Silicon Metallurgy and Ecology Problems

Modern silicon production technology is associated with a risk of negative environmental impact due to the fact that in addition to the final product, other reaction products are formed, including dust, from the incomplete use of charge materials. Gases released during silicon smelting in ore-thermal furnaces are characterized by the content of a large amount of fine dust. Dust consists of 94–96% of silicon dioxide. As a result of the use of sulfur-containing raw materials in furnaces as sulfur reducing agents, sulfur compounds in the form of SO2 are present in the furnace gases entering for purification, and nitrogen oxides are also present. The developed silicon recovery smelting technology reduces the technological energy consumption and increases the furnace productivity in proportion to the amount of carbon replaced by silicon carbide. Replacing carbon with silicon carbide reduces the dust content and the amount of exhaust furnace gases, and changes their composition. Thus, reducing the amount of pollutants reduces their anthropogenic impact on the environment. Keywords: silicon, gas cleaning dust, gas capture system, microsilica