A furnace construction process with low furnace loss ratio for medium frequency furnace

Abstract

This invention relates to the field of furnace lining equipment manufacturing technology, and particularly to a furnace lining process for medium-frequency furnaces with low furnace loss ratio. The process includes the following steps: S1, adding a first refractory material to the furnace bottom, leveling it, and then compacting it with vibration; then adding a second refractory material, leveling it, and compacting it with vibration; repeating this process of adding the first and second refractory materials until the bottom of the crucible is reached, thus obtaining the furnace bottom layer; S2, vibrating and tamping the furnace bottom layer three times to remove air, and then placing the crucible inside; S3, adding a third refractory material between the medium-frequency furnace shell and the crucible, compacting it, and then vertically tamping the crucible with a hammer; S4, then horizontally tamping the medium-frequency furnace shell with a hammer-type vibrator; S5, repeating S3 to S4 at least three times, continuously adding the third refractory material in between, and obtaining a qualified medium-frequency furnace lining after physical drying. The medium-frequency furnace lining obtained by this invention has a low loss ratio and a long furnace life.

Description

Technical Field

[0001] The invention belongs to the technical field of furnace building equipment manufacturing, and in particular relates to a furnace building process with a low furnace loss ratio for a medium frequency furnace. Background Art

[0002] A medium frequency furnace is a power supply device that converts 50Hz industrial frequency alternating current into medium frequency (150Hz to 20kHz). When working, it rectifies three-phase industrial frequency alternating current into direct current, and then converts direct current into adjustable medium frequency current, which is supplied to the capacitor and induction coil to flow through the medium frequency alternating current, generating high-density magnetic lines in the induction coil, cutting the metal material contained in the induction coil, generating large eddy currents in the metal material, and using the principle of electromagnetic induction to heat the metal until it melts.

[0003] However, in actual production, due to high temperature, rapid cooling and heating, strong slag erosion and intense electromagnetic stirring that directly washes the crucible lining, the induction furnace lining is easily damaged and destroyed, resulting in a short effective service life of the lining. The current medium-frequency induction furnace has a generally low furnace lifespan.

[0004] For example, CN109708475A discloses a furnace building process for medium frequency furnace for smelting aluminum alloy ingots, which relates to the technical field of smelting equipment. It includes the following steps: step 1, mixing water glass and quartz sand evenly to obtain furnace bottom material; step 2, laying insulation bricks, refractory bricks and quartz sand in the bottom of the medium frequency furnace shell from bottom to top in sequence; step 3, fixing the crucible inside the shell and coaxial with the shell; step 4, mixing refractory glue injection material and phosphoric acid evenly to obtain furnace wall material; step 5, laying furnace bottom material at the bottom between the inner wall of the medium frequency furnace shell and the outer wall of the crucible, tamping and laying another layer of furnace bottom material, tamping again, filling the furnace wall material between the inner wall of the medium frequency furnace shell and the outer wall of the crucible, tamping; step 6, adding an iron pipe into the crucible, powering on the medium frequency furnace, controlling the current to 50-60A, heating for 2-3h, then increasing the current to 70-80A, keeping for 5-6h, removing the iron pipe, and completing the furnace building. However, the furnace-building technology applied for is only vertical, and the furnace life still needs to be improved.

[0005] For example, CN102706162A discloses a 3t medium frequency electric furnace wet method furnace construction process that can be used for 3T material smelting and improves service life, including a 3t medium frequency electric furnace, (1) a steel crucible mold in the shape of a truncated hollow cone; (2) laying of the insulating layer and the heat insulating layer: using two layers of asbestos cloth; (3) laying of the furnace bottom: laying two layers of asbestos cloth on the furnace bottom, and the two layers are laid alternately; (4) laying of the furnace wall: laying two layers of asbestos cloth close to the inner wall of the induction coil, when laying, first the upper layer and then the lower layer, each layer is flat and wrinkle-free, and the longitudinal seams are overlapped The joints are glued with water glass, and the joints of the two adjacent layers are staggered. The asbestos cloth extending from the upper plane is glued to the refractory brick plane at the top of the furnace with water glass; (5) Furnace lining materials and their preparation: The furnace lining material is refined quartz sand; (6) The furnace lining is knotted by artificial methods. Before filling, a layer of water glass is brushed on it, and then the filler is compacted; (7) Furnace baking and sintering: After the wet furnace is built, only firewood is used for baking. The firewood used for baking the furnace is 50-60kg, which is added into the furnace several times to make it completely burn and bake the furnace lining. However, the refractory performance of the furnace lining material in this application is not high, resulting in a low furnace life.

[0006] In view of this, the present invention is proposed. Summary of the invention

[0007] The purpose of the present invention is to provide a furnace construction process with a low furnace loss ratio for a medium frequency furnace. The medium frequency furnace obtained by the present invention has a low furnace loss ratio and a long furnace life.

[0008] In order to achieve the above object, the present invention provides the following technical solutions:

[0009] In a first aspect, an embodiment of the present invention provides a furnace construction process with a low furnace loss ratio for a medium frequency furnace, comprising the following steps:

[0010] S1, adding a first refractory material to the furnace bottom, paving it flat and then shaking and ramming it, then adding a second refractory material, paving it flat and then shaking and ramming it, repeatedly paving the first refractory material and the second refractory material, ramming it to the height of the bottom of the crucible, to obtain a furnace bottom layer;

[0011] S2, vibrate and vent the bottom layer of the furnace three times, and then put the crucible in;

[0012] S3, adding a third refractory material between the intermediate frequency furnace shell and the crucible, tamping it, and then using a hammer to vertically hit the crucible;

[0013] S4, then use a hammer head furnace vibrator to vibrate and beat the intermediate frequency furnace shell horizontally;

[0014] S5, repeat S3 to S4 at least 3 times, continuously add the third refractory material in the middle, and obtain the medium frequency furnace after physical furnace baking.

[0015] In a preferred embodiment, in step S1, the thickness of each layer of the first refractory material is 20-40 mm.

[0016] In a preferred embodiment, in step S1, the thickness of each layer of the second refractory material is 30-80 mm.

[0017] In a preferred embodiment, in step S1, the first refractory material includes zircon sand and silica powder, and the mass ratio of the zircon sand to the silica powder is (1-4):1.

[0018] In a preferred embodiment, in step S1, the particle size of the zircon sand is 20-200 mesh, and the particle size of the silicon powder is 400-800 mesh.

[0019] The present invention greatly improves the thermal expansion performance, slag erosion resistance, high temperature stability and compactness of the furnace bottom layer by limiting the type and particle size of the first refractory material. Specifically, the zircon sand particle size distribution is relatively coarse, and it can be used as an aggregate in the furnace bottom layer, occupying a large space, forming a preliminary skeleton structure, and providing certain strength and stability for the material, while the silicon micropowder particles are fine and have good filling properties, and can be filled into the tiny pores between the zircon sand particles and other tiny gaps in the furnace bottom layer, making the structure of the furnace bottom layer more compact and reducing the porosity, thereby improving the volume density and strength of the furnace bottom layer and enhancing its ability to resist high temperature erosion and penetration. In addition, zircon sand itself has a high melting point of 90°C, generally around 2550°C. It can maintain good stability at high temperatures and is not prone to deformation or melting, providing a good high-temperature support skeleton for the furnace bottom layer. At high temperatures, the silanol groups on the surface of the silicon micropowder will undergo a dehydration reaction to form a siloxane network structure. This structure has high stability and can maintain the strength and integrity of the material at high temperatures, and is not prone to breakage. The two work together to improve the refractory performance of the furnace bottom layer. Furthermore, zircon sand has good chemical stability. When facing corrosive substances such as high-temperature slag, it can prevent the penetration and erosion of slag to a certain extent, protecting the bottom layer. The internal structure of the furnace bottom layer, the siloxane network structure formed by the silicon micropowder and the dense phase generated by the reaction with other substances can improve the surface hardness and density of the furnace bottom layer, making it difficult for slag to adhere and penetrate, thereby enhancing the slag erosion resistance of the furnace bottom layer; finally, zircon sand has a low thermal expansion coefficient, and its volume change is relatively small when the temperature changes, which can inhibit the stress and cracks caused by thermal expansion of the refractory material to a certain extent, and the addition of silicon micropowder can adjust the thermal expansion coefficient of the furnace bottom layer to match it with other components, reduce material damage caused by mismatch of thermal expansion coefficients, and improve the thermal stability and service life of the furnace bottom layer.

[0020] In a preferred embodiment, in step S1, the second refractory material includes fused white corundum, fused magnesia, plate-shaped corundum, fused spinel, alumina powder, aluminum lactate and magnesium lactate, and the mass ratio of the fused white corundum, fused magnesia, plate-shaped corundum, fused spinel, alumina powder, aluminum lactate and magnesium lactate is (80-90): (5-10): (1-5): (1-5): (1-5): (0.1-1): (0.1-1).

[0021] In a preferred embodiment, the average particle size of the fused white corundum is 1-5 mm.

[0022] In a preferred embodiment, the particle size of the fused magnesia is 100-300 mesh.

[0023] In a preferred embodiment, the particle size of the plate-like corundum is 200-400 mesh.

[0024] In a preferred embodiment, the particle size of the fused spinel is 200-400 mesh.

[0025] In a preferred embodiment, the average particle size of the alumina powder is 1-10 μm.

[0026] Similarly, the present invention defines that the second refractory material further improves the refractory performance of the furnace bottom layer. The fused white corundum has the characteristics of high hardness, good wear resistance, and high temperature resistance, while the fused magnesia has good high temperature resistance, corrosion resistance, and creep resistance. When the two are combined, the fused magnesia can fill the gaps between the fused white corundum particles, improve the density of the material, and thus enhance the mechanical properties and high temperature resistance of the material. The plate-like corundum has a regular grain shape and uniform particle size. When used in combination with fused white corundum, it can optimize the particle grading of the material, increase the packing density, and thus improve the mechanical properties. Further, fused spinel has good thermal shock resistance and chemical stability. When combined with fused white corundum, spinel can be distributed at the grain boundaries of white corundum, hindering the movement of grain boundaries and improving the high temperature strength and creep resistance of the material. Alumina micropowder can be filled between the fused white corundum particles to promote the densification of the material and improve the mechanical properties at room temperature and high temperature. The added aluminum lactate will decompose to produce aluminum oxide during the heating process, which complements the aluminum oxide in the fused white corundum, increases the effective content of aluminum oxide, and helps to improve the high-temperature stability and mechanical properties of the material. At the same time, the decomposition products of aluminum lactate may also form some tiny pores inside the material, which play a certain role in heat insulation and buffering, improve the thermal shock resistance of the material, and can be used in high-temperature insulation materials in the aerospace field. What's more, the magnesium oxide produced by the decomposition of magnesium lactate can react with the aluminum oxide in the fused white corundum to generate a magnesium-aluminum spinel phase, which has good high-temperature resistance and mechanical properties, thereby improving the comprehensive performance of the material.

[0027] Moreover, the first refractory material and the second refractory material also have excellent synergistic effects. Through different skeletons and different filling particle sizes, the adaptability of the furnace bottom layer is greatly improved, and the particle grading and filling effect, high temperature resistance, chemical stability, and close surface bonding are greatly improved.

[0028] In a preferred embodiment, in step S3, the third refractory material comprises the following preparation steps:

[0029] Diatomaceous earth is mixed with water, sodium hydroxide is added, silane coupling agent Si69 is added after the reaction, a solid phase is obtained after washing and drying after the reaction, and then the solid phase, gypsum powder, glass fiber, carbon fiber and ceramic fiber are mixed to obtain a third refractory material.

[0030] In a preferred embodiment, the mass ratio of diatomaceous earth, water and sodium hydroxide is (100-200): (200-400): (10-20).

[0031] In a preferred embodiment, the reaction time after adding sodium hydroxide is 10-20 minutes.

[0032] In a preferred embodiment, the mass ratio of the diatomaceous earth to the silane coupling agent Si69 is 100:(10-23).

[0033] In a preferred embodiment, after adding the silane coupling agent Si69, the reaction conditions are 40-60° C. and the reaction time is 2-4 h.

[0034] In a preferred embodiment, the mass ratio of the solid phase, gypsum powder, glass fiber, carbon fiber and ceramic fiber is 100:(10-20):(2-5):(3-9):(10-20).

[0035] In a preferred embodiment, the particle size of the diatomaceous earth is 50-300 mesh, and the particle size of the gypsum powder is 400-800 mesh.

[0036] In a preferred embodiment, the particle size of the glass fiber is 20-50 μm, and the density of the carbon fiber is 1.5-2 g / cm 3 The density of the ceramic fiber is 100-200 kg / cm 3 .

[0037] The present invention uses a self-made third refractory material as a furnace lining material, which greatly improves the service life of the medium frequency furnace. First, the present invention can effectively improve the density of diatomaceous earth as the main furnace lining material by horizontal and vertical beating, so that the furnace loss ratio is reduced and the furnace life is increased, but the strength and fire resistance of diatomaceous earth need to be improved. The present invention first uses silane coupling agent Si69 to modify diatomaceous earth, wherein the silane coupling agent Si69 contains multiple active groups, which can react with the surface of diatomaceous earth and the matrix material to form a highly cross-linked network structure, thereby significantly improving the strength, wear resistance and aging resistance of the material. In addition, its sulfide structure also gives the material certain chemical corrosion resistance and antioxidant properties. While glass fiber has high strength and light weight, carbon fiber has higher strength and modulus, and is lighter in weight. When the two are combined, glass fiber can be used as an auxiliary reinforcement material to make up for the problems such as insufficient toughness of carbon fiber and improve the impact resistance of the overall material; carbon fiber can significantly improve the tensile strength and rigidity of the material, so that the third refractory material is not easy to deform and break when subjected to large external forces, and ceramic fiber has excellent high temperature resistance and certain tensile strength. When combined with glass fiber or carbon fiber, it can maintain the structural stability of the material under high temperature environment and prevent the material strength from dropping sharply due to temperature increase, thereby broadening the use temperature range of the material and enabling it to be applied to medium frequency furnaces. In addition, diatomaceous earth has a porous structure and a large specific surface area, which can absorb moisture in the air and regulate humidity; gypsum powder has good coagulation and certain strength. After the two are mixed, gypsum powder, as a cementing material, bonds the diatomaceous earth particles together to form a structure with certain strength and stability, reducing the humidity regulating function of diatomaceous earth, while glass fiber can enhance the toughness and flexural strength of gypsum powder, reduce the cracking and breakage of gypsum products during use, and improve its durability and service life. In addition, the present invention improves the bonding density between diatomite and other materials by modifying the diatomite, further improving the density of the entire furnace lining, and contributing to the improvement of the furnace life.

[0038] Compared with the prior art, the advantages and beneficial effects of the present invention are:

[0039] 1. The present invention greatly improves the thermal expansion performance, slag erosion resistance, high temperature stability and compactness of the furnace bottom layer by limiting the type and particle size of the first refractory material.

[0040] The present invention defines that the second refractory material further improves the refractory performance of the furnace bottom layer, and the first refractory material and the second refractory material also have excellent synergistic effects. Through different skeletons and different filling particle sizes, the adaptability of the furnace bottom layer is greatly improved, and the particle grading and filling effect, high temperature resistance, chemical stability, and close surface bonding are greatly improved.

[0041] 2. The present invention uses the self-made third refractory material as the furnace lining material, which greatly increases the service life of the medium frequency furnace. DETAILED DESCRIPTION

[0042] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] Unless otherwise specified, the raw materials used in the present invention are commercially available.

[0044] Example 1

[0045] This embodiment provides a furnace construction process with a low furnace loss ratio for a medium frequency furnace, comprising the following steps:

[0046] S1, add the first refractory material to the bottom of the furnace, each layer of the first refractory material is 30mm thick, and after paving, shake and ram, then add the second refractory material, each layer of the second refractory material is 50mm thick, and after paving, shake and ram, repeatedly lay the first refractory material and the second refractory material, ram to the height of the bottom of the crucible, and obtain the bottom layer of the furnace, wherein the first refractory material comprises zircon sand and silicon micropowder, the mass ratio of zircon sand to silicon micropowder is 2:1, the particle size of zircon sand is 50 mesh, the particle size of silicon micropowder is 600 mesh, and the second refractory material is 50mm thick. The second refractory material includes fused white corundum, fused magnesia, plate-shaped corundum, fused spinel, alumina powder, aluminum lactate and magnesium lactate, wherein the mass ratio of the fused white corundum, fused magnesia, plate-shaped corundum, fused spinel, alumina powder, aluminum lactate and magnesium lactate is 84:8:3:5:3:0.8:0.4, the average particle size of the fused white corundum is 3 mm, the particle size of the fused magnesia is 200 mesh, the particle size of the plate-shaped corundum is 320 mesh, the particle size of the fused spinel is 340 mesh, and the average particle size of the alumina powder is 5 μm;

[0047] S2, vibrate and vent the bottom layer of the furnace three times, and then put the crucible in;

[0048] S3, adding a third refractory material between the intermediate frequency furnace shell and the crucible, tamping it, and then using a hammer to vertically hit the crucible;

[0049] Wherein, the third refractory material comprises the following preparation steps:

[0050] By mass, 200 parts of diatomaceous earth and 400 parts of water are mixed, 20 parts of sodium hydroxide are added, and after reacting for 15 minutes, 20 parts of silane coupling agent Si69 (bis-(γ-triethoxysilylpropyl)-tetrasulfide) are added, reacting at 50°C for 3 hours, washing and drying to obtain a solid phase, and then the solid phase, gypsum powder, glass fiber, carbon fiber, and ceramic fiber are mixed, wherein the mass ratio of the solid phase, gypsum powder, glass fiber, carbon fiber and ceramic fiber is 100:18:3:6:12, to obtain a third refractory material;

[0051] Among them, the particle size of diatomite is 200 mesh, the particle size of gypsum powder is 700 mesh, the average particle size of glass fiber is 30μm, and the average density of carbon fiber is 1.6g / cm 3 The average density of ceramic fiber is 180kg / cm 3 .

[0052] S4, then use a hammer head furnace vibrator to vibrate and beat the intermediate frequency furnace shell horizontally;

[0053] S5, repeat S3 to S4 for 4 times, and continuously add the third refractory material to physically bake the furnace to obtain a medium frequency furnace.

[0054] Example 2

[0055] This embodiment provides a furnace construction process with a low furnace loss ratio for a medium frequency furnace, comprising the following steps:

[0056] S1, add the first refractory material to the bottom of the furnace, each layer of the first refractory material is 30mm thick, and after paving, shake and ram, then add the second refractory material, each layer of the second refractory material is 50mm thick, and after paving, shake and ram, repeatedly lay the first refractory material and the second refractory material, ram to the height of the bottom of the crucible, and obtain the bottom layer of the furnace, wherein the first refractory material comprises zircon sand and silica powder, the mass ratio of zircon sand to silica powder is 2:1, the particle size of zircon sand is 70 mesh, the particle size of silica powder is 500 mesh, and the second refractory material is 500 mesh. The refractory material comprises fused white corundum, fused magnesia, plate-shaped corundum, fused spinel, alumina powder, aluminum lactate and magnesium lactate, wherein the mass ratio of the fused white corundum, fused magnesia, plate-shaped corundum, fused spinel, alumina powder, aluminum lactate and magnesium lactate is 84:8:3:5:3:0.8:0.4, the average particle size of the fused white corundum is 3 mm, the particle size of the fused magnesia is 200 mesh, the particle size of the plate-shaped corundum is 320 mesh, the particle size of the fused spinel is 340 mesh, and the average particle size of the alumina powder is 5 μm;

[0057] S2, vibrate and vent the bottom layer of the furnace three times, and then put the crucible in;

[0058] S3, adding a third refractory material between the intermediate frequency furnace shell and the crucible, tamping it, and then using a hammer to vertically hit the crucible;

[0059] Wherein, the third refractory material comprises the following preparation steps:

[0060] By mass, 200 parts of diatomaceous earth and 400 parts of water are mixed, 20 parts of sodium hydroxide are added, and after reacting for 15 minutes, 20 parts of silane coupling agent Si69 (bis-(γ-triethoxysilylpropyl)-tetrasulfide) are added, reacting at 50°C for 3 hours, washing and drying to obtain a solid phase, and then the solid phase, gypsum powder, glass fiber, carbon fiber, and ceramic fiber are mixed, wherein the mass ratio of the solid phase, gypsum powder, glass fiber, carbon fiber and ceramic fiber is 100:18:3:6:12, to obtain a third refractory material;

[0061] The particle size of diatomite is 80 mesh, the particle size of gypsum powder is 500 mesh, the average particle size of glass fiber is 30 μm, and the average density of carbon fiber is 1.6 g / cm 3 The average density of ceramic fiber is 180kg / cm 3 .

[0062] S4, then use a hammer head furnace vibrator to vibrate and beat the intermediate frequency furnace shell horizontally;

[0063] S5, repeat S3 to S4 for 4 times, continuously add the third refractory material and water glass in the middle, and obtain the medium frequency furnace after physical furnace baking.

[0064] Comparative Example 1

[0065] The difference between this comparative example and Example 1 is that the first refractory material is not added.

[0066] Comparative Example 2

[0067] The difference between this comparative example and Example 1 is that the second refractory material is not added.

[0068] Comparative Example 3

[0069] The difference between this comparative example and Example 1 is that the third refractory material is changed to 200-mesh quartz sand.

[0070] Comparative Example 4

[0071] The difference between this comparative example and Example 1 is that the third refractory material includes the following preparation steps:

[0072] Calculated by weight, diatomaceous earth, gypsum powder, glass fiber, carbon fiber and ceramic fiber are mixed, wherein the mass ratio of diatomaceous earth, gypsum powder, glass fiber, carbon fiber and ceramic fiber is 100:18:3:6:12, to obtain a third refractory material;

[0073] Among them, the particle size of diatomite is 200 mesh, the particle size of gypsum powder is 700 mesh, the average particle size of glass fiber is 30μm, and the average density of carbon fiber is 1.6g / cm 3 The average density of ceramic fiber is 180kg / cm 3 .

[0074] Comparative Example 5

[0075] The difference between this comparative example and Example 1 is that no gypsum powder is added to the third refractory material.

[0076] Comparative Example 6

[0077] The difference between this comparative example and Example 1 is that no ceramic fiber is added to the third refractory material.

[0078] Performance Testing

[0079] Test method: The intermediate frequency furnace was built by using the furnace building process in the embodiment and the comparative example. The volume of the intermediate frequency furnace was 90 tons. The furnace age was recorded (the furnace age refers to the number of times the intermediate frequency furnace was built). The results are shown in Table 1:

[0080]

[0081] It can be seen from the above performance test results that the furnace loss of Examples 1-2 is relatively low and the furnace life is relatively long, especially the comprehensive performance of Example 1 is the most outstanding. This is mainly because the third refractory material of the present invention has excellent bonding with horizontal and vertical hammers, and the third refractory material and the second refractory material and the first refractory material have excellent synergistic effects in high temperature resistance, aging resistance and other properties.

[0082] The comparative examples are obviously inferior to the examples in terms of corresponding performance tests because they do not adopt the necessary technical solutions, which better proves the irreplaceability of the specific technical solutions of the present application in achieving technical effects and solving technical problems. The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A furnace construction process with low furnace loss ratio for medium frequency furnace, characterized in that: The following steps are involved: S1, adding a first refractory material to the furnace bottom, paving it flat and then shaking and ramming it, then adding a second refractory material, paving it flat and then shaking and ramming it, repeatedly paving the first refractory material and the second refractory material, ramming it to the height of the bottom of the crucible, to obtain a furnace bottom layer; S2, vibrate and vent the bottom layer of the furnace three times, and then put the crucible in; S3, adding a third refractory material between the intermediate frequency furnace shell and the crucible, tamping it, and then using a hammer to vertically hit the crucible; S4, then use a hammer head furnace vibrator to vibrate and beat the intermediate frequency furnace shell horizontally; S5, repeat S3 to S4 at least 3 times, continuously add the third refractory material in the middle, and obtain the medium frequency furnace after physical furnace drying; The first refractory material includes zircon sand and silicon powder; The second refractory material includes fused white corundum, fused magnesia, plate-shaped corundum, fused spinel, alumina powder, aluminum lactate and magnesium lactate; The third refractory material comprises the following preparation steps: Mix diatomaceous earth with water, add sodium hydroxide, add silane coupling agent Si69 after reaction, wash and dry after reaction to obtain a solid phase, then mix the solid phase, gypsum powder, glass fiber, carbon fiber and ceramic fiber to obtain a third refractory material; The mass ratio of the diatomaceous earth to the silane coupling agent Si69 is 100:(10-23); The mass ratio of the solid phase, gypsum powder, glass fiber, carbon fiber and ceramic fiber is 100:(10-20):(2-5):(3-9):(10-20).

2. The furnace construction process with low furnace loss ratio of the medium frequency furnace according to claim 1 is characterized in that: In step S1, the thickness of each layer of the first refractory material is 20-40 mm; And / or, in step S1, the thickness of each layer of the second refractory material is 30-80 mm.

3. The furnace construction process with low furnace loss ratio of the medium frequency furnace according to claim 1 is characterized in that: In step S1, the mass ratio of zircon sand to silica powder is (1-4):

1.

4. The furnace construction process with low furnace loss ratio of the medium frequency furnace according to claim 1 is characterized in that: The particle size of the zircon sand is 20-200 meshes, and the particle size of the silicon micropowder is 400-800 meshes.

5. The furnace construction process with low furnace loss ratio of the medium frequency furnace according to claim 1 is characterized in that: In step S1, the mass ratio of the fused white corundum, fused magnesia, plate-shaped corundum, fused spinel, alumina powder, aluminum lactate and magnesium lactate is (80-90): (5-10): (1-5): (1-5): (1-5): (0.1-1): (0.1-1).

6. The furnace construction process with low furnace loss ratio of the medium frequency furnace according to claim 1 is characterized in that: The average particle size of the fused white corundum is 1-5 mm; And / or, the particle size of the fused magnesia is 100-300 mesh; And / or, the particle size of the plate-like corundum is 200-400 mesh; And / or, the particle size of the fused spinel is 200-400 mesh; And / or, the average particle size of the alumina powder is 1-10 μm.

7. The furnace construction process with low furnace loss ratio of the medium frequency furnace according to claim 1 is characterized in that: In step S3, the mass ratio of diatomaceous earth, water and sodium hydroxide is (100-200): (200-400): (10-20).

8. The furnace construction process with low furnace loss ratio of the medium frequency furnace according to claim 1 is characterized in that: The reaction time after adding sodium hydroxide is 10-20 minutes.

9. The furnace construction process with low furnace loss ratio of the medium frequency furnace according to claim 1 is characterized in that: After adding silane coupling agent Si69, the reaction conditions are 40-60°C and the reaction time is 2-4h.

10. The furnace construction process with low furnace loss ratio of the medium frequency furnace according to claim 7, characterized in that: The particle size of the diatomaceous earth is 50-300 mesh, and the particle size of the gypsum powder is 400-800 mesh; And / or, the particle size of the glass fiber is 20-50 μm, and the density of the carbon fiber is 1.5-2 g / cm 3 The density of the ceramic fiber is 100-200 kg / cm 3 .

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