Optimization of the sintering process with particular reference to energy saving

European Union

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Energy research

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• Sciences et techniques

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• Publié par: EUROPEAN-UNION
• Nombre de lectures: 13
• Langue: English
• Poids de l'ouvrage: 3 Mo

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Commission of the European Communities
technical steel research
Reduction of ores
OPTIMISATION OF THE SINTERING PROCESS
WITH PARTICULAR REFERENCE TO ENERGY
SAVING
Report
EUR 9433 EN
Blow-up from microfiche original Commission of the European Communities
technical steei research
Reduction of ores
OPTIMISATION OF THE SINTERING PROCESS
WITH PARTICULAR REFERENCE TO ENERGY
SAVING
J. O'HANLON
BRITISH STEEL CORPORATION
9, Albert Embankment
GB-LONDON SE1 7SN
Contract No 7210.AA/803
(1.7.1979 - 31.12.1982)
FINAL REPORT
Directorate-General
Science, Research and Development
1985 EUR 9433 EN Published by the
COMMISSION OF THE EUROPEAN COMMUNITIES
Directorate-General
Information Market and Innovation
L-2920 LUXEMBOURG
LEGAL NOTICE
Neither the Commission of the European Communities nor any person acting
on behalf of then is responsible for the use which might be made of
the following information
>ECSC-EEC-Euratom, Brussels· Luxembourg OPTIMISATION OF THE SINTERING PROCESS
WITH PARTICULAR REFERENCE TO
ENERGY SAVING
FINAL REPORT
Agreement No. 7210.AA/803
J. O'Hanlon
British Steel Corporation
Teesside Laboratories
EUR 9^+33 EN FR 64 8 822 7210.AA/803
OPTIMISATION OF THE SINTERING PROCESS WITH PARTICULAR REFERENCE TO
ENERGY SAVING
British Steel Corporation
ECSC Agreement No. 7210.AA/803
Final Summary Report
Work was undertaken in four main areas:
(1) Sinter box testwork. This demonstrated that reduction of coke size
increased productivity but at the expense of fuel economy. Reduction of
dolomite size had no effect on sintering parameters, but substitution of
olivine for dolomite improved productivity, coke rate and sinter quality.
Anthracite was demonstrated to be a suitable replacement for coke breeze,
but attempts to investigate the possible benefits of split coke addition
were not successful - it did not prove possible to obtain micropellets
with a satisfactory coke coating.
(2) A microscale sintering apparatus was developed which allowed virtually
instantaneous quenching of a partially sintered bed, and thus study of
phenomena not normally observable. The fusion zone was seen to be
preceded by a thin solid state reduction zone. No evidence of early
calcium ferrite formation was seen - calcium ferrite is formed behind the
combustion zone, when oxygen potential is sufficiently high. Degradation
of micropellets during sintering is minimal, except in the case of
carbonate nuclei, when degradation is rapid and extensive. Two major
pore types were seen, the larger types frequently being connected by
thermal stress crack fractures.
A study of LD slag assimilation during sintering quantified the
relationship between LD slag particle size and the degree of
assimilation. The slag is poorly assimilated, e.g. 20% of the -1 mm
fraction remains unassimilated after normal sintering.
A study of magnesia addition showed that Hi + H2 type hematites decreases
with increasing magnesia content.
Hematite ores can be classified by use of the apparatus in order of their
ease of assimilation. Four mineralogicai components of hematite ores
were identified which allow prediction of the ore's behaviour during
sintering - hard, non-porous specular hematite, hard finer-grained
hematite of intermediate porosity, highly porous limonite, and martite.
(3) An optical method for continual determination of crushed coke breeze size
distribution has been developed. The accuracy on plant is within 4%
accumulated oversize in the range 0.5 to 6 mm. Automatic presentation of
wet coke breeze to the analyser remains to be achieved.
(4) Determinations of cooler air temperatures, velocities and dust loading
aided in the design of a system for use of hot air from the cooler as the
combustion air in the ignition furnace at the Redcar Works of BSC. The
sytem was commissioned in February 1983, and has resulted in 32%
reduction in ignition gas requirements. FR 64 8 822 7210.AA/803
CONTENTS
Page
1. INTRODUCTION 1
2. SINTER BOX WORK
2.1 Split Coke Additions
2.2 Replacement Of Coke By Anthracite 3
2.3 Effect Of Variation Of Coke Size Distribution 4
2.4 Dolomite v. Olivine
3. THE SINTERING SIMULATOR 6
3.1 Introduction
3.2 Description
3.3 Commissioning 7
3.4 Testwork
4. THE COKE GRAIN SIZE ANALYSER 24
24.1 Introduction
24.2 Requirements
25 4.3 Technique
25 4.4 Laboratory Work
26
4.5 Particle Handling System
26 4.6 Data Analysis
27 4.7 Application
27
4.8 Discussion
5. RECUPERATION OF SINTER COOLER WASTE HEAT 27
5.1 Introduction 2
5.2 Description Of Sinter Plant
5.3 Measurements
5.4 Discussion8
5.5n Of Scheme9
5.6 Effects Of Heat Recuperation On Sinter Plant Performance 2
5.7 Future Developments 30
3
6. CONCLUSIONS
32
TABLES
56
FIGURES
XXI