A permanent layer of a phosphoric acid binding agent for a ladle

Abstract

The application provides application of phosphoric acid in preparation of permanent layer of ladle wall. The application also provides a permanent layer for the ladle wall and a ladle. The application particularly applies phosphoric acid as a binding agent in preparation of the permanent layer of the ladle wall, and designs a permanent layer with specific composition and proportion. The application uses phosphoric acid as a binding agent to produce a permanent layer with undefined shape, which is convenient for construction, reduces carbon emission caused by sintering, and thins the permanent layer to about 2 / 3 of the original thickness. The application solves the problem of waste of steel loading caused by the thick permanent layer, improves the corrosion resistance of the permanent layer, ensures the safety of the permanent layer, reduces carbon emission, and achieves the purpose of capacity expansion under the premise of meeting the production needs of the iron mill.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of permanent layer preparation of the ladle wall of a hot metal ladle, and relates to application of phosphoric acid in preparation of a permanent layer of the ladle wall of a hot metal ladle, a permanent layer for the ladle wall of a hot metal ladle and a hot metal ladle, in particular to application of phosphoric acid in preparation of a permanent layer of the ladle wall of a hot metal ladle, a permanent layer for the ladle wall of a hot metal ladle and a hot metal ladle adopting a permanent layer of a phosphoric acid binder. BACKGROUND

[0002] With the macro-control of the state on the steel output, the large blast furnace cannot be approved to be built, but during the development of the steel industry, who can expand the production capacity means that better development opportunities can be obtained when having market advantages. Therefore, it is necessary to always base on the high furnace to achieve the load, and strive to add scrap steel in each process to improve the steel production capacity. Under the premise of this background, the requirement of increasing the pig iron processing capacity of the hot metal ladle is born, so it is necessary to expand the capacity of the existing hot metal ladle.

[0003] Therefore, how to find a more suitable way to expand the capacity on the basis of the existing hot metal ladle, while ensuring the use performance, and trying to reduce the improvement cost has become one of the problems to be solved by many front-line researchers in the industry. SUMMARY

[0004] Therefore, the technical problem to be solved by the application is to provide application of phosphoric acid in preparation of a permanent layer of the ladle wall of a hot metal ladle, a permanent layer for the ladle wall of a hot metal ladle and a hot metal ladle. The hot metal ladle provided by the application reduces the thickness of the permanent layer under the condition that the thickness of the working layer is unchanged, solves the problem of expanding the capacity of the hot metal ladle. The application reduces the thickness of the permanent layer by 1 / 3 under the condition of ensuring the safety of the hot metal ladle, and the pressure resistance cannot be reduced, and the construction scheme is simpler and more feasible, and has strong operability, and is more suitable for industrialization popularization and application.

[0005] The application provides application of phosphoric acid in preparation of a permanent layer of the ladle wall of a hot metal ladle.

[0006] Preferably, the application is specifically application as a binder.

[0007] The raw material for preparing the permanent layer of the ladle wall of the hot metal ladle further comprises sintered mullite.

[0008] The mass ratio of the phosphoric acid to the solid raw material in the raw material for preparing the permanent layer of the ladle wall of the hot metal ladle is 12% to 15%.

[0009] The permanent layer is specifically a layer arranged between the ladle wall of the hot metal ladle and the working lining of the ladle wall.

[0010] Preferably, the phosphoric acid comprises a phosphoric acid solution.

[0011] The concentration of the phosphoric acid solution is greater than or equal to 85%;

[0012] The mass content of Al2O3 in the sintered mullite is greater than or equal to 70%;

[0013] The mass content of the sintered mullite in the raw material for preparing the permanent layer of the ladle wall is 50% to 55%.

[0014] The application provides a permanent layer for a ladle wall, the permanent layer comprising, in terms of mass fractions of raw materials:

[0015] 50 to 55 parts by weight of sintered mullite and / or electrically fused mullite;

[0016] 20 to 25 parts by weight of calcined flint clay;

[0017] 18 to 23 parts by weight of Guangxi white clay;

[0018] 7 to 10 parts by weight of micro powder and additives;

[0019] The mass ratio of the phosphoric acid solution to the above-mentioned solid raw materials in the raw materials is 12% to 15%.

[0020] Preferably, the sintered mullite and / or electrically fused mullite is specifically M70 sintered mullite and / or M70 electrically fused mullite;

[0021] In the sintered mullite and / or electrically fused mullite, the mass content of particles with a particle size of 3 to 5 mm is 9% to 12%;

[0022] In the sintered mullite and / or electrically fused mullite, the mass content of particles with a particle size of 1 to 3 mm is 20% to 25%;

[0023] In the sintered mullite and / or electrically fused mullite, the mass content of particles with a particle size of 0 to 1 mm is 18% to 21%.

[0024] Preferably, the micro powder is specifically micro powder with a particle size of less than 5 microns;

[0025] The micro powder comprises active alumina micro powder and / or silicon oxide micro powder;

[0026] The additives comprise one or more of oxalic acid, tartaric acid and sodium tripolyphosphate;

[0027] The permanent layer is a non-brick permanent layer.

[0028] Preferably, the permanent layer has a layer number greater than or equal to 2;

[0029] The single-layer thickness of the permanent layer is 19 to 21 mm;

[0030] The permanent layer is obtained by mixing raw materials, coating on the wall of the hot metal ladle, and curing.

[0031] The curing time is 3-4 days.

[0032] The permanent layer has a reticular structure formed by polyaluminum phosphate and branched polyaluminum phosphate.

[0033] The application further provides a hot metal ladle, wherein a wall permanent layer is arranged on the wall of the hot metal ladle.

[0034] The wall permanent layer is the permanent layer in any one of the technical solutions or the permanent layer in any one of the technical solutions.

[0035] Preferably, the arrangement mode comprises coating.

[0036] The wall permanent layer is further compounded with a wall working lining.

[0037] The total thickness of the wall permanent layer is 39-41 mm.

[0038] The thickness of the wall working lining is 159-161 mm.

[0039] The material of the wall working lining comprises aluminum-silicon carbide-carbon bricks.

[0040] Preferably, the hot metal ladle further comprises a bottom permanent layer arranged on the bottom and a bottom working layer compounded on the bottom permanent layer.

[0041] The bottom permanent layer specifically comprises two clay brick layers.

[0042] The thickness of the bottom permanent layer is 98.5-99.5 mm.

[0043] The bottom working layer comprises aluminum-silicon carbide-carbon bricks.

[0044] The thickness of the wall working layer is 298-302 mm.

[0045] The application provides application of phosphoric acid in preparation of a permanent layer of a wall of a hot metal ladle. Compared with the prior art, the application considers that, to expand the capacity of the existing hot metal ladle at low cost, expanding the refractory of the hot metal ladle is an effective research direction. Because the working layer of the hot metal ladle is in a positive correlation with the thickness, to not affect the cost and benefits, the technical research is placed on the permanent layer, the permanent layer is designed as two clay brick layers, each layer is 33 mm thick, and the total thickness is 66 mm.

[0046] Based on this, the application particularly applies phosphoric acid as a binding agent in the permanent layer of the ladle wall, and designs a permanent layer with specific composition and ratio. The application uses phosphoric acid as a binding agent to produce a permanent layer with irregular shape, which facilitates construction, reduces carbon emission caused by firing, and thins the permanent layer to about 2 / 3 of the original thickness. The application solves the problem of waste of steel loading caused by the thick permanent layer, improves the corrosion resistance of the permanent layer, ensures the safety of the permanent layer, and reduces carbon emission; under the premise of meeting the production needs of the iron mill, the expansion purpose is achieved.

[0047] The application reduces the thickness of the permanent layer under the condition that the thickness of the working layer is unchanged. Under the condition of ensuring the safety of the ladle, the permanent layer is thinned by 1 / 3, and the pressure resistance cannot be reduced. The application provides a permanent layer with irregular shape, and maintains the performance of the original machine pressure fired permanent layer brick. The application adopts the method of combining the permanent layer with phosphoric acid, which solves the problems of strength and safety of the permanent layer, and also solves the problem of loading of the ladle, and simplifies the construction process and the firing process of the original permanent layer; under the condition of the limit thickness of the permanent layer, the thickness is reduced by leaps and bounds.

[0048] The application provides a permanent layer for the ladle wall and a corresponding construction method. Since the liquidity of molten iron is very strong, the thinnest permanent layer of the brick needs two layers, and the penetration of molten iron to the steel structure occurs to cause leakage accidents. The permanent layer is formed by smearing, has good integrity, no brick joints are generated, and safety is ensured. Although phosphoric acid has no adhesion, when it contacts with refractory materials, a rapid reaction occurs between them to generate phosphate, form aluminum polyphosphate and branched aluminum polyphosphate, and form a network structure with strong mechanical strength, so that the thickness of the smearing material is reduced, and the overall room temperature strength reaches 50Mpa, which exceeds the performance index of 35Mpa of ordinary clay bricks. The permanent layer provided by the application adopts a smearing construction method, avoids a pouring construction method, reduces the construction thickness of the material to the lowest, and ensures that the molten iron loading capacity is increased by about 7 tons. BRIEF DESCRIPTION OF DRAWINGS

[0049] Figure 1 The application is aimed at improving the structure and layer parameters of the conventional ladle. DETAILED DESCRIPTION

[0050] In order to further understand the application, the preferred embodiments of the application are described below in combination with examples, but it should be understood that these descriptions are only for further illustrating the features and advantages of the application, and are not limitations of the claims.

[0051] All raw materials of the application have no special limitation on the source, and can be purchased on the market or prepared according to the conventional method known to those skilled in the art.

[0052] The raw materials used in the present application are not particularly limited in purity, and the present application preferably has an industrial purity or a conventional purity in the field of permanent layer manufacturing of molten iron ladle.

[0053] The grade and abbreviation of all raw materials used in the present application belong to the conventional grade and abbreviation in the art, and each grade and abbreviation is clear and explicit in the field of its relevant use. The skilled person can purchase or prepare by conventional method according to the grade, abbreviation and corresponding use.

[0054] The abbreviation of all processes used in the present application belongs to the conventional abbreviation in the art, and each abbreviation is clear and explicit in the field of its relevant use. The skilled person can understand the conventional process steps according to the abbreviation.

[0055] The present application provides the use of phosphoric acid in the preparation of a permanent layer of a molten iron ladle wall.

[0056] In the present application, the use is particularly preferably the use as a binding agent.

[0057] In the present application, the raw materials for preparing the permanent layer of the molten iron ladle wall further preferably include sintered mullite.

[0058] In the present application, the mass ratio of the phosphoric acid to the solid raw materials in the raw materials for preparing the permanent layer of the molten iron ladle wall is preferably 12% to 15%, more preferably 12.5% to 14.5%, and more preferably 13% to 14%.

[0059] In the present application, the permanent layer is particularly preferably a layer arranged between the molten iron ladle wall and the working lining of the ladle wall.

[0060] In the present application, the phosphoric acid preferably includes a phosphoric acid solution.

[0061] In the present application, the concentration of the phosphoric acid solution is preferably greater than or equal to 85%, more preferably greater than or equal to 87%, and more preferably greater than or equal to 89%.

[0062] In the present application, the mass content of Al2O3 in the sintered mullite is preferably greater than or equal to 70%, more preferably greater than or equal to 72%, and more preferably greater than or equal to 74%.

[0063] In the present application, the mass content of the sintered mullite in the raw materials for preparing the permanent layer of the molten iron ladle wall is preferably 50% to 55%, more preferably 51% to 54%, and more preferably 52% to 53%.

[0064] The present application provides a permanent layer for a molten iron ladle wall, which comprises, in terms of mass parts of raw materials:

[0065] Sintered mullite and / or electrically fused mullite 50-55 parts by weight;

[0066] Focalite 20-25 parts by weight;

[0067] Guangxi white clay 18-23 parts by weight;

[0068] Micro powder and additives 7-10 parts by weight;

[0069] The mass ratio of the phosphoric acid solution to the above-mentioned solid raw materials in the raw materials is 12%-15%.

[0070] In the present application, the sintered mullite and / or electrically fused mullite is added in an amount of 50-55 parts by weight, which can be 51-54 parts by weight, or 52-53 parts by weight.

[0071] In the present application, the focalite is added in an amount of 20-25 parts by weight, which can be 21-24 parts by weight, or 22-23 parts by weight.

[0072] In the present application, the Guangxi white clay is added in an amount of 18-23 parts by weight, which can be 19-22 parts by weight, or 20-21 parts by weight.

[0073] In the present application, the micro powder and additives are added in an amount of 7-10 parts by weight, which can be 7.5-9.5 parts by weight, or 8-9 parts by weight.

[0074] In the present application, the mass ratio of the phosphoric acid solution to the above-mentioned solid raw materials (clay) in the raw materials is 12%-15%, which can be 12.5%-14.5%, or 13%-14%.

[0075] In the present application, the sintered mullite and / or electrically fused mullite is specifically preferably M70 sintered mullite and / or M70 electrically fused mullite.

[0076] In the present application, in the sintered mullite and / or electrically fused mullite, the mass percentage of particles with a particle size of 3-5 mm is preferably 9%-12%, more preferably 9.5%-11.5%, or more preferably 10%-11%.

[0077] In the present application, in the sintered mullite and / or electrically fused mullite, the mass percentage of particles with a particle size of 1-3 mm is preferably 20%-25%, more preferably 21%-24%, or more preferably 22%-23%.

[0078] In the present application, the mass percentage of the particles with a particle size of 0-1mm (less than or equal to 1mm) in the sintered mullite and / or the electrically fused mullite is preferably 18%-21%, more preferably 18.5%-20.5%, and more preferably 19%-20%. Specifically, the particle size is 0.01-1mm, or 0.05-1mm, or 0.1-1mm.

[0079] In the present application, the micropowder is specifically preferably micropowder with a particle size of less than 5μm, more preferably micropowder with a particle size of less than 4.5μm, and more preferably micropowder with a particle size of less than 4μm.

[0080] In the present application, the micropowder preferably includes active alumina micropowder and / or silica micropowder, and more preferably active alumina micropowder or silica micropowder.

[0081] In the present application, the additive preferably includes one or more of oxalic acid, tartaric acid, and sodium tripolyphosphate, and more preferably oxalic acid, tartaric acid, or sodium tripolyphosphate.

[0082] In the present application, the permanent layer is preferably a non-brick permanent layer.

[0083] In the present application, the number of layers of the permanent layer is preferably greater than or equal to 2 layers, more preferably greater than or equal to 3 layers, and more preferably greater than or equal to 4 layers.

[0084] In the present application, the thickness of a single layer of the permanent layer is preferably 19-21mm, more preferably 19.4-20.6mm, and preferably 19.8-20.2mm. Specifically, the permanent layer in the present application is calibrated to 20mm.

[0085] In the present application, the permanent layer is preferably obtained by mixing raw materials, applying the mixture on the wall of the hot metal ladle, and curing.

[0086] In the present application, the curing time is preferably 3-4 days.

[0087] In the present application, the permanent layer preferably has a reticular structure formed by aluminum polyphosphate and branched aluminum polyphosphate.

[0088] The present application provides a hot metal ladle, wherein a permanent layer is arranged on the wall of the hot metal ladle.

[0089] The permanent layer is the permanent layer in any one of the above technical solutions or the permanent layer as defined in any one of the above technical solutions.

[0090] In the present application, the arrangement is preferably by applying. That is, the construction method of the permanent layer in the present application is prepared by applying, without using the bricklaying method.

[0091] In the present application, the permanent layer of the tank wall is further preferably compounded with a working lining of the tank wall.

[0092] In the present application, the total thickness of the permanent layer of the tank wall is preferably 39-41 mm, more preferably 39.4-40.6 mm, and more preferably 39.8-40.2 mm.

[0093] In the present application, the thickness of the working lining of the tank wall is preferably 159-161 mm, more preferably 159.4-160.6 mm, and more preferably 159.8-160.2 mm.

[0094] In the present application, the material of the working lining of the tank wall preferably comprises aluminum-silicon carbide-carbon bricks. Among them, aluminum-silicon carbide-carbon is a general material of refractory, which is an aluminum-silicon carbide-carbon brick with aluminum oxide, silicon carbide and carbon in the main chemical proportion.

[0095] In the present application, the molten iron tank further preferably comprises a permanent layer of the tank bottom arranged on the tank bottom and a working layer of the tank bottom compounded on the permanent layer of the tank bottom.

[0096] In the present application, the permanent layer of the tank bottom is specifically preferably two layers of clay bricks.

[0097] In the present application, the thickness of the permanent layer of the tank bottom is preferably 98.5-99.5 mm, more preferably 98.7-99.3 mm, and more preferably 98.9-99.1 mm.

[0098] In the present application, the working layer of the tank bottom preferably comprises aluminum-silicon carbide-carbon bricks.

[0099] In the present application, the thickness of the working lining of the tank wall is preferably 298-302 mm, more preferably 298.5-301.5 mm, more preferably 299-301 mm, and more preferably 299.5-300.5 mm.

[0100] The present application is a complete and detailed overall technology, which better guarantees the overall performance of the molten iron tank, further improves the strength and high temperature resistance of the permanent layer, and better reduces the thickness of the permanent layer. The permanent layer for the tank wall of the molten iron tank and the molten iron tank with the permanent layer of the phosphoric acid binder can specifically include the following contents:

[0101] Reference Figure 1 , Figure 1 The present application is aimed at improving the structure and layer parameters of the conventional molten iron tank. In the figure, the unit of the distance parameter is mm.

[0102] Existing 140-ton molten iron tank design

[0103] 1. Inner lining design

[0104] 1.1 Permanent layer of tank wall

[0105] Two layers of clay bricks are used, thickness 33 mm*2+1 mm=67 mm;

[0106] 1.2 Working lining of the tank wall

[0107] Aluminum-silicon carbide-carbon bricks are used, thickness 160 mm for the remaining layers and 200 mm for the first layer;

[0108] 1.3 Permanent layer of the tank bottom

[0109] Clay bricks are used, one layer of flat half bricks and one layer of T-3, thickness 33+65+1=99 mm;

[0110] 1.4 Working layer of the tank bottom

[0111] Aluminum-silicon carbide-carbon bricks are used, thickness 300 mm.

[0112] 2. Iron loading capacity

[0113] 2.1 Theoretical calculation

[0114] Premise: the liquid level is 875 mm considering the influence of KR stirring;

[0115] The minimum iron loading capacity is calculated according to the newly repaired tank; the volume is 20.108 m 3 ; the bulk density of molten iron is 6900 kg / m 3

[0116] Theoretical iron loading capacity: 6900x20.108 / 1000=138.74 tons.

[0117] 2.2 Currently, due to the adhesion of slag to the tank body, the actual iron loading capacity is as follows:

[0118] For the new tank, the iron loading capacity without desulfurization is 135-137 tons, and the iron loading capacity with desulfurization is 128-132 tons.

[0119] For a tank used more than 1000 times, the iron loading capacity increases by 5-8 tons.

[0120] 3. Molten iron tank usage

[0121] The service life of the current molten iron tank is about 1450 times, and the residual thickness of the working layer after use is 50 mm, and the residual thickness of the bottom brick is 100 mm.

[0122] The molten iron tank provided by the present application uses a phosphoric acid binding agent for the permanent layer, i.e. an expansion scheme:

[0123] 1. The permanent layer of the molten iron tank wall is changed from the original two layers of flat half bricks to a 40 mm thick phosphoric acid binding molten iron tank permanent layer, and the reduced thickness of the permanent layer is: 67-40=27 mm;

[0124] 2. The method for constructing the permanent layer of the phosphoric acid combined iron ladle comprises the following steps: firstly, welding the "Y" type anchor nails on the steel shell of the iron ladle, the height of the anchor nails is 30mm, the front and back and left and right are spaced 50mm, and the anchor nails are evenly welded and fixed as the support; then, configuring the permanent layer of the iron ladle according to the formula, and smearing the permanent layer on the steel shell of the iron ladle, the first smearing is about 20mm thick, and the second smearing is about 20mm, and the anchor nails steel structure cannot be seen after the second smearing; and after the natural air drying for one week, the normal working layer is built to realize the expansion.

[0125] 3. The iron loading capacity after expansion: after the expansion, the same theoretical calculation principle of the new ladle iron loading mentioned above can be used to estimate the theoretical increased iron loading capacity of 7 tons.

[0126] The composition of the permanent layer of the phosphoric acid combined iron ladle provided by the application and the weight ratio of each component are as follows: M70 sintered mullite, coke, Guangxi white clay, micro powder (5 microns or less) and additives, and phosphoric acid solution (external) 12-15%.

[0127] The M70 sintered mullite is mixed by particles with different particle sizes, including 3-5mm, 1-3mm and 0-1mm, and the proportion of each particle size of the M70 sintered mullite in the phosphoric acid combined iron ladle permanent layer mud is the proportion in the phosphoric acid combined iron ladle permanent layer mud.

[0128] The micro powder and the additives contain various raw materials for strengthening the bonding strength, stabilizing the product firing line change rate and moisturizing agent, and the raw materials are mixed in advance in the mixing mill before preparation, so that the components of each matrix are mixed more uniformly.

[0129] The phosphoric acid is a liquid concentrated phosphoric acid solution.

[0130] The performance indexes of the raw materials are as follows:

[0131] The M70 sintered mullite: the chemical composition AL2O3≧70% (M70), Fe2O3≦1.5%, TiO2≦3%, K2O+Na2O≦0.4%, the physical indexes bulk density≧2.7g / cm 3 , porosity≦3%, H2O≦0.5%, refractoriness≧1800℃. The specific composition or requirement of the M70 electrically fused sintered mullite can also refer to the above description. Moreover, Fe2O3 can be less than or equal to 1.0% or lower.

[0132] The coke: the chemical composition AL2O3≧44% and≦50%, Fe2O3≦1.3%, the physical indexes bulk density≧2.5g / cm 3 , water absorption≦2.5%, H2O≦0.5%, refractoriness≧1760℃.

[0133] Guangxi white mud: AL2O3 in chemical composition is greater than or equal to 32%, Fe2O3 is less than or equal to 1.5%, plasticity in physical index is greater than or equal to 2.0%, loss on ignition is less than or equal to 15%, H2O is less than or equal to 8%, refractoriness is greater than or equal to 1710 DEG C.

[0134] Phosphoric acid solution: H3PO4 is greater than 85%, specific gravity is greater than or equal to 1.55 g / cm 3 .

[0135] The permanent layer of the phosphoric acid combined iron ladle provided by the application has the following properties:

[0136] Al2O3 content is greater than or equal to 48%

[0137] Fe2O3 content is less than or equal to 2.5%

[0138] Normal temperature compressive strength / MPa is greater than or equal to 50

[0139] Bulk density is greater than or equal to 2.4 g / cm 3 .

[0140] The application provides the application of phosphoric acid in the preparation of the permanent layer of the ladle wall of the iron ladle, a permanent layer for the ladle wall of the iron ladle and an iron ladle with the permanent layer of the phosphoric acid binder. The application applies phosphoric acid as a binder in the preparation of the permanent layer of the ladle wall of the iron ladle, and provides the permanent layer with specific composition and ratio. The application mainly uses phosphoric acid as a binder to produce a non-determinate permanent layer, which facilitates construction, reduces carbon emission caused by firing, and thins the permanent layer to about 2 / 3 of the original thickness. The application solves the problem of waste of the steel loading capacity caused by the thick permanent layer, improves the corrosion resistance of the permanent layer, ensures the safety of the permanent layer, reduces carbon emission, and achieves the purpose of capacity expansion under the premise of meeting the production needs of the iron mill.

[0141] The application reduces the thickness of the permanent layer under the condition that the thickness of the working layer is unchanged, thins the permanent layer by 1 / 3 under the condition of ensuring the safety of the iron ladle, and does not reduce the compressive strength. The application provides a non-determinate permanent layer, and maintains the performance of the original machine pressure fired permanent layer brick. The application adopts the mode of combining the permanent layer with phosphoric acid, solves the problems of the strength and use safety of the permanent layer, solves the problem of loading of the iron ladle, simplifies the construction process and the firing process of the original permanent layer, and realizes the stepwise reduction of the thickness under the condition of the limit thickness of the permanent layer.

[0142] The application provides a permanent layer for a molten iron tank wall and a corresponding construction method. Since the molten iron has strong fluidity, the thinnest permanent layer of the brickwork needs two layers, and the staggered joints are used to prevent the molten iron from penetrating the steel structure and causing leakage. The permanent layer is formed by smearing and has good integrity and no brick joints, thus ensuring safety. Although the phosphoric acid has no adhesion, when it contacts with the refractory material, a rapid reaction occurs to generate phosphate, aluminum polyphosphate and branched aluminum polyphosphate, and a net structure with strong mechanical strength is formed, so that the thickness of the smearing material is reduced, and the overall room temperature strength reaches 50Mpa, which exceeds the index performance of 35Mpa of the ordinary clay brick.

[0143] The permanent layer provided by the application adopts a smearing construction method, avoids the pouring construction method, reduces the construction thickness of the material to the minimum, and ensures that the molten iron loading capacity is increased by about 7 tons.

[0144] In order to further illustrate the application, the application of the phosphoric acid in the preparation of the permanent layer of the molten iron tank wall, the permanent layer for the molten iron tank wall and the molten iron tank are described in detail in combination with the embodiments, but it should be understood that these embodiments are implemented on the premise of the technical scheme of the application, and the detailed implementation mode and specific operation process are given, which are only for further illustrating the features and advantages of the application, and are not a limitation on the claims of the application, and the protection scope of the application is not limited to the following embodiments.

[0145] Example 1

[0146] The structure of the molten iron tank is shown in Figure 1 .

[0147] The construction method of the permanent layer of the molten iron tank combined with the phosphoric acid is as follows: first, weld "Y" type anchor nails on the steel shell of the molten iron tank, the anchor nails have a height of 30mm, and are uniformly welded and fixed as supports with a spacing of 50mm in front, back, left and right. Then, the permanent layer of the molten iron tank is prepared according to the formula, and is smeared on the steel shell of the molten iron tank. The first smearing is about 20mm thick, and the second smearing is about 20mm thick. The anchor nail steel structure cannot be seen after the second smearing. After natural air drying for one week, the working layer is normally built to realize expansion.

[0148] After expansion, the same theoretical calculation principle of the new tank mentioned above is used to estimate that the theoretical molten iron loading capacity is increased by 7 tons after the expansion of the molten iron volume calculated by the CAD software.

[0149] The composition of the permanent layer of the molten iron tank combined with the phosphoric acid and the weight ratio of each component are as follows: M70 sintered mullite 50%, coke stone 22%, Guangxi white clay 20%, industrial silicon powder (silicon oxide) (5 microns or less) and additives oxalic acid 8%, and phosphoric acid solution (additional) 15%.

[0150] M70 sintered mullite is mixed with different particle sizes, 3-5mm accounts for 10%, 1-3mm accounts for 20%, 0-1mm accounts for 20%, and the proportion of each particle size of M70 sintered mullite is the proportion in the permanent layer mud of the phosphoric acid combined iron ladle.

[0151] The micro powder and the additive are mixed in a mixing mill for 15 minutes before preparation, so that the matrix components are mixed more uniformly.

[0152] The phosphoric acid is a liquid concentrated phosphoric acid solution.

[0153] The performance indexes of the raw materials are as follows:

[0154] M70 sintered mullite: AL2O3≧70% (M70) in the chemical composition, Fe2O3≦1.5%, TiO2≦3%, K2O+Na2O≦0.4%, bulk density≧2.7g / cm in the physical indexes, porosity≦3%, H2O≦0.5%, refractoriness≧1800℃. 3

[0155] Flint: AL2O3≧44% and≦50% in the chemical composition, Fe2O3≦1.3%, bulk density≧2.5g / cm in the physical indexes, water absorption≦2.5%, H2O≦0.5%, refractoriness≧1760℃. 3

[0156] Guangxi white mud: AL2O3≧32% in the chemical composition, Fe2O3≦1.5%, plasticity≧2.0% in the physical indexes, loss on ignition≦15%, H2O≦8%, refractoriness≧1710℃.

[0157] Phosphoric acid solution: H3PO4>85%, specific gravity≧1.55g / cm. 3

[0158] The phosphoric acid combined iron ladle with the permanent layer prepared in Example 1 of the present application is detected.

[0159] The physicochemical properties of the permanent layer of the phosphoric acid combined iron ladle are as follows:

[0160] The content of Al2O3 is 53.5%

[0161] The content of Fe2O3 is 1.78%

[0162] The cold compressive strength is≧54.3 MPa

[0163] The bulk density is≧2.42g / cm. 3

[0164] Example 2

[0165] ​​​​Keeping the design of Example 1, the M70 sintered mullite of each particle size in Example 1 is replaced with the same proportion of all-natural electrically fused mullite, and a phosphoric acid binder permanent layer is used for detection.

[0166] The ladle prepared in Example 2 of the present application is detected by using a phosphoric acid binder permanent layer.

[0167] The physical and chemical properties of the ladle permanent layer of the phosphoric acid binder are as follows:

[0168] The Al2O3 content is 54.8%

[0169] The Fe2O3 content is 1.84%

[0170] The cold compressive strength is ≧53.2 MPa

[0171] The bulk density is ≧2.44 g / cm 3 .

[0172] Example 3

[0173] Keeping the design of Example 1, the additive oxalic acid in Example 1 is replaced with the same proportion of additive tartaric acid, and a phosphoric acid binder permanent layer is used for detection.

[0174] The ladle prepared in Example 3 of the present application is detected by using a phosphoric acid binder permanent layer.

[0175] The physical and chemical properties of the ladle permanent layer of the phosphoric acid binder are as follows:

[0176] The Al2O3 content is 53.2%

[0177] The Fe2O3 content is 1.79%

[0178] The cold compressive strength is ≧55.6 MPa

[0179] The bulk density is ≧2.42 g / cm 3 .

[0180] The application of the phosphoric acid in the preparation of the permanent layer of the ladle wall, the permanent layer for the ladle wall and the ladle with the permanent layer of the phosphoric acid binding agent are described in detail, and the principles and implementation manners of the application are described by using specific examples. The above description of the examples is only used to help understand the method of the application and the core idea, including the best mode, and also enables any person skilled in the art to practice the application, including manufacturing and using any device or system, and implementing any combined method. It should be pointed out that, for those skilled in the art, some improvements and modifications can be made to the application without departing from the principles of the application, and these improvements and modifications also fall within the protection scope of the claims of the application. The scope of the patent protection of the application is limited by the claims, and can include other embodiments that can be thought of by those skilled in the art. If these other embodiments have structural elements that are not different from the literal expression of the claims, or if they include equivalent structural elements that are not substantially different from the literal expression of the claims, then these other embodiments should also be included in the scope of the claims.

Claims

1. Application of phosphoric acid in the preparation of a permanent layer on the wall of a molten iron ladle; The specific application is as a binder; The raw materials for preparing the permanent layer of the molten iron ladle wall also include sintered mullite; The mass ratio of phosphoric acid to the solid raw materials in the raw materials for preparing the permanent layer of the molten iron ladle wall is 12%~15%. The permanent layer is a non-brick permanent layer; The sintered mullite has a mass content of 50% to 55% in the raw materials used to prepare the permanent layer of the molten iron ladle wall.

2. The application according to claim 1, characterized in that, The permanent layer is specifically a layer disposed between the ladle wall and the working lining of the ladle wall.

3. The application according to claim 2, characterized in that, The phosphoric acid includes a phosphoric acid solution; The concentration of the phosphoric acid solution is greater than or equal to 85%; The Al2O3 content in the sintered mullite is greater than or equal to 70%.

4. A permanent layer for the wall of a molten iron ladle, characterized in that, The permanent layer, by mass fraction of raw materials, comprises: 50-55 parts by weight of sintered mullite and / or electrofused mullite; 20-25 parts by weight of charred gemstones; 18-23 parts by weight of Guangxi white clay; 7-10 parts by weight of micro powder and additives; The mass ratio of phosphoric acid solution to the above-mentioned solid raw materials in the raw materials is 12%~15%; The permanent layer is a non-brick permanent layer.

5. The permanent layer according to claim 4, characterized in that, The sintered mullite and / or electrofused mullite are specifically M70 sintered mullite and / or M70 electrofused mullite; In the sintered mullite and / or fused mullite, the mass percentage of particles with a diameter of 3-5 mm is 9%-12%. In the sintered mullite and / or fused mullite, the mass percentage of particles with a diameter of 1-3 mm is 20%-25%. In the sintered mullite and / or fused mullite, the mass percentage of particles with a diameter of 0-1 mm is 18%-21%.

6. The permanent layer according to claim 4, characterized in that, The micro powder specifically refers to micro powder with a particle size of less than 5 μm; The micro powder includes activated alumina micro powder and / or silica micro powder; The additives include one or more of oxalic acid, tartaric acid, and sodium tripolyphosphate.

7. The permanent layer according to claim 4, characterized in that, The number of permanent layers is greater than or equal to 2; The thickness of a single permanent layer is 19~21mm; The permanent layer is obtained by mixing raw materials, applying them to the wall of a molten iron ladle, and then curing them. The maintenance period is 3 to 4 days.

8. A molten iron ladle, characterized in that, The molten iron ladle has a permanent wall layer on its wall. The permanent layer on the tank wall is the permanent layer in any of the applications of claims 1 to 3 or the permanent layer described in any of claims 4 to 7.

9. The molten iron ladle according to claim 8, characterized in that, The setting method includes application; The permanent layer of the tank wall is also composited with a working lining. The total thickness of the permanent layer on the tank wall is 39~41mm; The thickness of the working lining of the tank wall is 159~161mm; The working lining of the tank wall is made of aluminum-silicon carbide-carbon brick.

10. The molten iron ladle according to claim 8, characterized in that, The molten iron ladle also includes a permanent bottom layer disposed on the bottom of the ladle and a working bottom layer composited on the permanent bottom layer; The permanent layer at the bottom of the tank is specifically composed of two layers of clay bricks. The thickness of the permanent layer at the bottom of the tank is 98.5~99.5 mm; The working layer at the bottom of the tank comprises aluminum-silicon carbide-carbon bricks; The thickness of the working layer of the tank wall is 298~302mm.

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