A refractory mortar for a blast furnace ceramic cup and a preparation method and a construction method thereof

Abstract

The application discloses a kind of refractory mortar for blast furnace ceramic cup and its preparation method and construction method, belong to refractory mortar technical field.The refractory mortar raw material components are as follows by mass percentage: microporous corundum fine powder 0.074-0mm 25-35%; active alumina powder 25-30%; silicon oxynitride microcrystalline powder 5-8%; alumina fiber 10-20%; silicon-aluminum alloy powder 10-15%; carbon black N990 5-8%; polyacrylic acid ammonium salt dispersing agent 0.5-1.5%; acidic zirconium dioxide sol (plus) 8-10%.The refractory mortar has good fluidity, simple and efficient construction method, can fully fill the blast furnace ceramic cup brick joint, and the brick joint can meet the construction requirements at 1.5mm, effectively resists the penetration and erosion of high-temperature molten iron from the brick joint caused by oversized joint and loose joint mortar.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of refractory mortar, and particularly relates to a refractory mortar for a blast furnace ceramic cup, and a preparation method and a construction method thereof. BACKGROUND

[0002] The service effect of a blast furnace hearth is an important influencing factor for determining a blast furnace service life. When the bottom of the blast furnace is constructed, the outermost steel shell is first constructed, a circle of cup-shaped carbon bricks is built inside the steel shell, and a ceramic cup structure is built inside the carbon bricks to hold high-temperature molten iron. The ceramic cup blocks the 1150 DEG C isotherm (i.e. the solidification line of molten iron) in the ceramic layer, so that the bottom carbon bricks avoid the brittle fracture zone of 800-1100 DEG C. Due to the existence of the ceramic cup, the molten iron does not directly contact the carbon bricks, the penetration and scouring damage of the molten iron and alkali metals to the carbon bricks are relieved from the structural design, and the service life of the blast furnace hearth can be effectively prolonged.

[0003] The ceramic cup pad adopts large corundum precast blocks or corundum bricks with self-locking structures, and the ceramic cup wall adopts large precast blocks with special shapes, wings on the left and right, and insertion and occlusion from top to bottom. The traditional construction method adopts masonry construction, and the supporting refractory mortar generally does not have fluidity. The ceramic cup bricks or precast blocks are heavy and irregular in shape, and are installed at accurate positions through mechanical hoisting, and the mortar is filled in the gaps between the two bricks through external force kneading. Therefore, a larger brick joint is designed to meet the construction requirements, and the ceramic cup brick joint is generally designed to be 3 mm. As known, there are two problems in the refractory mortar for the ceramic cup. One is that the mortar filled between the brick joints and the density, strength and other properties of the masonry bricks are greatly different. The second is that the construction personnel need to very skillfully control the amount of mortar applied at different positions of the precast blocks during the masonry construction. In addition, the brick or precast block has a large porosity and strong water absorption, and the mortar dries quickly. Therefore, the precast block with the applied mortar needs to be placed in place as soon as possible, otherwise the mortar will quickly lose water, and more "flower faces" will be formed, and the fullness of the mortar cannot be easily met. The above reasons cause the refractory mortar construction quality and performance to become the weak point of the entire masonry, and the high-temperature molten iron is more likely to penetrate and erode through the brick joint, so that the ceramic cup disintegrates. Therefore, how to reduce the brick joint, improve the density, strength and molten iron erosion resistance of the refractory mortar is an urgent matter. SUMMARY

[0004] The present application aims to provide a refractory mortar for a blast furnace ceramic cup, and a preparation method and a construction method thereof. The refractory mortar has good fluidity, the construction method is simple and efficient, can fully and fully fill the ceramic cup brick joint of the blast furnace, the brick joint can be 1.5 mm to meet the construction requirements, and the penetration and erosion of high-temperature molten iron from the brick joint caused by the large brick joint and the loose mortar of the brick joint are effectively resisted.

[0005] To achieve the above-mentioned purpose, the technical scheme of the present application is as follows:

[0006] The application provides a refractory mortar for a blast furnace ceramic cup, and raw material components are as follows in percentage by mass:

[0007]

[0008] According to the scheme, the pore size distribution of the microporous corundum powder is between 0.1 and 1 microns, and the apparent porosity is less than or equal to 8%.

[0009] According to the scheme, Al2O3 in the microporous corundum powder is greater than or equal to 98%, and the bulk density is less than or equal to 3.4 g / cm 3 .

[0010] According to the scheme, the content of a-Al2O3 in the active alumina micropowder is greater than or equal to 99%, Fe2O3 is less than or equal to 0.1%, R2O is less than or equal to 0.1%, and d50 is 1.4-1.8 microns.

[0011] According to the scheme, the silicon oxynitride micropowder is a composite micropowder with Si2N2O and Si3N4 as main components, and mainly exists in amorphous and microcrystalline forms, wherein the content of Si2N2O is between 40 and 50%.

[0012] According to the scheme, the average diameter of the alumina fiber is 2-4 microns, and the length is 0.2-0.5 mm.

[0013] According to the scheme, the content of Al2O3 in the alumina fiber is greater than or equal to 95%, the content of SiO2 is less than or equal to 5%, and the content of Fe2O3 is less than or equal to 0.1%.

[0014] According to the scheme, the silicon-aluminum alloy powder is an alloy powder with Si less than or equal to 40%, Al greater than or equal to 55%, and particle size less than or equal to 0.074 mm.

[0015] According to the scheme, the carbon black N990 is high-purity carbon black with a particle size d50 of 2-5 microns, and the content of main chemical component C is greater than or equal to 98%.

[0016] According to the scheme, the pH value of the acidic zirconia sol solution is 3-5.

[0017] According to the scheme, the acidic zirconia sol is a transparent sol-like aqueous liquid, wherein the particle size of zirconia is less than 10 nm, and the content of ZrO2 is 10-15%.

[0018] According to the scheme, the polyammonium acrylate dispersant is an anionic polymer dispersant.

[0019] The application further provides a preparation method of the refractory mortar for the blast furnace ceramic cup.

[0020] Mixing the microporous corundum powder 0.074-0mm, active alumina powder, alumina fiber, silicon-aluminum alloy powder, silicon oxynitride composite powder, carbon black N990 and polyacrylamide ammonium salt dispersant uniformly, then adding acidic zirconia liquid sol to stir and mix, so that it becomes a homogeneous slurry with good fluidity, and the refractory slurry for blast furnace ceramic cup is obtained.

[0021] According to the above scheme, the stirring and mixing time is 8-10 min.

[0022] A construction method of the refractory slurry for blast furnace ceramic cup is provided, comprising the following steps:

[0023] 1) First, the blast furnace ceramic cup prefabricated part or brick is positioned according to the construction specification to complete the masonry of the blast furnace ceramic cup masonry, wherein the gap between the prefabricated parts, the bricks or the prefabricated parts and the bricks is 1.5mm;

[0024] 2) Then, the inner surface of the obtained blast furnace ceramic cup masonry is fully paved with a rubber film, and the rubber film surface and the surrounding are pressed tightly with sand bags to ensure that the blast furnace ceramic cup masonry forms a closed space; the surface of the blast furnace ceramic cup masonry in four directions is reserved for vacuum holes connected to a vacuum pumping device; and a grouting hole is reserved at the center position of the inner surface of the bottom of the ceramic cup masonry, and connected to a grouting device;

[0025] 3) Start the vacuum pumping device to pump, then start the grouting device, and the slurry flows into the gap of the ceramic cup masonry through the reserved grouting hole, and after filling, the vacuum state is still maintained for 30-60 min, that is, the construction is completed.

[0026] According to the above scheme, the vacuum pressure is set to 0.2-0.3MPa.

[0027] According to the above scheme, the rubber film, the blast furnace ceramic cup masonry and the blast furnace bottom form a closed space.

[0028] The application provides a refractory slurry for blast furnace ceramic cup, which is prepared from microporous corundum powder, silicon-aluminum alloy powder, silicon oxynitride microcrystalline powder, active alumina powder, carbon black powder, alumina fiber, polyacrylamide ammonium salt, zirconia sol and the like as main raw materials, and has high self-flowing performance.

[0029] The polyacrylamide ammonium salt is used as a dispersant in the application, which is adsorbed on the surface of alumina microparticles and generates electrostatic repulsion to disperse the microparticles, so that the slurry is prevented from settling and coarsening, the viscosity of the slurry is greatly reduced, the slurry has self-leveling effect under the condition of reduced liquid addition amount during stirring, and the dispersant is completely volatilized during product calcination, which does not affect the physical and chemical properties of the product in the later stage.

[0030] The application introduces elemental silicon and elemental aluminum in the form of silicon-aluminum alloy, which can be more uniformly dispersed in the refractory mortar, and is beneficial to the subsequent reaction to generate ceramic phases that can be uniformly distributed in the mortar. At the same time, the acidic zirconia sol solution oxidizes the surface of the aluminum to form an aluminum oxide film, which inhibits the hydration of aluminum to generate gas at room temperature and causes the mortar to swell and become loose. In addition, the melting point of silicon is 1420 DEG C, and the melting point of aluminum is 660 DEG C. The silicon-aluminum alloy powder is uniformly dispersed and melted into a high-temperature liquid phase at high temperature, which wets carbon black, silicon oxynitride microcrystal composite powder, and alumina micro powder, etc., and promotes the continuous reaction of them in a larger temperature range to generate a large amount of silicon carbide, aluminum carbide, and sialon high-temperature ceramic phase. The generated ceramic phase fills the pores left by the evaporation of water in the mortar, reduces the large pores in the mortar, and forms a ceramic combined mortar with a large number of micro-pores, thereby improving the density and strength of the mortar.

[0031] In addition, the liquid phase formed by the silicon-aluminum alloy powder at high temperature cooperates with the tough structure of the alumina fiber at high temperature, and the phase transformation toughening of zirconia is used at the same time, which buffers the expansion of the ceramic cup during the heating and high-temperature service process, so that the refractory mortar still has a good solid-phase tough structure at high temperature, effectively buffers the thermal stress of the ceramic cup masonry, and ensures the structural integrity of the ceramic cup in the whole service stage.

[0032] The application provides a construction method of the refractory mortar for the blast furnace ceramic cup. The outer surface of the blast furnace ceramic cup masonry is surrounded by carbon bricks, steel shells and the like, the inner surface is covered with a rubber film and fixed and compacted by sand bags, so that a closed space of the blast furnace ceramic cup masonry can be formed. Then, the high flowability of the refractory mortar is utilized, the mortar can only flow and fill the gaps in the brick joints when the mortar is grouted by vacuumizing, so that the full filling of the mortar in the gaps of the ceramic cup is ensured, the density of the masonry is improved, the gaps of the masonry are effectively reduced from 3 mm to 1.5 mm, the amount of the mortar is reduced, and the performance of the ceramic cup is improved.

[0033] The application has the following beneficial effects:

[0034] 1. The application provides a refractory mortar for the blast furnace ceramic cup, which has low viscosity and high self-flowing performance. In a high-temperature reducing atmosphere, a large amount of reaction occurs between the phases to form a high-strength high-melting-point ceramic combined phase that is uniformly distributed. The generated new substances are evenly distributed and fill the large pores formed by the evaporation of the liquid phase, so that the large pores of the mortar are reduced and a large number of micro-pores are formed, the strength of the mortar is high, and the mortar is densified. At the same time, the mortar still has a good solid-phase tough structure at high temperature, effectively buffers the thermal stress of the ceramic cup masonry, ensures the structural integrity of the ceramic cup in the whole service stage, and has a wide application prospect.

[0035] 2. The application provides a construction method of refractory mortar for blast furnace ceramic cup, which changes the traditional ceramic cup construction method by using the high self-flow characteristics of the refractory mortar, forms a new construction method that all ceramic cup bricks are installed at the specified position according to the predetermined sequence, and then the high flowability refractory mortar is pumped to fill the gaps of the ceramic cup bricks under vacuum, avoids the disadvantages of the traditional masonry construction, reduces the gaps of the masonry from 3mm to 1.5mm, reduces the possibility of the molten iron penetrating through the brick gaps, reduces the amount of the refractory mortar, increases the content of the masonry bricks with better high-temperature performance per unit volume, ensures the full filling of the mortar in the gaps of the ceramic cup, improves the density of the masonry, reduces the probability of the molten iron penetrating through the mortar at high temperature, and improves the construction efficiency and construction quality. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the application will be clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all the other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the application.

[0037] The raw materials used in the embodiment are as follows:

[0038] Microporous corundum fine powder Al2O3: 98.3%, particle size 0.074-0mm; pore size distribution between 0.1-1um, apparent porosity ≤8%, bulk density ≤3.4g / cm 3 .

[0039] Active alumina powder Al2O3: 99.4%, Fe2O3≤0.1%, R2O≤0.1%, particle size d50=1.72um.

[0040] Silicon oxynitride microcrystalline powder is a composite microcrystalline powder with main components of Si2N2O and Si3N4, mainly existing in amorphous and microcrystalline forms, wherein Si2N2O: 49.2%, Si3N4: 35.1%, particle size d90=4.7um.

[0041] Alumina fiber, average diameter 3um, length 0.2-0.5mm, Al2O3 content 95.3%, SiO2 4.1%, Fe2O3≤0.1%,

[0042] Silicon-aluminum alloy powder, Si content 37.3%, Al content 59.1%, particle size 0.044-0mm.

[0043] Carbon black N990, particle size d50=2.47um, carbon content: 98.5%.

[0044] Polyacrylic acid ammonium salt dispersant: industrial reagent.

[0045] Liquid binding agent: zirconium oxide sol solution, ZrO2 content: 14.5%, zirconium oxide particle size distribution is about 5-10 nm, pH value 3-5.

[0046] In the embodiment of the present application, the preparation method of the refractory mortar for blast furnace ceramic cup comprises the following steps:

[0047] After the components except the liquid zirconium oxide sol are uniformly mixed in the blender, the liquid zirconium oxide sol is added and stirred for 10 minutes to form a homogeneous slurry with good fluidity, and the refractory mortar for blast furnace ceramic cup is obtained.

[0048] Example 1

[0049] A refractory mortar for blast furnace ceramic cup is provided, and the raw material components are as follows in terms of mass percentage:

[0050]

[0051] The performance index test results of the refractory mortar for ceramic cup provided in the embodiment are shown in Table 1.

[0052] Example 2

[0053] A refractory mortar for blast furnace ceramic cup is provided, and the raw material components are as follows in terms of mass percentage:

[0054]

[0055] The performance index test results of the refractory mortar for ceramic cup provided in the embodiment are shown in Table 1.

[0056] Example 3

[0057] A refractory mortar for blast furnace ceramic cup is provided, and the raw material components are as follows in terms of mass percentage:

[0058]

[0059]

[0060] Example 4

[0061] A construction method of a refractory mortar for blast furnace ceramic cup is provided, comprising the following steps:

[0062] 1) Install the blast furnace ceramic cup prefabricated parts or bricks to the specified position according to the construction requirements to obtain the blast furnace ceramic cup masonry, and leave a gap of 1.5 mm between the prefabricated parts, between the bricks, or between the prefabricated parts and the bricks.

[0063] 2) Then the resulting blast furnace ceramic cup masonry inner surface full paving film, in the film surface and around the use of sandbags to ensure that the blast furnace ceramic cup masonry form airtight space; in the blast furnace ceramic cup masonry around the four directions on the surface of the reserved vacuum air hole, connecting the vacuum equipment; and in the ceramic cup masonry body bottom inner surface center reserved grouting hole, connecting grouting equipment pipeline.

[0064] 3) The vacuum pressure is set to 0.2MPa, start the vacuum equipment for 5min, start the grouting equipment, the resulting refractory mortar of the present application is filled into the gap of the ceramic cup masonry through the pipeline from the reserved grouting hole, after filling, still keep the vacuum state for 60min, so that the mortar is fully immersed with the brick or prefabricated piece, and is dried. After closing the equipment, remove the film, sandbags and other equipment, the construction of this process is completed.

[0065] Comparative Example 1

[0066] A kind of blast furnace ceramic cup is provided with refractory mortar, according to mass percentage, raw material components are as follows:

[0067]

[0068] The performance index test results of the refractory mortar for ceramic cup provided by the comparative example are shown in Table 1.

[0069] Comparative Example 2

[0070] A kind of blast furnace ceramic cup is provided with refractory mortar, according to mass percentage, raw material components are as follows:

[0071]

[0072]

[0073] The performance index test results of the refractory mortar for ceramic cup provided by the comparative example are shown in Table 1.

[0074] Comparative Example 3

[0075] A kind of blast furnace ceramic cup is provided with refractory mortar, according to mass percentage, raw material components are as follows:

[0076]

[0077] Silica sol (SiO2 content 30%, PH value: 8-10) plus 13.1%.

[0078] The performance index test results of the refractory mortar for ceramic cup provided by the comparative example are shown in Table 1.

[0079] Comparative Example 4

[0080] A traditional non-flowing mud is provided, and the raw material components are as follows in mass percentage:

[0081]

[0082] The performance index test results of the refractory mud for ceramic cups provided by the comparative example are shown in Table 1.

[0083] The mud of the comparative example has good plasticity, no flowability, and can only be constructed by masonry method, and the construction joint is designed to be 3mm.

[0084] Table 1 shows the performance test results of the refractory mud prepared in the examples and the comparative example.

[0085]

[0086]

[0087] Table 1 shows that the refractory mud obtained in the examples has good flowability, and can realize mud pouring and filling construction; the micro-porosity of the mud is high, and there are few large pores, so the molten iron is not easy to penetrate through the micro-pores, and the heat conduction performance of the mud is reduced, so that the 1150℃ isotherm is blocked in the ceramic layer; the adhesive strength of the mud is high, so that the ceramic cup can be sintered and bonded to form a firm whole at high temperature; the molten iron corrosion index is low, and the mud has strong resistance to molten iron corrosion.

[0088] In summary, the polyacrylic acid ammonium salt is used as the dispersant of the alumina micropowder to prepare the high-flowability refractory mud, so that the refractory mud is infiltrated into the ceramic cup gap in a vacuum pouring manner, the traditional masonry construction method is changed, the mud gap in the ceramic cup is reduced from 3mm to 1.5mm, which meets the construction requirements, thereby reducing the contact area of the mud and the molten iron in the ceramic cup structure, and reducing the risk of molten iron leakage from the mud gap. The silicon oxynitride microcrystalline powder, the silicon-aluminum alloy powder, the alumina micropowder and the carbon black powder are used as the main sintering materials, the acidic zirconia sol is used as the binder of the high-flowability refractory mud, so that the mud reacts to form a high-strength high-melting-point ceramic bond, the new substance generated by the reaction fills the mud to have a high micro-porosity, the 1150℃ isotherm (i.e. the molten iron solidification line) is blocked in the ceramic layer, and the carbon brick avoids the brittle fracture zone of 800-1100℃. The above measures work together to create a new type of refractory mud and a new construction method, which effectively improves the use effect of the ceramic cup.

[0089] It should be understood that those skilled in the art can make improvements or changes according to the above description, and all these improvements and changes shall belong to the protection scope of the appended claims of the present application.

Claims

1. A method of applying a refractory mortar for a blast furnace ceramic cup, characterized by, The raw material components of the refractory slurry for the blast furnace ceramic cup, by mass percentage, are: microporous corundum fine powder 0.074-0 mm 25-35%; active alumina powder 25-30%; silicon oxynitride microcrystalline powder 5-8%; alumina fiber 10-20%; silicon-aluminum alloy powder 10-15%; carbon black N990 5-8%; polyacrylammonium salt dispersant 0.5-1.5%; acidic zirconia sol, plus 8-10%; The construction method comprises the following steps: 1) first, the blast furnace ceramic cup prefabricated part or brick is positioned according to the construction specification to complete the masonry of the blast furnace ceramic cup masonry, wherein the gap between the prefabricated parts, between the bricks, or between the prefabricated parts and the bricks is 1.5 mm; 2) then, the inner surface of the obtained blast furnace ceramic cup masonry is fully paved with a rubber film, and sandbags are used to compress the surface and the periphery of the rubber film to ensure that the blast furnace ceramic cup masonry forms a sealed space; the surface of the blast furnace ceramic cup masonry in four directions around is reserved for air holes for vacuumizing, and the connection of the vacuumizing equipment; and the center position of the inner surface of the bottom of the ceramic cup masonry is reserved for a grouting air hole, and the connection of the grouting equipment; 3) start the vacuumizing equipment to perform vacuumizing, and then start the grouting equipment, the slurry flows and fills into the gaps of the ceramic cup masonry through the reserved grouting air hole, and after the filling is completed, the vacuumizing state is still maintained for 30-60 min, that is, the construction is completed.

2. The construction method according to claim 1, characterized in that, The microporous corundum powder has a pore size distribution of 0.1-1 μm, and the apparent porosity is ≤8%.

3. The construction method according to claim 1, characterized in that, The microporous corundum powder has Al2O3≥98%, and a volume density ≤3.4 g / cm 3 The active alumina powder has a content of a-Al2O3≥99%, Fe2O3≤0.1%, R2O≤0.1%, and d50 is 1.4-1.8 μm. The alumina fiber has a content of Al2O3≥95%, SiO2≤5%, and Fe2O3≤0.1%.

4. The construction method according to claim 1, characterized in that, The silicon oxynitride microcrystalline powder is a composite microcrystalline powder mainly composed of Si2N2O and Si3N4, mainly existing in amorphous and microcrystalline forms, wherein the content of Si2N2O is 40-50%.

5. The construction method according to claim 1, characterized in that, The alumina fiber has an average diameter of 2-4 μm and a length of 0.2-0.5 mm.

6. The construction method according to claim 1, characterized in that, The silicon-aluminum alloy powder is an alloy powder with Si≤40%, Al≥55%, and particle size ≤0.074 mm.

7. The construction method according to claim 1, characterized in that, The pH value of the acidic zirconia sol solution is 3-5.

8. The construction method according to claim 1, characterized in that, In the acidic zirconia sol, the particle size of zirconia is below 10 nm, and the content of ZrO2 is 10-15%.

9. The construction method according to claim 1, characterized in that, The preparation method of the refractory slurry for the blast furnace ceramic cup comprises the following steps: The microporous corundum fine powder 0.074-0 mm, the active alumina powder, the alumina fiber, the silicon-aluminum alloy powder, the silicon oxynitride composite powder, the carbon black N990, and the polyacrylammonium salt dispersant are uniformly mixed, and then the acidic zirconia liquid sol is added and stirred to mix, so that a homogeneous slurry with good fluidity is obtained, that is, the refractory slurry for the blast furnace ceramic cup.

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