Specialized metallurgical processes – compositions for use therei – Processes – Electrothermic processes
Patent
1992-12-10
1994-05-31
Rosenberg, Peter D.
Specialized metallurgical processes, compositions for use therei
Processes
Electrothermic processes
C21C 552
Patent
active
053165667
DESCRIPTION:
BRIEF SUMMARY
SUBJECT OF THE INVENTION
The present invention relates to a method for reheating a liquid steel bath contained in a metallurgical vessel.
TECHNOLOGICAL BACKGROUND
In the event of an accidental interruption in the running of the metallurgical process, between the smelting of the steel in the converter and the solidification operation, the liquid steel bath contained in a metallurgical vessel cools down and it is conventional to have to reheat it in order to permit the subsequent normal continuation of the process.
Such a bath can be reheated using a flame or electrically.
Various methods are also known which involve metallothermy, according to which methods a metallic fuel, for example aluminum, is introduced into the liquid steel bath and put into contact with an oxidizing agent, for example gaseous oxygen. The reaction between the combustible metal and the oxidant is exothermic, and the heat obtained is used for reheating the bath.
DESCRIPTION OF THE PRIOR ART
A vessel containing a liquid steel bath, which is reheated by using an aluminothermic method and by injecting stirring gas, is known from U.S. Pat. No. 4,761,178 and its equivalent, the application WO 89/01984.
A single consumable lance injects, under the liquid steel, oxidizing agents, especially gaseous oxygen, and an inert gas which are introduced, separately or as a mixture, at a depth of from 15 to 40% of the bath, by a plurality of parallel channels. Moreover, aluminum is introduced into the bath as close as possible to the point of oxygen injection.
It has been observed that the introduction of such a lance at this depth caused a significant amount of wear thereof. In addition, the reheating of the lower and the heat obtained is used for reheating the bath.
DESCRIPTION OF THE PRIOR ART
A vessel containing a liquid steel bath, which is reheated by using an aluminothermic method and by injecting stirring gas, is known from U.S. Pat. No. 4,761,178 and its equivalent, the application WO 89/01984.
A single consumable lance injects, under the liquid steel, oxidizing agents, especially gaseous oxygen, and an inert gas which are introduced, separately or as a mixture, at a depth of from 15 to 40% of the bath, by a plurality of parallel channels. Moreover, aluminum is introduced into the bath as close as possible to the point of oxygen injection.
It has been observed that the introduction of such a lance at this depth caused a significant amount of wear thereof. In addition, the reheating of the lower part of the bath is not particularly effective, as movements there are not very significant and the liquid steel is homogeneous neither in terms of temperature nor in terms of cleanliness with regard to inclusion.
A device is also known, from Document EP-A-0,352,254, for reheating a liquid steel bath during the filling of a metallurgical vessel via the top. This bath is covered by a slag rich in iron oxide. A metal or an alloy capable of reacting with the iron oxide of the slag and the oxides of the bath on the one hand, and an inert gas on the other hand, are injected, during the filling of the ladle, via its bottom. Furthermore, the reheating is completed by the presence of a burner in the region of the lid of the ladle.
Such a device does not provide for direct injection of oxidizing gas into the steel bath and is not intended to be used for reheating steel contained in a ladle which is already filled.
Document JP-A-5989708 describes a method according to which a current in a liquid steel bath is induced. An oxygen lance is introduced in the bath, and a stirring gas is injected in the bottom of the vessel by a porous brick located just in front of the oxygen lance. Uncontrollable turbulences in the steel, an imperfect distribution of the fuel and consequently a relatively low efficiency have been observed.
Finally, a ladle is known, from U.S. Pat. No. 486,935, containing liquid steel above the surface of which a bell is placed enclosing a non-consumable lance.
OBJECTS OF THE INVENTION
The object of the present invention is to provide a pe
REFERENCES:
patent: 4200452 (1980-04-01), Savov
Cockerill Sambre S.A.
Rosenberg Peter D.
LandOfFree
Liquid steel bath reheating method does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Liquid steel bath reheating method, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Liquid steel bath reheating method will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1625479