Experimental Study of Ball Milling Effect on the Structureal Properties and Bleaching Performance of Bentonite

In this study, effect of ball milling on the structural properties and bleaching performance of the Kerman bentonite sample was investigated. The bentonite sample consisted mainly of montmorillonite and small amount of impurities. The sample was ground with a high energy ball mill and characterized by X-Ray Diffraction (XRD), X-Ray Fluorescence (XRF), Fourier Transform Infra Red spectrometer (FT-IR) and Scanning Electron Microscopy (SEM). Also particle size distribution and specific surface area of the sample were obtained. The results showed that the crystalline form of the clay was changed by milling with high energy ball mill. With increasing of milling time more fractures and more disorder in structure of sample was happened. In addition, after ball milling the particle size of the bentonite was reduced even to nano metric scale but almost these very small particles re-aggregated. Due to reduction of particle size the specific surface area of the ground sample was increased. The oil bleaching experiment were carried out using the above ground bentonite and acid activated bentonite in a batch process and results showed that both modified bentonite have higher bleaching power. Therefore with bring together experimental conditions the ball milling method is suggested for preparation of bleaching earth.