The technological process of carbothermic silicon reduction in an ore-thermal furnace (OTF) has features that hinder adequate monitoring and control of the entire technological process. High temperature makes it difficult to obtain objective data on melting parameters in the furnace. The main factor contributing to the difficulty of controlling the process is the formation of large volumes of by-product components. Coal and silica dust emissions in the flue gases reach 40–50 % of the finished product – technical silicon. The article is devoted to analysis of dependence of temperature of exhaust gases of OTF silicon production on concentration of solids in them by means of computer simulation. The paper describes the solution of the following tasks: a preliminary assessment of the effect of the concentration of solids on the temperature of the dispersed medium; development of a computational fluid dynamics (CFD) model of the gas exhaust duct of OTF using the ANSYS Fluent software; simulation of the behavior of exhaust gases at different concentrations of silica fume. As a result of analysis of the simulation results, a polynomial dependence of the exhaust gas temperature on the concentration of silica fume in the exhaust gas from the OTF was obtained.