No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Blast furnace relining strategies for campaign lives of more than 20 years
Abstract
Owing to the concentration of hot-metal production on a few large-capacity blast furnaces only, it is imperative to fully use all technical opportunities for extending the blast furnace campaigns. The design and the layout of blast furnaces together with the blast furnace operation are the most important criteria for the campaign life. The admittedly high level of the state of the art, at the same time be regarded as a challenge for the future to expand the available know-how to ensure minimization of the abrasive, thermal and chemical wear and as such to massively extend the service life of all units of an integrated furnace plant.
The damage of cooling devices is the barometer for people to observe the damage of furnace body. Once the cooling devices are burned, the surface is deformed and cracked, gas and flame will be ejected if it occurs in the stack; if it is in the belly of the furnace, coke and slag will be ejected. At that time, if water leaks into the furnace in an instant, a large amount of water gas would be produced and thus leading to explode, which is enough to destroy the furnace itself. If it occurs in the hearth, the hot metal will outflow from the hearth, leading to destructive, unpredictable explosion when meets with water.
The growing production of hot metal - in due relation to the demand - forms the basis of the world's increasing demand for steel. In this context the blast furnace process will remain the number one ore reduction process. In Germany hot metal and crude steel are produced on a competitive basis at several integrated steel works using blast furnaces and basic oxygen converters which are world leading in terms of plant technology and operation. Within the framework of research programs, the development of an oxygen blast furnace process is underway, which - in combination with a CO2 capture and storage (CCS) system - is expected to massively reduce CO2 emissions from hot metal making. Direct reduction processes produce solid direct reduced iron (DRI) from iron ore without the use of coke. DRI is mostly used as input material in electric steelmaking. The majority of the DRI is produced in gas-based processes, especially at locations where low-cost natural gas is available. The intention of coal-based smelting reduction processes is to produce liquid hot metal without or only with very small amounts of coke. Of the various technologies, the Corex and the Finex processes have so far been applied to industrial-scale production. Whereas the Corex process relies on the use of lumpy ore charge, Finex can be operated with fine ores. Both processes will require the CCS technology to achieve a substantial reduction in CO 2 emissions.
Data on some novel kinds of refractory articles and materials developed and produced by the Berezhnoy Ukrainian Research Institute
for Refractories (Berezhnoy UkrNIIO) are presented. Corundum articles with Sialon binder and unshaped materials of various
kinds (ramming mixtures, dry mixtures, traditional and low-cement refractory concretes) containing normal electrocorundum
or refractory scrap instead of the costly white electrocorundum are described.
The article contains sections titled:
Hearth life is a decisive factor for the economic efficiency of the blast furnace process and the production of hot metal as it has a prominent influence on the duration of blast furnace campaigns. Different hearth lining concepts are explained and evaluated, and several important findings from research on the topic of flow conditions and wear in blast furnace hearths are discussed. Hearth wear was the subject of direct simulation in a physical model developed by Betriebsforschungsinstitut, and was compared with the wear profile of a selected blast furnace currently operating at Thyssen Krupp Stahl AG. The influence of different parameters on the flow conditions in the hearth and on hearth drainage were additionally examined by mathematical simulation. The physical conditions in blast furnace hearths have hereby become more understandable. With due consideration given to operating data and experience, it can be said that the use of simulation methods constitutes a suitable means for developing specific operational measures with a view to enhancing the tapping technique and prolonging the hearth life.