EKSTRAKSI SILIKON DARI PASIR SILIKA DENGAN REDUKSI KARBOTERMIK DALAM MINI DC-EAF

• Main Author: Tandersen, Dale
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/73060
• Institution: Institut Teknologi Bandung

Silicon (Si) is one of the metals widely used in the production of solar cells and semiconductors for electronic components. Silicon worldwide is produced from silica-based raw materials (SiO2), commonly in the form of quartzite, using a carbon-based reductant also known as carbothermic reduction in a submerged electric arc furnace. Indonesia has abundant reserves of silica sand, estimated at 23 billion tons in 2020. The use of silica sand as a raw material for silicon production is expected to support silicon production in Indonesia. In this study, silicon extraction from silica sand was investigated using carbothermic reduction with graphite powder, coke, and coconut shell charcoal as the reductants. A series of silicon extraction experiments from silica sand were conducted to study the influence of carbon sources variation from graphite powder, coke, and coconut shell charcoal and the effect of briquetting on the resulting metallic silicon product. The experiments began with the characterization of the silica sand sample using Xray fluorescence and the characterization of the coke and coconut shell charcoal reductants using proximate analysis. The experiments utilized 50 grams of silica sand with varying amounts of graphite powder, coke, and coconut shell charcoal reductants at a C:SiO2 mole ratio of 1.8:1. Each reductant was used in the experiment twice, once without briquetting and once with briquetting, using a DC electric arc furnace for a heating time of 10 minutes. The experimental results were analyzed using SEM-EDS and X-ray diffraction. The analysis results is compared with the analysis results of coke, FeSi powder, and SiC rod using SEM-EDS. The XRD analysis results indicate peaks from Si, SiO2, SiC, and C in all experiments. The experiment using coke as a reductant with briquetting yielded the best result with a Si content in the metal of 97.82%. The experiment with a mixture of silica sand and coconut shell charcoal briquette resulted in a Si content of 34.11%, with the main phase being SiC. The experiment with a mixture of silica sand and graphite briquette resulted in a Si content of 27.07%, with the main phases being SiO2 and SiC. The experiment without briquetting using coke as a reductant showed a high SiO2 content, as seen from the oxygen content of 44.93%, carbon content of 18.28%, and Si content of 36.7%. The experiment without briquetting using coconut shell charcoal as a reductant showed SiC and SiO2 as the main phases, as seen from the carbon content of 41.86%, oxygen content of 17.96%, and Si content of 34.83%. The mixture of silica sand and graphite without briquetting formed SiC as the main phase, as seen from the carbon content of 48.083%, oxygen content of 1.027%, and Si content of 50.893%.