Improvement of the system of thermal energy recovery of exhausted gases for the RKO-11 ore thermal furnace

In the processes of carbothermal silicon and ferrosilicon reduction running in the ore-thermal furnace (OTF), we observe the formation of large amounts of flue gases whose temperature reaches 500–600 °C at the inlet of the smoke exhaust system. The amount of dust removed with flue gases may constitute up to a half of the mass of the final product and, therefore, the content of microsilica fume in the flue gases is quite high and requires mandatory utilization. According to the heat balance of the processes of silicon and ferrosilicon reduction in the OTF, the amount of heat removed with the flue gases and dust can be as high as up to 30%. Thus, the waste gases not only remove a significant amount of heat but also create a huge load on the aspiration system. This not only decreases the recovery rate but also creates serious problems connected with the pollution of the environment. The urgent task is to utilize the thermal energy of high-temperature waste gases and also to create conditions for the effective dust removal and, hence, for decreasing the prime cost of production.