Rice husk ash is one of the most silica rich raw materials containing about 90 – 98% silica after
complete combustion among the family of other agro wastes. Ash samples from rice husks of five
different origins were prepared at two different temperatures, 500 and 1000
oC, respectively and the ash
content was evaluated at each temperature. The interestingly high percentage of silica (taking up from
the soil during paddy growth) in rice husk ash which has various industrial and domestic applications
necessitated the process of determining the presence and amount of impurities or trace elements in ash
taking up from the soil during paddy growth. Small quantities of impurities present at concentrations
below one part per billion can have a significant effect on the quality of devices constructed form the
silica obtained from the ash. The X – Ray Fluorescence (XRF) technique was used to analyze each
sample heated to a temperature of 1000
0C at which excellent chemical activity could be exhibited to
characterize the ash in terms of the purity of the silica level by the determination of the trace (impurity)
elements present that has a nature that can determine their removal method to get the pure silica. The
result of the XRF showed that rice husk ash (RHA) had a very low impurity concentration of 1.1 (sample
1) to 5.58% (sample 4) corresponding to 98.9% (sample 1) and 94.42% (sample 4) purity level of silica
indicating that rice husk which is an agricultural waste is a potential source of silica with a high purity
level of 94 - 98.9%