Separation and Characterization of Silica from Rice Husk with Varying Heating Times

Rice husk is a by-product of rice processing that has many uses but is rarely used by most people. Rice husk has abundant silica content which can be used as an adsorbent. This research was conducted to separate silica from rice husk by using the alkali fusion method with varying heating times (30, 60, 120, and 180 minutes) and to characterize silica using FTIR, XRD, and SEM-EDS. the maximum silica yield achieved was 50.75% after heating 60 minutes. The results of XRD characterization showed the presence of a spectrum in the 22o region at an angle of 2θ with a non-sharp spectral shape which is an amorphous nature of silica. In the FTIR test, there is a typical absorption of the silanol group in the absorption area of 1099.48 cm-1, while the results of the SEM-EDS analysis show the percentage of silica mass is 34.39%.