Comparison of Biomass and Coal in the Recovery Process of silicon in an Electric Arc Furnace

Silicon recovery of silica ore (SiO2) has been studied with two types of carbon materials, charcoal as a biomass and coal as a fossil fuel, at elevated temperatures between 1800 and 2000 degrees C in an electric arc furnace. The effects of porosity and electrical resistance of the carbon materials were investigated. To this end, recovery of silicon and ferrosilicon production were tested separately by charcoal and coal, and the products were investigated both qualitatively and quantitatively. A higher electrical resistance of charcoal was found in comparison with coal, with increased efficiency of the furnace and decreased electric energy consumption (per ton of product). The efficiency of the furnace using charcoal and coal was 92.13% and 77.4%, respectively. In addition, the higher porosity of charcoal facilitates the flow of SiO gas through the carbon material leading to a higher reactivity and reducing the electric energy consumption for each ton of FeSi.