WO2010063157A1

WO2010063157A1 - An iron trough of single-taphole furnace

Info

Publication number: WO2010063157A1
Application number: PCT/CN2009/000293
Authority: WO
Inventors: 章荣会
Original assignee: 北京联合荣大工程材料技术研究院有限公司
Priority date: 2008-12-05
Filing date: 2009-03-18
Publication date: 2010-06-10
Also published as: CN101497930A

Abstract

An iron trough of single-taphole furnace comprises major iron trough and branch iron trough, in which the major iron trough is iron-storage iron trough. The material of the iron trough is Al₂O₃-SiC-C refractory castable material. The structure and material of the iron trough can extend the life of the iron trough.

Description

Description: A single iron mouth blast furnace tapping groove

The invention relates to a long-lived single iron mouth blast furnace tapping groove. Background technique

High-quality A1 ₂ 0 ₃ - SiC- C low cement castables have been widely used in modern large blast furnace tapping ditch. Because of the high casting density of the castable, the refractory castable is more resistant to erosion than the refractory ramming material of the same material, so the service life is longer. However, the traditional A1 ₂ 0 ₃ - SiC- C low-cement refractory castable cast iron trench must be cleaned, baked and dried before it can be put into use. The iron trench is poured (repaired) to put into use (starting iron tapping) It takes a long time (one day or even several days).

Generally, the large blast furnace has more than two iron taps. Therefore, when one of the iron trenches has to be re-lined or must be repaired, the iron trench is poured and cured after the iron gate of the iron trench is blocked. Dry and bake. At the same time, the tapping of other tapping outlets is normal and does not affect the normal production of the blast furnace.

However, small and medium sized blast furnaces with a volume of less than 1000 cubic meters are generally designed as a single taphole. Since there is only one tapping port, the normal tapping interval is only about 1~3 hours, and the planned wind-off time is usually only 8~10 hours, so it is impossible to have time to ensure the maintenance and baking required for the general castable lining. time. Therefore, blast furnaces with single iron outlets generally use ramming materials to construct iron lining linings, because ramming materials are generally made of resin or tar. After battering, there is no need to bake or a short time to bake. molten iron.

However, there is a problem that the service life of the ramming material is too short, and the service life of the ramming material used for the main iron sump is generally only 1 to 15 days, and most of it is 3 to 5 days. This is because the lining refractory material of the beating is generally only a layer of a relatively dense surface at the bottom of the ditch, and the surface below the surface layer and the ditch portion are loose and incapable of scouring. Because the service life of the beaten iron ditch is too short, the iron ditch repair is too frequent, and the labor intensity of the workers in front of the furnace is too high. The quality of the lining is even more difficult to guarantee.

Therefore, how to effectively solve the problem of the life of the iron slab of the single iron mouth blast furnace has attracted much attention.

Patent 200610086925 proposes to solve the problem of short service life of the iron tapping of the single iron mouth blast furnace by using a resin combined with baking-free casting material instead of the ramming material. However, since the casting material is mainly composed of resin, the amount of resin is relatively large. In the actual use process, the structure of the castable body after burning is still loose, so the service life is far less than the long service life of the low cement combined A1 ₂ 0 ₃ - SiC-C castable used in the large blast furnace.

In fact, the reason why the large blast furnace iron ditch has a high iron content and long service life is not only because of the use of castables but also because of the use of the iron storage structure. That is to say, the main trench of the tapping gully of the large blast furnace always stores a large amount of molten iron in the iron ditch during the tapping period and the interval between the tapping intervals, so that the temperature environment of the iron ditch refractory material is relatively constant. However, the iron sump of the small blast furnace is completely exposed to the air after the iron is discharged. The temperature of the iron sulcus is rapidly reduced, and the refractory material will repeatedly suffer from the problem of rapid cooling due to sudden temperature drop and shrinkage. In addition, there is always a large amount of molten iron remaining in the main ditch of the iron-storage structure. Therefore, the force of the molten iron that is washed out from the taphole and dropped into the bottom of the ditch is stored in the molten iron at the bottom of the ditch. The bottom of the iron ditch forms too much impact, and this drop iron impact is one of the most important reasons for the damage of the main iron ditch of the small blast furnace.

However, so far, there is no single iron-iron blast furnace iron furrow iron-type iron tapping process and practice, because if there is no suitable fast-hard baking iron ditch castable for matching, it will not be able to achieve subsequent rapid repair. And maintenance, and the repair of this iron ditch is necessary and continuous. Summary of the invention

The technical problem to be solved by the present invention is to provide a single iron mouth blast furnace tapping groove with a long service life. Firstly, an improved low-cement bonded Al ₂ O ₃ -SiC-C refractory castable with fast hardening properties and fast baking without bursting is provided, which can be used for on-site casting, And it can be poured by hot-dip refractory castable without long-time baking, so that high-density and erosion-resistant can be obtained, and the short curing and baking time required for the single iron mouth blast furnace tapping groove can be satisfied to adapt to the single iron mouth blast furnace. Produce a rhythm tapping groove to obtain a tapping groove that has a long service life and can withstand rapid baking without bursting; Moreover, an iron storage type iron sump for a single iron mouth blast furnace is provided, and the structure of the iron storage type iron sump is always rusted from the tap hole due to the fact that a large amount of molten iron remains in the main iron ditch. The strength of the molten iron that hits and falls down the bottom of the ditch is stored in the molten iron buffer at the bottom of the ditch, which does not cause too much impact on the bottom of the iron ditch, thereby improving the service life of the iron ditch.

The refractory castable provided by the invention adopts corundum or high-aluminum refractory aggregate as aggregate, SiC, fused white corundum powder, asphalt powder, metal Si powder and the like as a powder, and calcium aluminate cement as a binder, and Explosion-proof components such as metal aluminum powder, aluminum lactate, azoformamide, and polypropylene fiber are added. Therefore, a refractory castable which can be used for on-site casting and can pass through molten iron without long-time baking is prepared, and is used for lining or repairing the cast iron groove of the single iron mouth blast furnace.

The preferred composition of the specific material of the refractory castable is as follows:

The 15 materials in the above ingredients are mixed and mixed into a premix for use. When used, it is only necessary to add 5~8% of tap water weight to mix and mix into sand and slurry for pouring.

The invention also provides an iron storage type iron tapping groove, which is to transform the traditional non-storage iron tapping main trench into a main iron storage tapping trench. The specific structure of the iron storage main ditch is: firstly raise the elevation of the bottom of the iron ditch at the outlet end of the skimmer, so that the elevation of the bottom of the iron ditch at the exit end of the skimmer is much higher than that of the skimmer. The elevation of the bottom of the main ditch at the mouth; and to ensure that the elevation of the bottom of the iron ditch at the exit end of the skimmer is close to the height of the lower edge of the taphole of the blast furnace, only slightly lower than the height of the lower edge of the taphole of the blast furnace by 5~10cm; The ditch starts from the blast furnace taphole to the slag remover at about 1 m, and the ditch bottom elevation sinks rapidly, so that the ditch bottom slope is reduced, so that more molten iron can remain in the main ditch after each blast furnace discharge.

The iron storage main trench will be further described below with reference to the accompanying drawings - the conventional single iron mouth blast furnace main iron trench, see Figure 1. Among them, 1 is the blast furnace taphole, 2 is the main iron 'ditch, 3 is the skimmer beam, and 4 is the branch iron trench. The slope of the main iron groove bottom is large, and the bottom elevation of the iron sump outlet of the skimmer is almost close to the elevation b of the bottom of the main trench at the front entrance of the skimmer. Therefore, after the iron is discharged four times, there will be no residual molten iron at the bottom of the main iron ditch. In fact, after the iron is drained from the traditional main iron ditch, there is no molten iron left in the ditch. The traditional method of operation is to lay yellow sand on the bottom of the main ditch before the furnace is discharged, so that the next time Clean up a small amount of residual iron or residue.

The iron storage main tapping groove of the present invention can be seen in Fig. 2. Among them, 1 is the blast furnace taphole, 2 is the main iron trench, 3 is the skimmer lintel, and 4 is the branch iron trench. Firstly, raise the elevation of the bottom of the iron sulcus at the outlet end of the skimmer, so that the elevation c of the bottom of the iron sulcus at the outlet end of the skimmer is much higher than the elevation b of the bottom of the main trench at the inlet of the skimmer; The elevation c is close to the height a of the lower edge of the taphole, which is slightly lower than the height of the lower edge of the taphole by 5 to 10 cm. The main iron ditch starts from the taphole to the direction of the skimmer at about 1 m, and the elevation of the ditch bottom sinks rapidly. The slope of the ditch bottom is reduced, so that more molten iron can remain in the main ditch after the molten iron is discharged every time in the blast furnace.

In the tapping ditch provided by this scheme, a large amount of molten iron will always be stored in the main iron ditch, so that the main iron ditch iron becomes the main ditch of the iron storage type tapping. The iron storage type iron tapping groove will greatly improve the quenching and hot environment of the refractory material, and the refractory material is better sintered, which is more conducive to the longevity of the refractory material. The main iron ditch in the tapping ditch provided by the scheme, each time the new tap water is sprayed from the tapping ditch and the parabola falls, the molten iron will not directly lie on the refractory material at the bottom of the ditch, but falls on the remaining iron. On the water, this will provide excellent cushioning for the refractory material at the bottom of the trench, which will greatly improve the life of the refractory.

The residual iron mouth at the bottom of the skimmer is still the same as the traditional method of retaining. When the main iron trench or skimmer is to be repaired, the residual molten iron in the main iron trench and the skimmer will be from the residual iron mouth at the bottom of the skimmer. release.

The cast iron type iron tapping groove having the above structure is cast by using the castable according to the present invention, and the mold can be demolded in 1 hour after pouring, and can be immediately fired, and the iron can be used after about 30 minutes.

When the iron tap is repaired by the castable according to the present invention, the casting or smearing process can be adopted, and the mold can be demolded immediately after casting, and can be immediately fired for 10 to 20 minutes.

The advantages of the invention are:

1. Since there is always more molten iron in the main iron ditch, the molten iron will not fall directly on the ditch refractory material, but will fall on the remaining iron water, which will give the ditch refractory material excellent. Buffering has great benefits for extending the life of refractories;

2. Since a large amount of molten iron remains in the main iron ditch, the temperature in the ditch is relatively constant, and the refractory material is relatively less affected by rapid cooling and rapid heat, which has great benefits for extending the life of the refractory material;

3. Since the lining is constructed by pouring method, the groove lining constructed is dense from the surface to the inside, and there is no problem that the smashing material has only a dense surface and a loose interior, so the service life of the tapping groove can be greatly extended;

4, Because the rapid drying and explosion-proof technology is solved, the technical possibility of using the high-quality iron ditch of the large blast furnace for the iron slag of the small blast furnace can be solved. The castable foundation of the scheme is the cast iron pouring material of the large blast furnace. The use of blast furnace furrows for small blast furnace tapping trenches is expected to achieve longer life.

5. Due to the significant extension of the service life of the tapping ditch, the labor intensity of the maintenance work of the furnace workers is greatly reduced;

6. Since the service life of the iron tap is greatly prolonged, the consumption of iron trench material per unit of iron output is also greatly reduced, which not only brings about economic benefits, but also the benefits of resource conservation and waste reduction in environmental protection. DRAWINGS

1 is a schematic cross-sectional view of a conventional single iron mouth blast furnace main iron ditch, 1 is a blast furnace taphole, 2 is a main iron ditch, 3 is a skimmer lintel, and 4 is a branch iron ditch;

2 is a schematic view showing the structure of the main structure of the iron storage type tapping of the present invention, wherein 1 is a schematic diagram of the taphole of the blast furnace, 2 is a main iron ditch, 3 is a skimmer beam, and 4 is a branch iron ditch. EXAMPLES Using this scheme, the main iron ditch of a 450 cubic meter blast furnace of a steel company was reformed. The results are as follows: The material batching plan is shown in the following table -

The 15 materials in the above ingredients are mixed and mixed into a premix for use. Only dry mix is needed for use. After mixing 6% tap water into mortar, the 3# blast furnace iron ditch of the plant was transformed into iron storage type according to the structure of Fig. 2 above.

The casting range includes all the main iron furrows and all the iron furrows. The mold is demolded about 30 minutes after pouring and immediately fired. When the iron ditch was first modified, the roasting time was about 6 hours. After the surface became red, the iron was started.

The main iron ditch does not repair the amount of iron in excess of 100,000 tons at a time, and the iron-clad ditch does not repair more than 150,000 tons of iron.

When repairing the above-mentioned iron ditch, the operation method is to use the above-mentioned castable material for casting or smearing, and immediately after demolding, the mold is demolded and the fire is immediately started to be baked, and the application site is immediately started to bake. After the fire is baked for 20 to 30 minutes, the iron is discharged.

Claims

Claim

1. A single iron mouth blast furnace tapping ditch, the tapping ditch having a main iron ditch and a branch iron ditch, wherein: the tapping ditch adopts a low cement combination which has fast hard property and can be quickly baked without bursting.

Casting of A1203-SiC-C refractory castable; the main iron ditch in the tapping ditch is the main trough of the cast iron type, that is, in the interval of the two tappings, a large amount of molten iron remains in the main iron ditch.

2. The single iron mouth blast furnace tapping groove according to claim 1. wherein the iron storage type tapping main groove has the following features: raising the elevation of the bottom of the iron sulcus at the outlet end of the skimmer, so that the slag is slag The elevation of the bottom of the iron-ditch groove at the outlet end of the vessel is much higher than the elevation of the bottom of the main trench at the inlet of the skimmer, and the elevation of the bottom of the iron-ditch of the outlet of the skimmer is close to the height of the lower edge of the taphole of the blast furnace. , only slightly lower than the height of the lower edge of the blast furnace taphole 5~10cm, the same; the main iron ditch starts from the blast furnace taphole to the slag remover at about 1 meter, and the ditch bottom elevation sinks rapidly, making the ditch' bottom slope It is reduced to ensure that there is always more molten iron in the main iron ditch after the molten iron is discharged every time.

3. The single iron mouth blast furnace tapping groove according to claim 1 or 2, characterized in that: the refractory castable is provided with metal aluminum powder, azoformamide, aluminum lactate and polypropylene fiber as explosion-proof components. .

4. The single iron mouth blast furnace tapping groove according to claim 1 or 2, wherein: the refractory castable used is composed of the following materials:

Material name particle size ratio

number

1 brown corundum 8~5mm 18~25 servings

2 5~3mm 10~18 parts

3 3~lmm 15~25 parts

4 1~ 0mm 3~9 parts

5 SIC95 l~0mm 5~8 parts

6 325 mesh 10 to 15 servings 7 fused white corundum 325 mesh 3~8 parts

8 high temperature asphalt 0.5mm 2~4 parts...

9 silicon micropowder 2~4 parts

10 metal silicon (97) 2~3 parts

11 polypropylene fiber 0.05~ 0.3

Share

12 calcium aluminate cement 2~5 parts

13 metal aluminum powder 0.05~ 0.5

Share

14 aluminum lactate 0.05~ 0.5

Share

15 azocarboxamide 0.05~ 0.5

Share

A single iron mouth blast furnace, characterized in that: the tapping groove of the blast furnace adopts the tapping groove according to any one of claims 1-4.

6. A method of preparing a tapping groove according to claim 1 or 2, comprising the steps of: mixing the refractory castable into a premix, adding 5 to 8% by weight of the mixture, mixing and stirring Cast after the mortar.

7. The method according to claim 6, wherein: the refractory material is selected from corundum or high alumina refractory aggregate, SiC:, fused white corundum powder, asphalt powder and metal Si powder. The material is a calcium aluminate cement as a binder, and metal aluminum powder, aluminum lactate, azoformamide, and polypropylene fiber are added as an explosion-proof component.

8. The method of claim 6 or 7, wherein the refractory material consists of the following materials:

Material name particle size ratio number

1 brown corundum 8~5mm 18~25 servings

2 5~3mm 10~18 parts

3 3~lmm 15~25 parts 4 l~0mm 3~9 parts

5 SIC95 l~0mm 5~8 parts

6 325 mesh 10 to 15 servings

7 fused white corundum 325 mesh 3 to 8 servings

8 high temperature asphalt 0.5mm 2~4 parts

9 silicon micropowder 2~4 parts

10 metal silicon (97) 2~3 parts

11 polypropylene fiber 0.05~ 0.3 parts

12 calcium aluminate cement 2~5 parts

13 metal aluminum powder 0.05~ 0.5 parts

14 aluminum lactate 0.05~ 0.5 parts

15 azocarboxamide 0.05~ 0.5 parts