Rice husks as source for pozzolan nanomaterials

Abstract

Amorphous nanosilica with high surface area was produced by washing Mexican rice husks in diluted HCl to remove most of the metallic ingredients before thermal treatment at 600°C. This material was used for producing pozzolan cement. The compressive strengths determined by standard test reveal that there is a substantial increase in performance over the control mortar block. As a conclusion of this study, we have found that washing rice husks in diluted HCl helps to obtain active nanosilica that is completely white and with high surface area. Use of this material as pozzolan to replace cement reduces the amount of clinker necessary to obtain ordinary Portland cement. Thus, this technique appears to be economically viable as well as a solution for the environmental problem.

Keywords:

• Rice husk
• Amorphous silica
• Pozzolan cement

We are grateful to Dr D. Mendoza, Dr M. Espinosa and Dr J. B. Hernández-Zaragoza for providing the facilities needed to carry out the experiments. Comments on the manuscript by Professor W. Brostow are gratefully acknowledged.