Balanço de massa integrado do ferro-gusa entre altos-fornos e Aciaria da Aperam South America

Abstract

Motivated by the low yield of pig iron in 2015 for this work was a mass balance that delivers the production of blast furnaces and refining stages of pig iron in Steelmaking in order to identify the main variables that affect the yield. The mass balance designed for blast furnaces showed satisfactory results when compared to industrial values. The presented variations are related to the chemical composition of the charged materials. Where production calculated by the SIP (System Process Information) uses the daily average chemical composition of materials and the mass balance calculation uses the annual average. The mass balance of pig iron delivered to Steelmaking presented the generation of solid pig iron as the variable that most impacts the performance of pig iron. It is 79.2% of the mass loss of pig iron. The mass balance developed for the refining steps presented satisfactory results whencompared industrial values. The presented variations are related to the weight loss during the slag scraping and losses projections (mass loss of hot metal and slag during desiliconization). The overall yield of hot metal after desiliconization had to be dependent on silicon percentage dissolved in the pig iron, with a correlation coefficient R = 0.74 (R2 = 0.54). The effects of silicon percentage dissolved in the hot metal are observed in the dephosphorization stage, where the treatment time and consumption of dephosphorization agent are dependent on this element.The integrated mass balance allowed us to calculate the pig iron mass solidified due to the production of Blast Furnace, the quality of pig iron (silicon percentage), refining route and reduced steel type in Steelmaking. Previously know the value of the solidified pig iron mass is essential for planning the production of blast furnaces and steel in Steelmaking. Strategic changes in planning can prevent or reduce the generation of solid pig iron, allowing it to better use in Steelmaking thus improving performance.