Optimalization of silicon extraction from husk ashes by excessive magnesium addition on increasing rate of temperature reduction

Abstract

The Silicon can be extracted from rice husk ash by reducing silica with magnesium. In this study the use of Magnesium and Silica was 49:60 with various rate of increase in the reduction temperature (1 °C/minutes, 3 °C/minutes, and 5°C/minutes). It was done in order to obtain silicon with a higher purity than previous studies. The results of EDX showed that the purity silicon with the increase rate of 1 °C/minutes and 5 °C/minutes were 1.78% and 29.39%, respectively. Then, silicon was not formed by increasing rate of 3 °C/minutes. Moreover, XRD results of the samples by using the increase rate of 1 °C/minutes and 5 °C/minutes showed that the pattern correspond to Silicon while the sample with increase rate of 3 °C/min corresponds to Silica. The FTIR spectra indicate the presence of stretching vibration an harmonic for functional groups of Si-O-Si with spring constant for the increase rate of 1 °C/minutes, 3 °C/minutes, and 5 °C/minutes respectively were 977.23 N/m, 1003 N/m, and 982.3 N/m. FTIR result was consistent with EDX and XRD result proving by the existence of Si-O-Si functional group which showed the purity silicon produced was not optimum and presence of OH-functional group indicate that sample contained water.