| 1. |
- Gustavsson, J., et al.
(författare)
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Meltdown behaviour of pellets reduced in a laboratory reduction furnace
- 2003
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Ingår i: Scandinavian journal of metallurgy. - : Wiley. - 0371-0459 .- 1600-0692. ; 32:2, s. 100-111
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Tidskriftsartikel (refereegranskat)abstract
- The meltdown behaviour of pellets reduced under different conditions in a reduction under load furnace has been examined. The pellet type, temperature increase rate, the gas flow and the applied load over the crucible were varied between trials. Samples from 12 trials interrupted just before meltdown were studied under an optical microscope and it was found that all iron oxides in the samples were reduced to iron. After the etching of the samples the carbon content was estimated. The carbon content differs within the samples as well as between the samples. A correlation exists between the average carbon content in a sample and the meltdown temperature. Some differences in the iron structure and the carbon content between the crucible wall and the crucible centre are discussed. Because no big difference in carbon content was found between the crucible wall and the crucible centre most of the carbon in the samples probably dissolves in the metal by a gas reaction where CO gas forms carbon and CO2 .
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| 2. |
- Hahlin, Pär, et al.
(författare)
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Raceway depth measurements in the blast furnace using microwave technology
- 2006
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Ingår i: 4th International Congress on the Science and Technology of Ironmarking, ICSTI 2006, Proceedings. ; , s. 504-507
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Konferensbidrag (refereegranskat)abstract
- Attempts to control the raceway depth have been made with many different technologies however none of them have had the capability to measure during operation. By using microwave technology the problem with interfering obstacles such as the coal injection can be avoided since the technology is not susceptible to this kind of interference. In this paper a novel approach using microwave technology to measure the raceway variations during operation will be described. MEFOS, The Metallurgical Research Institute AB, Lulea, Sweden, has tested an especially developed microwave unit to continuously measure the variations of the raceway during operation in the Blast Furnace. The trials were performed as a single tuyère trial on Blast Furnace 3 at SSAB Tunnplat AB, Lulea, Sweden with excellent results.
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| 3. |
- Malmberg, Donald, et al.
(författare)
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Microwave Technology in Steel and Metal Industry, an Overview
- 2007
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Ingår i: ISIJ International. - Tokyo : Nippon Tekko Kyokai. - 0915-1559 .- 1347-5460. ; 47:4, s. 533-538
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Tidskriftsartikel (refereegranskat)abstract
- In many metallurgical operations, effective analysis of the processes can be very difficult with available technology. This is especially true if the analysis is to be performed on-line and in a harsh environment characterized by high temperatures, dust and liquid metal. Protection of the equipment requires both rugged encapsulation as well as elaborate sampling systems and exposure of the equipment to the hazardous environment must be minimised. Often this result in an increased level of service and maintenance requirements and, in the worst case, the maintenance cost might be so high that the equipment is not installed. Microwave technology is a versatile and powerful tool with many different applications in the scientific community. It is insensitive to dust and fume and, for several years, the technology has been tested at MEFOS and evaluated for different metallurgical processes. It has been applied to slag thickness measurement and slag composition in an induction furnace, 3D imaging of the burden surface in a charging model on pilot scale as well as raceway depth measurements in a Blast Furnace. The idea of using microwave technology for gas analysis in metallurgical processes has also been explored. However, despite its many advantages, microwave technology is still not employed extensively in the steel and metal industries. Copyright © 2007 ISIJ.
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| 4. |
- Sundqvist Ökvist, L., et al.
(författare)
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Effect of coal properties, injection rate and O2 addition on BF conditions
- 2006
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Ingår i: 4th International Congress on the Science and Technology of Ironmarking, ICSTI 2006, Proceedings. ; , s. 327-330
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Konferensbidrag (refereegranskat)abstract
- A test with different coal grades, injection rates and methods for oxygen addition has been performed in the LKAB experimental BF (EBF). The EBF test results are compared with results achieved at BF No. 3 at SSAB Tunnplåt in Luleå. The BF conditions have been studied by evaluation of process data, vertical temperature measurements and under-burden probe data in terms of temperature and gas composition. The generation of fines has been studied in samples taken out by solid sampling in the shaft and in samples of BF flue dust and sludge. The samples have been analysed by tumbler tests, chemical analyses, XRD and light microscopy. The type of PC used turned out to have a great effect on the consumption of reducing agents as well as on the dust generation. Effects seen on the BF gas composition and alkali behaviour that affected the raw material behaviour could be seen when the low volatile coal was changed into a high volatile coal. The vertical temperature profile was greatly influenced by the PCR, which also had an effect on the dust generation.
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