Minimum Carbon Consumption Diagram. Application to the Blast Furnace Ironmaking Process.

The Brazilian steel industry uses blast furnace - BF as the main technology to produce hot metal. Currently, the blast furnace continues being the best option among the several ironmaking technologies, due to its high production rate, optimized thermal performance, operational stability and safety, as well as great longevity of the equipment performance. However, various improvements are still being researched, such as the operational control of the reactor and the reduction of its energy consumption, both aiming to prevent failures, to reduce its energy consumption and keep competitive the productivity in an international market point of view. This work presents a model with the objective to generate a surface of minimum consumption for the major reductant (carbon) used in BF. In developing the model the equilibrium conditions, the mass and energy balances and the equations of the major operational parameters, were fully considered. Its application to the blast furnaces is exemplified for real operational conditions, using databases extracted from industrial reports of an integrated steelworks . It was also possible to obtain, from cutting plans on these surfaces, binary diagrams, of RC-DR type (Reductant Consumption-Direct Reduction), able to be generated on-line with the process. Among the results obtained from the real case studies, one was of particular interest, since it confirmed and predicted important thermodynamic unfeasibility of the furnace, called “furnace frozen”, which, additionally also provide greater operational safety to the process. The results obtained applying this model to regular and abnormal blast furnace operational condition, also led to conclude that the main objectives were fully succeeded. References: [1] APARECIDO C. WELLINGTON, Aplicacao de um metodo de Simulacao - otimizacao na cadeia produtiva de minerios de ferro, Master Dissertation. EPUSP, Logistic System Engineering Post Graduation. September, 2007. [2] BILIK J.; KRET J.; BEER H.: Application of The Simulating Mathematical Models for Decreasing of The Blast Furnace Fuel Rate; available on: http://www.ams.tuke.sk/data/ams_online/1998/number1/mag07.pdf [3] DA SILVEIRA RIZZO, ERNANDES MARCOS. Introducao aos processos Siderurgicos. Sao Paulo, 2005. [4] DA SILVEIRA RIZZO, ERNANDES MARCOS. Processo de Fabricacao de ferro-gusa em Alto-Forno. ABM. Sao Paulo, 2009. [5] DE AGUIAR MELGACO JR., HELIO. Aplicacao dos metodos graficos de Rist e Reichard no controle operacional de Altos Fornos a coque. Master Dissertation. PUC-RIO, Metallurgical Engineering Post-Graduation (Advisor: Jose Carlos D’ABREU). September, 1985. [6] DE ARAUJO, L.A. Manual de siderurgia. 1° volume. Sao Paulo: Editora Arte & Ciencia, 1997. [7] DE CASTRO, L.A., Desenvolvimento De Um Modelo de Controle de Processo Para Altos-Fornos A Carvao Vegetal, Doctoral These. UFMG, Metallurgical and Mines Engineering Post-Graduation. August, 2002. [8] DE MELO WILSON ROBERTO, Controle do processo de Reducao no Alto-Forno II da Cosipa aplicacao do diagrama CRRD. Master Dissertation. PUC-Rio, Metallurgical Engineering Post-Graduation (Advisor: Jose Carlos D’ABREU). February, 1987. [9] FUMITADA NAKATANI, T. MUKAI, F. NAKAMURA, Theoretical Consideration on Coke Ratio of the Blast Furnace Operation, Steel Science Portal. November, 1965. [10] DIONISIO CALDERON, ENRIQUE R., Superficie de Minimo Consumo de Carbono do Processo de Reducao em Altos-Fornos. Doctoral These, PUC-Rio, Chemical and Materials Engineering Department (Advisor: Jose Carlos D’ABREU). February, 2016.