Evaluation of the effects of lime injection on the Electric Arc Furnace performances

In recent years, the pneumatic injection of lime in Electric Arc Furnaces by the use of insufflation lances has acquired interest in becoming a viable tool for the steelmaking industry, thanks to its surprising results in terms of raw materials consumption reduction, foaming benefits, operational cost benefits and improvement in environmental aspects. Acciaierie di Calvisano steelmaking plant, in collaboration with Unicalce S.p.A., decided to implement a new system of lime injection, in place of the traditional procedure, which is based on lime addition in lumps within the scrap bucket. The benefits of injecting lime in fine particles, compared to the standard technique were evaluated from energy, consumptions and emissions point of view. Data for more than 1200 heats was acquired and several slag samples were analyzed. Results showed considerable savings in electrical consumptions, oxygen, methane and lime, with an overall save of more than 4,500 t/year of equivalent CO2