Erosion-resistant iron mouth mud sleeve repair material and preparation method thereof

Abstract

The application discloses a kind of scouring-resistant iron mouth mud sleeve repair material and preparation method thereof. By mass percentage, including the following raw materials: pretreated vanadium-titanium iron channel slag 50-60%; fast cooling white corundum 16-26%; elemental silicon powder 12-20%; magnesium-aluminum alloy powder 3-5%; dextrin 1.5-2.5%; salicylic acid 0.1-0.2%; glycerol and ethylene glycol mixed solution 4-6% are added externally. Among them: the pretreated vanadium-titanium iron channel slag is prepared by first removing impurities by pickling, then washing and drying, and then vacuum impregnating with ammonium ion stabilized silica sol, and then high-temperature sintering; the porosity of fast cooling white corundum is greater than or equal to 9%. The obtained iron mouth mud sleeve material does not add resin and other high-pollution carbon-containing raw materials, can be stored on site for a long time, has good filling performance, fast hardening speed, and low thermal conductivity; it does not stick to slag iron during use, has high strength, does not produce peeling during repeated tapping, and has long service life for one-time construction.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of refractory materials, and particularly relates to a scouring-resistant iron notch clay sleeve repairing material and a preparation method thereof. BACKGROUND

[0002] The furnace front iron notch qualified rate is an important index, and the maintenance of the iron notch will directly affect the operation and service life of the blast furnace, and is a long-term important work. The clay sleeve is an important component of the iron notch, and the iron notch clay sleeve is an annular structure which is subjected to the impact and erosion of molten iron and slag and the mechanical impact of the iron notch blocking machine every time in the long-term use process. The iron notch clay sleeve is divided into a permanent layer and a working layer, the permanent layer is prepared into a shape by pouring during the construction of the blast furnace, and the working layer is a part which is in long-term contact with the molten iron and the iron notch blocking machine. The clay sleeve repairing material is mainly used for repairing and maintaining the working layer of the clay sleeve, and the quality of the repairing material directly affects the frequency of daily repair.

[0003] Two kinds of iron notch clay sleeve repairing materials are mainly used in the prior art, one of which is combined with resin or tar and tamped for construction, and the other is combined with cement and poured for construction. The clay sleeve tamping material combined with resin or tar has poor heat stability, short storage period, and is easy to solidify and lose the construction performance in the storage process, and the clay sleeve is repaired in the hot state in the taphole gap, and the resin or tar is carbonized and releases a large amount of toxic and harmful smoke during the tamping construction process, which deteriorates the on-site environment and increases the construction difficulty of workers. The clay sleeve material combined with cement needs to be stirred on site before use and then poured, because the baking time is short, the taphole needs to be tapped before the baking is completed, the castable is easy to crack and peel off due to the rapid heating, and the water vapor in the castable is also easy to cause the splashing of the molten iron. The traditional iron notch clay sleeve material is made of alumina-silicon carbide-carbon material, and the thermal conductivity of the material is generally above 7 (w / m.k) at 1400 DEG C. The high thermal conductivity reduces the temperature of the liquid high-temperature molten iron and slag, increases the viscosity, and is easy to adhere to the iron notch, causing the iron notch to be blocked and the iron notch blocking machine to be difficult to open the iron notch, and the molten slag reacts with the iron notch material to produce erosion.

[0004] Patent 201710468632.4 discloses a blast furnace taphole clay sleeve castable, which is formed by cement combination pouring, facilitates furnace operation, reduces labor intensity, and has good volume stability, but the cement combined castable has low high-temperature strength, is prone to burst due to incomplete baking, and is prone to molten iron spatter during tapping. Patent 201810632239.9 discloses a low-cost long-life blast furnace taphole clay sleeve and a preparation method thereof, which is prepared from a large amount of waste into a prefabricated part, and the prefabricated part has high size requirements, which is prone to cause installation difficulties on site, and the gap between the prefabricated part and the surrounding part is prone to become a weak point of erosion. Patent 201910535478.7 high-temperature resistant plastic for repairing blast furnace taphole clay sleeve and preparation method thereof, which uses aluminum sulfate solution and clay as a binder, can quickly harden after construction, but contains a large amount of low-melting substances, has low high-temperature strength, and is not resistant to erosion. SUMMARY

[0005] The purpose of the present application is to provide a kind of erosion-resistant taphole clay sleeve repair material and preparation method thereof. The taphole clay sleeve material can be stored on site for a long time, has good filling performance, fast hardening speed and low thermal conductivity; In the use process, it does not stick to slag and iron, has high strength, does not produce peeling during repeated tapping, and has long service life after one-time construction.

[0006] To achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0007] A kind of erosion-resistant taphole clay sleeve repair material is provided, which comprises the following raw materials in mass percentage:

[0008]

[0009] Among them:

[0010] The pretreated vanadium-titanium iron channel slag is prepared by first acid pickling and removing impurities, washing and drying, and then vacuum impregnating with ammonium ion stabilized silica sol, and then high-temperature sintering.

[0011] In the fast-cooling white corundum, Al2O3≥98.5wt%, R2O≤0.25wt%, porosity≥9%, bulk density≤3.5g / cm 3 .

[0012] According to the above scheme, the pretreated vanadium-titanium iron channel slag has TiO2≥14wt%, Al2O3≥20wt%, SiO2≥30wt%, CaO≤30wt%, MgO≤10wt%, K2O+Na2O+Fe2O3≤0.3wt%, and its apparent porosity is between 12-17%;

[0013] According to the above scheme, the acid in the acid pickling and impurity removing is 2-4wt% oxalic acid aqueous solution.

[0014] According to the above scheme, the drying temperature is 105-115℃.

[0015] According to the above scheme, the SiO2 content in the ammonium ion stabilized silica sol solution is 30-40%. The ammonium ion stabilized silica sol solution is prepared by using ammonium ion as a stabilizer, and the ammonium ion volatilizes upon heating without leaving impurities.

[0016] According to the above scheme, the vacuum impregnation is vacuum impregnation at a pressure of 0.1-0.15MPa for 20-30h.

[0017] According to the above scheme, the sintering temperature is 1000-1100℃, and the sintering time is 10-12h.

[0018] According to the above scheme, the sintered channel slag is crushed into a uniform material with a particle size of 5-1mm.

[0019] According to the above scheme, the fast-cooling white corundum is prepared by long-arc oxidation smelting, and then the electric arc furnace is powered off to rapidly cool the fused block to obtain high-purity white corundum with more closed pores. The fused block is crushed to obtain white corundum with a particle size of 3-1mm.

[0020] According to the above scheme, the mass ratio of glycerol to ethylene glycol in the mixed solution of glycerol and ethylene glycol is 2.5-3.5:1.

[0021] According to the above scheme, the Al content in the aluminum-magnesium alloy powder is ≥50wt%, the Mg content is ≥45wt%, and the particle size is 0.1-0mm.

[0022] According to the above scheme, the Si content in the elemental silicon powder is ≥95wt%, and the particle size is 1-0mm.

[0023] According to the above scheme, the yellow dextrin is an industrial malt dextrin.

[0024] The application provides a kind of iron mouth mud sleeve repair material of erosion resistance, with vanadium-titanium iron channel slag treated by pickling and vacuum impregnation as main raw material, cooperate fast cooling white corundum, elemental silicon powder, magnesium-aluminum alloy powder, dextrin and salicylic acid, then synergistic external doping glycerol and ethylene glycol mixed solution is obtained, wherein:

[0025] Vanadium titanium iron channel slag contains Fe, Na and K and other alkaline low melting impurities, and has many loose pores after cooling, and the particle strength is not high, so it cannot be directly used. In the application, the vanadium titanium blast furnace channel slag is pickled to remove impurities, which can fully remove the Fe, Na and K and other impurities in the channel slag, reduce the content of alkaline low melting substance, and increase the content of calcium titanate, aluminum titanate, titanium nitride, titanium carbide and other high melting point refractory substances; and after pickling and removing impurities, the apparent porosity of the vanadium titanium slag increases, and the thermal conductivity is reduced; further, the vanadium titanium slag is vacuum impregnated by using ammonium ion stabilized silica sol, which is beneficial to the silica sol to fully absorb into the vanadium titanium iron channel slag and fill the large pores, and then after high temperature sintering, the high activity SiO2 in the silica sol reacts with aluminum oxide, calcium oxide and titanium oxide in the vanadium titanium ore, which significantly improves the structural strength of the slag channel material as an aggregate, and the large pores become micro-pores, further reducing the thermal conductivity.

[0026] After the construction is completed, due to the high temperature of the construction position, the magnesium-aluminum alloy powder burns and releases heat in the baking process, so that the repair material itself sintering rapidly, so that the mud sleeve material can be quickly dried and hardened, and high structural strength is obtained.

[0027] The massive oxidation reaction of elemental aluminum and elemental silicon generates SiO2 and Al2O3, and continues to polymerize with vanadium titanium blast furnace slag to generate mullite, spinel, calcium titanium aluminate, etc. These newly generated substances are distributed in a network shape, enhancing the bonding property and density of the matrix, while retaining the higher micro-porosity of the aggregate, making the material have a lower thermal conductivity while the high-temperature strength is greatly improved and the erosion resistance is enhanced.

[0028] After the white corundum smelting is completed, it is quickly cooled by power-off, and the gas cannot timely float up, so that the white corundum forms a large number of closed pore structures after cooling, which is combined with the vanadium titanium ore blast furnace iron channel slag which also has a large number of micro-pores, thereby significantly reducing the thermal conductivity of the mud sleeve repair material; when the high-temperature molten slag contacts the repair material, due to the low thermal conductivity of the repair material, the heat of the molten slag cannot be timely transferred, so the temperature of the molten slag is always maintained above 1500 DEG C, thereby keeping the viscosity of the channel slag at a low level, so that it will not adhere to the iron notch, ensuring that the iron notch does not stick to the slag during the iron tapping process, so that the iron notch channel always remains unobstructed, reducing the damage of the iron notch material caused by slag cleaning and the erosion caused by the reaction of the slag adhered to the iron notch with the iron notch material, thereby prolonging the service life of the iron notch repair material.

[0029] Dextrin and salicylic acid provide the normal temperature strength of the repair material, so that the repair material has good plasticity and viscosity at normal temperature, and is easy to be formed by tamping or machine pressing; glycerol and ethylene glycol have good moisture retention, so that the material has a long shelf life, and the repair material still has good construction performance after long-term storage, and is harmless to the environment during use.

[0030] A preparation method of the above-mentioned erosion-resistant iron notch clay sleeve repair material is provided, comprising the following steps:

[0031] 1) The pretreated vanadium-titanium iron channel slag, fast-cooling white corundum, elemental silicon powder, magnesium-aluminum alloy powder, dextrin and salicylic acid are mixed and stirred uniformly to obtain a premix;

[0032] 2) The mixed solution of glycerol and ethylene glycol is added to the premix according to 4-6% of the mass of the premix, and stirred uniformly to obtain the erosion-resistant iron notch clay sleeve repair material.

[0033] According to the above scheme, in step 1), the mixing and stirring time is 6-8 min; preferably, the mixing and stirring is carried out in a planetary mixer.

[0034] According to the above scheme, in step 2), the stirring time is 8-10 min.

[0035] Compared with the prior art, the present application has the following advantages:

[0036] 1. The present application provides an erosion-resistant iron notch clay sleeve repair material, which uses recycled vanadium-titanium ore channel slag as refractory aggregate and performs acid washing and vacuum impregnation treatment to become a high-strength low-thermal-conductivity refractory aggregate, high-porosity white corundum as a secondary aggregate, dextrin and salicylic acid as a binding agent, ethylene glycol and glycerol as a humectant, and aluminum-magnesium alloy powder as a self-sintering agent; the obtained iron notch clay sleeve repair material has a low thermal conductivity and a high structural strength; it can be self-heat-sintered, so that each part of the repair material is uniformly heated to form a homogeneous sintered body, has a high medium-high temperature strength, does not stick to slag, and is not easy to peel off; has good plasticity and viscosity at room temperature, good construction performance, excellent long-term stability, and a wide application prospect.

[0037] 2. The clay sleeve repair material of the present application first performs acid washing to remove impurities from the vanadium-titanium blast furnace channel slag, then performs vacuum impregnation on the slag using ammonium ion stabilized silica sol, and finally performs high-temperature sintering, so that the vanadium-titanium blast furnace slag has a low thermal conductivity and a high strength, realizes the secondary recycling and high-value utilization of the vanadium-titanium blast furnace slag, and reduces the problem of large-scale site stacking and environmental pollution.

[0038] 3. The present application provides a preparation method of an erosion-resistant iron notch clay sleeve repair material, which is simple to operate, uses inexpensive and readily available raw materials, realizes the secondary utilization of waste, is green and environmentally friendly, has a low cost, and has an industrial application prospect. DETAILED DESCRIPTION

[0039] The following examples further illustrate the technical solutions of the present application, but do not limit the scope of protection of the present application.

[0040] The raw material properties involved in the examples are as follows:

[0041] The specific preparation steps of the pretreated vanadium-titanium iron channel slag are as follows: the vanadium-titanium blast furnace channel slag is soaked and stirred in an oxalic acid aqueous solution with a concentration of 4 wt%, and the soaking and stirring time is 24 h, so as to sufficiently remove impurities such as Fe, Na and K in the channel slag. Then, the channel slag is soaked in clean tap water, and the outlet is washed with flowing water and filtered by a sieve with a mesh size of 1 mm. Finally, the sieve material after washing is dried at 110 DEG C, and then is treated by vacuum impregnation in a vacuum impregnation tank at a pressure of 0.1-0.15 MPa for 24 h, and then is sintered in a rotary kiln at 1000 DEG C for 10 h. Finally, the sintered channel slag is crushed into a uniform material with a particle size of 5-1 mm. After the pretreatment, the vanadium-titanium iron channel slag has the following components: SiO2: 30.96%, Al2O3: 21.7%, CaO: 21.45%, MgO: 8.14%, and TiO2: 16.75%; and the apparent porosity is 14.7%.

[0042] The preparation process of the fast-cooling white corundum is as follows: long-arc oxidation smelting is adopted, then the electric arc furnace is powered off to rapidly cool the clinker, and high-purity white corundum with more closed pores is obtained, and the clinker is crushed to obtain white corundum with a particle size of 3-1 mm; wherein, Al2O3: 99.01%, R2O: 0.15%, closed porosity: 10.5%, and bulk density: 3.19 g / cm 3 .

[0043] Elemental silicon powder: Si: 96.5%, particle size: 1-0 mm.

[0044] Aluminum-magnesium alloy powder: Al: 51.5%, Mg: 46.8%, particle size: 0.1-0 mm.

[0045] Dextrin: malt dextrin.

[0046] In the glycerol and ethylene glycol mixture, the mass ratio of glycerol to ethylene glycol is 3:1.

[0047] Example 1

[0048] A kind of iron mouth mud sleeve repair material is provided, which is composed of the following components and weight percentages:

[0049]

[0050] The additional amount of the glycerol and ethylene glycol mixture is 6%.

[0051] Example 2

[0052] A kind of iron mouth mud sleeve repair material is provided, which is composed of the following components and weight percentages:

[0053]

[0054]

[0055] The additional amount of the glycerol and ethylene glycol mixture is 4.5%.

[0056] Example 3

[0057] A scour-resistant iron notch clay sleeve repair material is provided, comprising the following components and weight percentages:

[0058] The additional amount of the glycerol and ethylene glycol mixture is 5%.

[0059] Comparative Example 1

[0060] An iron notch clay sleeve repair material is provided, comprising the following components and weight percentages:

[0061]

[0062] The additional amount of the glycerol and ethylene glycol mixture is 6%.

[0063] Comparative Example 2

[0064] An iron notch clay sleeve repair material is provided, comprising the following components and weight percentages:

[0065]

[0066] The additional amount of the glycerol and ethylene glycol mixture is 6%.

[0067] Comparative Example 3

[0068] An iron notch clay sleeve repair material is provided, comprising the following components and weight percentages:

[0069]

[0070] The additional amount of the glycerol and ethylene glycol mixture is 6%.

[0071] Comparative Example 4

[0072] An iron notch clay sleeve repair material is provided, comprising the following components and weight percentages:

[0073]

[0074] The additional amount of the glycerol and ethylene glycol mixture is 6%.

[0075] The physico-chemical parameters of the iron notch clay sleeve repair materials obtained in Examples 1, 2, 3 and Comparative Examples are shown in Table 1.

[0076] Table 1 Physico-chemical parameters of each example and comparative example

[0077]

[0078]

[0079] Table 1 shows that the iron notch clay sleeve material provided by the embodiments 1-3 of the present application uses the recycled vanadium-titanium ore tailings as the refractory aggregate and carries out acid washing and vacuum impregnation treatment to become a high-strength and low-thermal-conductivity refractory aggregate, uses high-micro-porosity white corundum as the main matrix material, uses dextrin and salicylic acid as the binder, uses ethylene glycol and glycerol as the humectant, and uses aluminum-magnesium alloy powder as the self-sintering agent to prepare a low-thermal-conductivity iron notch clay sleeve repairing material which is not sticky to slag, has high strength, is resistant to erosion, and has a long shelf life

[0080] It should be understood that, for those skilled in the art, improvements or changes can be made 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. An erosion resistant nozzle bushing repair material, characterized by, By mass percentage, including the following raw materials: Pre-treated vanadium-titanium iron channel slag 5-1mm 50~60%; Fast-cooling white corundum 3-1mm 16~26%; Elemental silicon powder 12~20%; Magnesium-aluminum alloy powder 3~5%; Dextrin 1.5~2.5%; Salicylic acid 0.1~0.2%; Glycerol and ethylene glycol mixed solution 4~6% added externally; Among them: The pre-treated vanadium-titanium iron channel slag is prepared by first removing impurities by pickling, washing with water and drying, then vacuum impregnating it with ammonium ion stabilized silica sol, and finally sintering at high temperature; The fast-cooling white corundum has Al2O3≥98.5wt%, R2O≤0.25wt%, porosity≥9%, and volume density≤3.5g / cm3 3 .

2. The erosion-resistant nozzle bushing patch of claim 1, wherein, In the pre-treated vanadium-titanium iron channel slag, TiO2≥14wt%, Al2O3≥20wt%, SiO2≥30wt%, CaO≤30wt%, MgO≤10wt%, K2O+Na2O+Fe2O3≤0.3wt%, and the apparent porosity is between 12-17%.

3. The erosion-resistant nozzle bushing patch of claim 1, wherein, The acid used in the pickling process is a 2-4wt% oxalic acid aqueous solution.

4. The erosion-resistant nozzle bushing patch of claim 1, wherein, In the ammonium ion stabilized silica sol solution, the SiO2content is 30-40%.

5. The erosion-resistant nozzle bushing patch of claim 1 wherein, The vacuum impregnation is performed at a pressure of 0.1-0.15MPa for 20-30h.

6. The erosion-resistant nozzle bushing patch of claim 1, wherein, The sintering temperature is 1000-1100℃, and the sintering time is 10-12h.

7. The erosion-resistant nozzle bushing patch of claim 1, wherein, The fast-cooling white corundum is prepared by long-arc oxidation smelting, then the arc furnace is powered off to make the melt block cool quickly, and finally the melt block is crushed to obtain 3-1mm white corundum.

8. The erosion-resistant nozzle bushing patch of claim 1, wherein, In the glycerol and ethylene glycol mixed solution, the mass ratio of glycerol to ethylene glycol is 2.5-3.5:

1.

9. The erosion-resistant nozzle bushing patch of claim 1, wherein, In the aluminum-magnesium alloy powder, the Al content is ≥50wt%, the Mg content is ≥45wt%, and the particle size is 0.1-0mm; in the elemental silicon powder, the Si content is ≥95wt%, and the particle size is 1-0mm; the dextrin is industrial malt dextrin.

10. A method of preparing an erosion-resistant casthouse spout patching compound as claimed in any one of claims 1 to 9, characterised in that, Including the following steps: 1) Mix and stir the pre-treated vanadium-titanium iron channel slag, fast-cooling white corundum, elemental silicon powder, magnesium-aluminum alloy powder, dextrin and salicylic acid uniformly to obtain a premix; 2) Add the glycerol and ethylene glycol mixed solution to the premix according to 4~6% of the mass of the premix, and stir uniformly to obtain the erosion-resistant iron mouth mud sleeve repair material.

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