SELECTION OF PULVERIZED COAL FUEL COMPONENTS FOR BLAST FURNACES BASED ON THE STUDY OF PHYSICO-CHEMICAL PROCESSES DURING THEIR HEATING

There is a global tendency to use technologies to save energy costs per unit of production in blast furnace production. This is due to the use of pulverized coal fuel (PCF) instead of part of the coke. Selecting the components of the PCF charge from a wide range of carbon-containing materials to expand the raw material base and minimize costs is an important task. One of these materials is peat. The aim of this work is to develop a methodology for the selection of pulverized coal fuel components based on a comprehensive study using peat milling as an example. Industrial experiments were carried out in an operating metallurgical plant. The particle size of PCF is no more than 70-100 mu m. Thermal destruction of peat in an inert atmosphere is responsible for 59% of the mass loss. The maximum destruction rate is 2.69%/min compared to 2.0%/min for long-burning coal. The release of volatiles starts at 425 degrees C for lean coal, 300 degrees C for brown coal and 220 degrees C forpeat. The destruction of the coal also leads to an increase in the specific surface area. It increases from 2.04 to 161.3 m2/g for brown coal. Combustion accounts for about 27% of the total loss of peat mass; this value is twice as high for long- burning coal. The total thermal effect for coal ranges from 15510 to 17751 kJ/kg, for peat from 12816 to 14148 kJ/kg. The pulverized coal fuel produced during the pilot phase was blown into an industrial blast furnace. The equipment of the PCF feed path, the poppet mill, worked stably without changing the operating parameters. There were no deviations in the operation of the blast furnace. The introduction of peat reduced the consumption of lean coal. The consumption of PCF and natural gas has practically not changed.