HUT60789A - Furnace pot for steel production and process for forming fireproof bottom lining of furnace pot - Google Patents

Abstract

The invention concerns a metallurgical vessel, in particular a transfer ladle or treatment vessel, with a floor (2b) having a refractory lining (3) with a basic main layer (5). In order to give a long-lasting lining, the invention calls for the main layer (5) to consist at least in part of dry, basic material which is poured in and the top of which is covered, before the vessel is heated for the first time, with a chemically hardened protective layer (6) and which, after the vessel (1) has been filled, consists partly of a monolithic layer, or the work layer (5) is covered, before the vessel (1) is filled for the first time, with a basic monolithic sintered layer produced by heating the basic material poured in. The invention also concerns a process for producing the refractory lining of a vessel of this kind.

Description

BACKGROUND OF THE INVENTION The present invention relates to a metallurgical vessel for the manufacture of steel having a refractory liner provided with a basic working layer, and to a process for making a refractory bottom liner of a vessel.

The quality of the linings of the metallurgical vessels used for the production of steel (electric furnaces, pig iron conveyors, steel conveyors or treatment vessels) depends on the metallurgical processes involved and the composition of the steel or slag, but in most cases basic linings are used.

Lining bodies are generally made of tar or synthetic resin, or otherwise made of chemically bonded and fused magnesite or dolomite blocks. However, there has long been experimentation with replacing such lining bodies with magnesite or dolomite masses in order to reduce the cost of producing and laying the lining bodies. All such attempts have been made using basic ramming compounds in the direction of replacing the sintered magnesite or dolomite with a binder which is activated by water and thus allows the mass to be cured as a monolithic liner. However, these attempts were not cost effective.

Monolithic liners containing such basic, chemically reactive binder at room temperature are highly rigid in all of them. Therefore, when heated, cracks are formed and the molten steel penetrates deeper into them and then destroys the liner over large areas.

In addition, chemical solutions for these solutions • ·

- Created by adding 3 water. However, this water does not completely leave the liner after hardening and drying and also causes cracking during heating. The use of water, especially for dolomite materials, also leads to hydration and, consequently, to a deterioration of the fire resistance properties.

In addition to the above, lining of dry basic material is used on the horizontal surfaces of electric furnaces. Most of the problem with these solutions is that the first time it is filled, the crushed material is washed away by the liquid steel. Therefore, if the dose includes a melt, the bottom of the furnace should be protected by draining cold waste.

However, in cases where the jet of molten metal falls freely to the bottom of the pan, especially in the case of steel conveyors or handling panes, the melting of the rammed liner during the first filling of the vessel remains a serious problem.

It is therefore an object of the present invention to provide a solution which enables the liner lined at the bottom of such metallurgical ladles to be formed in a simple and inexpensive manner, without the above disadvantages.

SUMMARY OF THE INVENTION According to the present invention, the basic working layer of the metallurgical vessel is formed at least in part by a dry rammed basic material with a chemically hardening, at least partly monolithic protective layer.

In another embodiment of the invention, the upper layer of the working layer forms at least partially a monolithic aggregate crust.

In the first embodiment of the present invention, a dry basic crushed material is applied to the working layer which forms a chemically hardening protective layer prior to the first heating of the vessel and forms at least partially a monolithic layer upon filling.

In fact, this layer is the most important layer of the liner that comes in direct contact with the liquid steel melt and remains permanently in the vessel, except for wear. This liner is surrounded by a protective layer. The working layer is introduced into the vessel as a dry substance, i.e. no water is used during its application. Optionally, however, the material may be impregnated with oil, bitumen, resin or the like, for example, to facilitate shaping and to avoid dust formation. The first heating of the liner is accomplished either by introducing the liquid steel or by heating the liner to operating temperature by means of burners.

When sintermagnesite or sinterdolomite is used, the material will aggregate at about 1200 ° C and form a crust layer. The temperature of the liquid steel is usually sufficient for the formation of such ceramic material to a depth of 40-60 mm. The monolithic lining layer formed after the introduction of the steel has a continuous wear on the molten side of the metal during operation, but at the same time it is continuously extended towards the jacket. The elongation of the ceramic layer during temperature changes (such as emptying or filling) is absorbed by the non-cured material on the cold side, i.e. no coarse cracking of the ceramic layer occurs.

In such a thin, ceramic-bonded flexible layer, the temperature changes produce fine cracks and any steel that leaks through it can flow into the cold-bonded non-bonded layer.

The protective layer thus has the function of preventing the lined liner from being washed during the first filling.

In an embodiment of the present invention wherein a cured base layer is formed, the liner is protected from leaching by heating the applied material and forming a monolithic cohesive layer on its surface.

If necessary, an insulating layer may be provided between the bottom of the vessel and the refractory basic working layer. The insulating layer may be sprayed and cured at room temperature, such as chamomile or clay paste.

The bottom of the vessel may have inserts, such as spout stones, stop stones or jets, which are rigidly connected to the bottom of the vessel or the insulating layer. It is generally necessary to tilt the metallurgical vessel during operation. This creates the risk that the relatively thin, cohesive working layer cannot support the heavy spout or other liner. It is generally necessary to form the insulating layer as a molded layer or otherwise secure the liners.

The impact plate inserted into the working layer is preferably molded at room temperature from a chemically bonded material. This is where the melt jet enters the vessel. Generally, however, the pad is protected by a protective layer against leaching.

Particularly advantageous when inserting the pads is protective ······ · · · · · · · · · · · · · · ·

- They are incised at the level of 6 layers. In this way, their interconnection is particularly well done.

Otherwise, it is advisable to form the insert elements with oblique sidewalls such that their cross-section changes as the wear progresses. This ensures that the continuously formed sintered layer always fits snugly into my insert. In general, it is practical to experiment with the optimum tilt angle in a given vessel.

The working layer material can be composed of color space magnesite, which preferably has a high lime content (CaO> 7%). The material may contain color space dolomite or a mixture of color space magnesite, color space dolomite and chromium or corundum. A material containing sintering aids such as iron oxide, boric acid, boron compounds, water glass or metal oxide powders proved to be particularly useful.

In the process of the present invention, the base liner of the metallurgical vessels is formed by layering a layer of dry basic blasting material on the bottom and / or insulating layer of the vessel, compacting the material by vibration or pounding, forming a protective layer curing the refractory mass and finally heating the liner.

The liner may be heated by introducing burners into the vessel or by pouring the first batch of molten metal.

In another embodiment of the process of the present invention, a dry, basic, refractory material is provided at the bottom of the container and / or. A layer is formed on the insulating layer, the layer is vibrated or rammed and the liner is heated with burners.

In general, it is preferable to use a paste which ceramically binds at the temperature of the steel melt and transfers the heat to the crushed layer. In this way, a crust forms on the steel bath side.

Preferably, sintering aids are used on the inside of the rammed layer.

Further details of the invention will be illustrated by way of an exemplary embodiment. In the drawing it is

Fig. 1 is a sectional view of the bottom of the bottom lining of the present invention, a

Figure 2 is a sectional view of the bottom of a bottom lined vessel made in accordance with another embodiment of the present invention;

Figure 3 is a top plan view of a possible design of a stop plate and a

Figure 4 is a sectional view of the stop plate shown in Figure 3 in a cosmetic vessel.

The metallic vessel 1 shown in the figures consists of side walls 2a and bottom plate 2b. The bottom plate 2b has a bottom liner 3 formed. It consists of 4 insulating layers and 5 working layers. The working layer 5 is made of a refractory basic material and has a protective layer 6.

In the embodiment shown in Figure 2, a nozzle 11 is disposed in the bottom lining 3. The nozzle 11 is fixed in 13 holes. The side walls 10 of the hole 13 are formed at an angle. At the level of the protective layer 6, a shoulder 8 is formed in the hole 13.

• «1« 4 * · · · · · · · · · · · · · · · · · · · · ·

4 4 44

444 444 · 4 444444

In addition, the anchor 7 is secured to the bottom plate 2b by means of iron.

The stop plate 9 shown in Figures 3 and 4 is also provided with angled side surfaces 10a and a shoulder 8a is formed at its upper part. This is where the protective layer 6 fits. The side 12 of the stop plate 9 is curved to fit the side wall 2a of the container 1.

Claims (14)

PATENT CLAIMS A metallurgical vessel for the manufacture of steel with a refractory liner having a basic working layer, characterized in that the working layer (5) is at least partially dry rammed base material, which is chemically hardened, at least partially provided with a monolithic protective layer (6). A metallurgical vessel for the manufacture of steel with a refractory liner having a basic working layer, characterized in that the working layer (5) is at least partially a dry crushed basic material having an upper layer at least partially forming a monolithic aggregate crust. Container according to claim 1 or 2, characterized in that there is an insulating layer (4) between the bottom plate (2b) and the refractory basic working layer (5). 4. Container according to any one of claims 1 to 3, characterized in that the insulating layer (4) is a sprayed and hardened mass at room temperature, preferably of chamomile or clay. 5. Container according to any one of claims 1 to 3, characterized in that inserts such as a hole (13), a stop plate (9) or a nozzle (11) are arranged in the bottom liner (3) so that they are rigidly connected to the protective layer (4) or bottom plate (2b). are turned on. Container according to claim 5, characterized in that the inserts are provided at the height of the protective layer (6). Container according to claim 5 or 6, characterized in that the inserts are formed with angled side walls (10, 10a). 8. Container according to any one of claims 1 to 3, characterized in that the material constituting the working layer (5) consists of a color space magnesite, preferably having a CaO content of more than 7%, a color space dolomite or mixtures of color space magnesite and color space dolomite and chromium or corundum. 9. Container according to any one of claims 1 to 4, characterized in that the material constituting the working layer (5) comprises sintering aids, such as iron oxide, boric acid, boron compounds, dry water glass or metal oxide powders. 10. A method of forming the bottom of a metallurgical vessel used in steel production, characterized in that: - forming a layer of dry basic refractory material on the bottom of the vessel and / or on the insulating layer, - compressing the layer by vibration or vibration, - applying a protective layer made of chemically hardening mass to the working layer, and then drying and curing the mass and finally heating the bottom liner. 11. A process for producing a bottom liner for a metallurgical vessel used in steel production, characterized in that: - forming a layer of dry basic refractory material on the base plate and / or insulating layer, - compacting the layer by vibrating or ramming and heating the bottom liner with burners. 12. The method of claim 10, wherein said material is joined by a ceramic bond at the temperature of the steel melt and fused with said metal melt. ··· · 13. The method of claim 10, wherein the vessel is heated by means of burners prior to introducing the molten metal. 14. A 10-13. A process according to any one of claims 1 to 3, characterized in that sintering aids are applied to the outer part of the working layer.