Factor analysis of the specific consumption of graphitized electrodes

Abstract

The decrease in the demand for metallurgical products resulted from the global economic crisis lead to shutdown and closure of several non profitable plants. In April 2009, Novokuznetsk Metallurgical Integrated Works (NMIW) performed shutdown of a blast furnace, which determined transfer to steelmak ing in electric arc furnaces without liquid cast iron. Therefore, the energetic technological conditions of steelmaking and furnace charge preparation were optimized to decrease the production costs.The optimization was performed on a DSP 100N10 furnace having bay window tapping and water cooled walls and roof and equipped with a 95 MV A transformer, an ArCos NT (Vatron) arc power regulator, and a BSE melting intensification system (which consists of 3 MW four wall fuel-oxy gen tuyere burners and three injectors for coke dust blowing.It should be noted that the technology of steelmak ing with the application of up to 50% of liquid cast iron for 40 and 100 t DSP furnaces that was developed by us and widely applied at NMIW demonstrated high tech nical-economical characteristics [1][2][3][4][5][6][7][8][9][10][11][12][13]. The subse quent activities on the optimization of the electric and operating modes of the melting intensification system (air-gas tuyere-burner, coke dust injectors) and the development and implementation of new flowcharts of bucket charge preparation and feeding sequences of slag forming materials did not result in the specific con sumption of graphitized electrodes comparable with the values achieved for operation with liquid cast iron (see table). However, further operation carried out several months after the implementation of the new technology revealed an increase in the specific consumption of electrodes in comparison with the reference time inter val of implementation.Abstract-The main factors affecting the specific consumption of graphitized electrodes are studied, and their interrelations are revealed. A statistical model is developed.