Influence of Calcite in the Filtration Properties of Clay Dispersions

Abstract

This project had as objective to evaluate the influence of the content and particle size of the calcite in the filtration properties of clay dispersions. For that, it was realized the characterization of a bentonite clay sample using X-Ray Fluorescence and X-Ray Diffraction. In addition, two samples of calcite (CaCO3) were granulometrically analyzed by Laser Diffraction. The dispersions were prepared with fixed concentration of clay (10g) and different concentrations of carboxymethylcellulose of low viscosity (0 to 2g), and calcite (0 to 20g). After 24 hours of repose, it were determined the filtration properties (filtrate volume (FV), mudcake thickness (h), and mudcake permeability (k)). It was observed that the lowest filtrate volume was acquired using CaCO3 sample with the lowest average diameter, and, also, a bigger concentration of calcite was not able to promote a considerable reduction of the filtrate.

Influence of the chemical structure of different carboxymethylcelluloses on the performance of clay dispersions

“…In this state, there were few electrical and mass interactions between the clay particles. According to the literature [28,29], Volclay is a natural sodium bentonite from Wyoming/USA, which has a large amount of fine fraction (with an average particle size <2 μm), high cation exchange capacity and high specific area. These physicochemical characteristics, together with the low clay content (15 g/350 mL of water) used, promoted a greater dispersion of the colloidal particles, resulting in a low viscosity for dispersion 1.…”