Two different types of rice husk were used for this work, named agulhinha and cateto. Distilled water, solutions of citric acid (10%,w/v), acetic acid (10%, v/v), and phosphoric acid 0.2 mol L−1 were used in the chemical treatment process. Also, two available silicas were used to compare with the obtained silica from this study, Aldrich and Tixosil