some acidic surface impurity and both Mon - 60 and Rust Lick - 900 are adsorbed on the alumina surface below pH 9. The sedimentation behavior of these alumina powders from their dispersions is independent of the classification of the alumina and nature of the additive but is dependent on the pH of the dispersion.