Effect of Different Acids on Rice Husk Calcination and Extraction of Bio-Silica

Abstract

Silica is an essential material which has many applications in various fields such as construction, catalyst, optical fibers and raw material of metallurgical industry. This work observed the recent trends in silica extraction from agro and natural wastes for high-tech applications. Hence, this work approached in new way for the bio-silica extraction from waste rice husk using HCl, H2SO4 and CH3COOH for the calcination. The results revealed that the effect of pH on ash nature and silica purity. The purity of silica was differed based on metal ions, rice husk ash color and non-combusted carbon. The results were compared with treatment in absence of acid ash using FT-IR, SEM, EDAX and XRD analysis to measure the effect of pH on the bio-silica purity. This work observed the lower carbon content in acid treated ash when compare to water washed rice husk.