阅读说明：本技术 一种长寿命的转炉出钢口 (Long-life converter tapping hole ) 是由 董战春 刘涛 周立平 李涛 王丽丽 于 2020-12-02 设计创作，主要内容包括：本发明属于钢铁冶炼技术领域,具体涉及一种长寿命的转炉出钢口,所述出钢口的套砖为添加有抗氧化剂的MT-18镁碳耐火砖；所述出钢口处的填充料为包括电熔镁砂、SiO-2微粉、Cr-2O-3粉、减水剂PS10和悬浮剂的混合物。针对目前现场使用的出钢口情况和出现的问题,本发明通过对转炉出钢口的材料进行改进,并对出钢口填充物料成分配比方案进行优化,可有效延长转炉出钢口的综合使用寿命,更加方便服务于生产。(The invention belongs to the technical field of steel smelting, and particularly relates to a converter steel-tapping hole with a long service life, wherein a sleeve brick of the steel-tapping hole is an MT-18 magnesia carbon refractory brick added with an antioxidant; the filler at the tap hole comprises fused magnesia and SiO 2 Micro powder, Cr 2 O 3 A mixture of powder, water reducing agent PS10 and a suspending agent. Aiming at the condition and the problems of the steel tapping hole used on site at present, the invention improves the material of the steel tapping hole of the converter and optimizes the component proportioning scheme of the filling material of the steel tapping hole, thereby effectively prolonging the comprehensive service life of the steel tapping hole of the converter and being more convenient for service in production.)

1. The long-life converter steel tapping hole is characterized in that a sleeve brick of the steel tapping hole is an MT-18 magnesia carbon refractory brick added with an antioxidant;

the filler of the steel tapping hole comprises fused magnesia aggregate, fused magnesia fine powder and SiO₂Micro powder, Cr₂O₃A mixture of powder, water reducing agent PS10 and a suspending agent.

2. The converter tap hole of claim 1, wherein said antioxidant is a mixture of aluminum powder and silicon powder; preferably, the mass ratio of the aluminum powder to the silicon powder is 1: 0.1-1: 0.5.

3. The converter tap hole of claim 1, wherein said filler comprises 55-75 parts of fused magnesite aggregate and 20-35 parts of fused magnesite fine powder per 100 parts of filler; SiO2₂4-8 parts of micro powder and Cr₂O₃2-4 parts of powder;

the addition amount of the water reducing agent PS10 is fused magnesite aggregate, fused magnesite fine powder and SiO₂Fine powder of (2) and Cr₂O₃0.2-1% of the total powder; the addition amount of the suspending agent is fused magnesia aggregate, fused magnesia fine powder and SiO₂Fine powder of (2) and Cr₂O₃0.3-0.5% of the total powder.

4. The converter tap hole of claim 1 or 3, wherein the fused magnesite aggregate has a particle size of 0.074-8 mm, and/or the fused magnesite fine powder has a particle size of < 0.074 mm.

5. The converter tap hole of claim 1 or 3 wherein said SiO is₂The granularity of the micro powder is D50 not more than 2 um.

6. The converter tap hole of claim 1 or 3, wherein said Cr is present in a form selected from the group consisting of₂O₃The granularity of the powder is less than or equal to 0.044 mm.

7. The converter tap hole of claim 1 or 3 wherein said suspending agent is one or more of carboxymethylcellulose, yellow dextrin or gelatine powder.

8. The converter tap hole according to any one of claims 1 to 7, wherein the size of the tap hole is controlled so that the tapping time of the molten steel is controlled to be 3.0 to 4.0 min.

9. The tap hole of the converter according to any one of claims 1 to 7, wherein said tap hole has an inner diameter of 140 to 150mm and an outer diameter of 280 to 290 mm.

10. The converter tap hole of any one of claims 1 to 9, wherein said brick jacket is an MT-18 magnesia carbon refractory brick added with an antioxidant; the antioxidant is a mixture of aluminum powder and silicon powder; the mass ratio of the aluminum powder to the silicon powder is 1: 0.2-1: 0.4;

the filler of the steel tapping hole comprises fused magnesia aggregate, fused magnesia fine powder and SiO₂Micro powder, Cr₂O₃A mixture of powder, water reducing agent PS10 and suspending agent; every 100 parts of the filler comprises 58-62 parts of fused magnesia aggregate and 29-33 parts of fused magnesia fine powder; SiO2₂4-8 parts of micro powder and Cr₂O₃2-4 parts of powder;

the addition amount of the water reducing agent PS10 is fused magnesite aggregate, fused magnesite fine powder and SiO₂Fine powder of (2) and Cr₂O₃0.2-1% of the total powder; the addition amount of the suspending agent is fused magnesia aggregate, fused magnesia fine powder and SiO₂Fine powder of (2) and Cr₂O₃0.3-0.5% of the total powder;

the inner diameter of the steel tapping hole is 140-150 mm, and the outer diameter of the steel tapping hole is 280-290 mm.

Technical Field

The invention belongs to the technical field of steel smelting, and particularly relates to a converter steel tapping hole with a long service life.

Background

The converter is the main equipment for steel making at present, the tap hole is used as a necessary channel for pouring molten steel from the converter into a ladle, the working condition is quite severe, and the converter is often affected by the effects of the erosion of molten steel and slag, mechanical scouring damage, chemical erosion of high-temperature slag and the like. During the use process, the traditional tapping hole has the phenomenon that the expansion rate of the inner diameter is too fast, and the phenomenon can bring the following problems to the production of the converter: 1) the aperture of the steel-tapping hole tubular brick is continuously enlarged in the using process, the steel flow is simultaneously increased, the steel-tapping time is shortened, in order to ensure the normal smelting rhythm, the steel-tapping time must be controlled within a certain range and exceeds the range, the steel-tapping hole tubular brick must be replaced to meet the process requirement, the hot repair frequency needs to be increased, the production operation rate is indirectly reduced, and the converter smelting cost is increased; 2) when the steel-tapping hole pipe brick is used to the final stage, the phenomenon of molten steel scattering can be caused due to serious reaming of the tail part of the steel-tapping hole pipe brick, so that part of molten steel is oxidized again, the yield is reduced, the quality of the molten steel is influenced, and extra smelting cost is added to the refining and continuous casting process; 3) in order to ensure normal production, the existing converter site generally adopts magnesium or magnesium-chromium castable to fill and repair on time according to needs so as to slow down the damage speed of a steel tapping hole, but the repair operation difficulty is high, and the repair process can influence the production of steel.

Disclosure of Invention

Aiming at the problems of easy loss of the steel tapping hole and high difficulty in repair operation in the prior art, the invention provides an optimized steel tapping hole structure.

The sleeve brick of the steel tapping hole is an MT-18 magnesia carbon refractory brick added with an antioxidant;

the filler at the steel tapping hole is fused magnesia aggregate, fused magnesia fine powder and SiO₂Micro powder, Cr₂O₃A mixture of powder, water reducing agent PS10 and a suspending agent.

The invention can effectively improve the wear resistance of the steel-tapping hole by the optimized selection of the sleeve brick and the matched selection of the filling material connected with the sleeve brick, the material quality of the steel-tapping hole is improved from MT-14A to MT-18A, and simultaneously, the antioxidant is added, so that the steel-tapping hole sleeve brick has better high-temperature corrosion resistance and high-temperature compressive strength, has higher antioxidant capacity, and creates basic conditions for prolonging the service life of the steel-tapping hole. The magnesia is fused by using the special magnesia gravity-flow filling material which has high magnesia content, good high-temperature thermal gravity-flow performance, fine particle size distribution and uniformity and no sedimentation in the conveying processUnder the action of the external force, the gap between the steel-tapping hole pocket brick and the sleeve brick can be completely filled, the sintering layer is uniform, the strength is high, and the advantage of long service life of the improved steel-tapping hole sleeve brick can be effectively ensured. Meanwhile, the gravity-flow filling selects fused magnesia fine powder and Cr with high magnesia content by taking fused magnesia particles as aggregate₂0₃Powder, SiO₂The micro powder and the like are taken as substrates, so that the phosphorus increase of molten steel during the tapping process by the filler at the tapping hole can be avoided. The use of the water reducing agent PS10 improves the repulsive force of particle surface enlarging particles in the solution to a greater extent, increases the wetting effect of material molecules, promotes the material to disperse quickly and uniformly, reduces the formation of magnesium-silicon gel due to the precipitation of free water in a condensation structure, and improves the high-temperature heat fluidity of the magnesium castable.

Preferably, the antioxidant is a mixture of aluminum powder and silicon powder. The mixture of the aluminum powder and the silicon powder is used as a composite antioxidant, which is beneficial to prolonging the service life of the steel tapping hole.

Preferably, the mass ratio of the aluminum powder to the silicon powder is 1: 0.1-1: 0.5.

Preferably, each 100 parts of the filler comprises 55-75 parts of fused magnesia aggregate, 20-35 parts of fused magnesia fine powder with high magnesia content and SiO₂4-8 parts of micro powder and Cr₂O₃2-4 parts of powder.

The addition amount of the water reducing agent PS10 is 0.2-1% of the total amount of fused magnesia, SiO2 micro powder and Cr2O3 powder; the addition amount of the suspending agent is 0.3-0.5% of the total amount of the fused magnesia, the SiO2 micro powder and the Cr2O3 powder.

Preferably, the granularity of the fused magnesia is 0.074-8 mm, the maximum critical granularity can reach 8mm, the structure of a filling layer can be more compact, and the scouring resistance and the erosion resistance are better.

Preferably, the granularity of the fused magnesia fine powder is less than 0.074mm, the fine powder with the granularity has good self-flowing performance and more uniform filling layer structure, and the filler at the steel tapping hole is prevented from increasing phosphorus to molten steel in the steel tapping process.

Preferably, the SiO₂The granularity of the micro powder is D50 not more than 2 um.

It is preferable thatSaid Cr being₂O₃The granularity of the powder is less than or equal to 0.044 mm.

Preferably, the suspending agent is one or more of carboxymethyl cellulose, yellow dextrin and rubber powder.

Preferably, the caliber of the steel tapping hole is controlled to control the steel tapping time of the molten steel to be 3.0-4.0 min. The tapping time of the tapping hole is shorter than that of the common tapping time, so that the corrosion to the tapped steel product can be reduced.

Preferably, the inner diameter of the steel tapping hole is 140-150 mm, and the outer diameter of the steel tapping hole is 280-290 mm. The tapping time of the Korea-grade molten steel within the diameter range is 3.0-4.0 min.

Preferably, the sleeve brick of the steel tapping hole is an MT-18 magnesia carbon refractory brick added with an antioxidant; the antioxidant is a mixture of aluminum powder and silicon powder; the mass ratio of the aluminum powder to the silicon powder is 1: 0.2-1: 0.4;

the filler of the steel tapping hole comprises fused magnesia aggregate, fused magnesia fine powder and SiO₂Micro powder, Cr₂O₃A mixture of powder, water reducing agent PS10 and suspending agent; every 100 parts of the filler comprises 58-62 parts of fused magnesia aggregate and 29-33 parts of fused magnesia fine powder; SiO2₂4-8 parts of micro powder and Cr₂O₃2-4 parts of powder;

the addition amount of the water reducing agent PS10 is fused magnesite aggregate, fused magnesite fine powder and SiO₂Fine powder of (2) and Cr₂O₃0.2-1% of the total powder; the addition amount of the suspending agent is fused magnesia aggregate, fused magnesia fine powder and SiO₂Fine powder of (2) and Cr₂O₃0.3-0.5% of the total powder.

The inner diameter of the steel tapping hole is 140-150 mm, and the outer diameter of the steel tapping hole is 280-290 mm.

The invention has the following beneficial effects:

1) the invention selects MT-18 as the casing brick and selects fused magnesia and SiO₂Micro powder Cr₂O₃The mixture of the powder, the water reducing agent PS10 and the suspending agent is used as a filling material to be matched with the filling material, so that the gap between the steel outlet pocket brick and the sleeve brick can be completely filled without the help of external forceThe solid and sintered layer is uniform and high in strength, and the advantage of long service life of the steel-tapping hole sleeve brick with improved structure and material can be effectively guaranteed.

2) The invention further shortens the tapping time of the molten steel, greatly lightens the oxidation erosion and the mechanical scouring of the high-temperature molten steel to the inner wall of the tapping hole, and effectively prolongs the whole service life.

3) The steel tapping hole is matched with the quick-change bowl brick for use, so that the service life of the steel tapping hole can be further effectively prolonged.

Drawings

FIG. 1 is a schematic view of the structure of the tap hole according to example 1.

Detailed Description

The present invention will be described below with reference to specific embodiments, but the following examples are not intended to limit the present invention.

Example 1

The embodiment relates to a steel-tapping hole (the structural schematic diagram of the steel-tapping hole is shown in figure 1), the steel-tapping hole is an MT-18 magnesia carbon refractory brick, an antioxidant is added into the refractory brick, the antioxidant is a composite antioxidant of aluminum powder and silicon powder, the mass ratio of the aluminum powder to the silicon powder is 1:0.35, the inner diameter of the steel-tapping hole is 150mm, and the outer diameter of the steel-tapping hole is 290 mm.

The filler at the tap hole in this example was 60% (w) fused magnesia particles, 31.5% (w) fused magnesia fine powder, 5.5% (w) SiO₂Fine powder of (2), 3.0% (w) of Cr2O3 powder. Adding water reducing agent PS10 accounting for 0.5% (w) of the filler and suspending agent accounting for 0.4% (w).

The granularity of the fused magnesia particles is 0.074-8 mm, the granularity of fused magnesia fine powder is less than 0.074mm, and the SiO is₂The granularity of the micro powder is D50 which is not more than 2um, and the Cr is₂O₃The granularity of the powder is less than or equal to 0.044 mm.

Example 2

The embodiment relates to a steel tapping hole, wherein the steel tapping hole is an MT-18 magnesia carbon refractory brick, an antioxidant is added into the refractory brick, the antioxidant is a composite antioxidant of aluminum powder and silicon powder, the mass ratio of the aluminum powder to the silicon powder is 1:0.35, the inner diameter of the steel tapping hole is 150mm, and the outer diameter of the steel tapping hole is 290 mm.

The filler at the tap hole in this example was 60% (w) fused magnesia particles, 33% (w) fused magnesia fine powder, 4.0% (w) SiO₂Micro powder of (2), 3.0% (w) of Cr₂O₃And (3) pulverizing. Adding water reducing agent PS10 accounting for 0.5% (w) of the filler and suspending agent accounting for 0.4% (w).

The granularity of the fused magnesia particles is 0.074-8 mm, the granularity of fused magnesia fine powder is less than 0.074mm, the granularity of SiO2 micro powder is D50 which is less than or equal to 2um, and the granularity of Cr2O3 powder is less than or equal to 0.044 mm.

Example 3

The embodiment relates to a steel tapping hole, wherein the steel tapping hole is an MT-18 magnesia carbon refractory brick, an antioxidant is added into the refractory brick, the antioxidant is a composite antioxidant of aluminum powder and silicon powder, and the mass ratio of the aluminum powder to the silicon powder is 1:0.35, the inner diameter of the steel tapping hole is 150mm, and the outer diameter of the steel tapping hole is 290 mm.

The tapping hole structure of the embodiment is provided with a bowl brick structure shown in a long-life quick-change bowl brick tapping hole in the attached figure 1.

The filler at the tap hole in this example was 60% (w) fused magnesia particles, 29% (w) fused magnesia fine powder, 8.0% (w) SiO₂Micro powder of (2), 3.0% (w) of Cr₂O₃And (3) pulverizing. Adding water reducing agent PS10 accounting for 0.5% (w) of the filler and suspending agent accounting for 0.4% (w).

The particle size of the electric melting magnesite grains is 0.074-8 mm, the particle size of the electric melting magnesite fine powder is less than 0.074mm, the particle size of the SiO2 micro powder is D50 which is less than or equal to 2um, and the particle size of the Cr2O3 powder is less than or equal to 0.044 mm.

Experimental example 1

Example 1, which uses the above process technology, follows the tapping time and usage of the tap hole # 1-7 of the company, as shown in table 1 below.

TABLE 1

The implementation effect is as follows:

after the implementation of the scheme, the steel tapping time is greatly shortened, the consumption of the repair materials is reduced, and the service life of the steel tapping hole is prolonged.

The preliminary statistics of relevant data before and after the process is used are shown in a table 2:

TABLE 2

As can be seen from the table 2, the optimized use of the process improves the service life of the steel tapping hole, the lifting amplitude is 42.64%, and the usage amount of single repair materials is reduced by 20.78%.

Experimental example 2

Tapping time and tap hole usage were tracked for tap hole of converter # 1 in example 2 using the above process technology, as shown in table 3 below.

In example 3 of the process technology, the steel tapping hole of the long-life quick-change bowl brick shown in the attached drawing 1 is installed, the steel tapping time and the service condition of the steel tapping hole at different stages of a 3# converter are tracked, and the rephosphorization condition of molten steel is tracked, as shown in the following table 3.

TABLE 3

The implementation effect is as follows:

in the embodiment 2, by optimizing the process, the service life of the tap hole is prolonged to 657 furnace after the No. 1 furnace is applied and implemented.

Embodiment 3, after the steel tapping hole of the long-life quick-change bowl brick shown in fig. 1 is used and implemented in a 3# furnace according to the repairing process technology, when the bowl brick is replaced when the furnace 661 is used, the residual 33mm of the platform edge on one side of the bowl brick installation female hole is observed, the bowl brick can still be used continuously, the final accumulated service life is up to 818 after-furnace offline, the residual 15mm of the bowl brick female hole matching platform surface is observed, the hole expansion of the bowl brick female hole is calculated to 240mm, and the length of the steel tapping hole is measured to be larger than 1 m finally. Example 3 the service life of the steel tapping hole is counted in the same period, compared with the steel tapping hole used in the No. 1 furnace in example 2, the furnace is increased by 161, and the lifting amplitude is 24.5%.

It can be seen from the example that after the process technology is applied and implemented, the service life of the steel tapping hole can be effectively and greatly prolonged to 661 furnaces, and meanwhile, the service life of the steel tapping hole can be prolonged to 818 furnaces by matching with a quick-change bowl brick structure.

Although the invention has been described in detail hereinabove with respect to a general description and specific embodiments thereof, it will be apparent to those skilled in the art that modifications or improvements may be made thereto based on the invention. Accordingly, such modifications and improvements are intended to be within the scope of the invention as claimed.