Filler used between cast iron and refractory brick at high temperature and preparation method thereof

Abstract

The filler used between the cast iron and the refractory brick at the high temperature is characterized by comprising the following components in percentage by weight: 3 to 5 weight percent of vermiculite, 5 to 10 weight percent of mullite particles, 35 to 55 weight percent of mullite powder, 20 to 35 weight percent of concentrate powder, 2 to 8 weight percent of silica powder, 2 to 10 weight percent of kyanite powder, 5 to 8 weight percent of glass powder, 1 to 5 weight percent of fiber, 2 to 5 weight percent of cement, 0.1 to 0.3 weight percent of water reducing agent and 10 to 30 weight percent of water. The filler used between the cast iron and the refractory brick at the high temperature and the preparation method thereof have the advantages that the risk that the filler is stripped from the cast iron due to mismatching of thermal expansion coefficients of the anti-seismic filler is reduced, the bonding force of the anti-seismic filler to the cast iron is improved, the sealing between the cast iron and the refractory brick is remarkably improved, and the risk of sealing failure of an industrial furnace is reduced; the preparation and construction processes are energy-saving and environment-friendly; and the cost performance and applicability of the product are improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of high-temperature sealing for industrial furnaces and kilns. Specifically, it is a filler for between cast iron and refractory bricks at high temperatures and a preparation method thereof. Background Art

[0002] Industrial furnaces and kilns are thermal processing equipment that use heat generated by fuel combustion or electrical energy conversion to heat materials or workpieces, and are usually composed of a working inner lining, i.e., the furnace and kiln masonry, and external cast iron components, etc. There are many parts in the entire industrial furnace and kiln where cast iron is in direct contact with refractory bricks. Sealing at such parts is one of the key means to improve heat utilization efficiency. Currently, the commonly used sealing material is refractory fiber products. Due to reasons such as vibration, shape, and size at some contact positions between cast iron and refractory bricks, the refractory fiber products cannot be sealed or cannot be completely sealed, or the sealing effect weakens after a period of time. For example, at the socket joints between some pipelines and the furnace and kiln masonry, it is usually a position with poor sealing effect and is also one of the key points of concern and maintenance in industrial furnace and kiln production.

[0003] Therefore, the known sealing materials have the above-mentioned various inconveniences and problems. Summary of the Invention

[0004] The object of the present invention is to provide a vibration-resistant filler for between cast iron and refractory bricks at high temperatures and a preparation method thereof.

[0005] To achieve the above object, the technical solution of the present invention is: A filler for between cast iron and refractory bricks at high temperatures, characterized in that, by weight percentage, it comprises the following components: Vermiculite 3 - 5wt% Mullite particles 5 - 10wt% Mullite powder 35 - 55wt Concentrate powder 20 - 35wt% Silica fume 2 - 8wt% Kyanite powder 2 - 10wt% Glass powder 5 - 8wt% Fiber 1 - 5wt% Cement 2 - 5wt% Water reducing agent 0.1wt% - 0.3wt% Water 10wt% - 30wt%.

[0006] The filler for between cast iron and refractory bricks at high temperatures and the preparation method thereof of the present invention can also be further realized by adopting the following technical measures.

[0007] The method as described above, wherein the vermiculite is expanded vermiculite with a particle size of 20 - 150 mesh.

[0008] The foregoing method, wherein the mullite particles are sintered mullite particles.

[0009] The foregoing method, wherein the mullite powder is sintered mullite powder, and the particle size of the mullite powder is ≤ 0.088 mm.

[0010] The foregoing method, wherein the particle size of the concentrate powder is ≤ 5 μm.

[0011] The foregoing method, wherein the content of SiO2 in the silica fume is ≥ 92%, and the particle size is ≤ 0.6 μm.

[0012] The foregoing method, wherein the particle size of the kyanite powder is ≤ 0.74 mm.

[0013] The foregoing method, wherein the particle size of the glass powder is 1 - 3 μm.

[0014] The foregoing method, wherein the length of the ceramic fiber is ≤ 8 mm.

[0015] The foregoing method, wherein the water reducing agent is one or more of sodium tripolyphosphate and sodium hexametaphosphate.

[0016] The foregoing method, wherein the modulus of the water glass is not greater than 2.0.

[0017] A preparation method of a filler between cast iron and refractory bricks at high temperature, the components are in weight percentages, and it is characterized by including the following steps: a. Mix the mullite powder, concentrate powder, silica fume, kyanite powder and cement evenly; b. Add vermiculite, mullite particles and fibers and continue to mix evenly; c. Add water glass and water and stir evenly to obtain a vibration-resistant filler.

[0018] After adopting the above technical solution, the filler between cast iron and refractory bricks at high temperature and its preparation method of the present invention have the following advantages: 1. Reduce the risk of the vibration-resistant filler peeling off the cast iron due to the mismatch of the thermal expansion coefficient, and improve the adhesion of the vibration-resistant filler to the cast iron; 2. Significantly improve the seal between the cast iron and the refractory brick, and reduce the risk of seal failure of industrial furnaces; 3. The preparation and construction processes are energy-saving and environmentally friendly, and the cost performance and applicability of the product are improved. Specific embodiments

[0019] The following further illustrates the present invention in conjunction with embodiments.

[0020] In the implementation of the present invention, to avoid repetition, the specific implementation methods and the involved materials are uniformly described as follows, and will not be repeated in the embodiments.

[0021] The vermiculite is expanded vermiculite with a particle size of 20 - 150 mesh; The mullite powder is sintered mullite powder; The particle size of the mullite powder is ≤ 0.088 mm; The particle size of the concentrate powder is ≤ 5 μm; The content of SiO2 in the silica fume is ≥ 92%, and the particle size is ≤ 0.6 μm; The particle size of the kyanite powder is ≤ 0.74 mm; The particle size of the glass powder is 1 - 3 μm; The length of the ceramic fiber is ≤ 8 mm.

[0022] The modulus of the sodium silicate is not greater than 2.0 Example 1 A vibration-resistant filler for flexible sealing between cast iron and refractory bricks at high temperatures and its preparation method. The implementation scheme described in this example is: Using 3 wt% of vermiculite, 5 wt% of 0 - 1 mm mullite particles, 50 wt% of mullite powder, 24 wt% of concentrate powder, 5 wt% of silica fume, 3 wt% of kyanite powder, 5 wt% of glass powder, 2 wt% of fiber, and 3 wt% of cement as raw materials, and 0.1 wt% of water reducer as an additive. First, mix the mullite powder, concentrate powder, silica fume, kyanite powder, and cement evenly according to the above percentage content, then add vermiculite, mullite particles, and fiber and continue to mix evenly, and then add 45 wt% of sodium silicate and 20% of water and stir evenly to obtain the vibration-resistant filler.

[0023] The particle size of the vermiculite is 100 - 150 mesh; The fiber length is 2 - 4 mm; The fiber is inorganic fiber.

[0024] Construction method: Use a shotcrete machine to inject the filler with compressed air and compact the outer surface.

[0025] Example 2: A vibration-resistant filler for flexible sealing between cast iron and refractory bricks at high temperatures and its preparation method. The implementation scheme described in this example is: Using 3 wt% vermiculite, 5 wt% 0-1 mm mullite particles, 47 wt% mullite powder, 24 wt% concentrate powder, 5 wt% silica fume, 5 wt% kyanite powder, 5 wt% glass powder, 3 wt% fiber, and 3 wt% cement as raw materials, and 0.15 wt% water reducing agent as an additive. First, mix the mullite powder, concentrate powder, silica fume, kyanite powder, and cement evenly according to the above percentage content, then add vermiculite, mullite particles, and fiber and continue to mix evenly. Then, add 45 wt% water glass and 20% water and stir evenly to obtain the anti-vibration filler.

[0026] The particle size of vermiculite is 100-150 mesh; The fiber length is 2-4 mm; The fiber is inorganic fiber.

[0027] Construction method: Use a shotcreting machine to inject the filler using compressed air and compact the outer surface.

[0028] Example 3 An anti-vibration filler for flexible sealing between cast iron and refractory bricks at high temperatures and its preparation method. The implementation scheme described in this example is: Using 4 wt% vermiculite, 8 wt% 0-1 mm mullite particles, 37 wt% mullite powder, 30 wt% concentrate powder, 3 wt% silica fume, 5 wt% kyanite powder, 6 wt% glass powder, 4 wt% fiber, and 3 wt% cement as raw materials, and 0.3 wt% water reducing agent as an additive. First, mix the mullite powder, concentrate powder, silica fume, kyanite powder, and cement evenly according to the above percentage content, then add vermiculite, mullite particles, and fiber and continue to mix evenly. Then, add 25 wt% water glass and 15% water and stir evenly to obtain the anti-vibration filler.

[0029] The particle size of vermiculite is 20-100 mesh; The fiber length is 4-8 mm.

[0030] Construction method: Use the troweling method and trowel and compact with a putty knife.

[0031] Perform performance testing on the high-temperature flexible anti-vibration filler of the present invention, and the test results are shown in Table 1.

[0032] Table 1 Performance test results of high-temperature flexible anti-vibration filler Perform performance testing on the anti-vibration filler of the present invention, and the results are as follows: At 1000 °C, the hot-state shear strength after burning is greater than 1.5 Mpa; after 110 °C × 24 h, the cold-state shear strength is greater than 1 Mpa, and the linear change rate after burning at 1000 °C × 3 h is -4~-0.5%.

[0033] The present invention has substantial features and significant technological progress. The packing material for between cast iron and refractory bricks at high temperatures and its preparation method according to the present invention Starting from the sealing and earthquake resistance between cast iron and refractory bricks, inorganic fibers are used as the framework of the earthquake-resistant packing material, and various powders and aggregates are used as the matrix materials of the framework. Among them, concentrate powder plays an important role in the present invention. The concentrate powder contains a large amount of total iron. Iron is a variable-valence metal and is prone to chemical reactions, which reduces the softening temperature under load of the material. It can enable the anti-vibration packing material to have good deformation under temperature and pressure, and can also buffer the stress caused by the vibration of cast iron, reducing the destructive impact of stress on refractory bricks. At the same time, the difference in the coefficient of thermal expansion between the anti-vibration packing material and cast iron is reduced, which can reduce the risk of the packing material peeling off from the cast iron due to the mismatch of the coefficient of thermal expansion. The concentrate powder can also be well combined with the cast iron, playing a bonding role on the cast iron and improving the bonding force of the anti-vibration packing material to the cast iron. Vermiculite and inorganic fibers are stress buffer materials during vibration, enabling the packing material to form a flexible seal; glass powder can reduce the initial melting temperature of the anti-vibration packing material so that a bonding layer can be formed between the anti-vibration packing material and cast iron and refractory bricks at a lower temperature, improving the bonding strength of the anti-vibration material to the two. By adjusting the consistency of the anti-vibration packing material under different sealing conditions and using corresponding construction methods, the sealing effect of industrial furnaces can be improved specifically. The present invention has a relatively large bonding strength to both cast iron and refractory bricks, and the construction methods are quite targeted and very convenient to implement, which can significantly improve the sealing between cast iron and refractory bricks and reduce the risk of seal failure of industrial furnaces; the preparation process and construction process of the present invention are both energy-saving and environmentally friendly, improving the cost performance and applicability of the product.

[0034] The above embodiments are only for illustrating the present invention, rather than limiting the present invention. Those skilled in the relevant technical fields can also make various transformations or changes without departing from the spirit and scope of the present invention. Therefore, all equivalent technical solutions should also fall within the scope of the present invention and should be defined by each claim.

Claims

1. A filler for between cast iron and refractory bricks at high temperatures, characterized in that, By weight percentage, it includes the following components: Vermiculite 3 - 5wt% Mullite particles 5 - 10wt% Mullite powder 35 - 55wt Concentrate powder 20 - 35wt% Silica fume 2 - 8wt% Kyanite powder 2 - 10wt% Glass powder 5 - 8wt% Fiber 1 - 5wt% Cement 2 - 5wt% Water reducing agent 0.1wt% - 0.3wt% Water 10wt% - 30wt%.

2. The filler for between cast iron and refractory bricks at high temperatures as described in claim 1, wherein, The vermiculite is expanded vermiculite with a particle size of 20 - 150 mesh.

3. The filler for between cast iron and refractory bricks at high temperatures according to claim 1, characterized in that, The mullite particles are sintered mullite particles.

4. The filler for between cast iron and refractory bricks at high temperatures according to claim 1, characterized in that, The mullite powder is sintered mullite powder with a particle size of the mullite powder ≤ 0.088mm.

5. The filler for between cast iron and refractory bricks at high temperatures according to claim 1, characterized in that, The particle size of the concentrate powder is ≤ 5μm.

6. The filler for between cast iron and refractory bricks at high temperatures according to claim 1, characterized in that, The content of SiO2 in the silica fume is ≥ 92% and the particle size is ≤ 0.6μm.

7. The filler for between cast iron and refractory bricks at high temperatures according to claim 1, characterized in that, The particle size of the kyanite powder is ≤ 0.74mm.

8. The filler for between cast iron and refractory bricks at high temperatures according to claim 1, characterized in that, The particle size of the glass powder is 1 - 3μm.

9. The filler for between cast iron and refractory bricks at high temperature according to claim 1, characterized in that, The length of the ceramic fiber is ≤ 8mm.

10. The filler for between cast iron and refractory bricks at high temperatures according to claim 1, characterized in that, The water reducing agent is one or more of sodium tripolyphosphate and sodium hexametaphosphate.

11. The filler for between cast iron and refractory bricks at high temperatures according to claim 1, characterized in that, The modulus of the water glass is not greater than 2.

0.

12. A preparation method of a filler between cast iron and refractory bricks at high temperatures as described in claim 1, characterized in that It includes the following steps: a. Mix the mullite powder, kaolin, silica fume, kyanite powder and cement evenly; b. Add vermiculite, mullite particles and chopped fibers and continue to mix evenly; c. Then add 25 - 50wt% of water glass and stir evenly to obtain a high-temperature flexible anti-vibration filler.

13. The preparation method of the filler between cast iron and refractory bricks at high temperatures according to claim 1, wherein the components are in weight percentages, characterized in that It includes the following steps: a. Mix the mullite powder, concentrate powder, silica fume, kyanite powder and cement evenly; b. Add vermiculite, mullite particles and fibers and continue to mix evenly; c. Add water glass and water and stir evenly to obtain an anti-vibration filler.

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