A pouring material for the working lining of a ladle, the working lining of a ladle and a preparation method thereof

Abstract

The present invention belongs to the technical field of ladles in iron and steel metallurgy, and discloses a ladle working lining castable, a ladle working lining and a preparation method thereof. The ladle working lining castable comprises component A and component B. Component A comprises raw materials in the following mass percentages: 18-24% of chrome corundum aggregate with a particle size of 5-8 mm, 15-25% of chrome corundum aggregate with a particle size of 3-5 mm, 10-18% of high-aluminum particles with a particle size of 1-3 mm, 12-16% of high-aluminum particles with a particle size of ≤1 mm, 6-9% of silicon carbide with a particle size of 0.074-1 mm, 4-8% of silicon carbide with a particle size of ≤0.074 mm, 6-10% of brown fused alumina dust, 4-8% of α-Al2O3 micropowder, 2-4% of silica fume, 1-3% of an additive, and 1-3% of spherical pitch. Component B is a modified silica sol, and the mass ratio of component A to component B is 100:(3.5-4.5). The present invention solves the problems of iron leakage and iron drilling at the brick joints of the brick lining of the ladle working lining from the root by developing a new type of ladle working lining castable for preparing the ladle working lining, and improves the cyclic service life of the ladle working lining.

Description

Technical Field

[0001] The present invention belongs to the technical field of ladles in iron and steel metallurgy, and particularly relates to a pouring material for the working lining of a ladle, a working lining of a ladle, and a preparation method thereof. Background Art

[0002] As the most important transfer device in the BF-converter connection section of the iron and steel industry, with the development of metallurgical technology and the proposal of the "one-package-to-the-end" technical solution, the ladle not only undertakes the tasks of loading and transporting hot metal, but also undertakes the "three-removal" treatment of desulfurization, dephosphorization, and desiliconization of hot metal during this process. The existing permanent lining of the ladle is usually built with lightweight insulation bricks or integrally cast with pouring materials, while the main construction method of the working lining is the forming by laying Al2O3-SiC-C bricks. Special-shaped bricks need to be used for laying in complex positions during the masonry construction, which not only increases the construction cost, but also makes it difficult to avoid residual masonry joints at the joints, resulting in poor bonding. During the service process, the phenomenon of molten iron drilling through the brick joints occurs, which is likely to shorten the service life of the ladle and even cause safety accidents.

[0003] Patent CN108500249A discloses a bottom lining structure and a laying method of a spherical-bottom ladle. When laying the working layer of the ladle bottom, the gap at the connection part between the ladle bottom and the ladle wall is filled with corundum pouring material, reducing the masonry joints at complex parts and solving the problem of difficult connection and combination at complex parts. However, the spherical structure of this invention not only bears the impact in the vertical direction when the hot metal falls, but also generates a horizontal tensile torque, which will cause the bricks to split and the damage to accelerate. Moreover, the ladle wall and ladle bottom of the ladle still adopt masonry construction, and the problem of molten iron seeping through and drilling through the masonry joints in the working lining of the ladle during the service process is not fundamentally solved.

[0004] Patent CN102728828A discloses a working lining of a ladle and a preparation method thereof. The bottom part of its working lining is composed of a three-layer structure of flat-laid refractory bricks + vertically-laid refractory bricks + pouring material, and the wall part is composed of a two-layer structure of refractory bricks + coating material, effectively improving the service life of the ladle. However, this invention adopts a flat-bottom design in the bottom impact area, which is greatly impacted during the periodic falling of hot metal. In addition, if the surface pouring material at the bottom of the ladle or the surface coating material on the ladle wall peels off, the internal masonry joints will be exposed, and there is still a risk of molten iron seeping through and drilling through. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a pouring material for the working lining of a ladle, a working lining of a ladle, and a preparation method thereof in view of the deficiencies in the existing technology. By developing a new type of pouring material for the working lining of a ladle and using it to prepare the working lining of a ladle, the problem of molten iron seeping through and drilling through the brick joints of the brick-built working lining is fundamentally solved, and the cyclic service life of the working lining of the ladle is improved.

[0006] To solve the technical problems proposed by the present invention, the present invention provides a gunning mix for the working lining of a hot metal ladle, which includes component A and component B. Component A includes raw materials in the following mass percentages: 18-24% of chrome corundum aggregate with a particle size of 5-8 mm (excluding 5 mm), 15-25% of chrome corundum aggregate with a particle size of 3-5 mm (excluding 3 mm), 10-18% of high-alumina particles with a particle size of 1-3 mm (excluding 1 mm), 12-16% of high-alumina particles with a particle size of ≤1 mm, 6-9% of silicon carbide with a particle size of 0.074-1 mm (excluding 0.074 mm), 4-8% of silicon carbide with a particle size of ≤0.074 mm, 6-10% of brown fused alumina dust, 4-8% of α-Al2O3 micropowder, 2-4% of silica fume, 1-3% of additive, and 1-3% of spherical pitch. Component B is modified silica sol, and the mass ratio of component A to component B is 100:(3.5-4.5).

[0007] In the above solution, the preparation method of the modified silica sol is as follows: water-soluble resin, NaOH, and Ba(OH)2 are sequentially added to the silica sol, and under the condition of heating and constant temperature, it is oscillated, mixed, and reacted to obtain the modified silica sol.

[0008] Further, the solid content of the silica sol is not less than 30 wt%.

[0009] Further, the water-soluble resin is one or a mixture of more than one of water-soluble cellulose derivatives, water-soluble epoxy resins, and water-soluble phenolic resins.

[0010] Preferably, the water-soluble resin is a mixture of water-soluble phenolic resin and water-soluble epoxy resin with a mass ratio of (6.5-9.5):2.

[0011] Further, in the preparation process of the modified silica sol, the dosage of each raw material is calculated by mass parts: 60-70 parts of silica sol, 20-25 parts of water-soluble resin, 8-12 parts of NaOH, and 2-5 parts of Ba(OH)2.

[0012] Further, the heating temperature is 50-65 °C, and the reaction time is 2-4 h.

[0013] In the above solution, the total content of Al2O3 and Cr2O3 in the chrome corundum aggregate is not less than 95 wt%.

[0014] In the above solution, the Al2O3 content in the high-alumina particles is not less than 80 wt%.

[0015] In the above solution, the SiC content in the silicon carbide particles is not less than 85 wt%.

[0016] In the above solution, the particle size of the brown fused alumina dust collector powder is ≤ 0.074 mm, the Al2O3 content is not less than 93 wt%, and the Fe2O3 content is not higher than 1.5 wt%.

[0017] In the above solution, the median particle size D of the α-Al2O3 micropowder and the silica micropowder 50 ≤ 10 μm.

[0018] In the above solution, the additive is one or a mixture of Si powder, carbon black, sodium tripolyphosphate, and sodium hexametaphosphate, and the particle size is ≤ 0.074 mm.

[0019] In the above solution, the particle size of the spherical pitch is ≤ 0.5 mm, and the C content is not less than 50 wt%.

[0020] The present invention also provides a working lining of a ladle using the above-mentioned casting material for the working lining of a ladle. The working lining of the ladle is located inside the permanent lining of the ladle and includes a spherical bottom, an upper ladle wall, and a lower ladle wall. The spherical bottom is a convex spherical surface that is centrosymmetric. The angle θ between the tangent line at the connection of the spherical bottom and the lower ladle wall and the horizontal plane is 12 to 18°.

[0021] In the above solution, the thickness d at the connection of the spherical bottom and the lower ladle wall is 400 to 550 mm.

[0022] In the above solution, the thickness e of the upper ladle wall is 120 to 180 mm.

[0023] In the above solution, the thickness g by which the lower ladle wall is thicker than the upper ladle wall is 10 to 30 mm.

[0024] In the above solution, the length f from the top end of the lower ladle wall to the connection of the spherical bottom and the lower ladle wall is 600 to 1000 mm.

[0025] In the above solution, the permanent lining of the ladle includes four layers, which are, from the outside to the inside, a lightweight spray coating layer, a fiber felt layer, a first insulating brick layer, and a second insulating brick layer. The outside of the permanent lining of the ladle is closely attached to the steel shell of the ladle.

[0026] Further, the thickness a of the lightweight spray coating layer is 10 to 15 mm.

[0027] Further, the thickness b of the fiber felt layer is 10 to 15 mm.

[0028] Further, the total thickness c of the first insulating brick layer and the second insulating brick layer is 90 to 120 mm.

[0029] The present invention also provides a preparation method for the working lining of a ladle using the above-mentioned casting material for the working lining of a ladle, including the following steps:

[0030] 1) Prepare each raw material of component A of the gunning mix for the working lining of the hot metal ladle according to the mass percentage, mix them evenly, and then add component B according to the mass ratio and mix evenly to obtain the gunning mix for the working lining of the hot metal ladle.

[0031] 2) Install the casting formwork. A casting cavity is formed between the casting formwork and the inner wall of the permanent lining of the hot metal ladle. Pour the gunning mix for the working lining of the hot metal ladle into the casting cavity through the pouring hole of the casting formwork.

[0032] 3) After completion of pouring, seal the pouring hole, open vent holes on the casting formwork, remove the formwork after curing, and obtain the working lining of the hot metal ladle.

[0033] In the above solution, the curing is natural curing, and the curing time is 4 - 6 h.

[0034] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0035] 1) The present invention develops a new type of gunning mix for the working lining of the hot metal ladle to prepare the working lining of the hot metal ladle, fundamentally solving the problems of iron leakage and iron penetration through the brick joints of the brick-lined working lining, and improving the cyclic service life of the working lining of the hot metal ladle. This gunning mix adopts a modified silica sol binding system to ensure the construction performance and service performance at different temperature ranges. At normal temperature, a long-chain Si - O - C network is formed through the reaction of modified silica sol and water quality, and a sol particle embedding structure is formed to greatly improve the construction performance and mechanical properties. At high temperature, the high reactivity of the modified silica sol prolongs the service life of the material. In addition, chromic corundum is used as the aggregate, and chromium in the chromic corundum will precipitate out at high temperature and penetrate between the aggregate and the matrix, further enhancing the binding ability. Therefore, this gunning mix can meet the service requirements of the hot metal ladle and has broad application prospects.

[0036] 2) The present invention designs a "convex spherical" bottom structure for the working lining of the hot metal ladle. The designed "convex spherical" bottom structure decomposes the impact force of the molten iron falling into two appropriate stresses in the horizontal and vertical directions by controlling the cut angle θ, reducing the damage of the impact force and prolonging the service life of the hot metal ladle during operation.

[0037] 3) The present invention develops a construction method for integral casting and molding of the working lining of the hot metal ladle, thus avoiding the problems of difficult construction for complex and irregular parts and iron leakage and iron penetration caused by residual masonry joints in the traditional masonry method, reducing the frequency of ladle repair and improving the transfer efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a schematic structural diagram of the working lining of the hot metal ladle in Embodiment 1 of the present invention.

[0039] Figure 2 It is a schematic structural diagram of the working lining of the hot metal ladle in Comparative Example 1 of the present invention.

[0040] Figure 3 This is a schematic structural diagram of the working lining of the ladle for Comparative Example 2 of the present invention.

[0041] Figure 4 This is a schematic structural diagram of the working lining of the ladle for Comparative Example 3 of the present invention.

[0042] Explanation of reference numerals: 1, steel shell; 2, light spraying coating layer; 3, fiber felt layer; 4, first insulating brick layer; 5, second insulating brick layer; 6, working lining. Specific embodiments

[0043] In order to better understand the present invention, the content of the present invention will be further clarified below in conjunction with embodiments, but the content of the present invention is not limited to the following embodiments.

[0044] In the following embodiments, the silica sol selected is a silica sol with a solid content of 32.5%; the water-soluble resin is a water-soluble phenolic resin with a solid content of 71.1% and a water-soluble epoxy resin with a solid content of 79.7% mixed in a mass ratio of 8:2; the total content of Al2O3 and Cr2O3 in the chrome corundum aggregate is not less than 95 wt%; the Al2O3 content in the high-aluminum particles is not less than 80 wt%; the SiC content in the silicon carbide particles is not less than 85 wt%; the particle size of the brown fused alumina dust collector powder ≤ 0.074 mm, the Al2O3 content is not less than 93 wt%, and the Fe2O3 content is not higher than 1.5 wt%; the median particle size D of the α-Al2O3 micropowder and silica powder 50 ≤ 10 μm; the particle sizes of Si powder, carbon black, sodium tripolyphosphate and sodium hexametaphosphate ≤ 0.074 mm; the particle size of the spherical pitch ≤ 0.5 mm, and the C content is not less than 50 wt%.

[0045] In the following embodiments, the flexural strength at 110°C × 24 h and 1450°C × 3 h is measured by the method in GB / T 3001-2017, the high-temperature flexural strength at 1450°C × 1 h is measured by the method in GB / T 3002-2017, the thermal shock resistance is measured by the method in GB / T 30873-2014 (water quenching method - small specimen), and the slag and iron erosion resistance is measured by the method in GB / T8931-2007 (static crucible method).

[0046] Example 1

[0047] A gunning mix for the working lining of a ladle, comprising component A and component B;

[0048] Component A comprises raw materials in the following mass percentages: chromic corundum aggregate with a particle size of 5 - 8 mm, 18%; chromic corundum aggregate with a particle size of 3 - 5 mm, 25%; high-alumina particles with a particle size of 1 - 3 mm, 10%; high-alumina particles with a particle size of ≤1 mm, 16%; silicon carbide with a particle size of 0.074 - 1 mm, 9%; silicon carbide with a particle size of ≤0.074 mm, 4%; brown fused alumina dust, 6%; α-Al2O3 micropowder, 6%; silica fume, 2%; additive (Si powder, carbon black, sodium tripolyphosphate, and sodium hexametaphosphate with a mass ratio of 1:1:1:1), 2%; spherical pitch, 2%.

[0049] Component B is modified silica sol, and its preparation method is as follows: by mass, 25 parts of water-soluble resin, 10 parts of NaOH, and 5 parts of Ba(OH)2 are successively added to 60 parts of silica sol, heated to 50 °C and kept at a constant temperature, shaken and mixed, and reacted for 3.5 h to obtain it;

[0050] The mass ratio of Component A to Component B is 100:3.5.

[0051] For the working lining of the ladle and the ladle using the above-mentioned pouring material for the working lining of the ladle, the structural schematic diagram is shown in Figure 1 ; the structure of the whole ladle from the outside to the inside is successively a steel shell 1, a light spraying coating layer 2, a fiber felt layer 3, a first insulating brick layer 4, a second insulating brick layer 5, and a working lining 6; the thickness a of the light spraying coating layer 2 is 10 mm, the thickness b of the fiber felt layer 3 is 15 mm, and the total thickness c of the first insulating brick layer 4 and the second insulating brick layer 5 is 90 mm; the working lining 6 includes a spherical bottom, an upper ladle wall, and a lower ladle wall; the spherical bottom is a convex spherical surface that is centrosymmetric, the tangent of the connection between the spherical bottom and the lower ladle wall and the horizontal plane has an angle θ of 12°, and the thickness d of the connection between the spherical bottom and the lower ladle wall is 550 mm; the thickness e of the upper ladle wall is 120 mm, the lower ladle wall is 10 mm thicker than the upper ladle wall, and the length f from the top of the lower ladle wall to the connection between the spherical bottom and the lower ladle wall is 1000 mm.

[0052] The preparation method of the working lining of the ladle using the above-mentioned pouring material for the working lining of the ladle includes the following steps:

[0053] 1) Prepare each raw material of Component A of the pouring material for the working lining of the ladle according to the mass percentage, mix them evenly, and then add Component B according to the mass ratio and mix evenly to obtain the pouring material for the working lining of the ladle;

[0054] 2) Install a pouring formwork. A pouring cavity is formed between the pouring formwork and the inner wall of the permanent lining of the ladle, and the pouring material for the working lining of the ladle is poured into the pouring cavity from the pouring hole of the pouring formwork;

[0055] 3) After pouring, seal the pouring hole, open exhaust holes on the pouring formwork, and remove the formwork after natural curing for 4 h to obtain the working lining of the ladle.

[0056] Example 2

[0057] A refractory castable for the working lining of a ladle, comprising component A and component B;

[0058] Component A comprises raw materials in the following mass percentages: 20% of chromic corundum aggregate with a particle size of 5 - 8 mm, 20% of chromic corundum aggregate with a particle size of 3 - 5 mm, 12% of high-alumina particles with a particle size of 1 - 3 mm, 14% of high-alumina particles with a particle size of ≤1 mm, 8% of silicon carbide with a particle size of 0.074 - 1 mm, 8% of silicon carbide with a particle size of ≤0.074 mm, 7% of brown fused alumina dust, 6% of α-Al2O3 micropowder, 1% of silica fume, 2% of an additive (Si powder, carbon black and sodium tripolyphosphate with a mass ratio of 1:1:1), and 2% of spherical pitch;

[0059] Component B is a modified silica sol, and its preparation method is as follows: by mass, 23 parts of water-soluble resin, 12 parts of NaOH and 2 parts of Ba(OH)2 are successively added to 63 parts of silica sol, heated to 55°C for constant temperature, shaken and mixed and reacted for 4 h to obtain;

[0060] The mass ratio of component A to component B is 100:3.8.

[0061] For the working lining of a ladle and the ladle using the above refractory castable for the working lining of a ladle, the structural schematic diagram is shown in Figure 1 ; The structure of the whole ladle from the outside to the inside is successively a steel shell 1, a light spraying coating layer 2, a fiber felt layer 3, a first insulating brick layer 4, a second insulating brick layer 5, and a working lining 6; The thickness a of the light spraying coating layer 2 is 12 mm, the thickness b of the fiber felt layer 3 is 13 mm, and the total thickness c of the first insulating brick layer 4 and the second insulating brick layer 5 is 100 mm; The working lining 6 includes a spherical bottom, an upper ladle wall and a lower ladle wall; The spherical bottom is a convex spherical surface that is centrosymmetric. The tangent of the connection between the spherical bottom and the lower ladle wall and the horizontal plane has an angle θ of 14°. The thickness d of the connection between the spherical bottom and the lower ladle wall is 500 mm; The thickness e of the upper ladle wall is 140 mm, the lower ladle wall is 18 mm thicker than the upper ladle wall, and the length f from the top end of the lower ladle wall to the connection between the spherical bottom and the lower ladle wall is 890 mm.

[0062] The preparation method of the working lining of a ladle using the above refractory castable for the working lining of a ladle includes the following steps:

[0063] 1) Weigh each raw material of component A of the refractory castable for the working lining of a ladle according to the mass percentage, mix them evenly, and then add component B according to the mass ratio and mix evenly to obtain the refractory castable for the working lining of a ladle;

[0064] 2) Install the casting template. A casting cavity is formed between the casting template and the inner wall of the permanent lining of the ladle, and the refractory castable for the working lining of a ladle is poured into the casting cavity from the pouring hole of the casting template;

[0065] 3) After pouring is completed, seal the pouring hole, open vent holes on the casting mold, and remove the mold after natural curing for 4.5 h to obtain the working lining of the ladle.

[0066] Example 3

[0067] A working lining casting material for a ladle, comprising component A and component B;

[0068] Component A includes raw materials in the following mass percentages: 22% of chromic corundum aggregate with a particle size of 5 - 8 mm, 15% of chromic corundum aggregate with a particle size of 3 - 5 mm, 18% of high-aluminum particles with a particle size of 1 - 3 mm, 12% of high-aluminum particles with a particle size of ≤1 mm, 6% of silicon carbide with a particle size of 0.074 - 1 mm, 6% of silicon carbide with a particle size of ≤0.074 mm, 9% of brown fused alumina dust, 4% of α-Al2O3 micropowder, 4% of silica fume, 3% of an additive (Si powder and carbon black with a mass ratio of 1:1), and 1% of spherical pitch;

[0069] Component B is a modified silica sol, and its preparation method is as follows: by mass, 22 parts of water-soluble resin, 8 parts of NaOH, and 4 parts of Ba(OH)2 are sequentially added to 606 parts of silica sol, heated to 60 °C for constant temperature, shaken and mixed, and reacted for 3 h to obtain it;

[0070] The mass ratio of component A to component B is 100:4.2.

[0071] For the working lining of the ladle and the ladle using the above-mentioned working lining casting material for the ladle, the structural schematic diagram is shown in Figure 1 ; The structure of the entire ladle from the outside to the inside is successively a steel shell 1, a lightweight spray coating layer 2, a fiber felt layer 3, a first insulating brick layer 4, a second insulating brick layer 5, and a working lining 6; the thickness a of the lightweight spray coating layer 2 is 13 mm, the thickness b of the fiber felt layer 3 is 12 mm, and the total thickness c of the first insulating brick layer 4 and the second insulating brick layer 5 is 110 mm; the working lining 6 includes a spherical bottom, an upper ladle wall, and a lower ladle wall; the spherical bottom is a convex spherical surface that is centrosymmetric, the tangent of the connection between the spherical bottom and the lower ladle wall and the horizontal plane has an angle θ of 16°, and the thickness d at the connection between the spherical bottom and the lower ladle wall is 450 mm; the thickness e of the upper ladle wall is 160 mm, the lower ladle wall is 24 mm thicker than the upper ladle wall, and the length f from the top of the lower ladle wall to the connection between the spherical bottom and the lower ladle wall is 760 mm.

[0072] The preparation method of the working lining of the ladle using the above-mentioned working lining casting material for the ladle includes the following steps:

[0073] 1) Weigh the raw materials of component A of the working lining casting material for the ladle according to the mass percentages, mix them evenly, and then add component B according to the mass ratio and mix evenly to obtain the working lining casting material for the ladle;

[0074] 2) Install the casting formwork. A casting cavity is formed between the casting formwork and the inner wall of the permanent lining of the ladle. Pour the working lining refractory of the ladle into the casting cavity through the casting hole of the casting formwork.

[0075] 3) After completion of pouring, seal the casting hole, open vent holes on the casting formwork, and remove the formwork after natural curing for 5 h to obtain the working lining of the ladle.

[0076] Example 4

[0077] A working lining refractory for a ladle comprises Component A and Component B;

[0078] Component A comprises raw materials in the following mass percentages: chromic corundum aggregate with a particle size of 5 - 8 mm, 24%; chromic corundum aggregate with a particle size of 3 - 5 mm, 15%; high-alumina particles with a particle size of 1 - 3 mm, 14%; high-alumina particles with a particle size of ≤1 mm, 12%; silicon carbide with a particle size of 0.074 - 1 mm, 7%; silicon carbide with a particle size of ≤0.074 mm, 4%; brown fused alumina dust, 10%; α-Al2O3 micropowder, 8%; silica fume, 2%; additive (Si powder and sodium tripolyphosphate with a mass ratio of 1:1), 1%; spherical pitch, 3%.

[0079] Component B is modified silica sol, and its preparation method is as follows: by mass, 20 parts of water-soluble resin, 8 parts of NaOH, and 2 parts of Ba(OH)2 are successively added to 70 parts of silica sol, heated to 65 °C for constant temperature, shaken and mixed, and reacted for 2 h to obtain it.

[0080] The mass ratio of Component A to Component B is 100:4.5.

[0081] For the working lining of the ladle and the ladle using the above-mentioned working lining refractory for the ladle, the structural schematic diagram is shown in Figure 1 ; The structure of the whole ladle from the outside to the inside is successively a steel shell 1, a lightweight spraying coating layer 2, a fiber felt layer 3, a first insulating brick layer 4, a second insulating brick layer 5, and a working lining 6; the thickness a of the lightweight spraying coating layer 2 is 15 mm, the thickness b of the fiber felt layer 3 is 10 mm, and the total thickness c of the first insulating brick layer 4 and the second insulating brick layer 5 is 120 mm; the working lining 6 includes a spherical bottom, an upper wall of the ladle, and a lower wall of the ladle; the spherical bottom is a convex spherical surface that is centrosymmetric. The angle θ between the tangent line at the connection of the spherical bottom and the lower wall of the ladle and the horizontal plane is 18°, and the thickness d at the connection of the spherical bottom and the lower wall of the ladle is 400 mm; the thickness e of the upper wall of the ladle is 180 mm, the lower wall of the ladle is 30 mm thicker than the upper wall of the ladle, and the length f from the top end of the lower wall of the ladle to the connection of the spherical bottom and the lower wall of the ladle is 600 mm.

[0082] The preparation method of the working lining of the ladle using the above-mentioned working lining refractory for the ladle includes the following steps:

[0083] 1) After preparing each raw material of component A of the pouring material for the working lining of the hot metal ladle according to the mass percentage and mixing them evenly, then adding component B according to the mass ratio and mixing evenly, the pouring material for the working lining of the hot metal ladle is obtained;

[0084] 2) Install the pouring formwork. A pouring cavity is formed between the pouring formwork and the inner wall of the permanent lining of the hot metal ladle. Pour the pouring material for the working lining of the hot metal ladle into the pouring cavity from the pouring hole of the pouring formwork;

[0085] 3) After completion of pouring, seal the pouring hole, open vent holes on the pouring formwork, and remove the formwork after natural curing for 6 h to obtain the working lining of the hot metal ladle.

[0086] Comparative Example 1

[0087] Comparative Example 1 is a working lining of a conventional structure hot metal ladle built with conventional refractory bricks. Its structural schematic diagram is shown in Figure 2 ; The structure of the entire hot metal ladle from the outside to the inside is successively a steel shell 1, a light spraying coating layer 2, a fiber felt layer 3, a first insulating brick layer 4, a second insulating brick layer 5, and a working lining 6; The structures of each layer except the working lining are the same as those in Example 1; Its working lining is built with two layers of aluminum silicon carbide carbon bricks to form the bottom and wall of the ladle. The thickness of the bottom of the ladle is 400 mm, and the thickness of the wall of the ladle is 180 mm.

[0088] Comparative Example 2

[0089] Comparative Example 2 is a working lining of the hot metal ladle of the structure of the present invention built with conventional refractory bricks. Its structural schematic diagram is shown in Figure 3 ; The structure of the entire hot metal ladle from the outside to the inside is successively a steel shell 1, a light spraying coating layer 2, a fiber felt layer 3, a first insulating brick layer 4, a second insulating brick layer 5, and a working lining 6; The structures of each layer except the working lining are the same as those in Example 1; Its working lining is built with 3 layers of aluminum silicon carbide carbon bricks to form the same bottom and wall shapes as in Example 1.

[0090] Comparative Example 3

[0091] Comparative Example 3 is a working lining of a conventional structure hot metal ladle poured with the pouring material of the present invention. Its structural schematic diagram is shown in Figure 4 ; The structure of the entire hot metal ladle from the outside to the inside is successively a steel shell 1, a light spraying coating layer 2, a fiber felt layer 3, a first insulating brick layer 4, a second insulating brick layer 5, and a working lining 6; The structures of each layer except the working lining are the same as those in Example 1; Its working lining is poured with the pouring material of Example 1 to form the bottom and wall of the ladle. The thickness of the bottom of the ladle is 400 mm, and the thickness of the wall of the ladle is 180 mm.

[0092] Comparative Example 4

[0093] The difference between Comparative Example 4 and Example 1 is only that: Component B directly uses silica sol without modification treatment.

[0094] Comparative Example 5

[0095] The difference between Comparative Example 5 and Example 1 is only that: when preparing the modified silica sol of Component B, NaOH and Ba(OH)₂ are not added.

[0096] Comparative Example 6

[0097] The difference between Comparative Example 6 and Example 1 is only that: when preparing the modified silica sol of Component B, the reaction is carried out with normal temperature oscillation and no heat preservation treatment is performed.

[0098] The performance test results of each example and comparative example are shown in Table 1. The gating system refractory castable prepared in the example of the present invention has a flexural strength of 9.2 - 12.8 MPa at 110°C × 24 h, a flexural strength of 13.3 - 15.7 MPa at 1450°C × 3 h, a high-temperature flexural strength of 12.7 - 15.5 MPa at 1450°C × 1 h, the strength retention rate after five water-cooling thermal shock cycle tests is not less than 80%, and the erosion index after the slag and iron erosion test at 1450°C × 6 h is not higher than 4.5%. Compared with the working lining of the gating system made of conventional refractory bricks by conventional structure, the overall construction period is shortened by more than 10% year-on-year, the cyclic service life of the working lining of the gating system is increased by 80 - 120 times year-on-year, and the refractory cost is reduced by more than 15%.

[0099] Table 1

[0100]

[0101]

[0102] The above examples are only for clearly illustrating the examples and not for limiting the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation manners here, and the obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims

1. A refractory castable for the working lining of a hot metal ladle, characterized in that, It includes component A and component B. Component A includes raw materials with the following mass percentages: corundum-chrome aggregate with a particle size of 5 - 8 mm, 18 - 24%; corundum-chrome aggregate with a particle size of 3 - 5 mm, 15 - 25%; high-alumina particles with a particle size of 1 - 3 mm, 10 - 18%; high-alumina particles with a particle size of ≤1 mm, 12 - 16%; silicon carbide with a particle size of 0.074 - 1 mm, 6 - 9%; silicon carbide with a particle size of ≤0.074 mm, 4 - 8%; brown fused alumina dust, 6 - 10%; α-Al2O3 micropowder, 4 - 8%; silica powder, 2 - 4%; additive, 1 - 3%; spherical pitch, 1 - 3%. Component B is modified silica sol, and the mass ratio of component A to component B is 100:(3.5 - 4.5); The preparation method of the modified silica sol is as follows: successively add water-soluble resin, NaOH, and Ba(OH)2 to the silica sol, and under the condition of heating and constant temperature, oscillate and mix and react to obtain the modified silica sol; the water-soluble resin is one or a mixture of two of water-soluble epoxy resin and water-soluble phenolic resin, and the water-soluble resin forms a Si - O - C network with the silica sol.

2. The ladle working lining castable according to claim 1, characterized in that The solid content of the silica sol is not less than 30 wt%.

3. The ladle working lining casting material according to claim 1, characterized in that, During the preparation process of the modified silica sol, the dosage of each raw material is calculated by mass parts: 60 - 70 parts of silica sol, 20 - 25 parts of water-soluble resin, 8 - 12 parts of NaOH, and 2 - 5 parts of Ba(OH)2; the heating temperature is 50 - 65 °C, and the reaction time is 2 - 4 h.

4. The gunning mix for the working lining of the hot metal ladle according to claim 1, characterized in that, The total content of Al2O3 and Cr2O3 in the corundum-chrome aggregate is not less than 95 wt%; the Al2O3 content of the brown fused alumina dust is not less than 93 wt%, and the Fe2O3 content is not higher than 1.5 wt%; the additive is one or a mixture of Si powder, carbon black, sodium tripolyphosphate, and sodium hexametaphosphate.

5. The working lining of the hot metal ladle using the gunning mix for the working lining of the hot metal ladle according to any one of claims 1 to 4, characterized in that, The working lining of the hot metal ladle is located inside the permanent lining of the hot metal ladle, and includes a spherical bottom, an upper ladle wall, and a lower ladle wall. The spherical bottom is a convex spherical surface that is centrosymmetric. The tangent of the connection between the spherical bottom and the lower ladle wall forms an angle θ of 12 - 18° with the horizontal plane.

6. The working lining of the hot metal ladle according to claim 5, characterized in that, The thickness e of the upper ladle wall is 120 - 180 mm; the lower ladle wall is 10 - 30 mm thicker than the upper ladle wall; the length f from the top of the lower ladle wall to the connection between the spherical bottom and the lower ladle wall is 600 - 1000 mm; the thickness d of the connection between the spherical bottom and the lower ladle wall is 400 - 550 mm.

7. The working lining of the hot metal ladle according to claim 5, characterized in that, The permanent lining of the hot metal ladle includes four layers, which are, from outside to inside, a lightweight spray coating layer, a fiber felt layer, a first insulating brick layer, and a second insulating brick layer. The outside of the permanent lining of the hot metal ladle is closely attached to the steel shell of the hot metal ladle.

8. The working lining of the hot metal ladle according to claim 7, characterized in that, The thickness a of the lightweight spray coating layer is 10 - 15 mm; the thickness b of the fiber felt layer is 10 - 15 mm; the total thickness c of the first insulating brick layer and the second insulating brick layer is 90 - 120 mm.

9. The preparation method of the working lining of the hot metal ladle using the castable for the working lining of the hot metal ladle according to any one of claims 1-4, characterized in that, It includes the following steps: 1) Weigh each raw material of component A of the hot metal ladle working lining casting material according to the mass percentage, mix them evenly, and then add component B according to the mass ratio and mix evenly to obtain the hot metal ladle working lining casting material; 2) Install the casting formwork. A casting cavity is formed between the casting formwork and the inner wall of the permanent lining of the ladle. Pour the ladle working lining refractory into the casting cavity through the casting hole of the casting formwork. 3) After pouring is completed, seal the casting hole, open vent holes on the casting formwork, and remove the formwork after curing to obtain the ladle working lining.

10. The preparation method of the working lining of the hot metal ladle according to claim 9, characterized in that, The curing is natural curing, and the curing time is 4 - 6 h.

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