SILICON PRODUCTION PROCESS WITH CARBOTHERMIC AND MAGNESIOTHERMIC: LITERATURE REVIEW AND THERMODYNAMIC SIMULATION WITH FACTSAGE

• Main Author: Firhan Fauzi, Muhammad
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/56043
• Institution: Institut Teknologi Bandung

Silicon is a chemical element with a wide range of applications. Silicon is generally produced using the main raw material silica in the form of rock or quartzite minerals. Indonesia has another source of silica, namely silica sand. However, until now, the use of silica sand as a raw material for silicon production has not been widely used. A common, industrial-proven process for producing silicon is done by reducing silica through a carbothermic process in an electric furnace. As an alternative to the carbothermic process, a magnesiothermic reduction process has been developed which requires lower energy consumption and does not cause gas and dust emissions. This literature study aims to review the parameters of the carbothermic and magnesiothermic processes, perform thermodynamic simulations with FactSageEdu related to carbothermic and magnesiothermic processes, and conduct analyzes related to the potential use of silica sand as raw material for silicon production. Literature study begins by collecting journals, books and proceedings related to carbothermic and magnesiothermic processes. The literature is then analyzed to obtain information which will then be used as discussion points to answer the objectives of this study. Carbothermic process simulations were carried out by varying the molar ratios of SiO2, C, and SiC over a temperature range of 0-3000oC. Magnesiothermic process simulations were carried out by varying the molar ratios of Mg and SiO2 at a temperature of 900oC. Then, conclusions and suggestions are drawn comprehensively. The results of the literature study show that in the carbothermic process, increasing the temperature will result in a purer silicon and also increase the silicon yield. The molar ratio of C/SiO2 has an effect on silicon yield and has a varied optimum value, however, in general, an increase in the molar ratio of C/SiO2 will increase the formation of SiC. In the magnesiothermic process, increasing the temperature will increase the silicon yield and reduce the formation of Mg2Si. The molar ratio of Mg/SiO2 affects the silicon yield, the use of less or excess Mg will have implications for the formation of Mg2Si and Mg2SiO4. The simulation results of the carbothermic process show that the addition of SiC in the feed will produce a better silicon yield than using only C. The simulation of the magnesiothermic process shows that the optimum Mg/SiO2 ratio is 2, any use other than this ratio will reduce the silicon yield with the formation of Mg2Si and Mg2SiO4 compounds. The potential that can be developed in the carbothermic process is by agglomerating the Indonesian silica sand with the addition of SiC. The potential that can be developed in a magnesiothermic process is to reduce Indonesian silica sand by adding NaCl and Al2O3 as additives in the feed.