Thermal operation of superlayer space in Romelt furnace

Abstract

From the point of metallurgical heat engineering, the Romelt process is promising for processing industrial waste, poor ores and secondary metals without their preliminary preparation and the use of coke. But one of the main disadvantages of this process is high specific consumption of oxygen and fuel for the production of 1 ton of primary metal. The peculiarity of the Romelt process is that the main amount of heat required for implementation of the technological process is supplied to the bubbling layer from the superlayer space due to afterburning of the exhaust gases with technical oxygen. Heat transfer is carried out by a radiation-convective mechanism. Any changes in the afterburning process are possible, if they do not entail an unacceptable change in temperature in combustion zone. In the work, a study was conducted to reduce the specific oxygen consumption per 1 ton of primary metal, based on the data of melting a mixture of blast furnace and converter slurries for pig iron. The authors studied the possibility of reducing the specific oxygen consumption supplied to the superlayer space of the furnace for afterburning gases leaving the bubbling layer during the Romelt process. When using blast heating supplied to the lower tuyeres and oxygen heating supplied to the afterburning zone, it is possible to reduce the specific oxygen consumption per 1 ton of cast iron by 11 % without reducing the furnace performance. In the afterburning zone, it is recommended to use oxygen heated up to 400 °C in the recuperator with simultaneous supply of a blast heated up to 600 °C to the lower tuyeres.