Main components of rice husk ash.

Component	Amount in ash (wt%)	Amount in rice husk (wt%)
SiO2	96.203	18.952
K2O	1.510	0.297
SO3	0.855	0.168
CaO	0.797	0.157
Fe2O3	0.422	0.083
Cr2O3	0.067	0.013
MnO	0.058	0.011
CuO	0.048	0.009
ZnO	0.020	0.004