View
4
Download
0
Category
Preview:
Citation preview
2
PROCESS METALLURGY DEPARTMENT OF PROCESS
ENGINEERING
ACTIVITY REPORT
FOR THE PERIOD 1.8.1991-31.7.1996
EDITED BY
JYRKI HEINO, JOUKO HÄRKKI,
RIKU MATTILA, KARI TERVOLA
CONTENTS
PREFACE ............................................................................................................................. 4
1. SHORT HISTORY OF THE PROCESS METALLURGY PROFESSORSHIP ............. 5
1.1 BACKGROUND .................................................................................................................... 5
1.2 CONTRACT BETWEEN THE UNIVERSITY AND THE STEEL COMPANIES ..................................... 5
1.3 EDUCATIONAL DESCRIPTION ............................................................................................... 6
1.4 LEVEL OF THE EDUCATION .................................................................................................. 6 1.5 RESEARCH ACTIVITIES ........................................................................................................ 7
1.6 FUTURE PLANS ................................................................................................................... 8
2 PERSONNEL AND STUDENTS ....................................................................................... 9
2.1 ACADEMIC STAFF (1991 - 1996) .......................................................................................... 9
2.2 RESEARCHERS (1992 - 1996)............................................................................................... 9
2.3 RESEARCH STUDENTS 31.7.1996 ...................................................................................... 10
2.4 STUDENTS (1991 - 1996) .................................................................................................. 10
2.5 POSTGRADUATE STUDENTS ............................................................................................... 11
3 EDUCATIONAL ACTIVITIES....................................................................................... 12
3.1 UNIVERSITY COURSES ...................................................................................................... 12
3.2 OTHER TEACHING ACTIVITIES ........................................................................................... 13
4 RESEARCH ACTIVITIES .............................................................................................. 14
4.1 BLAST FURNACE RESEARCH .............................................................................................. 14
4.1.1 The combustion phenomena in the raceway of the blast furnace ................................ 15
4.1.2 Gas phase reactions in a blast furnace...................................................................... 15
4.1.3 Injection of slag former into the blast furnace ........................................................... 16
4.1.4 Phenomena in the shaft of the blast furnace .............................................................. 17
4.2 STOFT - MINIMIZING THE EMISSIONS IN IRON AND STEEL MAKING ....................................... 17
4.3 SLAGS IN STEEL MAKING................................................................................................... 18
4.3.1 Formation of lime and bauxite based calcium aluminate ladle slag ........................... 19
4.3.2 The control of slag in the combined blowing converter.............................................. 19
4.3.3 Developing desulphurization slag to minimize hot metal losses ................................. 20
4.3.4 The influence of tundish slag on steel cleanliness when casting Al-killed low carbon steels ................................................................................................................................ 20
4.3.5 Cleanliness and castability of Al-killed low carbon steels .......................................... 21
4.4 FACTORS AFFECTING THE QUALITY OF FERRO-OXIDES ........................................................ 22
4.5 LASER MEASUREMENT MONITORING OF REFRACTORY WEAR, EQUIPMENT DEVELOPMENT .... 22
4.6 THERMODYNAMICS OF REFRACTORY MATERIALS ............................................................. 23
4.7 TITANIUM IN STAINLESS STEELS ........................................................................................ 23
4.8 REDUCTION PROPERTIES OF IRON ORE AGGLOMERATES .................................................... 25
4.9 THE RADICAL EVALUATION OF SECONDARY METALLURGY ............................................... 26
4.9.1 Refractory Lining of Ladle........................................................................................ 26
4.9.2 Flows of Liquid Steel in Converter and in Ladle ....................................................... 27
4.10 DIRECT TAPPING OF THE CONVERTER .............................................................................. 27 4.11 THE USE OF VACUUM IN STAINLESS STEELMAKING ........................................................... 27
5 THE METALLURGICAL SOCIETY ............................................................................. 29
6 PAPERS AND PUBLICATIONS..................................................................................... 30
7 THESIS............................................................................................................................. 37
7.1 DIPLOMA ENGINEER THESES (MASTER OF SCIENCE) .......................................................... 37
4
PREFACE
The Process Metallurgy Professorship has been one part of the Department of
Process Engineering at the University of Oulu since August 1, 1991. Quite a lot
has happened during the past five years: teaching is today in full operation and
research has begun well. The professorship has been permanent since August 1,
1996.
This short report dealing with education and research has been collected to
show how a big team of engineers from industry and university has participated
in the starting of the laboratory activities. Without research laboratories in
Rautaruukki Steel and Outokumpu Steel and, most of all, without the great
contribution of Rautaruukki and Outokumpu researchers to the education the
start of the research work in the Process Metallurgy Professorship would not
have been nearly as successful.
Many students have chosen process metallurgy as their study subject and they
have made it possible with their active participation to develop a deeper and
more diverse education program.
The fact is that the university has hired only one professor and one part-time
assistant. The researchers mentioned in this report form a group which has
carried part of the responsibility for the teaching activities, routine business
and, most of all, the fast start of the research work. To this group I owe my
special thanks: without them the result attained would have been totally
impossible.
In the publication list enclosed can be seen the activity but also the pressing
nature of the first academic years of the professorship. The greatest part of the
publicationsare reports and teaching materials. There are only seven
international papers or congress publications. The resources have not been
adequate to prepare the excellent research results for international forum. Thus,
this is one of the future challenges of the Process Metallurgy Professorship.
Jouko Härkki
Professor
Head of the Professorship
5
1. SHORT HISTORY OF THE PROCESS METALLURGY PROFES-
SORSHIP
The Chair in metallurgy was founded in August 1991 for five years and was
donated by Outokumpu Oy, Rautaruukki Oy and OVAKO Steel Oy. The
teaching has been defined as “Metallurgy; especially process metallurgy of
iron, steel and ferrous alloys." The Chair in metallurgy is situated at the
Department of Process Engineering. Graduated engineers (M.Sc.) have a strong
knowledge of mechanical and chemical process engineering, heat and diffusion
techniques and automation techniques in addition to metallurgical knowledge.
The University of Oulu established the professorship on 1.8.1996. At the same
time the Finnish metallurgical industry donated the funds for one assistant for
one year.
1.1 Background
Previously the high classic education of process metallurgy has been given
almost exclusively in Southern Finland, while the metallurgical industry is
situated chiefly in Northern Finland. The metallurgical industry of Northern
Finland has had difficulties in obtaining sufficient metallurgists from the south
for their Research and Development and service tasks. Supplementary courses
have been arranged for engineers of the Technical Faculty to have knowledge
for the metallurgical industry. Rautaruukki Oy has also sent the students from
the Department of Process Engineering to Otaniemi to study metallurgy as a so
called “godparent students." To solve the problem completely the University of
Oulu and the metallurgical industry considered it necessary to start the
education of process metallurgy in Oulu.
The founding of the Chair in metallurgy in Oulu was considered several times
since the nineteen seventies. At 16.8.1990 “Perus 3 Metalli” decided to found
sc. Mannerkoski Workgroup, with the mission of “the Development of
metallurgical education and research." In August 1990 this workgroup
suggested that the Chair in metallurgy be founded in the Department of process
engineering in University of Oulu for five years with the support of the
metallurgical industry. The project was quickly included in the 1991 Finnish
State Budget and the position of process metallurgy professor was created,
starting from the first of August, 1991. The statement of the contents of the
education for the University was completed on 10.11.1990. The statute of
founding of the Process metallurgy professorship in Oulu was given on
28.6.1991. On 21.8.1991, the council of the University of Oulu decided to call
Dr.tech. Jouko Härkki to the professorship of Process metallurgy. He was
inducted as professor of Process metallurgy on 24.1.1992.
6
1.2 Contract between the University and the steel companies
The contract between the University of Oulu, Rautaruukki Oy and Outokumpu
Oy made on 30.9.1991 defines several matters concerning the management of
the professorship of process metallurgy. The University of Oulu is committed
to arrange a furnished workroom and a part-time assistant for the professorship.
The companies donate the funds for hiring the professor and compensating the
overhead costs as agreed in the budget, give their own special teachers and
assistants for professorship by their own costs, also. The research facilities and
laboratories of the companies can be used by the professorship as agreed in the
education program. The companies arrange course books, technical journals and
papers, computers and software. The companies will compensate the travel
costs needed to manage the professorship efficiently. From the very beginning
the cooperation between the professorship and local steel industry has been
very close, and it still is. In Finland this kind of cooperation is unparalleled and
it creates a new kind of interesting experiment between the University and the
industry.
1.3 Educational description
The education began immediately after foundation in autumn 1991 together
with the assistants and the special teachers from the industry. In the beginning,
the greatest challenge was to create a high classic education program as quickly
as possible. The principle was: “The most significant purpose of the
professorship is to give high classic education." The implementation of the
education program was a great success. Now, five years after the foundation all
the courses are fully working. The level of the education program is as planned.
All of this was made possible because of the commitment of the best special
teachers from the local steel companies.
1.4 Level of the education
Without the great contribution of Rautaruukki and Outokumpu researchers to
the education the start of the research work in the Process Metallurgy
Professorship would not have been nearly as successful. The activity of the
professorship has been unique in many cases; the personnel of the industry and
the laboratory services have been joined tightly with the education given at the
University. On 30.11.1993, an information meeting was arranged for further
development of the professorship. The representatives of the industry, the
students and the special teachers were convened to the meeting. A second
meeting was in spring 1996. An inquiry about the level of the education was
conducted for the students, the special teachers and the representatives of the
7
industry. The feedback was mainly positive. The negative feedback led to
further development of the education program.
Figure 1. First teachers from left to right: Hannu Nevala, Jarmo Lilja, Salla
Sundström, Pekka Taskinen, Jouko Härkki, Seppo Ollila and Seppo
Louhenkilpi.
1.5 Research activities
“A high classic education needs high classic research” is a fact, because of
which the research started in University in 1992, although the first students
educated entirely at Oulu graduated in 1993. The basic idea of creating the
research activity was to include national and international cooperation. The
most important branch of the cooperation is between universities in blast
furnace research. The role of the professorship in this research program is
coordination and management. The cooperation has been very active with the
Jyväskylä Technical Research Centre of Finland (JVTT), the Åbo Akademi
University (ÅA), the Helsinki University of Technology (TKK) and the
Tampere University of Technology (TTKK). The project personnel are experts
of metallurgy and combustion techniques. Numeric modeling of flow and heat
transfer has also been studied in TKK and TTKK. One researcher has been in
Pori Outokumpu Research Centre to study water models of AOD-converters.
The professorship has sent representatives to the Nordic ironmaking and
steelmaking research programs (Jernkontoret) and to the European Coal and
Steel Committee (ECSC-Iron reduction).
8
The professorship has fifteen researchers and the budget for the year 1996 is
about three million Finnish marks. The growth of the financing of the research
and the education is described in figure 2.
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
1992 1993 1994 1995 1996
Mil
lion F
IM
External financing
Internal financing
Figure 2. The growth of the financing of the research and the education.
1.6 Future plans
Great international challenges, especially EU, demand a strong development of
the education. “Only a high classic education can guarantee an idea-rich
generation of researchers.” At the Department of process engineering process
metallurgy will be connected to the other branches of education. For good
reason, it can be said that process metallurgy is a chemistry of high
temperatures. Process metallurgy supplies the education of general process
engineering, especially liquid and solid state phenomena.
Cooperation between process metallurgy and the laboratory of materials
engineering at the Department of mechanical engineering is very active. Process
metallurgists study several courses of materials engineering. Post-graduate
students in materials techniques also study process metallurgy as a secondary
subject. Since November 1996 twenty-six students have graduated from process
metallurgy. The first licentiates will graduate during the year 1997. The first
doctoral thesis is due to be published in 1998.
9
2 PERSONNEL AND STUDENTS
2.1 Academic staff (1991 - 1996)
Härkki Jouko Dr.Tech., Professor, Head of the professorship
Taskinen, Pekka Dr.Tech., Docent in thermodynamics, Outokumpu
Research Centre
Heino, Jyrki Lic.Techn., Assistant 1.8.1992 -
Hooey, Lawrence B.A.Sc., Teaching assistant, Rautaruukki Steel, Raahe
Hooli, Paavo Dipl.Eng., Teacher, Outokumpu Steel, Tornio, 1.9.1994-
Intonen, Tero M.Sc., Teaching assistant, Rautaruukki Steel, Raahe
Karjalahti, Timo Dipl.Eng., Teaching assistant, Rautaruukki Steel, Raahe
Kivelä, Esa Dipl.Eng., Teaching assistant, Rautaruukki Steel, Raahe
Larkimo, Markus Dipl.Eng., Teacher, Outokumpu Steel, Tornio, 1.9.1994 -
Lindstedt, Anja Dipl.Eng., Teaching assistant, Rautaruukki Steel, Raahe
Lilja, Jarmo Dipl.Eng., Teacher, Rautaruukki Steel, Raahe,
-31.8.1995
Lintumaa, Timo Dipl.Eng., Teaching assistant, Outokumpu Steel, Tornio
Louhenkilpi, Seppo Dr.Tech.,Teacher, Helsinki University of Technology,
-31.8.1995
Nevala, HannuDipl.Eng., Teacher, Rautaruukki Steel, Raahe
Ollila, Seppo Dipl.Eng., Teacher, Rautaruukki Steel, Raahe
Palmu, Petri Dipl.Eng., Teaching assistant, Rautaruukki Steel, Raahe
Pirilä, Eero Lic.Techn., Assistant 1.8.1991 - 30.6.1992
Rytioja, Aija Student, Teaching assistant 1.9.1994 - 31.5.1996
Sundström, Salla Lic.Techn., Teacher, Rautaruukki Steel, Raahe,
-31.8.1995
2.2 Researchers (1992 - 1996)
Alamäki, Pekka Dipl.Eng., Researcher 3.5.1993 - 31.10.1995
Fabritius, Timo Student, Researcher 1.12.1995 -
Hooey, Lawrence B.A.Sc., Researcher 1.9.1995 - 29.2.1996
Karhu, Petri Student, Researcher 3.6.1996 -
Keränen, Anne Stud. Researcher 7.5.1996 -
Laukkanen, Janne Dipl.Eng., Researcher 1.2.1995 - 31.12.1995
Liao, Dongsheng M.Sc.,Researcher 1.4.1995 -
Makkonen, Hannu M.Sc,Researcher 1.1.1993 - 30.9.1994
Mannila, Päivi Dipl.Eng., Researcher 15.9.1994 -
Mattila, Riku Dipl.Eng., Researcher 3.6.1996 -
Myllymäki, Pekka Dipl.Eng., Researcher 1.10.1992 - 30.1.1996
Ollila, Janne Dipl.Eng., Researcher 1.1.1996 - 16.2.1996
Ollila, Seppo Dipl.Eng., Researcher 1.4.1992 - 31.8.1994
Pyykkö, Pekka Dipl.Eng., Researcher 1.4.1996 -
10
Päätalo, Mika Dipl.Eng., Researcher 3.6.1996 -
Sarkkinen, Riku Dipl.Eng., Researcher 3.1.1994 -
Seppälä, Kai Dipl.Eng., Researcher 3.6.1996 -
Tervola, Kari Dipl.Eng., Researcher 17.7.1995 -
Vatanen, Jukka M.Sc and student in metallurgy, Researcher
13.5.1996 -
2.3 Research students 31.7.1996
Subject of the work required for a diploma
Fabritius, Timo Modelling of the fluid flows in the AOD converter.
Karhu, Petri Cleanliness and castability of Al-killed low carbon steels.
Määttä, Pasi Solid state reduction of nickel bearing chromite pellets.
Keränen, Anne Improving energy efficiency in continuous
reheating
furnace by computational fluid dynamics modelling.
2.4 Students (1991 - 1996)
From 1.9.1991
Alamäki, Pekka Graduated 1994
Heiniemi, Riikka Graduated 1995
Jalonen, Antti Graduated 1994
Karjalahti, Timo Graduated 1994
Kivirauma, Tiina Graduated 1994
From 1.9.1992
Karhu, Petri
Koski, Saara Graduated 1995
Kääriä, Ismo Graduated 1995
Mattila, Riku Graduated 1996
Määttä, Pasi
Ollila, Janne Graduated 1995
Ollila, Janne Graduated 1996
Pyykkö, Pekka Graduated 1996
Päätalo, Mika Graduated 1996
Seppälä, Kai Graduated 1996
From 1.9.1993
Jauhiainen, Anu
Laine, Kim
Lohi, Tiina-Kaisa
Mustonen, Tuuli Graduated 1996
Rytioja, Aija
11
From 1.9.1994
Angerman, Mikko
Erkkilä, Helena
Fabritius, Timo
Kangas, Jyrki
Keränen, Anne
Mört, Juha
Niska, Arto
From 1.9.1995
Haapala, Mika
Karjalainen, Eveliina
Marjelund, Janne
Nikka, Marko
Pesonen, Kimmo
Pulkkinen, Kai
Sola, Petri
Vatanen, Jukka
2.5 Postgraduate students
Alamäki, Pekka
Heiniemi, Riikka
Heino, Jyrki
Hooey, Lawrence (In GSCE)
Jalonen, Antti
Kivirauma, Tiina
Liao, Dongsheng
Mannila, Päivi
Myllymäki, Pekka
Ollila, Seppo
Palmu, Petri
Sarkkinen, Riku (In GSCE)
Tervola, Kari
12
3 EDUCATIONAL ACTIVITIES
3.1 University courses
Metallurgical processes
Lecturers: Salla Sundström and Jarmo Lilja until 31.8.1996, Seppo Ollila from
1.9.1995, Teachers from Rautaruukki Raahe Steel
Contents: Pyro- and hydrometallurgical unit processes. The history of process
metallurgy. Metal production in Finland and in other countries. Raw materials.
Thermodynamics in different metallurgical systems. Equilibrium diagrams.
Metallurgical processes in Finland. Short survey of foundry-, powder- and
hydrometallurgy.
Thermodynamics in process metallurgy
Lecturer: Pekka Taskinen, docent, from Outokumpu Research Centre, Pori
Assistants: Seppo Ollila from 1.9.1992 until 31.8.1994 and Aija Rytioja from
1.9.1994
Contents: Reaction thermodynamics and heterogeneous chemical equilibrium in
metallurgical processes. Phase equilibrium and stability. Thermodynamics in
solutions and alloys. Standard states. Thermodynamical phase diagrams. The
basics of the thermodynamical surface phenomena. The use of computer-aided
calculation in thermodynamics.
Pyrometallurgical processes
Lecturer: Jouko Härkki, professor
Contents: The physical, chemical and technical basics of the metallurgical
processes. Calcination, sintering, reduction, smelting, conversion and refining
processes mainly in iron, steel and ferroalloys production.
New metallurgical processes
Lecturer: Jouko Härkki, professor
Contents: Factors influencing on the progress of the metallurgical industry. The
possibilities of the new processes in the view of the laws of nature. Recent
achievements of metallurgical research and progress. New processes such as
direct reduction, direct smelting, continuous processes and production of ultr-
apure materials.
High temperature chemistry
Lecturer: Jouko Härkki, professor
Contents: Chemical and electrochemical interaction at high temperatures.
Driving forces and mechanisms of the reactions. The influence of the state and
structure on mass transfer, heat transfer and surface properties. Applications in
high temperature processes and in both metals and inorganic materials in
interaction with each other and surroundings.
Casting and solidification
13
Lecturers: Seppo Louhenkilpi until 31.8.1994, Teacher, Helsinki University of
Technology and Paavo Hooli and Markus Larkimo from 1.9.1994, Teachers
from Outokumpu Steel, Tornio
Contents: Solidification of crystal and amorphous materials, continuous casting
of metals and new casting methods. The techniques and applications of quick
solidification.
Refractory materials in high temperature processes
Lecturer: Hannu Nevala, Teacher, Rautaruukki Raahe Steel and Jouko Härkki,
professor
Contents: The behaviour of refractory materials primarily in metallurgical
processes and reactions with metallurgical liquids. The destruction mechanisms
of refractory materials. The most important materials and their properties. The
grounds for the selection of the refractory materials. The most common ways to
use and install refractors. Metallurgical and economical impacts of lining
materials.
The laboratory work of process metallurgy
Contents:
In addition to the four laboratory exercises made in the Department of the
Process Engineering (shell-and-tube heat exchanger, drying, crushing and
dressing of minerals and decomposition of ammonium carbonate) another four
process metallurgy laboratory exercises are made in Rautaruukki Research
Centre Raahe and Outokumpu Research Centre Tornio. The subjects of
metallurgy laboratory work usually deal with high temperature problems and
they are closely related to the daily research subjects of the Research Centres’
laboratories.
3.2 Other teaching activities
Since 1993 an annual special subject day has been arranged called Steel Day.
The aim of this day is to bring together researchers and professionals from
industry and the other universities in Finland and Sweden. The subjects of the
Steel Days have been:
Blast furnace in future (1993)
Automation in steel industry (1994)
Refractories in steel industry (1994)
Environment and the process metallurgy industry (1995)
14
4 RESEARCH ACTIVITIES
4.1 Blast furnace research
The blast furnace research started in the University of Oulu, Process Metallurgy
in 1992. Rautaruukki Raahe Steel planned their blast furnace renovations for
1995 and 1996. It was known that the oil injection rate would be increased after
these renovations. The research of the combustion phenomena in the raceway of
the blast furnace was started at 1992. This project was accomplished with co-
operation of combustion laboratories of Åbo Akademi and Technical Research
Centre of Finland (VTT) Energy, Jyväskylä. As one of the results it was noticed
the need for more detailed research of the effect of high oil injection rate on
blast furnace behaviour. The co-operation between two national research
programs, SULA 2 - Energy in steel and base metal production and LIEKKI 2 -
Combustion and gasification, started concerning blast furnace research. Now
there are not only blast furnace projects, which are concerning only the high oil
injection rate of blast furnace, but also concerning circulating elements of the
blast furnace and injection of slag former at tuyere level.
Figure 3. Co-operation in blast furnace study.
15
Figure 4. Cross linking into the blast furnace research.
4.1.1 The combustion phenomena in the raceway of the blast furnace
Supervisors: Prof. J. Härkki, Prof. L. Holappa
S. Ollila
This research was the first one in this professorship concerning the blast
furnace. This project was accomplished with co-operation of the combustion
laboratories of Åbo Akademi and Technical Research Centre of Finland (VTT)
Energy, Jyväskylä. OIL DROP-program was used to calculate the pyrolysis and
combustion of an oil drop. OIL DROP-program was developed in VTT. This
research was funded by the Ministry of Trade and Industry and it was a part of
the SULA-program.
4.1.2 Gas phase reactions in a blast furnace
Supervisor: Prof. J. Härkki
S. Ollila, I. Kääriä, J. Laukkanen, D. Liao, P. Mannila (project manager)
The goal of this project is to apply the combustion models developed in
LIEKKI-program to the raceway of the blast furnace and gas phase of the shaft
with high oil injection rate. The effect of high oil injection rate as an auxiliary
fuel is also studied by other method during this project. This project is
connected to SULA2 -program. The project is funded by the Ministry of Trade
16
and Industry, Technology Development Centre, Finland, Finnish Akademi and
Rautaruukki. The project has progressed as a co-operation between University
of Oulu, Technical Research Centre of Finland, Helsinki University of
Technology, Åbo Akademi and Tampere University of Technology. The
research is organised by Rautaruukki and the University of Oulu, Process
Metallurgy.
The effect of oil injection of phenomena in the shaft of blast furnace. The
study aims to clarify the behaviour of the gas phase in the blast furnace with
high oil injection rates. The effect of hydrocarbons, hydrogen and sulphur on
the phenomena in the shaft of the blast furnace is investigated. The
investigations were done in Helsinki University of Technology, Laboratory of
Metallurgy and in Rautaruukki Research Centre.(I. Kääriä, P. Mannila, Prof. J.
Härkki)
Numerical modelling of turbulent oil combustion in the raceway of the
blast furnace. The aim of this study is to investigate the combustion of
pyrolysis gas from oil with computational fluid dynamics. In the University of
Oulu the computational fluid dynamic program CFDS-FLOW3D has been used
to study the effect of separate parameters on combustion of oil with simple
geometry. (J. Laukkanen, P. Mannila, Prof. J. Härkki). Much more complex
geometry has been used in the Tampere University of Technology. There the
computational work is doing by Phoenics program and it is the basis for the
total model of the raceway. (R. Mäkiranta, Prof. R. Karvinen)
Total model of the raceway. This work collects the knowledge about the oil
drop formation, pyrolysis and combustion of oil, mass flows and heat transfer in
the raceway. The basis for this model is computational fluid dynamic model
made in the Tampere University of Technology (Phoenics). The results at
Helsinki University of Technology about drop formation from the lances
(small-scale model) and at Åbo Akademi about soot formation (detailed kinetic
model) will also be considered in this model. (D. Liao, R. Mäkiranta, P.
Mannila, Prof. J. Härkki, Prof. R. Karvinen)
Gas phase reactions in the blast furnace, thermodynamics. In this work the
behaviour of the gas phase of the blast furnace has been calculated using
thermodynamic program (HSC Chemistry for Windows). The effect of different
injection parameters has been studied. This study is a basis for the other
thermodynamic calculations, for instance the behaviour of the circulating
elements in the blast furnace. (S. Ollila, P. Mannila, Prof. J. Härkki)
4.1.3 Injection of slag former into the blast furnace
17
Supervisor: Prof. J. Härkki
K. Tervola
This research is a part of the Nordic countries co-operation project “Blast
furnace tuyere injection”. In Finland the project is funded by Technology
Development Centre, Finland and it is a part of the SULA2 -program. Swedish
co-operation partners are MEFOS, Luleå University of Technology and Royal
Technical University in Stockholm. The purpose of this research is to pre-
evaluate the possibility of injecting slag components into the blast furnace at
tuyere level.
4.1.4 Phenomena in the shaft of the blast furnace
Supervisor: Prof. J. Härkki
P. Mannila, K. Tervola
This project is funded by Technology Development Centre, Finland and Finnish
Akademi. The work has started as literature research of circulating elements
such as alkalies (Na, K), sulphur, zinc and silicon. These elements might cause
disturbances in a blast furnace and lower the productivity. The study of these
elements continues by using thermodynamic calculations and evaluation of the
internal circulation processes in the blast furnace. Slag formation in the blast
furnace is also be studied in this project.
4.2 Stoft - minimizing the emissions in iron and steel making
Supervisors: Prof. J. Härkki and Prof. Kauko Leiviskä
P. Myllymäki, H. Makkonen
This project was done in co-operation with the Control Engineering Laboratory
in the University of Oulu and it is financed by Rautaruukki Oy and TEKES.
The project started at the end of 1992 and it lasted until the beginning this year.
It had also connections to a research project that was going on in Sweden that
concentrates on dusting problems in smelting shop.
Dust emissions are regarded as one of the most pronounced environmental
hazards in steelworks such as Rautaruukki Raahe Steel, where most of the dust
emissions are generated in the sintering unit. Enormous quantities of dust and
fine matter are circulated within the sintering process
The main target of the Finnish contribution to the project was to examine the
effect of the various operational parameters employed in the sintering plant and
the properties of certain raw materials with respect to dust formation and the
amount of return fines, and also to explore dust formation mechanisms. From
the metallurgical point of view the chemical and mineralogical changes in the
process that lead to dust emissions were of primary importance. The control
engineering contribution were modeling dust emissions and return fines so that
18
they can be minimised using control engineering methods while optimizing the
quality of raw materials.
Production of high Fe -sinter increases flow rates of return fines and dusts
within the sintering process. Flow rates of hot return fines and return fines from
sinter strands (material passing through the gaps between the grid bars) increase
especially clearly. Also coke consumption increases strongly and dust
emissions can increase clearly due to increased amount of dust during the high
Fe -sinter production.
Changes of the process parameters have little effect on the quality of dusts and
return fines but bigger changes in raw material mix, like changing the base
concentrates, changes slightly the compositions of the flows in question.
Compositions of separate flows of return fines differ clearly from each other
and also compositions of fine grained return fines (dust) differ from
compositions of coarser particles.
Mineralogical reactions have little effect on the compositions of coarser dusts
and return fines. Formation of these particles is more a physical than a
mineralogical process. Formation of chlorides is the most important
mineralogical reaction concerning dust formation. Formation of KCl and NaCl
and especially formation of ZnCl2 is affected very strongly by alkali and
chlorine content of sintering mix. So it is possible to decrease zinc content and
alkali content of sinter by adding adequate amounts of chlorine into sintering
mix, for example in the form of CaCl2. It seems to be possible to decrease the
dust flows from each phase of the process simultaneously by control of the
quality of raw material mix.
Separate circulated dust flow rates and circulated flow rates of undersize
material from screening can be decreased by increasing or decreasing separate
process variables. Strand speed, basicity of sinter, amount of burnt lime in
sintering mix and Fe and SiO2 contents of sinter, for example, are good
regressors in modelling.
4.3 Slags in steel making
Supervisor: Prof. J. Härkki
M. Päätalo, P. Karhu
Slags in steel making project is a part of SULA 2 program. The project started
at the University of Oulu in 1993. The target of the project is to study slags
used in steel making to achieve lower energy consumption and better quality of
steel. This project consists of a basic study of slags and research of slags used in
converter, ladle and tundish. The results are pursued for immediate use in the
industrial processes. Slags in the steel making project are very closely
19
associated with the plans of the Finnish steel industry to develop a direct
tapping practice for the converter.
Figure 5. Steel ladle into the purging station.
4.3.1 Formation of lime and bauxite based calcium aluminate ladle slag
Supervisor: Prof. J. Härkki
P. Alamäki
This research was started in 1993 and it was done in co-operation with the
Department of Process Metallurgy at the University of Oulu and in Rautaruukki
Raahe Steel. In this research formation of lime and bauxite based calcium
aluminate ladle slags was investigated. Full scale process tests were done at
Rautaruukki Raahe Steel Works. In these tests the influence of different slag
practices to formation of molten slag and to quality of steel were researched.
Based on the test results, it appeared that by increasing the lime/bauxite -ratio
the average total oxygen level of steel decreases. The new ladle slag practice
based on these results has been commissioned at Rautaruukki Raahe Steel
Works.
4.3.2 The control of slag in the combined blowing converter
Supervisor: Prof. J. Härkki
20
S. Koski
The purpose of this study was to find the best blowing practices for injection
treated and high carbon steels to achieve the best possible dephosphorization
without using flux as a slag former. The effects of different blowing practices
on the control of converter slag were tested in full scale plant trials at
Rautaruukki Raahe Steel Works in 1994.
Based on the test results, the content of iron in converter slag should be over 11
% in high carbon steel and over 14 % in injection treated steel. The best
phosphorus removal is accomplished by high carbon at the temperature of
under 1670 C. For treated steels the temperature had no clear effect on
dephosphorization. The use of crushed aggregate of MgO reduced the wearing
away of the lining of converter, but simultaneously, it made the control of slag
more difficult. The influence of different blowing practices and slag formers on
converter process and steel making is very important while optimizing the
production.
4.3.3 Developing desulphurization slag to minimize hot metal losses
Supervisor: Prof. J. Härkki
J. Ollila
At Rautaruukki Raahe Steel Works the hot metal desulphurization slag contains
a high percentage of metallic iron. The purpose of this study was to reduce the
amount of iron in the desulphurization slag and so minimize the hot metal
losses. The full scale plant trials were done in 1995.
The plant trials were done by mixing fluorspar, sodium carbonate or nepheline
syenite into the injected desulphurization agent (CaO) or blast-furnace slag. The
best result was achieved by using sodium carbonate as a desulphurization agent.
The hot metal content of desulphurization slag was reduced from 41 % to 30 %.
4.3.4 The influence of tundish slag on steel cleanliness when casting Al-killed
low carbon steels
Supervisor: Prof. J. Härkki
M. Päätalo
The purpose of this study was to find a functional tundish flux for Al-killed low
carbon steels in order to achieve the best possible steel cleanliness. The change
of slag composition during casting as well as the layer structure of tundish slag
were studied. Full scale plant trials were done at Rautaruukki Raahe Steel
Works in winter 1996. Based on the experiments, it appeared that the melting of
flux as well as the carry over of ladle slag and sand filler to the tundish had a
significant influence on the composition and on the layer structure of the
tundish slag. Sand filler seemed to cause reoxidation of steel especially at the
beginning of the casting sequence. The total oxygen content of steel with
21
different practices is seen in figure 6. The total oxygen content was increased
by the ladle slag carried over to the tundish.
0
5
10
15
20
25
30
Reference serie Slag carry-over prevention Rice ash + slag carry-over
prevention
Partly deoxidation
Tota
l oxy
gen
/ p
pm
25 t
90 t
Figure 6. Total oxygen with different practices.
4.3.5 Cleanliness and castability of Al-killed low carbon steels
Supervisor: Prof. J. Härkki
P. Karhu
The purpose of this study was to increase steel cleanliness and lengthen casting
sequences of low carbon Al-killed steels. Alumina inclusions, which have
formed during deoxidation and reoxidation, adhere into submerged entry nozzle
(SEN). The accumulation of alumina in the SEN leads to interruption of the
casting process. Full scale plant trials were done at Rautaruukki Raahe Steel
Works in winter 1996.
In the plant trials the effects of deoxidation methods, slag carry-over, argon
rinsing, tundish flux and steel temperature on steel cleanliness and castability
were investigated. Samples from SEN were analyzed with an X-ray
diffractometer and an SEM. Based on the experiments, it appeared that the
variation of steel temperature during casting sequence has the strongest effect
on steel castability, figure 7. The low total oxygen content of steel ( 12 - 14
ppm) can be achieved by preventing the slag carry-over in the tundish and by
using a partial deoxidation practice.
22
0
100
200
300
400
500
600
Reference serie Slag carry-over
prevention
Rice ash + slag carry-
over prevention
Partly deoxidation
Ste
el c
aste
d /
ton
s
1554
1556
1558
1560
1562
1564
1566
1568
Ste
el t
emper
ature
in
tund
ish /
°C
Temperature
Figure 7. The average steel tons casted with TCD-nozzle and the average steel
temperature in tundish.
4.4 Factors affecting the quality of ferro-oxides
Supervisor: Prof. J. Härkki
R. Sarkkinen
Steel coils are etched before they are cold rolled. The etching is done by
hydrochloric acid and the acid is regenerated in two reactors. During the
regeneration solid product will be ferro-oxide particles, and they are also sold.
In the project factors affecting the ferro-oxide quality were first considered
theoretically. Full scale experiments were then done to check the process
parameters affecting the quality of ferro-oxides in the reactors.
The project was done with co-operation between Rautaruukki Strip Products
Hämeenlinna Works and Process Metallurgy Professorship. The project started
in January 1994 and completed in May 1994.
4.5 Laser measurement monitoring of refractory wear, equipment
development
Supervisor: Prof. J. Härkki
R. Sarkkinen
Rautaruukki New Technology is producing laser measurement equipment to
measure how much there is refractory material is left in LD converter. They
wanted to develop the equipment such that it could be used also to measure
other reactor vessels. During the project it was considered if it would be
economically lucrative and also how to make the refractory wear measurements
in EAF, AOD, iron and steel ladles.
23
The project was done with cooperation between Rautaruukki New Technology
and Process Metallurgy Professorship. The project started in September 1994
and completed in December 1994.
4.6 Thermodynamics of Refractory Materials
Supervisor: Prof. J. Härkki
R. Sarkkinen
Magnesia refractory materials are widely used in steelmaking, for example in
converters. Antioxidants are added to magnesia refractory materials to prevent
chemical abrasion. The antioxidant materials can be: metallic aluminum,
magnesium, silicon or a mixture of these. Chemical reactions and chemical
balance of the refractory components, antioxidants and external oxygen inside
the bricks in different pressures, for example in ladle vacuum pressure, is
evaluated by thermodynamic calculations. Tools for the thermodynamic
calculations are computer programs HSC, SolGasMix and ThermoCalc.
External elements cause abrasion on the surface and slightly inside of the brick.
Slag aggressively attacks refractory material and steel components also cause
erosion. These solid - liquid/solid multi-component reactions are evaluated by
thermodynamic methods. The evaluation of brick wear is also done
experimentally.The project and the studies are financed by the Graduate School
in Chemical Engineering doctoral education program. The project started in
January 1995.
700 900 1100 1300 1500 1700 1900
0.0
0.1
0.2
0.3
0.4
0.5
0.6mol
C
MgO
Mg(g)
CO(g)C
MgO*Al2O3
Al4C3
Temperature
Figure 8. Thermodynamic equilibrium of magnesia carbon brick with
aluminum antioxidant.
4.7 Titanium in stainless steels
24
Supervisor: Prof. J. Härkki
T. Kivirauma
The subject of the research is in an important branch of surface quality of
different grades of titanium stabilized stainless steel. Outokumpu Polarit has
made it possible for me to conduct experimental trials at their smelting plant in
Tornio. Their laboratories and services such as, chemical analysis, SEM etc.
have also been available for my research. Outokumpu Research supported my
project by offering me an office, a powerful computer and a generous amount
of help with thermodynamics and the thermodynamic calculation program,
Thermo-Calc.
Problems with stainless steel surface quality result from large, unformable
inclusions in the steel. A thermodynamic study on the formation of these
inclusions has been accomplished using the thermodynamic calculation
program Thermo-Calc. The inclusion formation has been simulated with
different kinds of equilibrium phase diagrams at many stages of the stainless
steel production. After this, the conditions of the calculations have been
modified within certain limits, to restrict or avoid the formation of inclusions.
This research has been complemented by a literature survey on the factors that
effect the formation of inclusions.
The conclusions, from both the calculations and literature survey, are that
deoxidation, reoxidation and the content of nitrogen in stainless steel are very
important regarding the formation of inclusions. It is recommended that further
research should be made about the benefits of adding the deoxidant at a later
stage of production. By making this change it would give the inclusions less
time to grow and would probably lower the nitrogen content. Further research
could also be done to investigate possible methods for eliminating reoxidation.
This research has been financed with a grant from the Foundation of
Outokumpu Oy.
25
Figure 9. Kellog-diagram for Ti-stabilized austenic stainless steel
4.8 Reduction Properties of Iron Ore Agglomerates
Supervisor: Prof. J. Härkki
L. Hooey
High temperature reduction, softening and melting behaviour of iron ore sinter
and pellets are being tested using the recently modified reduction under load
test at Rautaruukki OY. Tests will be carried out on sinter, pellets and mixtures
of sinter, pellets and coke in gas mixtures with varying thermal profiles and
CO/H2/CO2/N2 concentrations. The thermal profile and gas compositions are
designed to take into account current blast furnace operation, especially the
increase in oil injection rates. Mineralogical studies of reduced compacts will
be made in order to establish the effects of thermal and gas composition profiles
on the reduction characteristics of the blast furnace burden materials. This
project is being funded by Rautaruukki OY.
26
Figure 10. High temperature test scheme. /Rautaruukki Oy/
4.9 The Radical Evaluation of Secondary Metallurgy
The purpose of this research project is to improve radically quality of steel
classes. The other aim is to develop more competitive industrial engineering.
The project has been divided into four smaller project divisions and these have
been subdivided divisions into many partial projects. In the University of Oulu
are researched two divisions: “Refractory Lining of Ladle” and “Flows of
Liquid Steel in Converter and in Ladle”. The research is cooperation project
with Finnish metallurgical industry. Helsinki University of Technology and
Åbo Akademi, in Turku, are also cooperation partners. The project is financed
by Finnish metallurgical industry and TEKES. The project was started at the
end of 1995 and it will last until 1998.
4.9.1 Refractory Lining of Ladle
Supervisor: Prof. J. Härkki
T. Fabritius
The aim of this literature review is to discover how thermal characteristics
influence heat transfer between the lining, slag and liquid steel. Also, some
methods and differential equations to analyze time-dependent heat transport
system, which generates on slag layer of ladle are investigated.
27
4.9.2 Flows of Liquid Steel in Converter and in Ladle
Supervisor: Prof. J. Härkki
T. Fabritius
In addition to the literature evaluation, results of tests obtained by using
physical three-dimensional water model are evaluated. The purpose is to study
the impact of different factors on flow distribution in AOD-converter. It will
furthermore make process scale tests in industry.
4.10 Direct tapping of the converter
Supervisor: Prof. J. Härkki
P. Pyykkö
Aim of the project is to develop a direct tapping practice for the converters of
the Rautaruukki Raahe Steel Works. Liquid steel will be tapped directly after
converter blowing process into the ladle without interrupting the blow and
waiting for the results of the steel sample analysis. This will reduce analysis-,
energy- and material- expenses and improve the efficiency of steelmaking.
Converter control must be improved to make direct tapping possible. Converter
control is based on statistical models. They can be improved to a certain level.
A statistical model needs input data of ingoing materials (analysis, amount,
temperature) and ordered steel grade and quality. Inaccuracy of analysis and
weighing cause inaccuracy of statistical models. Accuracy of the control
improves if a dynamic model based on the measurements during the blowing is
used. Dynamic control follows the converter process and predicts the
temperature and the carbon level of the steel at the end of the blowing. This
reduces the amount of re-blows, increases capacity of steel plant and reduces
both expenses and dust formation.
Possibilities of dynamic control with free-fall drop-in probes and waste gas
analyser are studied in this project. Drop-in probes measure the temperature of
the steel just before the end of the blowing. Blowings need not be stopped for
the measurement. Project has started with test runs of drop-in probes and
MEFCON waste gas analysis and process control system. MEFCON is
developed by Mefos in Luleå, Sweden. Use of drop-in temperature probes
significantly reduced the number of re-blows during the test period. Next step is
to develop a model for bath temperature increase at the end of the blowing. This
model is needed when drop-in probes are taken as standard practice at the steel
plant.
4.11 The use of vacuum in stainless steelmaking
28
Supervisor: Prof. J. Härkki
T. Mustonen
The use of vacuum in steelmaking is based on the pressure dependent
deoxidation, decarburization and gas removal reactions. With decreasing
pressure the concentrations of the removable elements decrease according to the
equilibrium equations. The process metallurgy of stainless steel is controlled by
the thermodynamic equilibria between oxygen, carbon and chromium and the
kinetics of the refining process.
The hydrogen concentration of steel can be lowered to 1 - 2.5 ppm and nitrogen
concentration to 25 - 30 ppm by vacuum treatments. Total oxygen
concentration after vacuum treatments is usually 10 - 40 ppm depending on the
vacuum process used and steel quality. Vacuum refining decreases the amount
of internal and surface defects and hairline cracks and improves the cleanliness,
homogeneity, toughness and formability of the steel.
The increasing demands on steel cleanliness have further advanced the use of
vacuum technology in stainless steelmaking. There are several vacuum
processes used in stainless steelmaking. Perhaps most widely used is the
Vacuum Oxygen Decarburization (VOD) process in a ladle. VOD process has
also been modified into a converter version VODC. Vacuum circulation process
(RH process and its variants) and Vacuum Arc Degassing (ASEA-SKF and
FINKL-Mohr) have also been used in stainless steelmaking. In VAD processes
the cooling of the steel can be compensated with arc heating.
29
5 THE METALLURGICAL SOCIETY
Aija Rytioja
The Metallurgical Society was founded for metallurgy students and graduated
metallurgists. The purpose of the Society has been to promote metallurgical
skills of the members with different courses and excursions.
The Metallurgical Society was founded in 25.11.1992. The founder members of
the society are Professor Jouko Härkki and metallurgy students at the time:
Pekka Alamäki, Riikka Heiniemi, Timo Karjalahti, Riku Mattila, Seppo Ollila
and Jaakko Savola. The first Chair of the Metallurgical society was Professor
Jouko Härkki.
The Metallurgical Society has arranged post-graduate education, for example:
Blast Furnace in the Future 1.-2.12.1992, Automation in the Steel Industry
26.4.1994, Refractories in the Steel Industry 7.-8.6.1994 and Metallurgical
Industry and Environment 25.4.1995. In addition many engineers from industry
and professors from other universities have lectured about different
metallurgical fields at the request of the Metallurgical Society. There have been
also other occasions with different themes, for example geology and history of
production of iron. In spring 1995 there were ambitious attempt to produce iron
in an old-fashioned way.
The Metallurgical Society has tried to organize one professional excursion in
each year. In the year 1993 the Metallurgy Society visited in Luleå University
of Technology and SSAB. In the 1994 the Society made a long domestic
excursion to Helsinki University of Technology, Technical Research Centre of
Finland, Outokumpu Research Oy and Harjavalta works and Rautaruukki
Hämeenlinna works. The next excursion was in 1996, when the Society visited
again in Outokumpu Research Oy and the outdoor museum of Leineberg.
Furthermore the Metallurgical Society has arranged many kinds of sports
activities. During the year 1996 the members have played floor hockey two
times a week. The members have also organized cross country skiing trips in
the winter and wandering trips in the autumn. Moreover the Metallurgical
Society has played victorious volleyball challenge game against the rest of the
Process Engineering department. There was also table tennis contest for
members in the year 1995.
The Metallurgical Society will continue its activity in the same manner as
before and hopefully many new eager members take part in the function of the
Society in the future.
30
6 PAPERS AND PUBLICATIONS
1991
Härkki, Jouko & Suomi, M.-L. & Inkala, P. & Jokilaakso, A. & Raipala, K.
Bekräkningsmodell för Si-halt i råjärn. - Jernkontorets forskning 2119/188.
Stockholm 1991. 27 s.
Härkki, Jouko & Jyrkönen, S. & Kolsi, J. & Kärjä, J. Tapphålstegel för LD. -
Jernkontorets forskning TO 21-64. Stockholm 1991. 16 s.
Härkki, Jouko & Palander, M. Theoretical considerations about reaxidation of
the steel melt by refractory materials. - Interceram 40(1991):5 s. 284-289.
1992
Heino, J. (toim.) & Sohlo, J. (toim.). Ympäristönsuojelutekniikan lisensiaat-
tiseminaari keväällä 1992. Osa I: Ympäristö ja ihminen. Oulu 1993.
Heino, J. (toim.) & Sohlo, J. (toim.). Ympäristönsuojelutekniikan lisensiaat-
tiseminaari keväällä 1992. Osa II: Vesiensuojelu. Oulu 1993. Oulun yliopisto.
Heino, J. (toim.) & Sohlo, J. (toim.). Ympäristönsuojelutekniikan lisensiaat-
tiseminaari keväällä 1992. Osa III: Ilmansuojelu. Oulu 1993. Oulun yliopisto.
Härkki, Jouko & Suomi, M.-L. & Inkala, P. & Jokilaakso, A. & Raipala, K.
Beräkningsmodell för Si-halt i råjärn. Slutrapport. - Jernkontorets forskning TO
21-73. Stockholm 1992. 29 s.
Härkki, Jouko & Kuchàr, L. Refractory material as a source of reoxidation in
tundish. - Jernkontorets forskning TO 24-37. Stockholm 1992. 21 s.
L.Kuchar, J.Härkki. Reoxidation in tundish. Jernkontorets Forskning, Serie D,
1992, 23 p.
1993
Alamäki, P. & Härkki, J. Kuonat teräksen valmistuksessa, osa I teoria. Oulun
yliopisto, prosessitekniikan osasto, 1993. 85 s.
Sohlo, J., Nelo, S. & Heino, J. Lämpö- ja diffuusiotekniikan
etäopetusmateriaali: Siirtoilmiöt II. Opetushallituksen sarjat. Helsinki 1993. 87
s.
31
J.Härkki, Testning av eldfasta material för masugnen, raportti 135, Oulun
yliopisto prosessitekniikan osasto, 1993, 54 p.
Härkki, Jouko & Kuchar, L. Refractory material. Source of reoxidation in
tundish. - Unified International Technical Conference on Refractories. Third
Biennial Worldwide Conference on Refractories. Sao Paulo, Brazil, 31
October-3 November 1993. 13 s.
Härkki, Jouko (toim.) Korkealämpötilaprosessien rakennemateriaalit.
Metallurgin hyvä tietää. Oulun yliopisto. Prosessitekniikan osasto. Moniste 33.
Oulu 1993. 213 s.
Härkki, J. Testning av eldfasta material för masugnen, raportti 135, Oulun
yliopisto prosessitekniikan osasto, 1993, 54 p.
Laajoki, K. and Makkonen, H. 1993. Geology and geochemistry of Iivaara
Palaeozoic alkaline intrusion ( North Finland ). ( in Russian ) Geokhimia 8,
1245 - 1248.
Makkonen, H. T., Laajoki, K. and Devaraju, T. C. 1993. Mineral chemistry of
clinopyroxene and feldspars in the Neoproterozoic alkaline dykes of the
Bangalore district, Karnataka, India. Bull. Geol. Soc. Finland 65, Part II, 77-88.
Makkonen, H. ja Härkki, J. 1993. Sintrauksessa tapahtuvien mineralogisten
prosessien ja mineraalien fysikaalisten ominaisuuksien mahdolliset vaikutukset
pölyn muodostukseen. Report 134. Department of Process Engineering,
University of Oulu. 22 pp.
Myllymäki, P., Härkki, J. & Leiviskä, K. Sintterin valmistus, sintrauksen tär-
keimmät prosessiparametrit sekä pöly- ja palauteongelmat. Oulun yliopisto,
prosessitekniikan osasto, 1993, Report 136. 37 s.
Ollila, S. & Härkki, J. Palamisilmiöt masuunin hormeilla. Report 130.,
Department of Process Engineering, University of Oulu, 1993, 49 s.
Ollila, S. & Härkki, J. Palamisilmiöt masuunin hormeilla. SULA-ohjelman
päätösseminaari 14.4.1993, kokousjulkaisu, Espoo, Otaniemi, 15 s.
Ollila, S. & Härkki, J. Palamisilmiöt masuunin hormeilla. SULA-Metallien
energiataloudellinen valmistus, Energiatutkimusohjelman loppuraportti 1988-
1992, Kauppa- ja teollisuusministeriö, Energiaosasto. Katsauksia B:168.
Helsinki 1993. S. 31-36.
Ollila, S. & Härkki, J. Combustion phenomena in front of the tuyeres of a blast
furnace. SULA-Energy-efficient steel and metal production, Final report on the
32
energy researh programme 1988-1992, Ministry of Trade and Industry, Energy
Department. Reviews B: 169. Helsinki 1993. s. 32 - 39.
1994
Alamäki, P. & Härkki, J. Kuonat teräksen valmistuksessa, osa II
kuonapraktiikat Rautaruukin teräksenvalmistusprosessissa. Oulun yliopisto,
prosessitekniikan osasto, 1994. 94 s.
Alamäki, P. Kalkki- ja bauksiittipohjaisen kalsiumaluminaattikuonan
muodostuminen terässenkassa. Diplomityö, Oulun yliopisto, prosessitekniikan
osasto, 1994. 142 s.
Alamäki, P. & Härkki, J. Kalsiumaluminaattikuonan muodostuminen
terässenkassa. Raportti SULA 2 -tutkimusohjelman ”Raudan ja teräksen
valmistuksen perusprosessit” -painoalueen seminaarissa. Espoo 12.4.1994. 13 s.
Alamäki, P. & Härkki, J. Kalsiumaluminaattikuonien perusteet. Oulun
yliopisto, prosessitekniikan osasto, 1994. 81 s.
Ollila, J. M. M., Alamäki, P. & Härkki, J. Rautatappiot raakaraudan
rikinpoistossa. Oulun yliopisto, prosessitekniikan osasto, 1994. 59 s.
P.Alamäki, J.Härkki, Kuonat teräksen valmistuksessa, SULA 2-vuosikirja,
Suomen Teräksen- ja Metallintuottajien yhdistys, 1994, 75-86 pp.
Torvela, H. & Heino, J. Development trends in emission reduction
technologies. Oulu 1994. Oulun yliopisto, Ecocenter. 49 s.
Satta, M., Nelo, S., Heino, J. & Sohlo, J. Hyötymenetelmän kehittäminen
jätekaasujen puhdistukseen. Osa 1. Rikkidioksidin absorptio vetyperoksidin
vesiliuokseen pilot-mittaisessa suihkutornissa. Oulu 1994. Oulun yliopisto. 31
s.
Satta, M., Nelo, S., Heino, J. & Sohlo, J. Hyötymenetelmän kehittäminen
jätekaasujen puhdistukseen. Osa 5. Rikkidioksidin absorptio vetyperoksidin
vesiliuokseen täytekappaleko- lonnissa. Oulu 1994. Oulun yliopisto. 29 s.
Mattila, R., Larkimo, M. & Härkki, Jouko. FeCr-sulan konvertoinnin
vuorausmateriaalit ja valinta. Outokumpu Polarit, Metallurginen laboratorio,
Tornio. Raportti nro 5397-9. Tornio 1994. 23 s.
Jauhiainen, A., Laine, K., Lohi, T.-K., Rytioja, A., Heino, J. & Härkki, J (toim),
Raudan hapettuminen korkeassa lämpötilassa, Prosessitekniikan osasto, Oulun
yliopisto, 1994, 65 p.
33
Härkki, J. & Mannila, P. & Ollila, S. Kaasufaasin reaktiot masuunissa. - Sula 2.
Perusmetallien energiataoudellinen valmistus. Vuosikirja 1994. Projektiraportit.
Helsinki 1994. s. 61-73.
Härkki, J., Leiviskä, K., Myllymäki, P. ja Makkonen, H. Pölyn hyödyntäminen.
Teoksessa Hakulin, H. (toim.) SULA 2. Perusmetallien energiataloudellinen
valmistus. Vuosikirja 1994, projektiraportit. Suomen Teräksen ja
Metallintuottajien Yhdistys. Helsinki. ss. 127 - 142.
Makkonen, H. T. and Härkki, J. 1994. Effects of mineralogical sintering
processes and the physical properties of minerals on dust formation.
Jernkontorets Forskning, serie TO, nr 21-77. Stockholm. 19 pp.
Mannila, P., Ollila, S. & Härkki, J. Kaasufaasin reaktiot masuunissa. SULA 2 -
vuosikirja 1994. Projektiraportit. Håkan Hakulin (toim.). Suomen teräksen- ja
metallintuottajien yhdistys. Helsinki. 1994. ss. 61-73.
Myllymäki, P., Härkki, J. & Leiviskä, K. Sintering, essential process parameters
and problems with dust and return fines. Jernkontorets forskning, Nr 21-80,
1994. 36 s.
Myllymäki, P., Makkonen, H., Härkki, J & Leiviskä, K. Pölyn hyödyntäminen.
SULA 2 -vuosikirja. Suomen Teräksen- ja Metallintuottajien Yhdistys, toim.
Håkan Hakulin. 1994. ss. 127-142.
Myllymäki, P. Sintrausprosessin pöly- ja palautevirtausten mallintaminen.
Raportti julkaisussa "Oulun yliopiston säätötekniikan laboratorion
tutkimustoiminta 1994". Oulun yliopisto, prosessitekniikan osasto, 1994. 12 s.
Ollila, J., Alamäki, P. & Härkki, J. Typpi ja vety teräskuonissa. Oulun yliopisto,
prosessitekniikan osasto, 1994. 36 s.
Ollila, S. & Härkki, J. Kaasufaasin reaktiot masuunissa. SULA 2-
tutkimusohjelman "Raudan ja teräksen valmistuksen perusprosessit" -
painoalueen seminaari 12.4.1994, kokousjulkaisu, Espoo, Otaniemi, 15 s.
Ollila, Seppo & Mannila, Päivi & Härkki, Jouko Masuunin kaasufaasin reaktiot.
Osa 1. - University of Oulu. Department of Process Engineering. Report nro
145. Oulu 1994. 29 s.
Sarkkinen, Riku & Härkki, Jouko, Lasermittauksen soveltuvuuden
selvittäminen tulenkestävien vuorausten mittaamiseksi valokaariuunissa.
Raportti. Oulu 1994. 79 s.
34
Sarkkinen, Riku & Härkki, Jouko Rautaoksidin laatuun vaikuttavia tekijöitä
regenerointiprosessissa. Raportti. Oulu 1994. 49 s.
1995
Koski, S., Alamäki, P. & Härkki, J. Kuonan hallinta
yhdistelmäpuhalluskonvertterissa. Oulun yliopisto, prosessitekniikan osasto,
1995. 41 s.
Ollila, J.M.M, Alamäki, P., Mannila, P. & Härkki, J. Masuunikuonan
muodostuminen ja kuonakomponenttien vaikutus sulamispisteeseen ja
viskositeettiin. Report 160. Oulun yliopisto, prosessitekniikan osasto. Oulu
1995. 23 s.
Heino, J. Hyötymenetelmän kehittäminen jätekaasujen puhdistukseen. Osa 4.
Käytössä olevat poistokaasujen puhdistuksen hyötymenetelmät. Oulu 1995.
Oulun yliopisto. 27 s.
Heino, J., Leskelä, K., Nelo, S., Satta, M., & Sohlo, J. Recovery method for simultaneous NOx/SOx purification by oxidative scrubbing. Poster
presentation. Helsinki, 1995, Finnish Chemical Congress and Exhibition 14.-
16.11.1995.
Sohlo, J., Nelo, S. & Heino, J. Siirtoilmiöt II. Lämpö- ja diffuusiotekniikan
opetusmateriaali. Oulu 1995. Oulun yliopisto. 62 s
J.Härkki, P.Mannila, Paloilmiöt masuunien hormeilla, Metallurgisten
prosessien mallin-tamisen perusteet ja työkalut, POHTO 1.-2.1995, Oulu, 9 s.
H. Nevala, J. Kärjä, J. Härkki, Experiences of Different Tundish Lining
Materials in Continuous Casting, UNITECR 95, 19.-22.1995 Kyoto, Japan, pp.
133-140.
Laukkanen, J, Mannila, P, Härkki, J. & Pohjola, V. Öljyn turbulentin palamisen
numeerinen mallinnus masuunin raceway-alueella. Report 173. Oulun yliopisto,
prosessitekniikan osasto. Oulu 1995. 39 s.
Laukkanen, J., Mannila, P. & Härkki, J. Masuunin huokoisuus ja kaasun
permeabiliteetti masuunissa. Report 175. Oulun yliopisto, prosessitekniikan
osasto. Oulu 1995. 24 s.
Makkonen, H. T., Myllymäki, P. ja Härkki, J. 1995. Sintraamon pölyjen ja
palautteiden kemiallinen ja mineraloginen koostumus. Report 161. Department
of Process Engineering, University of Oulu. 82 pp.
35
Makkonen, H. T., Myllymäki, P. och Härkki, J. 1995. Den kemiska och
mineralogiska sammansättningen hos dammpartiklar och annat material som
separeras för recirkulation under processen vid ett sinterverk. Jernkontorets
Forskning, serie TO, nr 21-89. Stockholm. 45 pp.
Kääriä, I, Mannila, P & Härkki, J. Öljyinjektion vaikutus masuunin kuilun
tapahtumiin. Report 165. Oulun yliopisto, prosessitekniikan osasto. Oulu 1995.
24 s.
Myllymäki, P. Makkonen, H. T., Härkki, J. & Leiviskä, K. Pöly- ja
palautevirtaukset korkearautasintterin ja perinteisen sintterin valmistuksessa.
Oulun yliopisto, prosessitekniikan osasto, 1995. 81 s.
1996
Fabritius, T. & Härkki J. Terässenkan kuonarajan termisten olosuhteiden
tarkastelu. Oulu 1996. Oulun yliopisto. 38 s.
Määttä, P., Heino, J. & Sohlo, J. Hyötymenetelmän kehittäminen jätekaasujen
puhdistukseen. Osa 6. Rikkidioksidin vetyperoksidiabsorption simulointi Aspen
Plus -simulointiohjelmalla. Oulu 1996. Oulun yliopisto. 24 s.
L. Kuchar, F.Chowaniek, J.Härkki, Refractories and their Influences on
Reoxidation in Thundish, Nova HUT-Report, Ostrava, Czech Republic, 1996, 8
p.
Määttä, P. & Härkki J. Vakuumin käyttö ruostumattoman teräksen
valmistuksessa; Kirjallisuuselvitys. Oulu 1996. Oulun yliopisto. 24 s.
Laukkanen, J. & Härkki, J. Senkan kaasusekoituksen virtausmallinnus,
kirjallisuuskatsaus. Report 177. Oulun yliopisto, prosessitekniikan osasto. Oulu
1996. 37 s.
Liao, D., Mannila, P. & Härkki, J. Study on raceway. Report 181. University of
Oulu, Department of process engineering. Oulu 1996. 34 s.
Liao, D., Mannila, P. & Härkki, J. Analysis of combustion conditions in the
raceway and suggestions for improving combustion rate of oil. Report 182.
University of Oulu, Department of process engineering. Oulu 1996. 8 s.
Mannila, P., Salmi, T., Haario, H., Luoma, M., Härkönen, M. & Sohlo, J.
Stationary kinetics of essential reactions on automobile exhaust Pt-Rh/Al2O3
catalyst. Applied catalyst, B: Enviromental.7 (3-4) 1996. p.179-198.
36
Mannila, P. & Härkki, J. Phenomena in the raceway of the blast furnace with
high oil injection rate. In proceedings of “The International Conference on
Modelling and Simulation in Metallurgical Engineering and Materials Science”
11.-13.6.1996, Beijing, China.
Mannila, P., Salmi, T., Haario, H., Luoma, M. & Härkönen, M. Modelling of
propene oxidation kinetics on a Ce-promoted Pt-Rh/Al2O3-catalyst. In
Proceedings of “7th Nordic Symposium on Catalysis”, June 3-4,1996, Mauno
Koivisto Centre, Turku, Finland.
Mannila, P. & Härkki, J. Masuunin kaasufaasin reaktiot, osa II. Report 178.
Oulun yliopisto, prosessitekniikan osasto. Oulu 1996. 38 s.
Paloposki, T., Hakala, J., Mannila, P. & Laukkanen, J. Injection of heavy fuel
oil into the blast furnace. In proceedings of “3dr Colloquium on Process
Simulation” 12-14 June, 1996, Espoo, Finland. 10 p.
Tervola, K., Mannila, P. & Härkki, J. Masuunin sisäiset kiertoprosessit. Report
179. Oulun yliopisto, prosessitekniikan osasto. Oulu 1996. 70 s.
37
7 THESIS
7.1 Diploma Engineer Theses (Master of Science)
Seppälä Juha: Normalising rolling of welded steel tube (1992)
Palmu Petri: Refractory materials for clean steelmaking (1992)
Ylitalo Mikko: Influence of aluminium on microstructure and mechanical
properties of 17 Cr ferric stainless steel (Polarit 810) hot band (1993)
Ollila Seppo: Combustion phenomena in the race way of the blast furnace
(1993)
Sarkkinen Riku: The cleanliness and the type of inclusions of some stainless
steel -grades in the ladle practice (1993)
Pieskä Antti-Pekka: The flatness of the hot strip at user (1994)
Alamäki Pekka: Formation of lime and bauxite based calcium aluminate ladle
slag (1994)
Jalonen Antti: A method to evaluate the temperature distribution and refractory
wear on the electric arc furnace (1994)
Karjalahti Timo: Charge distribution in the blast furnace using a 1/10 small
scale model (1994)
Kivirauma Tiina: Control of formation of Titanium compounds in the
production of stainless steel (1994)
Koski Saara: The control of slag in the combined blowing converter (1995)
Kääriä Ismo: The effect of oil injection on phenomena in the shaft of blast
furnace (1995)
Heiniemi Riikka: The control of the sinter plant by using information on
exhaust gas oxygen content (1995)
Haikola Mika: Sinter bed thermochemical research (1995)
Laukkanen Janne: The numeric modelling of the turbulent oil combustion in the
race way (1995)
38
Ollila Janne: Optimisation of energy consumption during sintering by oxidation
of chromite (1995)
Ollila Janne: Developing desulphurization slag to minimise hot metal losses
(1996)
Seppälä Kai: Selective reduction of ilmenite (1996)
Pyykkö, Pekka: The effect of titanium on the wear of blast furnace hearth
refractories (1996)
Mattila, Riku: Selection of refractory material for ferrochromiumconverter
(1996)
Mustonen, Tuuli: Thermodynamics of aluminium and calcium treated stainless
steel (1996)
Päätalo, Mika: The influence of tundish slag on steel cleanliness when casting
Al-killed low carbon steels (1996)
Seppänen, Eero: The HF welding of ferric steel pipe (1996)
Recommended