Novel light thermal insulation powder material and preparation process thereof

Abstract

The invention provides a novel lightweight thermal insulation powder material and a preparation process thereof. The novel lightweight thermal insulation powder material comprises the following raw materials in parts by weight: 120-150 parts of refractory material solid waste, 10-20 parts of an active functional additive, 10-20 parts of a pore forming agent, 5-15 parts of a mineralizing agent and 10-20 parts of a sintering fluxing agent. In the invention, the resource utilization of the refractory material solid waste and the fly ash opens up a new feasible technical path, so that the cyclic utilization of resources can be realized, a large number of natural mineral raw materials are saved, the environmental pollution is reduced, and remarkable social ecological environmental benefits are brought.

Description

Technical Field

[0001] The present invention relates to the technical field of heat-insulating powder, and particularly relates to a novel lightweight heat-insulating powder material and a preparation process thereof. Background Art

[0002] Lightweight heat-insulating materials are materials with excellent heat-insulating performance, usually having a lightweight, loose, porous or fibrous structure, with excellent heat-insulating performance, low density, high porosity, and good fire resistance and high-temperature resistance. Lightweight heat-insulating materials block the conduction of heat through the air inside them and are widely used in the heat insulation of walls, roofs, thermal pipelines, furnaces, etc. to reduce heat transfer and save energy.

[0003] There are many types of lightweight heat-insulating materials. According to the material composition, they can be divided into two major categories: inorganic and organic. Among them, inorganic heat-insulating materials not only can withstand high temperatures, have good thermal stability and heat-insulating properties, but also have outstanding advantages such as stable performance (fireproof, small deformation coefficient, anti-aging, strong durability), safety and environmental protection, economy, and wide application range, becoming the focus of current research and development. Commonly used lightweight heat-insulating materials mainly include expanded perlite, ceramic fiber, aerogel, rock wool, mineral wool, glass wool, calcium silicate, foam or aerated concrete, and aluminosilicate lightweight refractory heat-insulating materials, etc.

[0005] In recent years, much research work has been carried out at home and abroad on the resource utilization of refractory waste and fly ash solid waste. Among them, refractory waste is mainly recycled for the preparation of refractory materials or castables after being crushed, sorted, and purified, while fly ash is mainly used for the preparation of concrete and cement admixtures. However, limited by the production process and product performance of solid waste recycled products, there are generally bottleneck problems such as low effective utilization rate of solid waste, low utilization added value, high cost, and narrow application fields of products. Summary of the Invention

[0006] Aiming at the problems existing in the prior art, the present invention provides a novel lightweight heat-insulating powder material and a preparation process thereof. This novel lightweight heat-insulating powder material has comprehensive properties such as high temperature resistance, fire resistance, and corrosion resistance, and has a relatively high utilization rate of refractory waste.

[0007] To achieve the above objectives, the present invention is realized through the following technical solutions:

[0008] A novel lightweight heat-insulating powder material, the composition of the heat-insulating powder includes the following raw materials in parts by weight: 120 - 150 parts of refractory waste, 10 - 20 parts of active functional additives, 10 - 20 parts of pore-forming agents, 5 - 15 parts of mineralizing agents, and 10 - 20 parts of sintering fluxes.

[0009] Preferably, the composition of the heat-insulating powder further includes the following raw materials in parts by weight: 10 - 20 parts of sodium fluoride.

[0010] Preferably, the composition of the heat-insulating powder includes raw materials in the following parts by weight: the refractory waste includes fly ash waste and high-aluminum refractory waste, the high-aluminum refractory waste is corundum-mullite or chrome corundum brick, and the fly ash waste and the high-aluminum refractory waste form the refractory waste according to a mass ratio of 1:1.5.

[0011] Preferably, the active functional additive is one or more of spodumene, bentonite, high-active aluminum source, high-active silicon source or high-active magnesium source.

[0012] Preferably, the pore-forming agent is one or more of polystyrene microspheres, wood chips, anthracite coal ash, starch, urea, silicon carbide or carbonate.

[0013] Preferably, the mineralizer is one or more of fluorite, gypsum, sodium fluorosilicate, barite, industrial waste residues, wherein the industrial waste residues are copper slag, titanium slag, phosphogypsum or fluorogypsum.

[0014] Preferably, the sintering flux is one or more of cobalt monoxide, manganese dioxide or feldspar.

[0015] A preparation process of a novel lightweight heat-insulating powder material includes the following steps:

[0016] S1. Weigh the fly ash waste in proportion, carry out pressure leaching and desilication with an alkali solution, separate the silicon slag and the filtrate, wash the silicon slag with hot water, then carry out alkali removal washing on the silicon slag with hydrochloric acid, and finally wash with clear water, dry and set aside;

[0017] S2. Take the high-aluminum refractory waste, crush it and then carry out classification screening, remove iron and calcium impurities in the crushed waste materials, and set aside;

[0018] S3. Weigh the remaining materials in proportion, fully mix them with the materials obtained in steps S1 and S2, dry them, then put them into an electric furnace, raise the temperature to 1500 - 1600 °C, keep the temperature for 2.5 - 3 h, then lower the temperature to 1300 °C at a rate of 1.5 - 2 °C / min, and then naturally cool with the furnace body, carry out crushing and classification treatment, and after passing the performance test, store the product in the warehouse to obtain the novel lightweight heat-insulating powder material.

[0019] Preferably, in step S3, the heating rate of the electric furnace is 6 °C / min.

[0020] Preferably, in step S1, the alkali solution is sodium hydroxide solution.

[0021] The beneficial effects of the present invention are:

[0022] Utilize fly ash solid waste and high-aluminum refractory solid waste (corundum-mullite or chrome corundum bricks) comprehensively to prepare mullite lightweight thermal insulation powder materials, which improves the resource utilization rate of fly ash solid waste and high-aluminum refractory solid waste. Alkaline treatment is carried out on fly ash solid waste. Impurities such as glass phase in fly ash react with the alkaline solution, removing a part of silicon oxide. Since the specific surface area determines the reaction rate between solid phases, the fly ash after alkaline treatment makes the particle surface more porous and the pores more dense, increasing the particle surface area and improving the reaction activity of fly ash. The fly ash after alkaline treatment is pickled with excessive acid to remove most of the alkali metal and alkaline earth metal oxides and aluminum-silicon complexes, etc. Acid-base treatment of fly ash not only greatly reduces the mass fraction of alkali metal oxides in fly ash, improves the refractory temperature of corundum mullite, but also improves the original activity of fly ash, enabling the filler to fully enter the pores of fly ash particles or wrap around the fly ash particles, increasing the density of the lightweight thermal insulation powder materials.

[0023] During the sintering process, sodium fluoride melts at a lower temperature, generating a large amount of liquid phase in the system, providing a liquid phase medium condition for solid-phase materials, which is beneficial to filling the pores in the sample and improving the density. Fluoride ions enter the glass network structure, reducing the glass viscosity, increasing the crystal nucleation rate, and promoting the sintering of the sample at low temperature. Adding a mineralizer speeds up the decomposition rate of calcium carbonate in the system, increases the solid-phase reaction rate, reduces the liquid-phase appearance temperature and firing temperature, and speeds up the generation rate of mullite lightweight thermal insulation powder materials.

[0024] Sintering fluxes can reduce the mullitization temperature and promote the anisotropic growth of mullite grains at the same time to toughen porous mullite lightweight thermal insulation powder materials. Description of the Drawings

[0025] Figure 1 It is the production process flow of lightweight thermal insulation powder materials. Specific Embodiments

[0026] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0027] Example 1

[0028] A new type of lightweight thermal insulation powder material. The composition of the thermal insulation powder includes the following raw materials in parts by weight: 120 parts of refractory waste, 10 parts of active functional additive, 10 parts of pore former, 5 parts of mineralizer, 10 parts of sintering flux, and 10 parts of sodium fluoride.

[0029] The composition of the thermal insulation powder includes the following raw materials in parts by weight: The refractory waste includes fly ash waste and high-alumina refractory waste. The high-alumina refractory waste is corundum-mullite, and the fly ash waste and high-alumina refractory waste form the refractory waste in a mass ratio of 1:1.5.

[0030] The active functional additive is spodumene.

[0031] The pore former is polystyrene microspheres.

[0032] The mineralizer is fluorite.

[0033] The sintering flux is cobalt monoxide.

[0034] A preparation process for a new type of lightweight thermal insulation powder material, including the following steps:

[0035] S1. Weigh the fly ash waste in proportion, perform pressure leaching desilication with sodium hydroxide solution, separate the silicon slag and the filtrate, wash the silicon slag with hot water, then perform dealkalization washing on the silicon slag with hydrochloric acid, and finally wash with clean water, dry, and set aside.

[0036] S2. Take the high-alumina refractory waste, crush it and then classify and screen it, remove iron and calcium impurities in the crushed waste materials, and set aside.

[0037] S3. Weigh the remaining materials in proportion, fully mix them with the materials obtained in steps S1 and S2, dry them, then put them into an electric furnace, heat up to 1500 °C at a rate of 6 °C / min, keep the temperature for 2.5 h, then reduce the temperature to 1300 °C at a rate of 1.5 °C / min, and then naturally cool with the furnace body, perform crushing and classification treatment, and after passing the performance test, store the product in the warehouse to obtain the new type of lightweight thermal insulation powder material.

[0038] Example 2

[0039] A new type of lightweight thermal insulation powder material. The composition of the thermal insulation powder includes the following raw materials in parts by weight: 150 parts of refractory waste, 20 parts of active functional additive, 20 parts of pore former, 15 parts of mineralizer, 20 parts of sintering flux, and 20 parts of sodium fluoride.

[0040] The composition of the heat-insulating powder includes the following raw materials in parts by weight: The refractory waste includes fly ash waste and high-aluminum refractory waste. The high-aluminum refractory waste is chromic corundum brick, and the fly ash waste and high-aluminum refractory waste form refractory waste according to a mass ratio of 1:1.5.

[0041] The active functional additive is bentonite.

[0042] The pore-forming agent is wood chips.

[0043] The mineralizer is gypsum.

[0044] The sintering flux is manganese dioxide.

[0045] A preparation process of a novel lightweight heat-insulating powder material includes the following steps:

[0046] S1. Weigh fly ash waste proportionally, carry out pressure leaching and desilication with sodium hydroxide solution, separate the silicon slag and the filtrate, wash the silicon slag with hot water, then carry out alkali removal washing on the silicon slag with hydrochloric acid, and finally wash with clear water, dry, and reserve.

[0047] S2. Take high-aluminum refractory waste, crush it and carry out grading and screening, remove iron and calcium impurities in the crushed waste materials, and reserve.

[0048] S3. Weigh the remaining materials proportionally, fully mix them with the materials obtained in steps S1 and S2, dry, then put them into an electric furnace, heat up to 1600 °C at a speed of 6 °C / min, keep the temperature for 3 h, then reduce the temperature to 1300 °C at a speed of 2 °C / min, and then naturally cool with the furnace body, carry out crushing and grading treatment, and after passing the performance test, store the product in the warehouse to obtain the novel lightweight heat-insulating powder material.

[0049] Example 3

[0050] A novel lightweight heat-insulating powder material, the composition of the heat-insulating powder includes the following raw materials in parts by weight: 135 parts of refractory waste, 15 parts of active functional additive, 15 parts of pore-forming agent, 10 parts of mineralizer, 15 parts of sintering flux, and 15 parts of sodium fluoride.

[0051] The composition of the heat-insulating powder includes the following raw materials in parts by weight: The refractory waste includes fly ash waste and high-aluminum refractory waste. The high-aluminum refractory waste is corundum-mullite, and the fly ash waste and high-aluminum refractory waste form refractory waste according to a mass ratio of 1:1.5.

[0052] The active functional additive is a highly active silicon source.

[0053] The pore-forming agent is anthracite coal ash.

[0054] The mineralizer is sodium fluorosilicate and barite.

[0055] The sintering flux is feldspar.

[0056] A preparation process of a new type of lightweight heat-insulating powder material comprises the following steps:

[0057] S1. Weigh the fly ash solid waste according to the proportion, carry out pressure leaching desilication with sodium hydroxide solution, separate the silicon slag and the filtrate, wash the silicon slag with hot water, then carry out alkali removal washing on the silicon slag with hydrochloric acid, and finally wash with clear water, dry, and reserve for use;

[0058] S2. Take the high-aluminum refractory solid waste, crush it and screen it by grading, remove iron and calcium impurities in the crushed waste materials, and reserve for use;

[0059] S3. Weigh the remaining materials according to the proportion, fully mix them with the materials obtained in steps S1 and S2, dry, then put them into an electric furnace, heat up to 1550 °C at a speed of 6 °C / min, keep the temperature for 3 h, then reduce the temperature to 1300 °C at a speed of 2 °C / min, and then naturally cool with the furnace body, carry out crushing and grading treatment, and after passing the performance test, the product is warehoused to obtain the new type of lightweight heat-insulating powder material.

[0060] Comparative Example 1:

[0061] A new type of lightweight heat-insulating powder material, the difference between this new type of lightweight heat-insulating powder material and Example 3 is only that: no highly active silicon source is added.

[0062] Comparative Example 2:

[0063] A new type of lightweight heat-insulating powder material, the difference between this new type of lightweight heat-insulating powder material and Example 3 is only that: no anthracite coal ash is added.

[0064] Comparative Example 3:

[0065] A new type of lightweight heat-insulating powder material, the difference between this new type of lightweight heat-insulating powder material and Example 3 is only that: no sodium fluorosilicate and barite are added.

[0066] Comparative Example 4:

[0067] A new type of lightweight heat-insulating powder material, the difference between this new type of lightweight heat-insulating powder material and Example 3 is only that: no feldspar is added.

[0068] Comparative Example 5:

[0069] A new type of lightweight heat-insulating powder material, the difference between this new type of lightweight heat-insulating powder material and Example 3 is only that: no sodium fluoride is added.

[0070] Comparative Example 6:

[0071] A new type of lightweight thermal insulation powder material, the difference between this new type of lightweight thermal insulation powder material and Example 3 is only that: sodium hydroxide solution is not added for alkali washing.

[0072] Comparative Example 7:

[0073] A new type of lightweight thermal insulation powder material, the difference between this new type of lightweight thermal insulation powder material and Example 3 is only that: hydrochloric acid is not added for acid washing.

[0074] Perform performance tests on the thermal insulation powders obtained in the above Examples 1-3 and Comparative Examples 1-7, and measure the comprehensive performance in the thermal insulation powders. The results are shown in Table 1.

[0075] Table 1 Performance parameters of the thermal insulation powders obtained in Examples 1-3 and Comparative Examples 1-7

[0076]

[0077] To sum up, the waste refractory materials are one or more of waste high-alumina bricks, magnesia bricks, silica bricks, and bauxite bricks, belonging to low-aluminum or high-magnesium, silicon refractory solid wastes. Together with waste fly ash, they are used to prepare cordierite-based lightweight thermal insulation powder materials, and finally fired into lightweight heat-insulating refractory thermal insulation bricks, which have good comprehensive properties such as fire resistance and heat insulation, making full use of low-aluminum or high-magnesium, silicon refractory solid wastes and fly ash solid wastes.

[0078] Aluminum silicate fiber has the advantages of high temperature resistance, good thermal stability, low thermal conductivity, small heat capacity, good resistance to mechanical vibration, small thermal expansion when heated, and good heat insulation performance. Alumina short fiber has better heat resistance stability. Alumina short fiber can be used in acidic environment, oxidation atmosphere, reduction atmosphere and vacuum conditions, and also has certain corrosion resistance to alkaline environment. Silicon carbide fiber has good heat resistance and oxidation resistance. Aluminum silicate fiber, alumina short fiber and silicon carbide fiber together form a hybrid fiber, which is doped into the raw materials to prepare lightweight heat-insulating refractory thermal insulation bricks, enhancing the comprehensive properties such as high temperature resistance, corrosion resistance and durability of the lightweight heat-insulating refractory thermal insulation bricks. The thermal insulation brick introduced with aluminum silicate ceramic fiber has better physical properties at room temperature and a smaller thermal expansion coefficient, and the specimen introduced with aluminum silicate ceramic fiber has the smallest thermal expansion coefficient and the highest compressive strength.

[0079] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A new type of lightweight thermal insulation powder material, characterized in that The composition of the heat-insulating powder includes the following raw materials in parts by weight: 120-150 parts of refractory waste, 10-20 parts of active functional additive, 10-20 parts of pore former, 5-15 parts of mineralizer, and 10-20 parts of sintering flux.

2. The novel lightweight thermal insulation powder material according to claim 1, wherein The composition of the heat-insulating powder also includes the following raw materials in parts by weight: 10-20 parts of sodium fluoride.

3. The novel lightweight thermal insulation powder material according to claim 1 or 2, characterized in that, The composition of the heat-insulating powder includes the following raw materials in parts by weight: the refractory waste includes fly ash waste and high-alumina refractory waste, the high-alumina refractory waste is corundum-mullite or chrome corundum brick, and the fly ash waste and high-alumina refractory waste form the refractory waste in a mass ratio of 1:1.

5.

4. The novel lightweight thermal insulation powder material according to claim 3, characterized in that, The active functional additive is one or more of spodumene, bentonite, high-activity aluminum source, high-activity silicon source, or high-activity magnesium source.

5. The novel lightweight thermal insulation powder material according to claim 3, characterized in that, The pore former is one or more of polystyrene microspheres, wood chips, anthracite coal ash, starch, urea, silicon carbide, or carbonate.

6. The novel lightweight heat-insulating powder material according to claim 3, characterized in that, The mineralizer is one or more of fluorite, gypsum, sodium fluorosilicate, barite, industrial waste residue, wherein the industrial waste residue is copper slag, titanium slag, phosphogypsum, or fluorogypsum.

7. The novel lightweight heat-insulating powder material according to claim 3, characterized in that, The sintering flux is one or more of cobalt monoxide, manganese dioxide, or feldspar.

8. A preparation process of the novel lightweight heat-insulating powder material according to any one of claims 3-7, characterized in that, It includes the following steps: S1. Weigh the fly ash waste in proportion, carry out pressure leaching and desilication with an alkali solution, separate the silicon slag and the filtrate, wash the silicon slag with hot water, then carry out alkali removal washing of the silicon slag with hydrochloric acid, and finally wash with clear water, dry, and reserve for use; S2. Take the high-alumina refractory waste, crush it and screen it by grading, remove iron and calcium impurities in the crushed waste materials, and reserve for use; S3. Weigh the remaining materials in proportion, fully mix them with the materials obtained in steps S1 and S2, dry, then put them into an electric furnace, heat up to 1500-1600 °C, keep warm for 2.5-3 h, then cool down to 1300 °C at a rate of 1.5-2 °C / min, and then naturally cool with the furnace body, crush and classify for treatment, and after passing the performance test, the product is warehoused to obtain the new lightweight heat-insulating powder material.

9. The preparation process of the novel lightweight thermal insulation powder material according to claim 8, characterized in that, In step S3, the heating rate of the electric furnace is 6 °C / min.

10. The preparation process of the novel lightweight thermal insulation powder material according to claim 8, characterized in that, In step S1, the alkali solution is sodium hydroxide solution.

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