STUDIES CONCERNING THE SUBSTANCES TRANSFER BETWEEN THE STEELMAKING PHASES

Transcription

1 TECHNICAL UNIVERSITY OF CLUJ - NAPOCA FACULTY OF MATERIALS SCIENCE AND ENGINEERING Eng. Dana Adriana VARVARA STUDIES CONCERNING THE SUBSTANCES TRANSFER BETWEEN THE STEELMAKING PHASES PHD THESIS THESIS ADVISOR: Prof. PhD. eng. Gheorghe ZIRBO CLUJ - NAPOCA 2007

2 TABLE OF CONTENTS INTRODUCTION 1 PRESENT STAGE OF THE KNOWLEDGE 2 Chapter I PREOCCUPATIONS ABOUT THE SUBSTANCES TRANSFER IN THE STEELMAKING PROCESS IN THE WORLD AND IN ROMANIA 6 Chapter II DATA ABOUT THE DEFINITION OF THE TRANSFER PHENOMENA 2.1 The substance transfer The substance transfer through molecular diffusion The substance transfer through convection diffusion The propinquity and the dimensional analysis to the substance transfer The characteristic criterions of the substance transfer The substance transfer between two fluid with concentration variation in the stationary 13 regime Chapter III THERMODYNAMICS AND THERMOCHEMICAL LAWS WHICH GOVERN THE TRANSFER PHENOMENAS THAT TAKE PLACE TO THE STEELMAKING 16 Chapter IV DATA ABOUT TO THE STEELMAKING PROCESS PHASES Charge and the phenomena which take place in the melting phase The oxidation of the chemical elements in the melting phase Metallic bath and its properties The slag structure and properties Phenomena which are produced in the refining phase Deoxidizing process (the deoxidization) The pollutant substances to the steelmaking in the electric arc furnace 53 RESEARCH DIRECTIONS 57 PERSONAL CONTRIBUTIONS 58 Chapter V CONTRIBUTIONS CONCERNING THE GENERATION AND THE TRANSFER MECHANISM OF THE SUBSTANCES BETWEEN PHASES IN CONTACT TO THE STEELMAKING The substance transfer between refractory lining and metallic bath The substance transfer between metallic bath slag and slag metallic bath The oxygen transport between phases The oxygen transport from atmosphere to slag The oxygen transition from slag to metallic bath The hydrogen and nitrogen transfer from atmosphere to the metallic bath The silicon transfer from metallic bath to the slag and inverse The manganese transfer from metallic bath to the slag and inverse The chromium transfer from metallic bath to the slag and inverse The carbon transfer from metallic bath to the atmosphere The phosphorus transfer from metallic bath to the slag and inverse The sulfur transfer from metallic bath to the slag and inverse The substance transfer between electrodes metallic bath slag 90

3 5.4 The substance transfer between metallic bath slag atmosphere and atmosphere slag The generation mechanism and transfer of the carbon oxides in the 92 atmosphere The generation mechanism and transfer of the sulfur oxides in the atmosphere The generation mechanisms and transfer of the nitrogen oxides in the atmosphere Establishing the mass balance to the steelmaking The calculation of the mass balance for melting phase 101 Chapter VI EXPERIMENTAL RESEARCHES CONCERNING THE SUBSTANCE TRANSFER Establishing of the substance wastages from the composition of the charge Conclusions Establishing the concentrations of the gaseous substances The calculation of the average concentrations and the maximum average concentration of the gaseous substances Conclusions Establishing the concentrations of the volatile organic compounds (VOC) Conclusions The identification of the compounds presented in the particulate matter evacuated to the steelmaking Conclusions 153 Chapter VII GENERAL CONCLUSIONS AND PERSONAL CONTRIBUTIONS General conclusions Personal contributions 157 BIBLIOGRAPHY PUBLICATION PAPERS ANNEXES KEY WORDS: steelmaking, pollutants, control pollution, monitoring pollution, substance transfer, electric arc furnace, volatile organic compounds, particulate matter, dioxins, furans, carbon oxides, nitrogen oxides, sulfur oxides, slag, metallic bath.

4 The doctoral thesis is structured in 7 chapters having 159 pages, 187 bibliographical references (14 of which belonging to the author of the thesis), 59 tables (55 of which belonging to the author of the thesis) and 64 diagrams (62 of which belonging to the author of the thesis). The purpose of the hereby thesis constitutes realisation of some studies concerning substances transfer between steelmaking phases, whose usage to assure the monitoring and limiting of substances in noxious form, transferred in the air environment factor. The importance of the doctoral thesis theme is justified by: The increase of pollutant substances volume transferred in the environment factors, especially in the air environment factor, to the steelmaking, these having negative impact upon the environment as well as upon human health; The steelmaking must assure four fundamental desiderates about the quality, technological and economical requirements and conforming with the legal environment requirements applicable nowadays ; The increase in the non-purification degree of ferrous waste with non- ferrous materials (like nickel, cooper, lead, zinc, etc) and plastic materials, which leads to serious professional illnesses of the human operators from the steelmaking sectors due to the generation of some extremely noxious substances; The increase of the greenhouse gases concentration resulted from steelmaking, with serious effects on climate changes. The doctoral thesis contains two distinct parts. In the first part of the thesis, called Current stage of knowledge I presented issues referring to: studies regarding the substances transfer in the steelmaking process, defining the substances transfer phenomenon, the laws governing the transfer phenomenon which take place during steelmaking and the process phases of the steelmaking. In the second part of the thesis named Personal Contributions I presented the results obtained from experiments made, regarding the substances transfer in noxious form evacuated during steelmaking as well as the contributions brought concerning the generation and transfer mechanisms of the substances between contact phases of steelmaking. The personal contributions which I bring through this doctoral thesis are materialized through: - The realisation of a bibliographical study; - The data systematisation from the technical literature regarding the approached theme - The identification of the pollutant substances which are generated during steelmaking;

5 - The identification substances/polluting substances which are generated during each technological phase of steelmaking - The conception and realisation of the basic scheme of the transfer direction between the existing phases in the electric arc furnace; - The conception and realisation of the scheme regarding the phases between which phenomena of substances transfer take place during steelmaking; - The conception and realisation of the scheme of substances transfer between metallic bath slag atmosphere ; - Computing of the ferrous oxide activity with respect to the temperature in the range K; - Plotting the variation diagram of ferrous oxide activity (FeO) with regard to the temperature; - Computing the oxygen saturation value with regard to temperature; - Plotting the maximum solubility of the oxygen in liquid iron pure form [FeO] with regard to temperature ; - The inception of variation diagram of maximum solubility of the oxygen with regard to temperature; - Computing the equilibrium constants of hydrogen and nitrogen with regard to temperature; - Plotting the equilibrium constant variation curves constants of hydrogen and nitrogen with regard to temperature; - Computing the equilibrium constants of silica with regard to temperature for the acid and basic process of steelmaking; - Plotting the equilibrium constant variation diagram of silica with regard to temperature for the acid and basic process ; - Computing the equilibrium constants of manganese with regard to temperature for the acid and basic process of steelmaking; - Plotting the equilibrium constant variation diagram of manganese with regard to temperature for the acid and basic process ; - Computing the equilibrium constants of chrome with regard to temperature; - Plotting the equilibrium constants variation diagram of chrome with regard to temperature ; - Computing the equilibrium constant of phosphorous with regard to temperature;

6 - Plotting the equilibrium constant variation diagram of phosphorous with regard to temperature ; - Computing the equilibrium constant of sulphur with regard to temperature in the case of de sulphur process with calcium; - Plotting the equilibrium constant variation diagram of sulphur with regard to temperature in the case of de sulphur process with calcium; - Computing the equilibrium constant of carbon with regard to temperature; - Plotting the equilibrium constant variation diagram of carbon with regard to temperature; - Identifying the sources that generates pollutant substances during the steelmaking process; - Realising of a detailed computation of the set of materials used during steelmaking, for the melting phase; - Conception and preparing experimental researches; - Conception of the receipts for the nine charge types; - Determining using an experimental approach of the substance losses from the composition of the nine charges; - Determining through similitude of the substance losses of the nine charges; - Conception of three types of receipts for determining gases substances concentrations; - Determining the concentrations of the gases substances (CO, NO, NO X and SO 2 ); - Determining the concentrations of volatile organic compounds (VOC) for the nine types charges; - Sampling twelve particulate matter probes from steelmaking in the electric arc furnace from S.C Industria Sârmei Câmpia Turzii S.A. - Identifying the compounds present in the particulate matter evacuated during steelmaking through X ray diffraction; - Interpretation of the results obtains through experiments; - Conception a number of 31 scientific papers, published on national and international conferences (4 of which as unique author, 6 as first author and 21 as co-author).

7 SELECTED REFERENCES 1. Rău, A., Tripşa, I. Metalurgia oţelului. Editura Didactică şi Pedagogică, Bucureşti, Gâdea, S., s.a. Manualul Inginerului Metalurg. Editura Tehnică, Bucureşti, U.S. E.P.A. Compilation of Air Pollutant Emission Factors. Vol. I : Stationary Point and Area Sources, AP 42, Fifth Edition, Goodfellow, H., Evenson, E. J., Li, H., Matheur, P., Thomson, M. NOx emission from EAF Steelmaking assessment and abatement. 58 th Electric Furnace Conference. Iron and Steel Society, Conference Proceedings, Orlando, Florida, U.S. EPA Alternative Control Technique Document. NOx emission from Iron and Steel Mills. Report 453/R Washington DC, Chan, E., Riley, M., Thomson, M. J., Evenson, E. J. Nitrogen oxides (NOx) formation and Control in an Electric Arc Furnace (EAF): Analysis with Measurements and Computational Fluid Dynamics (CFD) Modeling. ISIJ International, vol.44, 2004, p Kirschen, M., Voj. L., Pfeifer, H. NOx emission from electric arc furnace in steel industry Contribution from Electric Arc and from CO Combustion Reactions. Clean Technology and Environmental Policy, nr. 7, Brabie, V., Bratu, C., Chira, I. Tehnologia elaborării şi turnării oţelului. Editura Didactică şi Pedagogică, Bucureşti, Sofroni, L. Elaborarea şi turnarea aliajelor, fonte, oţeluri, aliaje neferoase. Editura Didactică şi Pedaogică, Bucureşti, Nagy, E.- Elaborarea oţelului în cuptorul electric cu arc. Editura George-Bariţiu, Cluj- Napoca, Turkdogan, E.T. Fundamentals of steelmaking. The University Press, Cambridge, Varvara, D. A. Problematica transferului poluanţilor la elaborarea oţelului. Revista de Turnǎtorie, nr. 5-6, 2006, pag , ISSN Nagy, E., Varvara, D. A. The influence of the electric arc furnance melting process upon the environmental factors. Acta Technica Napocensis, Seria: Constructii de Masini. Materiale, nr.47. Editura U.T.Pres, Cluj-Napoca, 2004, pag , ISSN Varvara, D. A., Nagy, E., Suciu, C. R., Thalmaier, G. Specificitatea poluării aerului la elaborarea oţelului. Stiinţă şi Inginerie, vol. 8, p , Editura AGIR, Bucureşti, 2005, ISBN , ISBN Nagy, E., Varvara, D.A., The monitorising of the greenhouse gases emited to the steel elaboration, În: Environment &Progress-2004, Presa Universitara Clujeana, 4/ 2005, Cluj- Napoca, 2005, Editura EFES, p , ISBN Varvara, D. A., Zirbo, G., Suciu, C. R., Thalmaier, G. Problematica transferului de substanţă la elaborarea oţelului. Stiinţă şi Inginerie, vol. 8, p , Editura AGIR, Bucureşti, 2005, ISBN , ISBN Varvara, D. A. - The problematic of interphase transfer of pollutant substances to the steelmaking,acta Technica Napocensis Buletinul Ştiinţific al Universităţii Tehnice Cluj Napoca. Seria: Construcţii de maşini Materiale, Cluj Napoca. pg , nr.49, 2006,ISSN Varvara, D. A. - The problematic of pollution with dioxins and furans to the steelmaking in the electric arc furnace, Acta Technica Napocensis Buletinul Ştiinţific al Universităţii Tehnice Cluj Napoca. Seria: Construcţii de maşini Materiale, Cluj Napoca. pg , nr.49, 2006, ISSN

8 101.Nagy, E., Nagy, A., Varvara, D. A. The Greenhouse Gases Monitorising to the Steel Elaboration. 9 th International Research / Expert Conference Trends in Development of Machinery and Associated Technology - TMT 2005, septembrie, Antalya, Turcia, 2005, p , ISBN Nagy, E., Varvara, D. A. Controlul gazelor cu efect de seră emise la obţinerea oţelului. Environment & Progress nr.6, Presa Universitară Clujeană, Editura EFES, pag , 2006, ISSN Nagy, E., Varvara D. A. - Estimarea gazelor cu efect de seră la nivel de instalaţie. Ştiinţă şi Inginerie, vol. 12, pag , Editura AGIR, Bucureşti, ISBN , ISBN Nagy, E., Varvara, D. A., Nagy, A. The Pollution Monitorising to the Electric Arc Furnace. 9 th International Research / Expert Conference Trends in Development of Machinery and Associated Technology - TMT 2005, septembrie, Antalya, Turcia, 2005, p , ISBN Varvara, D.A. - Cercetări experimentale asupra particulelor materiale emise la elaborarea oţelului. Revista de Turnătorie, nr. 7,8; pag , Varvara, D. A., Nagy, E. Problematica poluǎrii cu particule materiale la elaborarea oţelului. Ştiinţǎ şi Inginerie, vol. 10, 2006, pag , ISBN , ISBN Varvara, D. A., G. Zirbo Studiu asupra procedeelor de recuperare a elementelor din prafurile provenite de la elaborarea oţelului, Revista GeTraDe, Cluj Napoca, pg , nr. 1, septembrie, 2006, ISSN Birat, J.P.- A future study analysis of the technological evolution of the EAF by La Revue de Metallurgie CIT, noiembrie, 2000, p Lemmon, W.- Research on Technical Pollution Prevention Options for Steel Manufacturing Electric Arc Furnaces. Prepared for: The Canadian Council of Ministers of the Environment (CCME), 24 martie, Mapelli, C., Baragiola, S., Pauza, S. Valutazione critica dell impiego di energia elettrica e chimica in EAF per la diminuzione dell impatto ambientale. La Metallurgia Italiana, nr , 2004, p Nicolae, A., Nicolae, M., s.a. Dezvoltare durabilǎ în siderurgie prin valorificarea materialelor secundare. Editura Printech, Bucureşti, Nicolae, A., s.a. Teoria proceselor de generare a poluanţilor. Editura Printech, Bucureşti *** STAS 6058 :88 - Materiale refolosibile feroase pentru topire.