阅读说明：本技术 一种改性碳源优化高炉出铁沟用Al2O3-SiC-C耐火浇注料及其制备方法和应用 (Al for modified carbon source optimized blast furnace tapping channel2O3-SiC-C refractory castable and preparation method and application thereof ) 是由 童胜利 戚真健 李明晖 蒋亚强 沈望华 宋海平 于 2020-06-01 设计创作，主要内容包括：本发明公开了一种改性碳源优化高炉出铁沟用Al<Sub>2</Sub>O<Sub>3</Sub>-SiC-C耐火浇注料及其制备方法和应用,属于耐火材料技术领域。本发明以55.0～65.0wt％的棕刚玉骨料、17.0～25.0wt％的碳化硅、8.0～15.0wt％的活性α-氧化铝微粉、4.0～6.0wt％的可水合氧化铝、1.5～2.0wt％金属铝粉/单质硅粉复配抗氧化剂和1.5～2.0wt％的改性碳源@纳米二氧化硅复合添加剂为原料；按上述原料及其百分比重量配料,外加所述原料0.15～0.25wt％的减水剂制备得到改性碳源优化高炉出铁沟用Al<Sub>2</Sub>O<Sub>3</Sub>-SiC-C耐火浇注料,极大提高了高炉铁沟安全系数、运行寿命,降低总体成本。(The invention discloses Al for a modified carbon source optimized blast furnace tapping channel 2 O 3 A refractory castable material of-SiC-C, a preparation method and application thereof, belonging to the technical field of refractory materialsThe Al-corundum aggregate modified carbon source optimized blast furnace tapping channel is prepared by taking 55.0-65.0 wt% of brown corundum aggregate, 17.0-25.0 wt% of silicon carbide, 8.0-15.0 wt% of active α -alumina micro powder, 4.0-6.0 wt% of hydratable alumina, 1.5-2.0 wt% of metal aluminum powder/elemental silicon powder compound antioxidant and 1.5-2.0 wt% of modified carbon source @ nano-silica composite additive as raw materials, mixing the raw materials in percentage by weight, and adding 0.15-0.25 wt% of water reducing agent as the raw material 2 O 3 the-SiC-C refractory castable greatly improves the safety factor of the blast furnace iron runner, prolongs the service life of the blast furnace iron runner and reduces the overall cost.)

1. Al for modified carbon source optimized blast furnace tapping channel₂O₃The preparation method of the-SiC-C refractory castable is characterized by taking 55.0-65.0 wt% of brown fused alumina aggregate, 17.0-25.0 wt% of silicon carbide, 8.0-15.0 wt% of active α -alumina micropowder, 4.0-6.0 wt% of hydratable alumina, 1.5-2.0 wt% of metal aluminum powder/elemental silicon powder compound antioxidant and 1.5-2.0 wt% of modified carbon source @ nano-silica composite additive as raw materials, and adding 0.15-0.25 wt% of water reducing agent for dry mixing to obtain the Al-SiC-C refractory castable for the blast furnace iron runner with the optimized modified carbon source₂O₃-SiC-C refractory castable.

2. Al for the modified carbon source optimized blast furnace runner according to claim 1₂O₃The preparation method of the-SiC-C refractory castable is characterized in that the preparation method of the modified carbon source @ nano silicon dioxide composite additive is as follows:

1) placing plant debris, a catalyst, silica sol and water in a sealed hydrothermal kettle with a stirring function, keeping the temperature at 120-180 ℃ for 30-60 minutes, and drying the mixture at 110 ℃ for 12 hours after the reaction is finished to obtain a modified carbon source @ nano silicon dioxide precursor;

2) the modified carbon source @ nanosilica precursor was crushed to a powder using a pulverizer containing a tungsten carbide liner.

3. The modified carbon source-optimized Al for blast furnace tapping runners as defined in claim 2₂O₃The preparation method of the-SiC-C refractory castable is characterized in that the plant debris is one or more of wood chips, grass fibers and crushed straws, the catalyst is one or more of ferric nitrate, cobalt nitrate and nickel nitrate, the solid phase content of the silica sol is 5.0 wt%, and the mass ratio of the plant debris, the catalyst, the silica sol and water is 10: 2: 8: 80.

4. Al for the modified carbon source optimized blast furnace runner according to claim 1₂O₃The preparation method of the-SiC-C refractory castable is characterized in that the grain composition of the brown corundum aggregate is as follows: 5-3 mm of the brown fused alumina aggregate accounts for 40 wt%, 3-1 mm of the brown fused alumina aggregate accounts for 20 wt%, and 1-0.088 mm of the brown fused alumina aggregate accounts for 40 wt%.

5. Al for the modified carbon source optimized blast furnace runner according to claim 1₂O₃The preparation method of the-SiC-C refractory castable is characterized in that the grain size composition of the silicon carbide is as follows: 1-0.088 mm accounts for 40 wt% of the silicon carbide, and less than 0.088mm accounts for 60 wt% of the silicon carbide.

6. Al for the modified carbon source optimized blast furnace runner according to claim 1₂O₃The preparation method of the-SiC-C refractory castable is characterized in that Al in the α -alumina micro powder₂O₃The content is more than or equal to 98 wt%, the particle size distribution curve is a typical double-peak structure, and the peak values are 1.2 mu m and 7.6 mu m;

al in the hydratable alumina₂O₃The content is more than or equal to 85 wt%, the particle size distribution curve is a unimodal structure, and the peak value is 78.5 mu m;

the mass ratio of the metal aluminum powder to the elemental silicon powder in the metal aluminum powder/elemental silicon powder compound antioxidant is 0.1-0.2.

7. Al for the modified carbon source optimized blast furnace runner according to claim 1₂O₃The preparation method of the-SiC-C refractory castable is characterized in that the water reducing agent is one or more of sodium tripolyphosphate, sodium hexametaphosphate and German Pasteur imported polycarboxylic acid water reducing agent.

8. Al for blast furnace tapping channel optimized by modified carbon source as claimed in any one of claims 1 to 7₂O₃Al for modified carbon source optimized blast furnace tapping channel prepared by preparation method of-SiC-C refractory castable₂O₃-SiC-C refractory castable.

9. Use of the modified carbon source of claim 8 for optimizing Al for blast furnace tapping runners₂O₃-a blast furnace main iron runner lining made of SiC-C refractory castable, characterized in that the blast furnace main iron runner lining comprises a lining body (1) and a groove (2), the groove (2) being provided at the top end of the lining body (1), the lining body (1) comprising an open-ended first portion (3) and a terminal second portion (4), the first portion (3) having a U-shaped cross-section, the groove (2) at the top thereof being an inverted triangular groove (2), the second portion (4) having a semicircular cross-section, the groove (2) at the top thereof being an inverted trapezoidal groove (2); from the joint of the first part (3) and the second part (4) to the tail end of the second part (4), the bottom and the top of the inverted triangular groove (2) are gradually widened to form an inverted trapezoidal groove (2) with gradually increased cross section area.

Technical Field

The invention belongs to the technical field of refractory materials, and particularly relates to Al for a modified carbon source optimized blast furnace tapping channel₂O₃-SiC-C refractory castable and a preparation method and application thereof.

Background

Along with the continuous optimization and alternation of the iron-making process, the service environment of the refractory material for the blast furnace becomes more complex, and particularly, under the conditions of long-term molten iron scouring and penetration and certain periodic cold-heat circulation, the refractory material for the blast furnace tapping channel can generate larger thermal stress inside the material, even generate macroscopic cracks of a certain scale in severe cases, and bring important potential safety hazards to the tapping process. Therefore, the excellent comprehensive performance of the refractory material for the blast furnace tapping channel is an important guarantee for the safe, stable and efficient operation of the blast furnace iron-making link.

Because of the convenience of construction, the unshaped castable has become the main refractory material of choice for blast furnace tapping runners. Al (Al)₂O₃the-SiC-C refractory castable is widely used as a refractory material for a blast furnace tapping channel due to a series of excellent characteristics of low thermal expansion coefficient, high thermal conductivity, wear resistance, scouring resistance, erosion resistance and the like. However, it is restricted to Al₂O₃Al as the main component in the-SiC-C refractory castable₂O₃The product is easy to generate larger heat in the cold-heat exchange circulation process due to larger thermal expansion coefficient difference with SiCMismatch stress seriously restricts the structural stability of the long-term service of the steel pipe; in addition, the carbon component inside is highly oxidized, which causes Al₂O₃The molten iron corrosion resistance of the-SiC-C refractory castable is greatly reduced.

To solve the above-mentioned problems with respect to Al₂O₃The problem faced by the-SiC-C refractory castable is that on the basis of selecting proper grading proportion of aggregate and matrix, proper admixture is selected, and the admixture and substances in an original system form a single or composite reinforced structure in the high-temperature reaction process, so that Al is improved₂O₃The comprehensive performance of the-SiC-C refractory castable. For example; (1) ' Nano Al₂O₃SiC film coated carbon Al₂O₃the-MA-SiC-C refractory castable and the preparation method thereof (CN101767999A) are based on a sol-gel method, and the C @ Al is prepared by adopting a liquid phase dispersion coating process₂O₃SiC and C @ Al₂O₃MgO additive, carbon-containing nano secondary spinel and Al generated by in-situ synthesis reaction of modified carbon source and primary matrix at high temperature₂O₃And the SiC is the nano structure of the main crystal phase, so that the comprehensive performance of the refractory material for the tapping channel is improved, however, the carbon component is difficult to uniformly disperse in the matrix due to the spontaneous agglomeration effect generated by the nano structure, and the overall consistency of the material is influenced; in addition, the process for preparing the carbon-containing precursor is too complex, and the sol-gel method has a long period, so that large-scale industrial application is difficult to realize. (2) Glass ceramic composite ceramic Al₂O₃Al for iron runner of-SiC-C castable "(CN 102603326B)₂O₃Fly ash, magnesia alumina spinel, composite nucleating agent zirconia and zinc oxide with proper, controllable and adjustable proportion are introduced into the-SiC-C castable so as to form CaO-MgO-Al with CaO in calcium aluminate cement in raw materials under the working condition of high temperature₂O₃-SiO₂The quaternary system further adjusts the thermal expansion coefficient of the matrix, so that the thermal stress damage caused by thermal mismatch is relieved, however, excessive addition of the low-melting-point component inevitably leads to severe reduction of the overall high-temperature mechanical property of the material. (3) ' A kind of Al₂O₃the-SiC-C iron runner castable and the preparation method thereof "(CN 103011868A) use spherical asphalt as a carbon source, and under the action of a catalyst of a simple substance of iron, cobalt and nickel or alloy micro powder, carbon whiskers generated in situ at high temperature are expected to have the effects of reinforcing and toughening the refractory castable, but the used combined system is calcium aluminate cement, and the effect of improving the high-temperature strength is limited; in addition, it is difficult to know whether the catalyst added to the substrate portion is uniformly mixed with the spherical asphalt.

Disclosure of Invention

Aiming at the problems in the prior art, the invention aims to provide Al for a modified carbon source optimized blast furnace tapping channel₂O₃-SiC-C refractory castable. The invention aims to solve another technical problem of providing the Al for the modified carbon source optimized blast furnace tapping channel₂O₃A preparation method of-SiC-C refractory castable. Another technical problem to be solved finally by the present invention is to provide Al for the modified carbon source optimized blast furnace tapping channel₂O₃The specific application of the-SiC-C refractory castable is provided.

In order to solve the technical problems, the technical scheme adopted by the invention is as follows:

al for modified carbon source optimized blast furnace tapping channel₂O₃The preparation method of the-SiC-C refractory castable comprises the following steps of taking 55.0-65.0 wt% of brown fused alumina aggregate, 17.0-25.0 wt% of silicon carbide, 8.0-15.0 wt% of active α -alumina micro powder, 4.0-6.0 wt% of hydratable alumina, 1.5-2.0 wt% of metal aluminum powder/elemental silicon powder compound antioxidant and 1.5-2.0 wt% of modified carbon source @ nano-silica composite additive as raw materials, mixing the raw materials according to the weight percentage, and adding 0.15-0.25 wt% of water reducer.

Preferably, the preparation method of the modified carbon source @ nano-silica composite additive comprises the following steps:

step 1, a hydrothermal process, namely placing plant debris, a catalyst and silica sol into a sealed hydrothermal kettle with a stirring function, keeping the temperature at 120-180 ℃ for 30-60 minutes, and drying the mixture at 110 ℃ for 12 hours after the reaction is finished to obtain a modified carbon source @ nano silicon dioxide precursor;

the step 2 is a grinding process, and because the sample prepared by the hydrothermal method is in a pseudo-agglomerated state, in order to ensure the uniformity of the additive in the final product, a pulverizer containing a tungsten carbide lining is used for crushing the dried pseudo-agglomerated modified carbon source @ nano silicon dioxide composite additive into powder.

Preferably, the plant debris is one or more of wood chips, grass fibers and crushed straws, the catalyst comprises one or more of ferric nitrate, cobalt nitrate and nickel nitrate, the solid phase content of the silica sol is 5.0 wt%, and the mass ratio of the plant debris, the catalyst, the silica sol and water is 10: 2: 8: 80.

Preferably, the brown corundum aggregate has the following grain composition: 5-3 mm of the brown fused alumina aggregate accounts for 40 wt%, 3-1 mm of the brown fused alumina aggregate accounts for 20 wt%, and 1-0.088 mm of the brown fused alumina aggregate accounts for 40 wt%;

preferably, the grain size composition of the silicon carbide is: 1-0.088 mm accounts for 40 wt% of the silicon carbide, and less than 0.088mm accounts for 60 wt% of the silicon carbide.

Preferably, Al in the α -alumina fine powder₂O₃The content is more than or equal to 98 wt%, the particle size distribution curve is a typical double-peak structure, and the peak values are 1.2 mu m and 7.6 mu m; al in the hydratable alumina₂O₃The content is more than or equal to 85 wt%, the particle size distribution curve is a unimodal structure, and the peak value is 78.5 mu m; the mass ratio of the metal aluminum powder to the elemental silicon powder in the metal aluminum powder/elemental silicon powder compound antioxidant is 0.1-0.2.

Preferably, the water reducing agent is one or more of sodium tripolyphosphate, sodium hexametaphosphate and German Pasteur imported polycarboxylic acid water reducing agent.

Al for modified carbon source optimized blast furnace tapping channel prepared by the preparation method₂O₃-SiC-C refractory castable.

Al for optimizing blast furnace tapping channel by using modified carbon source₂O₃The blast furnace main iron runner lining is prepared from SiC-C refractory castable, and comprises a lining body and a groove, wherein the groove is arranged at the top end of the lining body, and the lining bodyThe cross section of the first part is U-shaped, the groove at the top of the first part is an inverted triangular groove, the cross section of the second part is semicircular, and the groove at the top of the second part is an inverted trapezoidal groove; from the junction of the first part and the second part to the end of the second part, the bottom and the top of the inverted triangular groove are gradually widened to form an inverted trapezoidal groove with gradually increased cross section area.

Preferably, the liner body has a cross-sectional width gradually widening from the junction of the first portion and the second portion to the end of the second portion.

Preferably, the liner body has a cross-sectional height gradually decreasing from a beginning of the first portion at the beginning to an end of the second portion near the end.

Preferably, the inverted triangular groove is an isosceles acute angle with a bottom vertex angle smaller than 45 degrees, and is positioned on the central axis of the cross section of the first part in bilateral symmetry.

Preferably, the inverted trapezoid-shaped groove is an inverted isosceles trapezoid and is positioned on the central axis of the cross section of the second part in bilateral symmetry.

Preferably, the bottom of the groove in the lining body forms an included angle with the horizontal plane, and the height difference between the bottom of the groove at the tail end of the lining body and the horizontal plane is 0.5-10% of the length of the lining body.

Preferably, the length of the first part is 1-3 m.

Compared with the prior art, the invention has the beneficial effects that:

(1) the invention takes the plant debris as the main carbon source, not only solves the problem that the agriculture and forestry resources such as the plant debris and the like occupy land resources when being randomly placed, but also recycles the plant debris, changes waste into valuable and is environment-friendly;

(2) the hydratable alumina is used as a gelling system to replace the mainstream calcium aluminate cement at present, so that the high-temperature strength of the refractory product is improved; in addition, the hydrated alumina reacts with water at normal temperature and generates a micro-pore structure pair at high temperature, so that Al is greatly slowly released through a microcrack toughening effect₂O₃Thermal stress due to mismatch with the coefficient of thermal expansion of SiC;

(3) because the matrix in the castable is an aluminum oxide-rich system, when a modified carbon source @ nano silicon dioxide composite additive is added, in the process of high-temperature heat treatment, on one hand, under the action of a catalyst, carbon-containing steam nucleates and grows on the surface of the catalyst through a decomposition-precipitation mechanism and gradually develops into a cluster-shaped structure, on the other hand, silicon dioxide in the composite additive and the aluminum-rich matrix react and combine to generate mullite whiskers, and finally, a special nano carbon cluster-shaped microstructure wrapped by the mullite whiskers is formed, and the carbon component is effectively wrapped by the special microstructure, so that the oxidation resistance, the molten iron corrosion resistance and the thermal shock stability of a product are greatly optimized;

(4) optimization of Al for blast furnace tapping channel using modified carbon source₂O₃The blast furnace main iron runner lining with a specific structure, which is prepared from the-SiC-C refractory castable, enhances the structural advantages of the blast furnace main iron runner lining, greatly improves the safety coefficient and the service life of the blast furnace iron runner, and reduces the overall cost.

Drawings

FIG. 1 is a schematic top view of a blast furnace main iron runner lining;

FIG. 2 is a schematic cross-sectional view of a first portion of the inner lining of the main iron runner of the blast furnace;

FIG. 3 is a schematic cross-sectional view of a second portion of the inner lining of the main iron runner of the blast furnace;

FIG. 4 is a schematic side view of the lining of the main iron runner of the blast furnace.

Detailed Description

The invention is further described with reference to specific examples.

In order to avoid repetition, the related technical parameters related to this specific embodiment are described in a unified manner as follows, and are not described in detail in the embodiments:

the brown corundum aggregate has the following grain composition: 5-3 mm accounts for 20-30 wt% of the total raw materials, 3-1 mm accounts for 10-15 wt% of the total raw materials, and 1-0.088 mm accounts for 15-20 wt% of the total raw materials;

the grain size composition of the silicon carbide is as follows: 1-0.088 mm accounts for 7-14 wt% of the total raw materials, and less than 0.088mm accounts for 5-10 wt% of the total raw materials.

α -Al in alumina micropowder₂O₃The content is more than or equal to 98 wt%, the particle size distribution curve is a typical bimodal structure, and the peak values are 1.2 mu m and 7.6 mu m.

Al in hydratable alumina₂O₃The content is more than or equal to 85 wt%, the particle size distribution curve is a unimodal structure, and the peak value is 78.5 mu m.

The mass ratio of the metal aluminum powder to the elemental silicon powder in the metal aluminum powder/elemental silicon powder compound antioxidant is 0.1-0.2.

The plant debris comprises but is not limited to wood chips, grass fibers, crushed straws and the like, the catalyst comprises but is not limited to ferric nitrate, cobalt nitrate, nickel nitrate and the like, the solid content of the silica sol is 5.0 wt%, and the mass ratio of the plant debris, the catalyst, the silica sol and water is 10: 2: 8: 80.

The water reducing agent includes, but is not limited to, sodium tripolyphosphate, sodium hexametaphosphate, and German Pasteur imported polycarboxylic acid water reducing agent.