Influence of the additivation process on cation exchange capacity and viscosity of bentonitic clay dispersions

Abstract

In Brazil, bentonite clays are not naturally sodic and it is an industrial practice the sodium additivation, since sodium ion expands their lamellae allowing a larger amount of water to penetrate. The objective was to analyze the influences of the use of sodium carbonate on the clay during the additivation process, the moisture content and the cure time on cation exchange and viscosity of bentonite clay dispersions for water-based drilling fluids, since there is a shortage of studies on this subject. Newly discovered bentonite clays in Paraíba State, Brazil, were chemically, physically and mineralogically characterized and were additivated with sodium carbonate in aqueous solution (process 1) or in powder form (process 2). Samples with 25% to 60% of moisture (dry basis) were prepared and submitted to cure times of 7 to 45 days. Process 1, as expected, showed better results of cation exchange capacity, viscosity and filtrate volume. The ideal cure time was 15 days. After this period there was a reversal of the cation exchange reactions.

Manufacturing and characterization of sustainable macroporous glass foams

“…The contents of MgO (2.75 wt%) and CaO (2.27 wt%) confirmed its polycationic nature. The values for the other oxides were within the expected range for bentonite clays [23][24][25]. Alumina had 99.4% Al 2 O 3 , and traces of SiO 2 , CaO, and Fe 2 O 3 were possible impurities impregnated during processing.…”

Synthesis, structure and thermal properties of montmorillonite/ionic liquid ionogels

“…The cation exchange capacity (CEC) of Na-MMT was determined using the methylene blue adsorption method. 35 The found value (84 meq./100 g of dry clay) correlates with the data reported in the literature. 26,36 The Na-MMT/IL composites were produced by mixing the components with a vibration shaker IKA VORTEX 4 basic (IKA-Werke GmbH & Co. KG, Germany).…”

Adsorption of Anionic Dye on the Acid-Functionalized Bentonite

“…The second event was endothermic as well and is related to the partial dehydroxylation of the octahedral sheet of smectite, and the peak maximum temperatures were 569.9 °C, 565.0 °C and 565.9 °C for the RF, RF1 e RF2 clays, respectively. The third thermal event was exothermic and is related to mullite nucleation [ 66 ], and the peak maximum temperatures were 930.0 °C, 921.0 °C, and 917.0 °C for the RF, RF1 e RF2 clays, respectively. There were no significant differences in the intensities of the thermal events in Figure 2 a.…”