PROCESS METALLURGY

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


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


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


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


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


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


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


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


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


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


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


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


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


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


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


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


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


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


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


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.


tiseminaari keväällä 1992. Osa II: Vesiensuojelu. Oulu 1993. Oulun yliopisto.


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)

PROCESS METALLURGY

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