INFLUENCE OF STEELMAKING PARAMETERS ON THE REFRACTORY LINING LIFE

One of the ways to increase the efficiency of steelmaking is to increase the service life of refractory lining. The durability of the lining is determined by the composition and properties of the refractories, the conditions of its execution and subsequent operation. The influence of steel smelting parameters on the resistance of the refractory lining of flexible modular furnaces (GMP) operated in the conditions of the Ural Steel electric steelmaking plant (ESPC) since 2019 has been studied. A special feature of the GMP is the ability to operate both in the mode of an arc steelmaking furnace (chipboard) and in a mode without the use of electric energy, that is, using converter melting technology with an increased proportion of cast iron. The durability of the GMP lining during the studied campaigns varied widely from 270 to 450 heats, with an average of 328 heats. The results of a study of the influence of the main technological parameters of steel smelting in a flexible modular furnace on the stability of the lining of walls and hearths are presented. It is shown that the main technological factors determining the durability of the lining and the duration of the GMP campaign are the duration of downtime (inter-melting periods), the oxidation of slag and the content of MgO oxide in it. Quantitative dependences of the influence of the studied technological parameters of melting on the resistance of the refractory lining are obtained. Technological recommendations have been developed to extend the service life of the refractory lining: reducing the duration of inter-melting periods, reducing overoxidation of metal and slag as a result of stopping purging at a given carbon content (in accordance with the grade of steel being smelted), increasing the content of MgO oxide in the slag to 8 ‒ 10 %. The implementation of technological recommendations will increase the resistance of refractory lining by at least 25 % with a corresponding reduction in costs for refractories and repairs.