Lightweight inorganic plastic ramming material

Abstract

The invention belongs to the technical field of ramming materials, and particularly relates to a light inorganic plastic ramming material. The composite material comprises a fiber base material, a low-density filler, a viscous filler, an inorganic binder and water, the inorganic binder is a jelly formed by mixing a polyaluminum chloride solution and alkaline silica sol, and the weight ratio of polyaluminum chloride to alkaline silica sol is 1: (55-70). According to the technical scheme provided by the invention, the inorganic binder is matched with the viscous filler to serve as a normal-temperature binder, and an organic binder such as polyacrylamide in the prior art is replaced; organic matters are avoided in the formula, the ramming material can be directly used after in-situ construction, transferring for pre-burning for discharging organic impurities and increasing redundant processes and energy consumption are not needed, the construction cost is lower, the long-term use temperature of the ramming material provided by the invention can reach 1050 DEG C, and the highest use temperature reaches 1100 DEG C.

Description

Technical Field

[0001] The invention belongs to the technical field of ramming materials, and in particular relates to a lightweight inorganic plastic ramming material. Background Art

[0002] Lightweight plastic ramming materials are widely used in many fields due to their excellent thermal insulation and refractory properties, high strength, low density and good corrosion resistance. For example, they can be used for the lining and bottom of blast furnaces, hot blast stoves, electric furnaces and other equipment; for the lining of various high-temperature reactors, distillation towers and other equipment; as well as the clarifiers, melting tanks and other parts of glass kilns; and for the lining of cement rotary kilns and lime kilns.

[0003] Lightweight plastic ramming materials are generally composed of fiber base materials, fillers and binders, wherein the base materials provide the main components after molding to ensure the performance of the core product, the fillers are used to fill the internal gaps, reduce costs and reduce product density, meet the lightweight requirements, and the binders are used to shape the product surface and provide bonding, curing and shaping of the base materials and fillers. In the prior art, the binder requires an organic binder for shaping at room temperature. During use, the organic binder will decompose and release toxic and harmful substances under high temperature conditions, and such indicators need to be strictly controlled in certain specific usage scenarios, otherwise other equipment and product quality will be damaged. Therefore, when the lightweight plastic ramming material is repaired or gap-filled in a high-temperature furnace, it cannot be constructed on site. The high-temperature furnace needs to be transferred out of an area without environmental restrictions. After the ramming material is repaired and the gaps are filled, it is sintered at high temperature to decompose and release the organic binder in advance, and then transferred to the working environment, which is time-consuming and labor-intensive.

[0004] However, there is currently no fully inorganic binder that can be used for lightweight plastic ramming materials to replace room temperature organic binders. Summary of the Invention

[0005] The invention provides a lightweight inorganic plastic ramming material, which is used to solve the problem that the current organic adhesive at room temperature releases toxic substances at high temperature and cannot be constructed in situ.

[0006] In order to solve the above technical problems, the technical solution of the present invention is: the lightweight inorganic plastic ramming material includes a fiber base material, a low-density filler, a viscous filler, an inorganic binder and water, the inorganic binder is a colloid formed by mixing polyaluminum chloride and alkaline silica sol, and the weight ratio of the polyaluminum chloride to the alkaline silica sol is 1:(55-70).

[0007] Alkaline silica sol (main component is stable SiO2 colloid, pH about 9-11, colloid particles are negatively charged) and polyaluminium chloride (hydrolyzed to generate positively charged Al 3+ and polynuclear hydroxyl complexes, such as [Al2(OH) n ] (6-n+)During mixing, due to the neutralization of positive and negative charges, the colloidal electrical neutralization occurs first, causing the SiO2 particles of the silica sol to condense. As the reaction proceeds, Al 3+ With silicate ions (SiO3 2- ) may undergo a double hydrolysis or polycondensation reaction, forming aluminosilicate gel or hydrated aluminosilicates. The system gradually forms a viscous gel-like precipitate or semi-solid product, manifested by a rapid increase in the mixture's turbidity and viscosity, resulting in a colloid of considerable strength. This colloid possesses excellent bonding properties and, after drying, forms a solid similar to a ceramic precursor, possessing high hardness and wear resistance. Therefore, even subsequent use in a high-temperature furnace will not produce any environmentally harmful substances.

[0008] Adding a viscous clay filler to the filler not only has the original filler function, but also can cooperate with the inorganic binder to shape the ramming material.

[0009] Optionally, the alkaline silica sol is an alkaline silica sol with a solid content of 30%.

[0010] Optionally, the components in the lightweight inorganic plastic ramming material are proportioned as follows by weight:

[0011]

[0012] Optionally, the fiber substrate includes short fibers and long fibers.

[0013] Optionally, the short-staple fibers are selected from washed cotton fibers and / or aluminum fibers, and the long-staple fibers are glass fibers.

[0014] Glass fiber material is added, that is, the content of pyrophyllite, quartz sand and silica alumina is increased. Due to the high rigidity, high tensile strength and high mechanical strength of glass fiber, the bonding performance and strength of the product are improved, and the fibers, powders and binders inside the product are more fully combined.

[0015] Optionally, the short fiber and long fiber are mixed in a weight ratio of (45-65):(3-10).

[0016] Optionally, the low-density filler is selected from fly ash floating beads and / or hollow glass microspheres.

[0017] Optionally, the viscous filler is selected from one or more of white mud, kaolin and bentonite.

[0018] Optionally, the stirring rate when the polyaluminium chloride and alkaline silica sol are mixed is 600-1000 r / min, preferably 600-800 r / min.

[0019] Optionally, the lightweight inorganic plastic ramming material is prepared by dry-mixing the fiber base material, low-density filler and viscous filler, then adding the prepared inorganic binder and stirring at high speed, and finally adding water and stirring at high speed to form an amorphous product.

[0020] Optionally, the stirring speed of the dry mixing is 150-350 r / min, and the rotation speed of the high-speed stirring is 600-1000 r / min, preferably 600-800 r / min.

[0021] The technical solution provided by the present invention adopts an inorganic binder combined with a viscous filler as a room-temperature binder to replace the organic binder in the prior art, such as polyacrylamide; the formula avoids the presence of organic matter and can be used directly after on-site construction without the need for transfer and pre-burning to remove organic impurities, which adds unnecessary steps and energy consumption, and lowers the construction cost. DETAILED DESCRIPTION

[0022] For ease of understanding, the lightweight inorganic plastic ramming material is described below in conjunction with examples. It should be understood that these examples are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0023] The raw materials used in this embodiment are all commercially available products unless otherwise specified, and the process used is also conventional operations of the prior art unless otherwise specified.

[0024] Example 1:

[0025] The lightweight inorganic plastic ramming material has the following components in parts by weight:

[0026]

[0027] Preparation of inorganic binder

[0028] 1.5 parts of polyaluminium chloride were slowly added to 90 parts of stirred alkaline silica sol with a solid content of 30%, and the mixture was stirred rapidly until the polyaluminium chloride was completely dissolved to form a colloid at a stirring rate of 600 r / min.

[0029] All aggregates were weighed in proportion and added to a mixing device for dry mixing at a stirring rate of 200 r / min; the prepared inorganic binder was then added to the evenly mixed aggregates and stirred rapidly, and finally water was added thereto and stirred at a high speed at a stirring rate of 800 r / min to form an amorphous material. The amorphous material was applied to a ceramic fiber furnace as a furnace lining and used directly at high temperature, and the ramming material was fused with the fiber furnace.

[0030] Example 2

[0031] The lightweight inorganic plastic ramming material has the following components in parts by weight:

[0032]

[0033]

[0034] Preparation of inorganic binder

[0035] Slowly add 1 part of polyaluminium chloride to 70 parts of stirred alkaline silica sol with a solid content of 30%, and stir rapidly until the polyaluminium chloride is completely dissolved to form a colloid. The stirring rate is 700 r / min.

[0036] All aggregates were weighed in proportion and added to a mixing device for dry mixing at a stirring rate of 150 r / min; the prepared inorganic binder was then added to the evenly mixed aggregates and stirred rapidly, and finally water was added thereto and stirred at a high speed at a stirring rate of 600 r / min to form an amorphous material. The amorphous material was applied to a ceramic fiber furnace as a gap filling and used directly at high temperature, and the ramming material was fused with the fiber furnace.

[0037] Example 3

[0038] The lightweight inorganic plastic ramming material has the following components in parts by weight:

[0039]

[0040] Slowly add 2 parts of polyaluminium chloride to 120 parts of stirred alkaline silica sol with a solid content of 30%, and stir rapidly until the polyaluminium chloride is completely dissolved to form a colloid. The stirring rate is 600 r / min.

[0041] All aggregates are weighed according to a proportion and added to a stirring device for dry mixing at a stirring rate of 200 r / min; the prepared inorganic binder is then added to the evenly mixed aggregate and rapidly stirred, and finally water is added thereto and stirred at a high speed at a stirring rate of 700 r / min to form an amorphous material. The amorphous material is applied to a ceramic fiber furnace for repairing it and used directly at high temperature. The ramming material is fused with the fiber furnace. The long-term use temperature of the ramming material provided by the present invention can reach up to 1050°C, and the maximum use temperature can reach 1100°C.

[0042] Example 4

[0043] The lightweight inorganic plastic ramming material has the following components in parts by weight:

[0044]

[0045] Preparation of inorganic binder

[0046] Slowly add 1 part of polyaluminium chloride to 60 parts of stirred alkaline silica sol with a solid content of 30%, and stir rapidly until the polyaluminium chloride is completely dissolved to form a colloid. The stirring rate is 600 r / min.

[0047] All aggregates were weighed in proportion and added to a mixing device for dry mixing at a stirring rate of 250 r / min; the prepared inorganic binder was then added to the evenly mixed aggregates and stirred rapidly, and finally water was added thereto and stirred at a high speed at a stirring rate of 650 r / min to form an amorphous material. The amorphous material was applied to a ceramic fiber furnace as a furnace lining and used directly at high temperature, and the ramming material was fused with the fiber furnace.

[0048] Comparative Example 1:

[0049] The difference from Example 1 is that the 90 parts of the composite polysilicon alumina precursor is replaced with 6 parts of polyacrylamide and 10 parts of alkaline silica sol. In the comparative example, the alkaline silica sol serves only as a high-temperature binder. If the alkaline silica sol is also added in a ratio of 90 parts, it will not form a thixotropic colloid, resulting in a sintered strength that is not practical. Therefore, the addition ratio is based on the prior art.

[0050] All aggregates are weighed in proportion and added to a mixing device, where they are slowly stirred until uniform. A polyacrylamide solution is then prepared. The polyacrylamide solution and alkaline silica sol are then added to the mixed aggregates and rapidly stirred. Finally, an appropriate amount of water is added and stirred at high speed until an amorphous refractory material is formed. The amorphous material is applied to a ceramic fiber furnace as a lining and pre-sintered at 800°C to decompose the polyacrylamide before use.

[0051] Comparative Example 2:

[0052] In this comparative example, water glass solution and polyaluminium chloride were used to prepare the inorganic binder, specifically 2 parts of polyaluminium chloride and 120 parts of water glass. After the preparation, the colloid hardened too quickly.

[0053] When the composite polysilicon alumina precursor in Example 3 is replaced by the composite polysilicon alumina precursor, the amorphous material prepared after stirring is not sticky and cannot be initially shaped at room temperature.

[0054] Comparative Example 3:

[0055] In this embodiment, an inorganic binder is prepared using aluminum sol and polyaluminum chloride solution, specifically 1.5 parts of polyaluminum chloride and 90 parts of aluminum sol, which cannot form a gel state.

[0056] When the composite polysilicon alumina precursor in Example 1 is replaced by the composite polysilicon alumina precursor, the powder is dispersed after the aggregate is added and cannot be combined to form a plastic material.

[0057] Comparative Example 4:

[0058] The difference between the inorganic binder and Example 2 is that 1 part of polyaluminium chloride and 75 parts of alkaline silica sol cannot form a thixotropic colloid after being mixed and stirred evenly, and the binder is too thin and has poor bonding properties.

[0059] Comparative Example 5:

[0060] The difference from Example 1 is that bentonite is replaced by hollow glass microspheres, and Guangxi white mud is replaced by lightweight fly ash floating beads, as follows

[0061]

[0062]

[0063] The product has no plasticity after preparation and cannot be formed, so the relevant experimental data cannot be tested.

[0064] Comparative Example 6

[0065] The difference from Example 1 is that the hollow glass microspheres are replaced with bentonite, and the lightweight fly ash floating beads are replaced with Guangxi white mud, as follows:

[0066]

[0067] Comparative Example 7

[0068] The difference from Example 1 is that the proportion of glass fiber is completely replaced by ordinary aluminum fiber, as follows:

[0069]

[0070] Simulate the material performance when used in a high-temperature furnace, simulate the temperature 1000℃×3h

[0071] 1. Bulk density after sintering: refer to GB / T17911.3-1999 "Test method for bulk density of refractory ceramic fiber products"

[0072] 2. Compressive strength (1000℃×3h): GB / T17911.5-1999 "Test method for tensile strength of refractory ceramic fiber products"

[0073] 3. Linear change after firing: (1000℃×3h): GB / T17911.4-1999 "Test method for permanent linear change of refractory ceramic fiber products after heating"

[0074] After sintering, the above performance tests were performed on Examples 1-4 and Comparative Examples 1, 6 and 7. The test results are shown in Table 1.

[0075] Table 1

[0076] <![CDATA[Volume density (kg / m 3 )]]> Compressive strength (Mpa) Line change after burning (%) Example 1 368 ≥0.81 ≤-0.7 Example 2 352 ≥0.95 ≤-0.6 Example 3 405 ≥1.3 ≤-0.98 Example 4 345 ≥1.03 ≤-0.8 Comparative Example 1 320 ≥0.07 ≤-1.3 Comparative Example 6 1260 ≥1.15 ≥2.5 Comparative Example 7 350 ≥0.05 ≤-2.0％

[0077] Comparative Example 1 needs to add a pre-firing process to decompose the organic binder. In addition, compared with Example 1, its bulk density and compressive strength also significantly decrease after high-temperature conversion. Comparative Examples 2-5 are unable to form a colloid, resulting in the ramming material being non-plastic and unable to be formed. Comparative Example 6 is no longer a lightweight ramming material because the fillers are all viscous fillers, resulting in excessive density. Although the compressive strength is excellent, the line changes greatly after burning. If used as a sealant at high temperature, new gaps will be generated. Comparative Example 7, compared to Comparative Example 1, lacks long fibers such as glass fiber, resulting in a sudden drop in compressive strength. The line changes also greatly after burning, and the compactness is also undesirable.

Claims

1. A lightweight inorganic plastic ramming material, characterized in that: The invention comprises a fiber base material, a low-density filler, a viscous filler, an inorganic binder and water. The inorganic binder is a colloid formed by mixing polyaluminum chloride and alkaline silica sol. The weight ratio of the polyaluminum chloride to the alkaline silica sol is 1:(55-70).

2. The lightweight inorganic plastic ramming material according to claim 1, characterized in that: The proportions of the components in the lightweight inorganic plastic ramming material in parts by weight are as follows:

3. The lightweight inorganic plastic ramming material according to claim 1, characterized in that: The fiber base material includes short fiber and long fiber.

4. The lightweight inorganic plastic ramming material according to claim 3, characterized in that: The short-staple fibers are selected from washed cotton fibers and / or aluminum fibers, and the long-staple fibers are glass fibers.

5. The lightweight inorganic plastic ramming material according to claim 3, characterized in that: The weight ratio of the short fiber and the long fiber is (45-65): (3-10).

6. The lightweight inorganic plastic ramming material according to claim 1, characterized in that: The low-density filler is selected from fly ash floating beads and / or hollow glass microspheres.

7. The lightweight inorganic plastic ramming material according to claim 1, characterized in that: The viscous filler is selected from one or more of white mud, kaolin and bentonite.

8. The lightweight inorganic plastic ramming material according to claim 1, characterized in that: The stirring rate of the polyaluminium chloride and alkaline silica sol when mixed is 600-1000 r / min.

9. The lightweight inorganic plastic ramming material according to claim 1, characterized in that: The preparation method of the lightweight inorganic plastic ramming material is to dry-mix a fiber base material, a low-density filler and a viscous filler, then add the prepared inorganic binder and stir and mix at high speed, and finally add water and stir and mix at high speed to form an amorphous product.

10. The lightweight inorganic plastic ramming material according to claim 9, characterized in that: The stirring speed of the dry mixing is 150-350 r / min, and the stirring speed of the high-speed mixing is 600-1000 r / min.

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