Geopolymer gelling stone based on industrial solid waste and preparation method of geopolymer gelling stone

Abstract

The invention relates to the technical field of building materials, discloses geopolymer gel stone based on industrial solid waste and a preparation method of the geopolymer gel stone, and aims to solve the problem that a complete scheme of'industrial solid waste main base material, pressurization kettle equipment adaptation and subcritical state industrial production 'is not formed in the prior art. According to the invention, 30-50 parts of fly ash, 20-30 parts of mineral powder, 10-20 parts of red mud and 5-15 parts of desulfurized gypsum are used as main base materials, an alkali activator, water and a modifier are matched, a reused or newly-built pressurization kettle is used as reaction equipment, and the production process comprises the following steps: 1) mixing and stirring to prepare slurry; (2) a mold frame is poured in; 3) performing wet curing at 50-60 DEG C for initial setting and demolding; 4) subcritical reaction in a pressurizing kettle; and 5) obtaining a finished product. According to the method, the industrial solid waste is efficiently consumed, the reused or newly-built pressurizing kettle serves as core reaction equipment, the extremely simple and efficient industrial production process is constructed, large-scale resource utilization of the industrial solid waste is achieved, the limitation that traditional stone cannot be produced in batches is broken through, and industrial mass production of geopolymer gelling stone is achieved.

Description

Technical Field

[0001] This invention relates to the field of building materials technology, and specifically to a method for preparing geopolymer aggregates from industrial solid waste under subcritical conditions. Background Technology

[0002] With the large-scale development of industry, the discharge of industrial solid wastes such as fly ash, desulfurized gypsum, mineral powder, and red mud has been increasing year by year. The stockpiling of these wastes occupies a large amount of land and causes ecological pollution, making the resource utilization of solid waste an urgent matter. Geopolymers, as a new type of cementitious material, have advantages such as high strength and low carbon emissions, but traditional preparation methods suffer from drawbacks such as mold dependence, long reaction cycles, and difficulty in scaling up. Meanwhile, traditional stone materials mostly rely on natural mining or complex processing, resulting in problems such as high resource consumption, low production efficiency, and inability to be mass-produced.

[0003] Meanwhile, the existing pressurized reactors and supporting facilities in industries such as aerated concrete blocks have parameters that are highly compatible with the requirements of subcritical reactions and can be directly reused. New pressurized reactors can also be quickly adapted to process requirements. Furthermore, geopolymer systems based on fly ash, desulfurized gypsum, mineral powder, and red mud possess abundant silicon-aluminum resources and high reactivity potential, making them an excellent choice for solid waste resource utilization. Currently, there is an urgent demand in many fields for high-performance, environmentally friendly, and scalable stone-like materials, but existing technologies have not yet formed a complete solution of "industrial solid waste as the main substrate + pressurized reactor equipment adaptation + subcritical state industrial production". Summary of the Invention

[0004] To address the aforementioned technical shortcomings, the present invention aims to provide a geological polymer granule based on industrial solid waste and its preparation method. The granule uses fly ash, desulfurized gypsum, mineral powder, and red mud as the main base materials, efficiently disposes of industrial solid waste, and uses a reused or newly built pressurized kettle as the core reaction equipment. Through subcritical state enhanced reaction, the industrial mass production of geological polymer granule is achieved.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] The geological polymer aggregate based on industrial solid waste, by weight, comprises the following raw materials: 30-50 parts fly ash, 20-30 parts mineral powder, 10-20 parts red mud, 5-15 parts desulfurized gypsum, 13-25 parts alkali activator, 20-30 parts water, and 3.3-9 parts modifier. The alkali activator comprises 5-10 parts sodium hydroxide and 8-15 parts water glass with a modulus of 2.0-2.8. The modifier comprises 0.3-1.0 parts sodium tripolyphosphate and 3-8 parts metakaolin.

[0007] This invention also relates to a method for preparing the above-mentioned geopolymer slurry, comprising the following steps:

[0008] S1. Mixing and stirring: Mix the main base materials such as fly ash, desulfurized gypsum, mineral powder, and red mud with the powder raw materials such as alkali activator and modifier evenly, add the formula amount of water, and stir to make a uniform polymer slurry.

[0009] S2. Pouring into the mold frame: Pour the slurry directly into the mold frame to complete the initial molding;

[0010] S3. High-temperature wet curing and initial setting: The molded slurry is placed in a curing environment of 50-60℃ and humidity ≥80% for static curing. After initial setting, it is demolded to obtain a stable green body.

[0011] S4. Subcritical reaction: The demolded green body is sent into a reused or newly built pressurized kettle, and the subcritical parameters are set: temperature 120-280℃, pressure 0.3-15MPa, and the reaction is carried out under heat and pressure for 2-6 hours.

[0012] S5. Finished product: After the reaction is completed, the product is cooled and depressurized naturally without additional curing, and the finished geological polymer stone is obtained directly.

[0013] The beneficial effects of this invention are as follows: 1. High efficiency in solid waste resource utilization: With fly ash, desulfurization gypsum, mineral powder and red mud as the main base materials, the total proportion of industrial solid waste is relatively high, realizing large-scale disposal of industrial solid waste and alleviating environmental pressure.

[0014] 2. Flexible equipment utilization: Existing pressure vessels can be directly reused (low modification costs) or new dedicated pressure vessels can be built to meet the production capacity needs of different enterprises and reduce investment costs.

[0015] 3. Subcritical process as the core: The subcritical state significantly shortens the reaction cycle, improves production efficiency, and enhances product performance, ensuring that the strength is stable at the C40-C60 level.

[0016] 4. Industrialization of traditional stone processing: Breaking the limitations of natural stone mining and traditional stone processing, achieving batch and standardized production, and improving production efficiency compared to traditional processes.

[0017] 5. Green, low-carbon and environmentally friendly: No high-temperature calcination is required, resulting in lower carbon emissions compared to traditional cement and natural stone processing.

[0018] 6. Diverse application scenarios: The product is highly resistant to water and corrosion, making it suitable for high-end building materials, agricultural water conservancy facilities, new rural construction and daily construction projects, with outstanding application value. Detailed Implementation

[0019] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0020] Example 1

[0021] Geopolymer aggregate based on industrial solid waste, raw material composition and mass ratio: core industrial solid waste base material (total proportion ≥80%): fly ash 30-50 parts, mineral powder 20-30 parts, red mud 10-20 parts, desulfurized gypsum 5-15 parts (the above are the main base materials, which constitute the core skeleton of the geopolymer).

[0022] Alkali activator: 5-10 parts sodium hydroxide, 8-15 parts water glass (modulus 2.0-2.8); water: 20-30 parts of the total mass of raw materials; modifier: 0.3-1.0 parts sodium tripolyphosphate, 3-8 parts metakaolin.

[0023] The preparation method of the geopolymer slab in this embodiment includes the following steps:

[0024] (1) Mixing and stirring: Mix the main substrate (fly ash, desulfurized gypsum, mineral powder, red mud) with the powder raw materials such as alkali activator and modifier evenly, add the formula amount of water, and stir to make a uniform polymer slurry.

[0025] (2) Pouring into the mold frame: The slurry is poured directly into the mold frame to complete the initial molding. The mold frame can be customized to meet the mass production of different sizes of stone.

[0026] (3) High temperature wet curing and initial setting: The molded slurry is placed in a curing environment of 50-60℃ and humidity ≥80% for static curing. After initial setting, it is demolded to obtain a stable green body.

[0027] (4) Subcritical reaction: The demolded blank is sent into a reused or newly built pressurized kettle, and the subcritical parameters are set: temperature 120-280℃, pressure 0.3-15MPa, and the reaction is carried out for 2-6 hours (core process).

[0028] (5) Finished product: After the reaction is completed, the product is cooled and depressurized naturally without additional maintenance, and the finished product of geological polymer solidified stone is obtained directly. Its compressive strength reaches the C40~C60 level (40MPa~60MPa), realizing industrial mass production.

[0029] The main base material of this invention accounts for ≥80%, the 28-day compressive strength reaches the C40~C60 level (40MPa~60MPa), and the water resistance coefficient is ≥0.9. It can realize the industrial mass production of traditional stone materials and is suitable for high-end building materials, agricultural water conservancy facilities and other fields.

[0030] This invention uses fly ash, desulfurized gypsum, mineral powder, and red mud as core materials. Fly ash provides a silica-alumina skeleton, mineral powder enhances density, red mud supplements aluminum components, and desulfurized gypsum regulates setting time, fully leveraging the potential of industrial solid waste resources. Furthermore, it is compatible with existing pressurized reactors used in the aerated concrete block industry (requiring only parameter adjustments) and new pressurized reactors, exhibiting strong equipment adaptability and lowering the industrialization threshold. The subcritical environment within the pressurized reactor accelerates the breaking of Si-O and Al-O bonds in the solid waste material, promoting rapid dissolution and reconstruction of active components, ensuring high strength and stability of the product. The simplified preparation process of this invention is suitable for mass production, the mold frame is reusable, and combined with continuous operation in the pressurized reactor, it enables standardized and large-scale production of traditional stone materials.

[0031] This invention focuses on three core aspects: "industrial solid waste as the main substrate + compatibility with pressurized reactor equipment + subcritical state industrial production." Using fly ash, desulfurized gypsum, mineral powder, and red mud as the main substrates, it is compatible with both existing pressurized reactors for reuse and new applications. By leveraging subcritical state to enhance the reaction, it constructs a simplified and efficient industrial production process. This achieves large-scale resource utilization of industrial solid waste and breaks through the limitations of traditional stone production, which cannot be mass-produced. The product strength is consistently at C40-C60 levels, combining green environmental protection, cost advantages, and wide application scenarios. Technically, this invention fills a gap in existing solutions; industrially, it provides a new path for the transformation and upgrading of the building materials industry, possessing significant economic and environmental value and industry-breaking significance, with broad market prospects.

[0032] Application Example 1:

[0033] 1. Proportion of raw materials for geopolymer aggregate (parts by weight): 35 parts fly ash, 25 parts mineral powder, 15 parts red mud, 10 parts desulfurized gypsum, 7 parts sodium hydroxide, 12 parts water glass (modulus 2.5), 25 parts water, 0.5 parts sodium tripolyphosphate, and 5 parts metakaolin.

[0034] 2. Production process:

[0035] (1) The main substrate is mixed evenly with other powders, and water is added and stirred to form a slurry;

[0036] (2) Pour into a 300mm×300mm×100mm mold frame, let it stand in an environment of 55℃ and 85% humidity for initial setting, and then demold.

[0037] (3) The green body is fed into the pressurized kettle of the reuse aerated brick production line, at a temperature of 180℃ and a pressure of 5MPa, and reacted for 4 hours.

[0038] (4) The finished product has a 28-day compressive strength of 48MPa (C48), enabling mass production of this specification of stone and making it suitable for ground paving projects.

[0039] Application Example 2:

[0040] 1. Proportion of raw materials for geopolymer slab (parts by weight): 45 parts fly ash, 20 parts mineral powder, 10 parts red mud, 8 parts desulfurized gypsum, 9 parts sodium hydroxide, 10 parts water glass (modulus 2.2), 22 parts water, 0.8 parts sodium tripolyphosphate, and 4 parts metakaolin.

[0041] 2. Production process:

[0042] (1) After mixing the main base materials, add water and stir to form a slurry, then pour it into a 500mm×250mm×150mm mold frame;

[0043] (2) Demold after initial setting in an environment of 60℃ and 82% humidity;

[0044] (3) The billet is sent into a newly built special pressure vessel, at a temperature of 220℃ and a pressure of 8MPa, and reacted for 3 hours;

[0045] (4) The finished product has a 28-day compressive strength of 55MPa (C55), which is suitable for agricultural water conservancy channel lining projects and has a stable supply on a large scale.

[0046] Application Example 3:

[0047] 1. Proportion of raw materials for geopolymer aggregate (parts by weight): 30 parts fly ash, 30 parts mineral powder, 20 parts red mud, 15 parts desulfurized gypsum, 5 parts sodium hydroxide, 15 parts water glass (modulus 2.8), 30 parts water, 1.0 part sodium tripolyphosphate, and 8 parts metakaolin.

[0048] 2. Production process:

[0049] (1) Mix the main base material (85% of the total) with water to form a slurry, and pour it into a 200mm×200mm×200mm mold frame;

[0050] (2) Demold after initial setting in an environment of 50℃ and 88% humidity;

[0051] (3) The billet is sent into a reusable pressure reactor at a temperature of 120℃ and a pressure of 0.3MPa for 6 hours;

[0052] (4) The finished product has a 28-day compressive strength of 42MPa (C42), which is suitable for wall construction in new rural areas and has significantly improved mass production efficiency.

[0053] Application Example 4:

[0054] 1. Proportion of raw materials for geopolymer aggregate (parts by weight): 40 parts fly ash, 28 parts mineral powder, 13 parts red mud, 9 parts desulfurized gypsum, 6 parts sodium hydroxide, 13 parts water glass (modulus 2.6), 24 parts water, 0.7 parts sodium tripolyphosphate, and 7 parts metakaolin.

[0055] 2. Production process:

[0056] (1) Mix the main base materials with water and stir to form a slurry, then pour it into a 600mm×300mm×200mm mold frame;

[0057] (2) Demolding after initial setting in an environment of 56℃ and 86% humidity;

[0058] (3) The billet is sent into the newly built pressure vessel, the temperature is 200℃ and the pressure is 6MPa, and the reaction is carried out for 3.5h;

[0059] (4) The finished product has a 28-day compressive strength of 58MPa (C58) and a texture close to that of natural stone, making it suitable for large-scale production of high-end building material decorative panels.

[0060] Effect verification

[0061] 1. Facility adaptability: When reusing existing pressure vessels, the equipment modification cost is only 30% of that of a new line, and stable mass production can be achieved within 30 days after modification; the commissioning cycle of a new pressure vessel production line is ≤3 months, and production capacity can be quickly formed.

[0062] 2. Capacity and Cost: The annual capacity of a single production line is 150,000-300,000 tons. The cost of the main base material (industrial solid waste) is low, and the overall production cost is 45% lower than that of natural stone processing, making it highly competitive in the market.

[0063] 3. Environmental protection and solid waste disposal: Continuous production for one year can dispose of 180,000 to 360,000 tons of industrial solid waste, with a solid waste utilization rate of 100% and carbon emissions reduced by more than 60% compared to traditional processes;

[0064] 4. Strength stability: The 28-day compressive strength fluctuation of 10 batches of continuously produced samples is ≤±3MPa, and all are stable in the C40~C60 range, meeting the quality consistency requirements of industrial mass production.

[0065] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A geopolymer aggregate based on industrial solid waste, characterized in that, By weight, the raw material composition includes: 30-50 parts fly ash, 20-30 parts mineral powder, 10-20 parts red mud, 5-15 parts desulfurized gypsum, 13-25 parts alkali activator, 20-30 parts water, and 3.3-9 parts modifier.

2. The geopolymer slurry according to claim 1, characterized in that, The raw material composition of the alkali activator includes: 5-10 parts of sodium hydroxide and 8-15 parts of water glass with a modulus of 2.0-2.8; the raw material composition of the modifier includes: 0.3-1.0 parts of sodium tripolyphosphate and 3-8 parts of metakaolin.

3. A method for preparing geopolymer slurry as described in any one of claims 1-2, comprising the following steps: S1. Mixing and stirring: Mix the main base materials such as fly ash, desulfurized gypsum, mineral powder, and red mud with the powder raw materials such as alkali activator and modifier evenly, add the formula amount of water, and stir to make a uniform polymer slurry. S2. Pouring into the mold frame: Pour the slurry directly into the mold frame to complete the initial molding; S3. High-temperature wet curing and initial setting: The molded slurry is placed in a curing environment of 50-60℃ and humidity ≥80% for static curing. After initial setting, it is demolded to obtain a stable green body. S4. Subcritical reaction: The demolded green body is sent into a reused or newly built pressurized kettle, and the subcritical parameters are set: temperature 120-280℃, pressure 0.3-15MPa, and the reaction is carried out under heat and pressure for 2-6 hours. S5. Finished product: After the reaction is completed, the product is cooled and depressurized naturally without additional curing, and the finished geological polymer stone is obtained directly.