Studies on silica obtained from rice husk

The potential and limits of rice husk to prepare relatively pure activated silica were investigated. For the activated silica, rice husk samples were submitted to a chemical pre-and post-treatment using HCl, H2SO4 and NaOH solutions. Samples were incinerated at 600°C under static air and flowing atmospheres (air, argon and oxygen). The product was characterized in terms of silica content, particle size distribution and morphology, specific surface area and porosity. The particle size distribution range from 0.030 to 100 μm. The structure is amorphous. The specific surface area reaches value of 321 m2/g, porosity diameter is 0.0045 μm, specific pore volume is 4.7297 cm3/g. Purity is 99.66% SiO2.