Strategy of automation of electric arc heating of steel melt in ladle-furnaceStrategy of automation of electric arc heating of steel melt in ladle-furnaceStrategy of automation of electric arc heating of steel melt in ladle-furnace

Prices hike for consumable materials and energy carriers, increase of requirements to steel quality stipulate the items of intensification of ladle treatment processes and decrease of their energy- and material capacity. Analysis of energy losses in ladlefurnace accomplished, as well as basic factors effecting the energy costs during treatment analyzed. A methodology elaborated for making thermal balance of ladle-furnace: it was proposed to present the melt treatment process in ladle-furnace as a series of separate operations, each having specific features of the process (heating, desulphurization, alloying) and their combination. Based on analysis of 20 thousand heats passports at ladle-furnace of MMK BOF shop, a mathematical model of energy supply system of ladle-furnace was elaborated. Based on the analysis made, a strategy of heating automation was proposed. In particular, electric losses were emphasized, t. e. total losses of electric arc energy, in which provisionally losses at arc open part radiation were included. Control of those flows creates conditions for heating efficiency increase. Conclusions were made that decrease of electric losses is observed at prolonged (about 8−12 min) heating periods and sufficient amount of slag, as well as at injection of additives after heating. Such a mode provides decrease of thermal losses by 4−5%. A new technology of steel melt treatment in ladle-furnace was proposed, characterized by decreased consumption of electric energy.