Preparation and characterization of silicon from rice hulls

Authors

E Swatsitang
M Krochai

Publication Date

2009-12-01

Abstract

High purity silica can be prepared by reflux raw rice hulls in 1 N HCl for 45 minutes first, then pyrolyzed at 650°C for 3 hours in O2 atmosphere. The obtained white ash was examined by XRD showing a broad peak of amorphous silica at 2 theta = 22 degree. Silicon can be prepared by metallothermal reduction of pure silica at 650°C in Ar atmosphere for 1-3 hours, using magnesium (99% purity) as a reducing agent. High purity silicon (99.98 %) can be obtained by subsequently washing the as-reduced silica with HCl: H2O and HF: H2O solutions. The results from XRD patterns and Raman spectra indicated that the obtained brownish powder was polycrystalline silicon. The impurity concentrations in the silicon was analyzed by ICPAES. The morphology of the powder was revealed by SEM showing porosity due to acid leach.

First Page

91

Last Page

94

Recommended Citation

Swatsitang, E and Krochai, M (2009) "Preparation and characterization of silicon from rice hulls," Journal of Metals, Materials and Minerals: Vol. 19: No. 2, Article 15.
Available at: https://digital.car.chula.ac.th/jmmm/vol19/iss2/15