| dc.description.abstract | High silica (SiO2) concentration in charcoal rice husk could be used as silicon with 40-60% level of purity. Low purity is caused by the effect of oxygen involved in the reduction process. The aim of this research was to optimize reduction process of silica from charcoal rice husk to obtain silicon with high purity level. The optimization process of silica reduction was conducted in closed reactor using alumina and stainless steel tube with magnesium as reducing agent in mass ratio of SiO2 and Mg 1:1 and 1:2. The reduction products were leached by HCl 10% at the first step, and a mixture of 2M HCl and CH3COOH 25% at the second step. Silicon products were characterized by X-ray diffraction (XRD) and MATCH 2 program. In mass ratio of SiO2 and Mg 1:1, quantitative value of XRD (QXRD) silicon in alumina tube reactor (22%) was higher than that in the stainless steel tube reactor (16%). In alumina tube reactor, QXRD silicon in mass ratio of SiO2 and Mg 1:1 that value was lower than that of 1:2 (50%). The acid leaching process removed major impurities, such as MgO, Mg2SiO4, and SiO2. The highest purity of silicon was produced from alumina tube reactor with mass ratio of SiO2 and Mg 1:2. | id |
