Controlling the peripheral temperature of the blast furnace

Abstract

Increase in FeO content lowers the initial melting temperature of primary slags in the blast furnace and prevents the formation of stable surface coatings. That increases the thermal loads on the coolers in the bosh and bosh extension and correspondingly increases the heat losses. The FeO content in the primary slags is determined by the indirect reduction. In the present work, means of reducing the thermal loads on the coolers in the bosh and bosh extension are assessed. Decrease in the gas temperature at the furnace periphery is accompanied by change in the degree of indirect reduction. Hence, the peripheral temperature may be regarded as an indicator of the degree of indirect reduction. A model of the gas temperature and the reducing effect of the gas at the furnace periphery is developed and may be used to optimize the thermal state of the furnace shaft in the peripheral zone.