Table 5: Contents of metal oxide in silica obtained from the rice husk and residue 2 under the optimum conditions of ethanediol pulping.

Metal oxide (wt.%)K2ONa2OCaOMgOAl2O3Fe2O3CuOMnO2ZnOSum

From RH0.98080.36897.92161.78770.45300.31580.00470.11210.114512.0616
From residue 20.01130.01450.02350.00110.01240.00350.00170.00000.00360.0716