Preparation method of aerated concrete for waste photovoltaic-vanadium titanium slag-lithium slag based wall material

Abstract

The invention relates to the technical field of waste recovery and comprehensive utilization, in particular to a preparation method of aerated concrete for a waste photovoltaic-vanadium titanium slag-lithium slag based wall material. The lithium tailings, the carbide slag, the papermaking causticized white mud, the waste photovoltaic panel, the coal gangue, the coal slime, the slag, the vanadium-titanium slag, the ardealite, the lithium slag and the inactivated ZSM-5 are used for replacing raw materials for traditional autoclaved aerated concrete production, and through specific crystal phase structure design and regulation, the low-carbon powder prepared from a high-temperature calcined product has the advantages that the production efficiency is improved, and the production cost is reduced. The ceramsite aerated concrete green body has higher physical and mechanical properties in a short time, the physical and mechanical properties are obviously superior to those of the existing similar ordinary Portland cement clinker, the paraffin solution is adopted for surface treatment in the ceramsite preparation process, and the problem of large slurry demand when the ceramsite is used for aerated concrete production is solved. The preparation method provided by the invention solves the problems of high water absorption rate, poor impermeability, incapability of hanging, short fire endurance and the like of the traditional aerated concrete.

Description

Technical Field

[0001] This invention relates to the field of waste recycling and comprehensive utilization technology, and in particular to a method for preparing aerated concrete for waste photovoltaic-vanadium-titanium slag-lithium slag-based wall materials. Background Technology

[0002] To effectively reduce the raw material cost of autoclaved aerated concrete (AAC), solid waste is currently being used as a raw material. This achieves resource utilization of solid waste and reduces the production cost of AAC. Researchers are currently using steel slag, iron tailings, phosphogypsum, coal gangue, rice husk ash, ZSM-5 zeolite, and air-cooled slag as raw materials for AAC production. Although ordinary AAC has readily available raw materials, a simple manufacturing process, and low cost, it suffers from low compressive strength, moisture absorption, easy surface peeling, and inability to be hung, limiting its use to interior walls rather than exterior walls.

[0003] To address the aforementioned shortcomings, some manufacturers add ceramsite to aerated concrete. Adding lightweight ceramsite to aerated concrete not only strengthens the concrete's skeletal structure but also effectively maintains the advantages of aerated concrete, overcoming its common quality defects and fully utilizing its thermal insulation properties. This makes it a new type of high-efficiency wall material for self-insulating exterior wall cladding, destined for widespread application. The general method involves mixing ceramsite with other components (cement, lime, gypsum, foaming agent, water, etc.) to form a slurry, followed by processes such as foaming, static curing, and maintenance to produce ceramsite aerated concrete products. However, because ceramsite is a hollow, lightweight aggregate, it tends to float during mixing due to the high specific gravity of the slurry, resulting in uneven distribution and product defects. Furthermore, the low strength of ceramsite aggregate makes it prone to breakage during mixing, increasing its water absorption and reducing the product's thermal insulation performance. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide a method for preparing aerated concrete for waste photovoltaic-vanadium-titanium slag-lithium slag-based wall materials, so as to at least solve the problems of high water absorption, poor impermeability, and high energy consumption in the preparation of existing aerated concrete.

[0005] In a first aspect, embodiments of the present invention provide a method for preparing aerated concrete for use as a wall material based on waste photovoltaic-vanadium-titanium slag-lithium slag, comprising the following steps: Preparation of various powders: Lithium tailings are pretreated to obtain powder 1; calcium carbide slag and papermaking causticizing mud are mixed and pretreated to obtain powder 2. Powder 2 will be used as a raw material for the subsequent preparation of low-carbon powder 4 and non-fired ceramsite, and will also be used as a raw material for the subsequent preparation of mixed slurry; vanadium-titanium ore slag and ore slag are mixed and pretreated to obtain powder 3. Powder 3 will also be used as a raw material for the subsequent preparation of low-carbon powder 4 and non-fired ceramsite; waste photovoltaic panels are pretreated to obtain powder 41. After pretreatment of coal gangue and coal slime, powder 42 is obtained; powder 1, powder 2, powder 41, powder 42 and powder 3 are mixed in a mass ratio of (10~15):(60~77):(5~10):(3~5):(5~10) to obtain low-carbon powder 4; after pretreatment of phosphogypsum and lithium slag, powder 5 is prepared; after pretreatment of deactivated ZSM-5, powder 6 is prepared; powder 1 and powder 6 are mixed in a mass ratio of (1~3):1 to obtain powder 7.

[0006] Preparation of non-fired ceramsite: Take powder 2, powder 3, low-carbon powder 4, powder 5 and fast-dissolving sodium silicate in a mass ratio of (10~16):(60~77):(7~12):(4~8):(2~4) and mix for 60~120s to obtain a mixed dry material; add 16~20% of the total mass of the mixed dry material to the mixed dry material and stir to mix evenly. After standing for 3~5h to digest, grind with a stirring wheel for 120~180s, pour into a pelletizing pan to form spheres, cover the surface of the spheres with a thin film to keep them moist, and place them in an environment of 20±5℃ for natural curing for 22~26h. Then place them in an environment of 55~65℃ and 85~95% humidity for curing for 3~5 days. Then, place them in an environment of 20±5℃ for natural curing for 2~4 days, dry to constant weight, soak in an 8~10% mass fraction liquid paraffin solution for 30~50min, and dry to constant weight to obtain non-fired ceramsite.

[0007] In the preparation of non-fired ceramsite, on the one hand, a method of two-stage water addition and mixing followed by one-stage mixing and grinding is adopted to ensure the uniformity of the materials. The mixed dry materials are left to stand for 3-5 hours to allow the calcareous materials to fully digest, ensuring that internal stress will not be generated after pelletizing due to continued digestion of the calcareous materials, thus affecting the strength of the ceramsite. A curing system using room temperature natural curing and steam curing is adopted, resulting in lower energy consumption. Compared with the currently commonly used sintered and autoclaved ceramsite, this method saves a significant amount of energy. Furthermore, the prepared ceramsite has a low shrinkage rate and can bond tightly to the interface of concrete or autoclaved concrete.

[0008] Casting: Take powder 7, powder 2, low carbon powder 4 and powder 5 and mix them in a mass ratio of (55~70):(15~23):(9~12):(6~10) to obtain a mixed dry powder; take 53~65% of the total mass of the mixed dry powder and 50~55℃ warm water as the total water for casting. Add 50~55℃ warm water to the mixed dry powder and stir to mix evenly. Then add 35~40% of the total mass of the mixed dry powder and non-fired ceramic particles and mix evenly. Then add 50~55℃ warm water, 0.5~0.7‰ of the total mass of the mixed dry powder and 5~11‰ of the total water mass of the foam stabilizer, stir to mix evenly, and pour the resulting slurry into the mold. Vibrate the mold for 60~120s.

[0009] Concrete curing: The mixture slurry poured into the mold is subjected to aeration, static curing, pre-curing, green body cutting and high-temperature autoclaving to obtain ceramsite aerated concrete.

[0010] Secondly, embodiments of the present invention also provide aerated concrete, which is prepared using the preparation method described in the first aspect above.

[0011] The aerated concrete of this invention uses industrial solid waste to replace the raw materials used in the traditional autoclaved aerated concrete production—sand or fly ash, cement, lime, and gypsum. Specifically, it utilizes low-carbon powder prepared from steel industry solid waste (vanadium-titanium slag and slag), power industry solid waste (waste photovoltaic panels), coal-based solid waste (coal gangue and coal slime), non-ferrous metallurgical solid waste (lithium tailings), and chemical solid waste (carbide slag and papermaking causticizing mud). This powder combines the mineral composition and content characteristics of green low-carbon cement clinker to achieve a replacement for silicate cement clinker. The low-carbon powder has a significant carbon reduction effect. Its firing process incorporates coal gangue and coal slime containing a large amount of carbonaceous material, allowing the firing temperature to be lowered by more than 100°C compared to silicate cement clinker, reducing energy consumption by more than 10%. Simultaneously, the calcination process uses all solid waste raw materials, without using limestone, reducing CO2 emissions by more than 20%, significantly reducing enterprise production costs.

[0012] This invention, through specific crystalline phase structure design and control, enables the application of low-carbon powder made from high-temperature calcination products in the production of expanded clay aerated concrete (ECC). This allows the ECC green body to achieve higher physical and mechanical properties in a short time, ensuring the smooth formation of the EC green body. Its performance is significantly superior to existing ordinary silicate cement clinker. Simultaneously, the low-carbon powder of this invention also exhibits significantly lower alkali content (alkali content <0.50%, lower than GB / T 21372-2024 ≤0.60%), higher strength (3-day compressive strength ≥29.9 MPa, 28-day compressive strength ≥53.9 MPa, significantly higher than the 3-day compressive strength ≥22.0 MPa, 28-day compressive strength ≥42.5 MPa of PˑO42.5 ordinary silicate cement clinker in GB / T 21372-2024), and lower chloride ion content (≤0.05%, lower than GB / T 21372-2024). The excellent properties of low-heat cement clinker (≤0.06% chloride ion content and ≤206kJ / kg and ≤228kJ / kg hydration heat in 3 days, significantly lower than those in GB / T 21372-2024) are evident in its low-heat clinker. This allows for shorter construction cycles and is of great significance for road and bridge repair, building decoration, emergency construction and repair of municipal engineering projects, as well as for use as a material and wartime emergency reserve technology.

[0013] This invention, in the process of preparing high-temperature calcined products using calcareous materials (carbide slag and causticizing mud for papermaking), siliceous materials (lithium tailings, waste photovoltaic panels), and ferroaluminous materials (slag, vanadium-titanium slag, coal gangue, coal slime) as raw materials, achieves this by rationally controlling the particle size (specific surface area of ​​400~500 μm²). 2 The optimal combination of four conditions—calcination conditions (pressed into cakes to ensure uniform heating of the calcined product), calcination temperature (1150~1250℃), and holding time (30~40min)—allows for the calcined product to form a specific crystal phase structure (C2S, C3S, C3A, and C4AF), resulting in excellent early, middle, and late-stage performance. This allows it to replace silicate cement clinker. This invention enables targeted and stable control of the composition and content ratio of each mineral in the calcined product (C3S content ≥ 62.0%, C2S content ≥ 14.0%, C3A content ≥ 3.1%, C4AF content ≥ 9.9%). f (CaO content ≤ 1.5%), its performance is excellent and can reach and exceed that of existing silicate cement clinker.

[0014] In the preparation method of aerated concrete of the present invention, the deactivated siliceous raw material ZSM-5 meets the requirements of JC / T 622-2009 "Sand for Silicate Building Products", replacing the traditional requirement of river sand and fly ash in aerated concrete production, which can solve the problem of raw material shortage in aerated concrete production in some areas; the calcareous raw material prepared by using carbide slag and papermaking causticized white mud meets the technical requirements of "Quicklime for Silicate Building Products" (JC / T 621-2021), and its firing temperature reduces energy consumption by more than 10% compared with the preparation of quicklime.

[0015] The aerated concrete of this invention solves the problems of high water absorption, poor impermeability, inability to be hung, and short fire resistance limit of traditional aerated concrete. In the process of preparing ceramsite, a paraffin solution is used for surface treatment, which solves the problem of large slurry volume required for ceramsite in aerated concrete production. The use of a vibrating table to drive the mold of the poured ceramsite aerated concrete slurry can improve the uniformity of the distribution of ceramsite aggregate in the solidified slurry and ensure the overall performance of aerated concrete. The performance indicators of the prepared ceramsite are superior to the requirements of lightweight coarse aggregate density grade 700 in GB / T17431.1-2010 "Lightweight Aggregates and Their Test Methods Part 1: Lightweight Aggregates" in terms of compressive strength (≥13.69MPa, exceeding the standard requirement of ≥5.0MPa), absolute drying shrinkage (≤0.92mm / m, exceeding the standard requirement of ≤1.20 mm / m), softening coefficient (≥1.0, exceeding the standard requirement of ≥0.8), and boiling mass loss (≤4.6%, exceeding the standard requirement of ≤5.0). The performance indicators of the prepared ceramsite aerated concrete are also superior to the requirements of GB / T17431.1-2010 "Lightweight Aggregates and Their Test Methods Part 1: Lightweight Aggregates" in terms of compressive strength (≥4.7MPa, far exceeding the standard requirement of ≥3.5MPa) and dry density (≤602kg / m³). 3 Superior grade products meeting the standard have a weight of ≤625 kg / m³. 3 ), frost resistance (post-freezing strength ≥4.3MPa, meeting the standard requirements for superior grade), water absorption (≤36%, better than the standard requirement ≤40%), average pull-out force (≥2.8kN, far exceeding the standard requirement ≥2.5kN), single-point suspension force (≥941N, far exceeding the standard ≥900N), thermal conductivity [W / (m·K)] (≤0.15, better than the standard requirement ≤0.16), heat storage coefficient ... 2 In terms of strength grade CA3.5 products, the fire resistance limit of 120mm thick walls (≥2.76, which is better than the standard requirement of ≥2.60) and fire resistance limit of 120mm thick walls (≥4.4h, which is much higher than the standard requirement of ≥4h) is better than the requirements of CA3.5 products in JG / T 504-2016 "Aerated Concrete Blocks with Ceramsite". Attached Figure Description

[0016] Figure 1 These are the X-ray diffraction patterns of the non-fired ceramsite after 1 day, 3 days, and 7 days of curing in Example 2; Figure 2 These are SEM images of the non-fired ceramsite curing process in Example 2 at 1 day, 3 days, and 7 days. Figure 3 This is a SEM image of the non-fired ceramsite from Example 2, which was first steam-cured and then naturally cured. Figure 4 yes Figure 3 EDS plots of points Q, W, and E in the middle; Figure 5 The images show the FT-IR infrared spectra of the non-fired ceramsite hydrated at 1d, 3d, and 7d in Example 2. Detailed Implementation

[0017] The following embodiments are provided to better understand the present invention and are not limited to the preferred embodiments described. They do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the protection scope of the present invention.

[0018] To improve the material properties of the wall, this application utilizes various industrial solid wastes (lithium tailings, carbide slag, papermaking causticizing mud, waste photovoltaic panels, coal gangue, coal slime, slag, vanadium-titanium slag, phosphogypsum, lithium slag, and deactivated ZSM-5) as raw materials to synergistically prepare composite thermal insulation wall material ceramsite aerated concrete, replacing traditional clay sintered bricks, cement-free bricks, and other wall materials. As a wall material for industrial and civil buildings, it not only fully recycles and utilizes industrial solid waste, increasing its recycling value, but also solves the problem of raw material shortage in traditional aerated concrete production, effectively reducing the production cost of aerated concrete.

[0019] Example 1

[0020] The preparation method of expanded clay aerated concrete in this embodiment is as follows: S1. Preparation of powder 1: First, the lithium tailings are sieved using a vibrating screen to remove impurities (such as branches, weeds, etc.) and organic matter. The sieved lithium tailings are then dried in a 105℃ electric heating blast drying oven until constant weight, and then placed in a cement ball mill and ground at a speed of 48 r / min until a specific surface area of ​​350 m² is obtained. 2 / kg, yielding powder 1. The technical specifications of powder 1 obtained in step S1 of this embodiment are shown in Table 1: Table 1: Technical specifications of powder 1 prepared in step S1 of Example 1

[0021] * in Table 1 represents the technical specifications of JC / T 622-2009, "Sand for Silicate Building Products".

[0022] S2. Preparation of Powder 2: First, place the carbide slag and papermaking causticized white mud in a 105℃ electric heating blast drying oven and dry them to constant weight. Then, mix the dried carbide slag and papermaking causticized white mud at a mass ratio of 1:1 until homogeneous. Next, place the mixed material into a cement mortar mixer, set the mixer to rotate at 140±5 r / min and revolve at 62±5 r / min, and mix at low speed for 70s. Then, add water equal to 8% of the total mass of the dry powders of carbide slag and papermaking causticized white mud, and set the cement mortar mixer to rotate at 285±10 r / min and revolve at 125±10 r / min, and mix at high speed for 140s. After homogeneous mixing, transfer the resulting mixture to a mold and apply pressure of 18... The mixture was pressed into cakes 1 cm thick and 6 cm in diameter. These cakes were then placed in an electric hot-air drying oven and dried at 100°C for 18 minutes. The dried cakes were then placed in a covered corundum crucible, which was placed in a muffle furnace. The temperature was first increased from room temperature to 200°C at a rate of 4°C / min, then held at 200°C for 20 minutes. Next, the temperature was increased from 200°C to the desired 700°C at a rate of 10°C / min, and held for 30 minutes to complete the high-temperature calcination. The material was then rapidly cooled using airflow. Finally, the cooled material was ground in a cement ball mill to a specific surface area of ​​400 m². 2 / kg, yielding powder 2. The technical specifications of powder 2 prepared in step S2 of this embodiment are shown in Table 2.

[0023] Table 2: Physicochemical properties of powder 2 prepared in step S2 of Example 1

[0024] * in Table 2 represents the technical specifications of JC / T 621-2021 "Quicklime for Silicate Building Products".

[0025] S3. Preparation of powder 41: First, remove the adhering materials (aluminum frame and rubber strips, etc.) from the surface of the waste photovoltaic panels. Then, use high-pressure water to remove impurities and dust adsorbed on the surface of the photovoltaic panels. After natural drying, set the feed particle size of the hammer crusher to ≤450mm and the discharge particle size to ≤25mm. Use the hammer crusher to crush the dried waste photovoltaic panels into pieces ≤25mm. Then, put the pieces into a cement ball mill and grind them at a speed of 48 r / min until the specific surface area is 260m². 2 / kg, yielding 41g of powder.

[0026] S4. Prepare powder 42. Screen out particles 4 with a particle size > 2 mm and particles 5 with a particle size ≤ 2 mm from the coal gangue. Put particles 4 into a jaw crusher. Set the feed particle size of the jaw crusher to ≤ 250 mm and the discharge particle size to ≤ 2 mm. Crush particles 4 to particles with a particle size ≤ 2 mm to obtain particles 6. Mix particles 5 and particles 6 and place them in an electric heating blast drying oven. Dry them at 105℃ to constant weight to obtain coal gangue powder. Place coal slime in an electric heating blast drying oven and dry it at 105℃ to constant weight to obtain coal slime powder. Add coal gangue powder and coal slime powder to a planetary ball mill at a mass ratio of 1:1. Set the speed to 200 r / min and ball mill for 15 min to obtain powder 42 with a particle size ≤ 2 mm.

[0027] S5. Prepare powder 3. Screen out particles 11 with a particle size ≤2mm and particles 12 with a particle size >2mm from the vanadium-titanium ore slag. Screen out particles 21 with a particle size ≤2mm and particles 22 with a particle size >2mm from the slag. Put particles 12 and 22 into a jaw crusher. Set the feed particle size of the jaw crusher to ≤250mm and the discharge particle size to ≤2mm. Crush particles 12 and 22 into particles with a particle size ≤2mm, respectively, to obtain particles 13 and 14. Mix particles 11 and 13 and place them in an electric heating forced-air drying oven. Dry them at 105℃ to constant weight to obtain particle 1. Mix particles 21 and 23 and place them in an electric heating forced-air drying oven. Dry them at 105℃ to constant weight to obtain particle 2. Mix the dried particles 1 and 2 at a mass ratio of 4:1 and put them into a cement ball mill. Grind them at a speed of 48 r / min to a specific surface area of ​​400m². 2 / kg, yielding 3g of powder.

[0028] S6. Prepare powder 4 by mixing powder 1, powder 2, powder 41, powder 42 and powder 3 in a weight percentage of 13%:65%:8%:5%:9%, then placing them into a cement ball mill and grinding them at a speed of 48 r / min until the specific surface area is 400 m². 2 / kg, then put the ground material into a cement mortar mixer, set the cement mortar mixer to rotate at 140±5 r / min and revolve at 62±5 r / min, and mix at low speed for 80s to obtain a mixture. Then add water accounting for 8% of the total mass of the mixture, set the cement mortar mixer to rotate at 285±10 r / min and revolve at 125±10 r / min, and mix at high speed for 130s. After mixing evenly, put the mixture into a mold, and apply pressure of 18 MPa through a hydraulic press to press the mixture into a cake with a thickness of 1cm and a diameter of 6cm. Place the cake in an electric heating blast drying oven and dry at 100℃ for 18min. The dried material cake was placed in a covered corundum crucible, which was then placed in a muffle furnace. The temperature was first increased from room temperature to 300℃ at a rate of 3℃ / min, and then held at 300℃ for 20 minutes. Next, the temperature was increased from 300℃ to the desired temperature of 1150℃ at a rate of 5℃ / min, and held for 30 minutes. After high-temperature calcination, the product was first cooled to 1000℃ with airflow at a rate of 18℃ / min, and then cooled to room temperature at a rate of ≥100℃ / min. The cooled product was then placed in a jaw crusher with a feed size ≤250mm and an output size ≤2mm. The crushed product was then fed into a cement ball mill and ground at 48 r / min until a specific surface area of ​​400 m² was achieved. 2 / kg, yielding 4g of low-carbon powder.

[0029] The chemical composition of the low-carbon powder 4 prepared in step S6 of this embodiment is shown in Table 3, and the activity index is shown in Table 4.

[0030] Table 3: Chemical composition of low-carbon powder 4 in Example 1

[0031] Table 4: Activity Index of Low-Carbon Powder 4 in Example 1

[0032] * in Table 4 refers to the test method of GB / T 17671-2021 "Test Method for Strength of Cement Mortar (ISO Method)".

[0033] S7. Prepare powder 5. Sift phosphogypsum and lithium slag separately using a vibrating screen to remove impurities and organic matter. Then, place them in an electric heating drying oven and dry at 105℃ to constant weight. Next, mix the dried phosphogypsum and lithium slag evenly at a mass ratio of 3:1, and place them in a cement ball mill. Grind at 48 r / min until the specific surface area is 350 m². 2 / kg, yielding 5g of powder.

[0034] The powder 5 prepared in this step meets the technical requirements specified in GB / T 21371-2019 "Industrial By-product Gypsum for Cement". The mixed industrial by-product gypsum contains 79% CaSO4·2H2O and 79% CaSO4 (the specification requires ≥75%), 0.48% chloride ion content (the specification requires ≤0.5%), a pH value of 4.8 (the specification requires ≤5), and radioactive material limits that meet the requirements of GB 6566 (internal exposure index ≤1.0, external exposure index ≤1.0).

[0035] S8. Preparation of powder 6: The deactivated ZSM-5 is screened using a vibrating screen to remove impurities, and then placed in an electric heating drying oven and dried at 105℃ to constant weight. The dried deactivated ZSM-5 powder is then placed in a cement ball mill and ground at 48 r / min until a specific surface area of ​​380 m² is achieved. 2 / kg, yielding 6g of powder.

[0036] S9. Add powders 2, 3, 4, and 5, and readily soluble sodium silicate to a cement mortar mixer in a mass percentage ratio of 14%:66%:10%:7%:3%. Set the cement mortar mixer to rotate at 140±5 r / min and revolve at 62±5 r / min, and mix at low speed for 80 seconds to obtain a dry mixture. Take 17% of the total mass of water from the dry mixture and add it to the dry mixture in two portions. The first portion adds 75% of the total water mass, and the cement mortar mixer is set to rotate at 285±10 r / min and revolve at 125±10 r / min, and mixed at high speed for 110 seconds. The second portion adds 25% of the total water mass, and the cement mortar mixer is set to rotate at 285±10 r / min and revolve at 125±10 r / min, and mixed at high speed for 50 seconds. Let the mixed material stand for 3 hours to allow it to digest. After the digested mixture is milled for 140 seconds by a stirring wheel, it is poured into a pelletizing pan to form spheres. A thin film is covered on the surface of the spheres to keep them moist, and they are naturally cured at 20±5℃ for 22 hours. Then, the temperature is increased to 57℃ at a rate of 5℃ / h, and steam cured at 57℃ and 86% humidity for 4 days. After that, they are naturally cured at 20±5℃ for 3 days. The resulting ceramsite is placed in an electric drying oven and dried at 105℃ to constant weight. Then, it is immersed in a liquid paraffin solution containing 8% by mass for 35 minutes, and then dried at 105℃ to constant weight to obtain non-fired ceramsite.

[0037] S10. Weigh powder 1 and powder 6 according to a mass ratio of 1:1 and mix them evenly to obtain powder 7. Take powder 7, powder 2, low-carbon powder 4 and powder 5 and add them to a mixing tank at a mass percentage of 65%:18%:10%:7% and mix for 40 seconds to obtain a mixed dry powder. Take 55% of the total mass of the mixed dry powder and 50℃ warm water as the total water for pouring. First, add 75% of the total mass of the water for pouring to the mixed dry powder and stir for 110 seconds. Then, add 36% of the total mass of the mixed dry powder and non-fired ceramsite and stir for 50 seconds to mix evenly. Then, add 25% of the total mass of the water for pouring and stir for 110 seconds. Then, add 0.5‰ of the total mass of the mixed dry powder and 5‰ of the total mass of the water for foam stabilizer and stir for 35 seconds to mix evenly. Pour the resulting slurry into the mold, ensuring that the temperature of the slurry entering the mold is 45℃ during pouring. Then, use a vibrating table to drive the mold to vibrate for 70 seconds. The foam stabilizer in this step is prepared from 88wt% distilled water, 8wt% oleic acid, and 4wt% sodium stearoyl lactylate. The aluminum powder has an active Al content ≥92%, a sieve residue of ≤2.5% on a 0.08mm square hole sieve, a gas generation rate ≥81%, a gas generation time ≤24min, and a hydrophilicity ≤20s.

[0038] S11. The slurry mixture poured into the mold is subjected to 3 hours of gas generation, 3 hours of static curing, and 3 hours of pre-curing at 57℃. The green body is then cut and subjected to high-temperature autoclaving to obtain ceramsite aerated concrete. In this step, the high-temperature autoclaving treatment includes three stages: heating and pressurizing, constant temperature and pressure, and cooling and depressurizing. Heating and pressurizing involves heating to 175℃ and pressurizing to a saturated vapor pressure of 1.3MPa over 2 hours; constant temperature and pressure involves curing at 175℃ and a saturated vapor pressure of 1.3MPa for 6 hours; and cooling and depressurizing involves reducing the temperature and pressure to normal for 1 hour.

[0039] Example 2 The preparation method of expanded clay aerated concrete in this embodiment is as follows: S1. Preparation of powder 1: First, the lithium tailings are sieved using a vibrating screen to remove impurities (such as branches, weeds, etc.) and organic matter. The sieved lithium tailings are then dried in a 100℃ electric heating blast drying oven until constant weight, and then placed in a cement ball mill and ground at a speed of 48 r / min until a specific surface area of ​​400 m² is obtained. 2 / kg, yielding powder 1. The technical specifications of powder 1 prepared in step S1 of this embodiment are shown in Table 5: Table 5: Technical Specifications of Powder 1 Prepared in Step S1 of Example 2

[0040] * in Table 5 represents the technical specifications of JC / T 622-2009 "Sand for Silicate Building Products".

[0041] S2. Preparation of Powder 2: First, place the carbide slag and papermaking causticized mud separately in a 100℃ electric heating blast drying oven and dry them to constant weight. Then, mix the dried carbide slag and papermaking causticized mud at a mass ratio of 2:1 until homogeneous. Next, place the mixed material into a cement mortar mixer, set the mixer to rotate at 140±5 r / min and revolve at 62±5 r / min, and mix at low speed for 120s. Then, add water equal to 9% of the total mass of the dry powders of carbide slag and papermaking causticized mud, and set the cement mortar mixer to rotate at 285±10 r / min and revolve at 125±10 r / min, and mix at high speed for 180s. After homogeneous mixing, transfer the resulting mixture to a mold and apply pressure of 25 kJ / min using a hydraulic press. The mixture was pressed into cakes 2 cm thick and 8 cm in diameter. These cakes were then placed in an electric hot-air drying oven and dried at 95°C for 25 minutes. The dried cakes were then placed in a covered corundum crucible, which was then placed in a muffle furnace. The temperature was first increased from room temperature to 200°C at a rate of 4°C / min, and then held at 200°C for 25 minutes. Next, the temperature was increased from 200°C to the desired 750°C at a rate of 10°C / min, and held for 35 minutes to complete the high-temperature calcination. The material was then rapidly cooled using airflow. Finally, the cooled material was ground in a cement ball mill to a specific surface area of ​​450 m². 2 / kg, yielding powder 2. The technical specifications of powder 2 prepared in step S2 of this embodiment are shown in Table 6. In Table 6, * represents the technical specifications of "Quicklime for Silicate Building Products" JC / T 621-2021.

[0042] Table 6: Physicochemical properties of powder 2 prepared in step S2 of Example 2

[0043] S3. Preparation of powder 41: First, remove the adhering materials (aluminum frame and rubber strips, etc.) from the surface of the waste photovoltaic panels. Then, use high-pressure water to remove impurities and dust adsorbed on the surface of the photovoltaic panels. After natural drying, set the feed particle size of the hammer crusher to ≤450mm and the discharge particle size to ≤25mm. Use the hammer crusher to crush the dried waste photovoltaic panels into pieces ≤25mm. Then, put the pieces into a cement ball mill and grind them at a speed of 48 r / min until the specific surface area is 300m². 2 / kg, yielding 41g of powder.

[0044] S4. Prepare powder 42. Screen out particles 4 with a particle size > 2 mm and particles 5 with a particle size ≤ 2 mm from the coal gangue. Put particles 4 into a jaw crusher. Set the feed particle size of the jaw crusher to ≤ 250 mm and the discharge particle size to ≤ 2 mm. Crush particles 4 to particles with a particle size ≤ 2 mm to obtain particles 6. Mix particles 5 and particles 6 and place them in an electric heating blast drying oven. Dry them at 100°C to constant weight to obtain coal gangue powder. Place coal slime in an electric heating blast drying oven and dry it at 100°C to constant weight to obtain coal slime powder. Add coal gangue powder and coal slime powder to a planetary ball mill at a mass ratio of 1:2. Set the speed to 200 r / min and ball mill for 18 min to obtain powder 42 with a particle size ≤ 2 mm.

[0045] S5. Prepare powder 3. Screen out particles 11 with a particle size ≤2mm and particles 12 with a particle size >2mm from the vanadium-titanium slag. Screen out particles 21 with a particle size ≤2mm and particles 22 with a particle size >2mm from the slag. Put particles 12 and 22 into a jaw crusher. Set the feed particle size of the jaw crusher to ≤250mm and the discharge particle size to ≤2mm. Crush particles 12 and 22 into particles with a particle size ≤2mm, respectively, to obtain particles 13 and 14. Mix particles 11 and 13 and place them in an electric heating forced-air drying oven. Dry them at 100℃ to constant weight to obtain particle 1. Mix particles 21 and 23 and place them in an electric heating forced-air drying oven. Dry them at 100℃ to constant weight to obtain particle 2. Mix the dried particles 1 and 2 at a mass ratio of 2:1 and put them into a cement ball mill. Grind them at a speed of 48 r / min to a specific surface area of ​​450m². 2 / kg, yielding 3g of powder.

[0046] S6. Prepare powder 4 by mixing powder 1, powder 2, powder 41, powder 42 and powder 3 in a weight percentage of 10%:72%:7%:3%:7%, then placing them into a cement ball mill and grinding them at a speed of 48 r / min until the specific surface area is 450 m². 2 / kg, then put the ground material into a cement mortar mixer, set the cement mortar mixer to rotate at 140±5 r / min and revolve at 62±5 r / min, and mix at low speed for 120s to obtain a mixture. Then add water accounting for 9% of the total mass of the mixture, set the cement mortar mixer to rotate at 285±10 r / min and revolve at 125±10 r / min, and mix at high speed for 180s. After mixing evenly, put the mixture into a mold, apply pressure of 15Mpa through a hydraulic press, and press the mixture into a cake with a thickness of 2cm and a diameter of 8cm. Place the cake in an electric heating forced-air drying oven and dry at 95℃ for 25min. The dried material cake was placed in a covered corundum crucible, which was then placed in a muffle furnace. The temperature was first increased from room temperature to 300℃ at a rate of 3℃ / min, and then held at 300℃ for 25 minutes. Next, the temperature was increased from 300℃ to the desired temperature of 1200℃ at a rate of 5℃ / min, and held for 35 minutes. After high-temperature calcination, the product was first cooled to 1000℃ with airflow at a rate of 19℃ / min, and then cooled to room temperature at a rate of ≥100℃ / min. The cooled product was then placed in a jaw crusher with a feed size ≤250mm and an output size ≤2mm. The crushed product was then fed into a cement ball mill and ground at 48 r / min until a specific surface area of ​​450 m² was achieved. 2 / kg, yielding low-carbon powder 4. The chemical composition of the low-carbon powder 4 prepared in step S6 of this embodiment is shown in Table 7, and the activity index is shown in Table 8.

[0047] Table 7: Chemical composition of low-carbon powder 4 in Example 2

[0048] Table 8: Activity Index of Low-Carbon Powder 4 in Example 2

[0049] * in Table 8 refers to the test method of GB / T 17671-2021 "Test Method for Strength of Cement Mortar (ISO Method)".

[0050] S7. Prepare powder 5 by sieving phosphogypsum and lithium slag separately using a vibrating screen to remove impurities and organic matter. Then, place them in an electric heating drying oven and dry them at 105℃ to constant weight. Next, mix the dried phosphogypsum and lithium slag evenly at a mass ratio of 2:1 and put them into a cement ball mill, grinding them at a speed of 48 r / min until the specific surface area is 400 m². 2 / kg, yielding 5g of powder.

[0051] S8. Preparation of powder 6: The deactivated ZSM-5 is screened using a vibrating screen to remove impurities, and then placed in an electric heating drying oven and dried at 100℃ to constant weight. The dried deactivated ZSM-5 powder is then placed in a cement ball mill and ground at 48 r / min until a specific surface area of ​​450 m² is achieved. 2 / kg, yielding 6g of powder.

[0052] S9. Add powders 2, 3, 4, and 5, and readily soluble sodium silicate to a cement mortar mixer in a mass percentage ratio of 11%:70%:9%:8%:2%. Mix for 100 seconds, then set the cement mortar mixer to rotate at 140±5 r / min and revolve at 62±5 r / min, and mix at low speed for 120 seconds to obtain a dry mixture. Take 16% of the total mass of water from the dry mixture and add it to the dry mixture in two portions. The first portion adds 75% of the total water mass, and the cement mortar mixer is set to rotate at 285±10 r / min and revolve at 125±10 r / min, and mixed at high speed for 120 seconds. The second portion adds 25% of the total water mass, and the cement mortar mixer is set to rotate at 285±10 r / min and revolve at 125±10 r / min, and mixed at high speed for 60 seconds. Let the mixed material stand for 4 hours to allow it to digest. After the digested mixture is milled for 120 seconds by a stirring wheel, it is poured into a pelletizing pan to form spheres. A thin film is covered on the surface of the spheres to keep them moist, and they are naturally cured at 20±5℃ for 24 hours. Then, the temperature is increased to 65℃ at 5℃ / h, and steam cured at 65℃ and 95% humidity for 3 days. After that, they are naturally cured at 20±5℃ for 3 days. The resulting ceramsite is placed in an electric drying oven and dried at 100℃ to constant weight. Then, it is immersed in a liquid paraffin solution containing 9% by mass for 50 minutes, and then dried at 100℃ to constant weight to obtain non-fired ceramsite.

[0053] S10. Weigh powder 1 and powder 6 according to a mass ratio of 2:1 and mix them evenly to obtain powder 7. Take powder 7, powder 2, low-carbon powder 4 and powder 5 and add them to a mixing tank at a mass percentage of 62%:20%:12%:6% and mix for 50 seconds to obtain a mixed dry powder. Take 53% of the total mass of the mixed dry powder and 52℃ warm water as the total water for pouring. First, add 75% of the total mass of the water for pouring to the mixed dry powder and stir for 120 seconds. Then, add 38% of the total mass of the mixed dry powder and non-fired ceramsite and stir for 50 seconds to mix evenly. Then, add 25% of the total mass of the water for pouring and stir for 120 seconds. Then, add 0.6‰ of the total mass of the mixed dry powder and 8‰ of the total mass of the water for foam stabilizer and stir for 60 seconds to mix evenly. Pour the resulting slurry into the mold, ensuring that the temperature of the slurry entering the mold is 48℃ during pouring. Then, use a vibrating table to drive the mold to vibrate for 60 seconds. The foam stabilizer in this step is prepared from 89.4 wt% distilled water, 7.0 wt% oleic acid, and 3.6 wt% sodium stearoyl lactylate. The aluminum powder has an active Al content ≥92%, a sieve residue of ≤2.5% on a 0.08 mm square hole sieve, a gas generation rate ≥81%, a gas generation time ≤24 min, and a hydrophilicity ≤20 s.

[0054] S11. The slurry mixture poured into the mold is subjected to 4 hours of gas generation, 4 hours of static curing, and 4 hours of pre-curing at 67℃. The green body is then cut and subjected to high-temperature autoclaving to obtain aerated concrete with expanded clay aggregate. In this step, the high-temperature autoclaving treatment includes three stages: heating and pressurizing, constant temperature and pressure, and cooling and depressurizing. Heating and pressurizing involves heating to 185℃ and pressurizing to a saturated vapor pressure of 1.2MPa over 2 hours; constant temperature and pressure involves curing at 185℃ and a saturated vapor pressure of 1.2MPa for 7 hours; and cooling and depressurizing involves reducing the temperature and pressure to normal for 1.5 hours.

[0055] Example 3 The preparation method of expanded clay aerated concrete in this embodiment is as follows: S1. Preparation of powder 1: First, lithium tailings are sieved using a vibrating screen to remove impurities (such as branches, weeds, etc.) and organic matter. The sieved lithium tailings are then dried in a 110℃ electric heating blast drying oven until constant weight, and then placed in a cement ball mill and ground at a speed of 48 r / min until a specific surface area of ​​450 m² is obtained. 2 / kg, yielding powder 1. The technical specifications of powder 1 obtained in step S1 of this embodiment are shown in Table 9: Table 9: Technical Specifications of Powder 1 Prepared in Step S1 of Example 3

[0056] * in Table 9 represents the technical specifications of JC / T 622-2009, "Sand for Silicate Building Products".

[0057] S2. Preparation of Powder 2: First, place the carbide slag and papermaking causticized white mud separately in a 100℃ electric heating blast drying oven and dry them to constant weight. Then, mix the dried carbide slag and papermaking causticized white mud at a mass ratio of 3:1 until homogeneous. Next, place the mixed material into a cement mortar mixer, set the mixer to rotate at 140±5 r / min and revolve at 62±5 r / min, and stir at low speed for 60 seconds. Then, add water equal to 10% of the total mass of the dry carbide slag and papermaking causticized white mud powder, and set the cement mortar mixer to rotate at 285±10 r / min and revolve at 125±10 r / min. Stir at high speed for 120 seconds at r / min; after uniform mixing, transfer the resulting mixture to a mold and press it into a cake with a thickness of 3 cm and a diameter of 5 cm using a hydraulic press with a pressure of 15 MPa. Place the cake in an electric heating drying oven and dry at 105℃ for 15 min; place the dried cake in a covered corundum crucible, and then place the crucible in a muffle furnace. First, heat the mixture from room temperature to 200℃ at a heating rate of 4℃ / min, then hold it at 200℃ for 30 min, then heat it from 200℃ to the required temperature of 800℃ at a heating rate of 10℃ / min, and then hold it for 40 min to complete the high-temperature calcination. Then, rapidly cool the mixture using air power, and then grind the cooled material in a cement ball mill to a specific surface area of ​​500 m². 2 / kg, yielding powder 2. The technical specifications of powder 2 prepared in step S2 of this embodiment are shown in Table 10: Table 10: Physicochemical properties of powder 2 prepared in step S2 of Example 3

[0058] In Table 10, * represents the technical specifications of JC / T 621-2021 "Quicklime for Silicate Building Products".

[0059] S3. Preparation of powder 41: First, remove the adhering materials (aluminum frame and rubber strips, etc.) from the surface of the waste photovoltaic panels. Then, use high-pressure water to remove impurities and dust adsorbed on the surface of the photovoltaic panels. After natural drying, set the feed particle size of the hammer crusher to ≤450mm and the discharge particle size to ≤25mm. Use the hammer crusher to crush the dried waste photovoltaic panels into fragments ≤25mm. Then, put the fragments into a cement ball mill and grind them at a speed of 48 r / min until the specific surface area is 350m². 2 / kg, yielding 41g of powder.

[0060] S4. Prepare powder 42. Screen out particles 4 with a diameter > 2 mm and particles 5 with a diameter ≤ 2 mm from the coal gangue. Put particles 4 into a jaw crusher. Set the feed particle size of the jaw crusher to ≤ 250 mm and the discharge particle size to ≤ 2 mm. Crush particles 4 to particles with a diameter ≤ 2 mm to obtain particles 6. Mix particles 5 and particles 6 and place them in an electric heating blast drying oven. Dry them at 110℃ to constant weight to obtain coal gangue powder. Place coal slime in an electric heating blast drying oven and dry it at 110℃ to constant weight to obtain coal slime powder. Add coal gangue powder and coal slime powder to a planetary ball mill at a mass ratio of 1:3. Set the speed to 200 r / min and ball mill for 20 min to obtain powder 42 with a particle size ≤ 2 mm.

[0061] S5. Prepare powder 3. Screen out particles 11 with a particle size ≤2mm and particles 12 with a particle size >2mm from the vanadium-titanium ore slag. Screen out particles 21 with a particle size ≤2mm and particles 22 with a particle size >2mm from the slag. Put particles 12 and 22 into a jaw crusher. Set the feed particle size of the jaw crusher to ≤250mm and the discharge particle size to ≤2mm. Crush particles 12 and 22 into particles with a particle size ≤2mm, respectively, to obtain particles 13 and 14. Mix particles 11 and 13 and place them in an electric heating forced-air drying oven. Dry them at 110℃ to constant weight to obtain particle 1. Mix particles 21 and 23 and place them in an electric heating forced-air drying oven. Dry them at 110℃ to constant weight to obtain particle 2. Mix the dried particles 1 and 2 at a mass ratio of 3:1 and put them into a cement ball mill. Grind them at a speed of 48 r / min to a specific surface area of ​​500m². 2 / kg, yielding 3g of powder.

[0062] S6. Prepare powder 4 by mixing powder 1, powder 2, powder 41, powder 42 and powder 3 in a weight percentage of 11%:69%:8%:4%:8%, then placing them into a cement ball mill and grinding them at a speed of 48 r / min until the specific surface area is 500 m². 2 / kg, then put the ground material into a cement mortar mixer, set the cement mortar mixer to rotate at 140±5 r / min and revolve at 62±5 r / min, and mix at low speed for 60s to obtain a mixture. Then add water accounting for 10% of the total mass of the mixture, set the cement mortar mixer to rotate at 285±10 r / min and revolve at 125±10 r / min, and mix at high speed for 120s. After mixing evenly, put the mixture into a mold, apply pressure of 25Mpa through a hydraulic press, and press the mixture into a cake with a thickness of 3cm and a diameter of 5cm. Place the cake in an electric heating blast drying oven and dry at 105℃ for 15min. The dried material cake was placed in a covered corundum crucible, which was then placed in a muffle furnace. The temperature was first increased from room temperature to 300℃ at a rate of 3℃ / min, and then held at 300℃ for 30 minutes. Next, the temperature was increased from 300℃ to the desired 1250℃ at a rate of 5℃ / min, and held for 40 minutes. After high-temperature calcination, the product was first cooled to 1000℃ with airflow at a rate of 20℃ / min, and then cooled to room temperature at a rate of ≥100℃ / min. The cooled product was then placed in a jaw crusher with a feed size ≤250mm and an output size ≤2mm. The crushed product was then fed into a cement ball mill and ground at 48 r / min to a specific surface area of ​​500m². 2 / kg, yielding low-carbon powder 4. The chemical composition of the low-carbon powder 4 prepared in step S6 of this embodiment is shown in Table 11, and the activity index is shown in Table 12.

[0063] Table 11: Chemical composition of low-carbon powder 4 in Example 3

[0064] Table 12: Activity Index of Low-Carbon Powder 4 in Example 3

[0065] * in Table 12 refers to the test method of GB / T 17671-2021 "Test Method for Strength of Cement Mortar (ISO Method)".

[0066] S7. Prepare powder 5. Sift phosphogypsum and lithium slag separately using a vibrating screen to remove impurities and organic matter. Then, place them in an electric heating drying oven and dry at 110℃ to constant weight. Next, mix the dried phosphogypsum and lithium slag evenly at a mass ratio of 2:2, and place them in a cement ball mill. Grind at 48 r / min until the specific surface area is 450 m². 2 / kg, yielding 5g of powder.

[0067] S8. Preparation of powder 6: The deactivated ZSM-5 is screened using a vibrating screen to remove impurities, and then placed in an electric heating drying oven and dried at 110℃ to constant weight. The dried deactivated ZSM-5 powder is then placed in a cement ball mill and ground at 48 r / min until a specific surface area of ​​350 m² is achieved. 2 / kg, yielding 6g of powder.

[0068] S9. Add powder 2, powder 3, powder 4, powder 5, and readily soluble sodium silicate to a cement mortar mixer in a mass percentage ratio of 10%:76%:7%:5%:2%. Mix for 120 seconds, then set the cement mortar mixer to rotate at 140±5 r / min and revolve at 62±5 r / min, and mix at low speed for 120 seconds to obtain a dry mixture. Take 20% of the total mass of water from the dry mixture and add it to the dry mixture in two portions. The first portion is 75% of the total water mass. Set the cement mortar mixer to rotate at 285±10 r / min and revolve at 125±10 r / min, and mix at high speed for 130 seconds. The second portion is 25% of the total water mass. Set the cement mortar mixer to rotate at 285±10 r / min and revolve at 125±10 r / min, and mix at high speed for 70 seconds. Let the mixed material stand for 5 hours to allow it to digest. After the digested mixture is milled for 180 seconds by a stirring wheel, it is poured into a pelletizing pan to form spheres. A thin film is covered on the surface of the spheres to keep them moist, and they are naturally cured at 20±5℃ for 26 hours. Then, the temperature is increased to 55℃ at a rate of 5℃ / h, and steam cured at 55℃ and 85% humidity for 5 days. After that, they are naturally cured at 20±5℃ for 4 days. The resulting ceramsite is placed in an electric drying oven and dried at 110℃ to constant weight. Then, it is immersed in a liquid paraffin solution containing 10% by mass for 30 minutes, and then dried at 110℃ to constant weight to obtain non-fired ceramsite.

[0069] S10. Weigh powder 1 and powder 6 according to a mass ratio of 3:1 and mix them evenly to obtain powder 7. Take powder 7, powder 2, low-carbon powder 4 and powder 5 and add them to a mixing tank at a mass percentage of 69%:15%:10%:6% and mix for 60 seconds to obtain a mixed dry powder. Take 65% of the total mass of the mixed dry powder and 55°C warm water as the total water for pouring. First, add 75% of the total mass of the water for pouring to the mixed dry powder and stir for 130 seconds. Then, add 40% of the total mass of the mixed dry powder and non-fired ceramsite and stir for 50 seconds to mix evenly. Then, add 25% of the total mass of the water for pouring and stir for 130 seconds. Then, add 0.7‰ of the total mass of the mixed dry powder and 11‰ of the total mass of the water for foam stabilizer and stir for 30 seconds to mix evenly. Pour the resulting slurry into the mold, ensuring that the temperature of the slurry entering the mold is 50°C during pouring. Then, use a vibrating table to drive the mold to vibrate for 120 seconds. The foam stabilizer in this step is prepared from 89.2 wt% distilled water, 7.9 wt% oleic acid, and 2.9 wt% sodium stearoyl lactylate. The aluminum powder has an active Al content ≥92%, a sieve residue of ≤2.5% on a 0.08 mm square hole sieve, a gas generation rate ≥81%, a gas generation time ≤24 min, and a hydrophilicity ≤20 s.

[0070] S11. The mixed slurry poured into the mold is subjected to 5 hours of gas generation, 5 hours of static curing, and 5 hours of pre-curing at 55℃. The green body is then cut and subjected to high-temperature autoclaving to obtain ceramsite aerated concrete. In this step, the high-temperature autoclaving treatment includes three stages: heating and pressurizing, constant temperature and pressure, and cooling and depressurizing. Heating and pressurizing involves heating to 195℃ and pressurizing to a saturated vapor pressure of 1.1 MPa over 3 hours; constant temperature and pressure involves curing at 195℃ and a saturated vapor pressure of 1.1 MPa for 8 hours; and cooling and depressurizing involves reducing the temperature and pressure to normal for 2 hours.

[0071] Using the non-fired ceramsite prepared in Example 2 as a sample, the following hydration mechanism tests were conducted: (1) XRD analysis Figure 1 X-ray diffraction patterns of non-fired ceramsite naturally cured at 1d, 3d, and 7d. Figure 1 The diffraction peak marked "3" at 10°~15° represents Ca(OH)₂, and it can be seen that the intensity of the diffraction peak first increases and then decreases. A strong Ca(OH)₂ diffraction peak appeared in the system during the first day of curing. This is because the hydration of powders 2 and 5 provided the system with a significant amount of Ca. 2+ OH - and SO4 2- This provides an alkaline environment for the reaction, promoting hydration. In this system, hydrated calcium aluminate and sulfate ions combine to form ettringite. After 3 days of curing, the Ca(OH)₂ content increases. This is because as C₂S and C₃S in the low-carbon powder continue to hydrate, the Ca(OH)₂ concentration increases, resulting in more OH⁻ ions appearing in the system. –However, after 7 days of curing, the Ca(OH)2 content decreased because powder 3 was reacted with Ca in an alkaline environment. 2+ The excitation causes some of the Ca(OH)2 to be consumed. As shown in the 25°~30° range, the diffraction peak of "2" is quartz, which is caused by the SiO2 in powder 3 that does not participate in the reaction. The fine quartz particles can act as micro-aggregates, which can improve the strength of the system. Figure 1 As shown in the 32°~35° range, the diffraction peak "1" represents ettringite. The diffraction peak intensity gradually increases, indicating an increased amount of ettringite. This is due to the hydration of C2S and C3S in low-carbon powder 4 with minerals such as active silica and active alumina in powder 3. In the later stages of curing, the diffraction peak intensity increases less significantly. This is because sodium silicate participates in the hydration reaction first, forming ettringite which covers the surface of powder 3 particles, thus hindering the hydration process to some extent. The ettringite in the system can serve as a source of early strength for the ceramsite. Figure 1 In the 1-day curing images, the diffraction peaks "4" and "5" corresponding to 34°~40° and 52°~58° represent C2S and C3S, respectively. In the early curing stage, C2S and C3S in the system participate in the hydration reaction, generating a large amount of hydration products. In the later curing stage, a large amount of C2S and C3S in the system are consumed, and the corresponding diffraction peaks disappear. Therefore, from... Figure 1 As can be seen from the data, the hydration products of non-fired ceramsite are mainly Ca(OH)2, ettringite, and anhydrite. In the early stage of curing, the main hydration products are Ca(OH)2 and a small amount of ettringite; in the later stage of curing, the main products are anhydrite, Ca(OH)2, and ettringite, with an increase in the amount of ettringite produced. Some of the active SiO2 in the system participates in the hydration reaction, and the remaining part is quartz.

[0072] (2) SEM analysis The non-fired ceramsite prepared in Example 2 was divided into two groups, namely Sample 1 and Sample 2. Sample 1 was naturally cured for 7 days, and Sample 2 was first steam cured at 60℃ for 3 days and then naturally cured for 4 days. Figure 2 These are SEM images of the non-fired ceramsite prepared in Example 2 after 1 day, 3 days, and 7 days of hydration. Figure 2 In the diagram, A-1d-1 represents sample 1 cured naturally for 1 day, A-3d-1 represents sample 1 cured naturally for 3 days, and A-7d-1 represents sample 1 cured naturally for 7 days; A-1d-2 represents sample 2 cured by steam for 1 day, A-3d-2 represents sample 2 cured by steam for 3 days, and A-7d-2 represents sample 2 cured by steam for 3 days followed by 4 days of natural curing.

[0073] Figure 2In the SEM image at 1 day of hydration, it can be seen that the main hydration products of the expanded clay aggregate after curing are amorphous CSH gel and a small amount of fibrous ettringite. Figure A-1d-2 shows that the generated ettringite is fine and scattered, indicating that the internal density of the expanded clay aggregate is relatively low in the early stages of hydration, suggesting that a certain degree of hydration reaction has occurred. However, since cement plays a dominant role in the initial hydration process, the activity of powder 3 is relatively poor, resulting in a low degree of early hydration. The presence of powder 5 in the material system promotes the formation of ettringite. Figure 2 At the 3-day incubation period, a large number of long rod-shaped ettringite particles were observed, which mostly aggregated into bundles and grew radially. The growth of ettringite was faster and the content was significantly increased compared to 1 day. A large amount of ettringite filled the gaps between the aggregated network of CSH gel, and the particles were embedded in the hydration products. The boundaries of the particles were blurred, indicating that the crystalline substances and glassy phase in the powder were fully activated and participated in the hydration reaction. Other components participated in hydration during this period, increasing the amount of hydration products and further improving the density. Figure 2 During the 7-day incubation period, the hydration products become coarser and shorter. Long, rod-shaped ettringite and well-crystallized CSH gel intergrow, resulting in a very dense structure that bonds together to form a tight three-dimensional network. With the abundant formation of hydration products, only a small portion of ettringite remains uncovered, further reducing the gaps in the system. The CSH gel completely encapsulates the ettringite crystals, making the structure even denser and forming a porous honeycomb structure. Figure 2 No obvious large pores were observed in the system. The synergistic effect of ettringite and CSH gel in the system gives the ceramsite good strength on a macroscopic scale.

[0074] Therefore, from Figure 2 It can be seen that the main hydration products of the non-fired ceramsite are CSH gel, ettringite, and Ca(OH)2. The CSH gel and ettringite intertwine to form a network structure, and some unreacted powder 3 fills the pores, which together improves the strength of the system, which is basically consistent with the XRD analysis results.

[0075] (3) EDS analysis Figure 3 These are SEM images of the non-fired ceramsite from Example 2, which were first steam-cured and then naturally cured. Among them, (a) is an SEM image of the non-fired ceramsite after steam curing at 60℃ for 1 day, (b) is an SEM image of the non-fired ceramsite after steam curing at 60℃ for 3 days, and (c) is an SEM image of the non-fired ceramsite after steam curing at 60℃ for 3 days and then naturally cured for 4 days. Figure 4 yes Figure 3 EDS plots of points Q, W, and E, where (Q) is the EDS plot of point Q, (W) is the EDS plot of point W, and (E) is the EDS plot of point E.

[0076] Combination Figure 3 and Figure 4 Point Q is a focal point image of a SEM image at 1 day after steam curing at 60℃. The main constituent elements are O and Ca, with a total calcium and oxygen content of 67.28% and a calcium-to-silicon ratio of 1.54. This suggests that the substance is ettringite. This indicates that a small amount of ettringite is generated during cement hydration at 1 day after steam curing at 60℃, which is consistent with the XRD and SEM analysis results. Point W is a focal point image of a SEM image at 3 days after steam curing at 60℃. The main elements are O, Ca, and Si, with Ca content of 17.95%, O content of 52.43%, and Ca content of 17.95%. The calcium-to-silicon ratio is 4.97. Based on the hexagonal plate-like shape of the substance in the SEM image, it is presumably calcium hydroxide crystals. Combined with the XRD pattern, the Ca(OH)₂ content increases at this age. Point E is a localized SEM image of the 3-day steam-cured and 4-day naturally-cured age at 60℃. The main constituent elements are O, Al, Ca, Si, and Fe. The O content is 14.12%, the Si content is 7.03%, and the Ca / Si ratio is 2.01, suggesting it is a CSH gel. In the later stages of hydration, the Si-O bonds in fly ash and iron tailings gradually break in the alkaline environment, interacting with Ca... 2+ The reaction generates CSH gel, which encapsulates ettringite. The two then interweave further, providing sufficient strength to the ceramsite.

[0077] Therefore, it can be concluded that the hydration products of expanded clay aggregate mainly consist of CSH gel, ettringite, and Ca(OH)2, which is consistent with the above conclusion. Figure 1 (XRD pattern) and Figure 2 The results presented in the (SEM image) are consistent.

[0078] (4) FT-IR analysis Figure 5 The images show the FT-IR infrared spectra of the non-fired ceramsite prepared in Example 2 after 1 day, 3 days, and 7 days of hydration. Figure 5 The medium wave number is 688 cm⁻¹ -1 The left and right sides represent Si-O-Si symmetric stretching vibrations belonging to the quartz group of minerals. The wavenumber is 1090 cm⁻¹. -1 The absorption peak is caused by the Si-O asymmetric vibration in the ettringite structure. At 1403 cm⁻¹ -1 The absorption peak appearing at this point is CO3. 2- The asymmetric stretching vibration bands are likely due to the production of more Ca(OH)₂ during hydration, which readily carbonizes with CO₂ in the air to form calcium carbonate. Alternatively, it could be caused by alkaline substances in the sample reacting with CO₂ in the air. The wavenumber is 1618 cm⁻¹. -1 The absorption peak at that point is formed by OH bond vibration. The wavenumber is 3425 cm⁻¹. -1The absorption peak corresponds to the vibrational band of water molecules in the CSH gel, indicating that more CSH gel is formed with increasing age. The wavenumber is 3635 cm⁻¹. -1 The absorption peaks of the OH stretching vibrations around the 3421 cm⁻¹ are not obvious. This is because the hydroxyl groups in ettringite and CSH gel are not typical hydroxyl groups; their hydrogen bonds and molecular bonds in the water of crystallization do not have clear boundaries, and therefore will be absorbed by the OH stretching vibrations around the 3421 cm⁻¹. -1 The peak of crystallization water at that location is obscured. 3635cm -1 The tiny vibrational peaks at that point correspond to the ν-type Ca(OH)₂. Ca-OH Absorption bands of stretching vibrations.

[0079] Samples of different ages in the longitudinal comparison chart, 1090cm -1 The vibration peak at 1090 cm⁻¹ increased with prolonged curing time. -1 A distinct absorption peak was observed at 3635 cm⁻¹, indicating the formation of ettringite after 1 day of hydration. The increased absorption peaks after 3 and 7 days of hydration suggest a greater quantity of ettringite formed in the later stages of hydration, consistent with XRD analysis results. The spectrum also shows that as hydration progresses, the absorption peak at 3635 cm⁻¹ increases. -1 The stretching vibration peaks in the vicinity first strengthen and then weaken. The Ca(OH)2 in the system is mainly produced by the hydration of powder 2 and powder 4. After 3 days of hydration, the vibration peaks are strengthened because the continued hydration of powder 4 provides more Ca(OH)2. However, as hydration progresses, the active SiO2 in powder 3 reacts chemically with Ca(OH)2, the amount of Ca(OH)2 decreases, the HOH stretching vibration peaks continue to weaken, and some of them do not participate in the reaction. This is the same as the change in the XRD pattern of the hydration products at different hydration ages.

[0080] therefore, Figure 5 The data show that the main peaks are basically the same in the spectra of three different hydration ages of 1 d, 3 d and 7 d, only the infrared light transmittance is slightly different, and all absorption peaks are shifted towards lower wavenumbers.

[0081] The performance indicators of the non-fired ceramsite prepared in Examples 1-3 are shown in Table 13: Table 13: Performance indicators of non-fired ceramsite prepared by step S9 in Examples 1-3

[0082] In Table 13, * indicates the test index requirements in GB / T 17431.1-2010, "Lightweight aggregates and their test methods - Part 1: Lightweight aggregates".

[0083] The performance indicators of the ceramsite aerated concrete prepared in Examples 1-3 are shown in Table 14.

[0084] Table 14: Performance indicators of the expanded clay aerated concrete prepared in Examples 1-3

[0085] In Table 14, * indicates the test index requirements in JG / T 504-2016 "Aerated Concrete Blocks with Expanded Clay".

[0086] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for preparing aerated concrete for use as a wall material based on waste photovoltaic-vanadium-titanium slag-lithium slag, characterized in that, Includes the following steps: Preparation of each powder: After pretreatment, lithium tailings are used to obtain powder 1; after pretreatment, calcium carbide slag and papermaking causticizing mud are mixed to obtain powder 2. Vanadium-titanium ore slag and ore slag were mixed and pretreated to obtain powder 3; Waste photovoltaic panels were pretreated to obtain powder 41; coal gangue and coal slime were pretreated to obtain powder 42; powder 1, powder 2, powder 41, powder 42 and powder 3 were mixed in a mass ratio of (10~15):(60~77):(5~10):(3~5):(5~10) to obtain low-carbon powder 4; phosphogypsum and lithium slag were pretreated to prepare powder 5; deactivated ZSM-5 was pretreated to prepare powder 6; powder 1 and powder 6 were mixed in a mass ratio of (1~3):1 to obtain powder 7. Preparation of non-fired ceramsite: Take powder 2, powder 3, low-carbon powder 4, powder 5 and fast-dissolving sodium silicate in a mass ratio of (10~16):(60~77):(7~12):(4~8):(2~4) and mix for 60~120s to obtain mixed dry material; add 16~20% of the total mass of the mixed dry material to the mixed dry material and stir to mix evenly. After standing for 3~5h to digest, grind with a stirring wheel for 120~180s, pour into a pelletizing pan to form spheres, cover the surface of the spheres with a thin film to keep them moist, and place them in an environment of 20±5℃ for natural curing for 22~26h. Then place them in an environment of 55~65℃ and 85~95% humidity for curing for 3~5 days. Then, place them in an environment of 20±5℃ for natural curing for 2~4 days, dry to constant weight, soak in an 8~10% mass fraction liquid paraffin solution for 30~50min, and dry to constant weight to obtain non-fired ceramsite; Casting: Take powder 7, powder 2, low carbon powder 4 and powder 5 and mix them in a mass ratio of (55~70):(15~23):(9~12):(6~10) to obtain a mixed dry powder; take 53~65% of the total mass of the mixed dry powder and 50~55℃ warm water as the total water for casting, add warm water to the mixed dry powder and stir well, then add 35~40% of the total mass of the mixed dry powder and mix well; then add warm water, 0.5~0.7‰ of the total mass of the mixed dry powder and 5~11‰ of the total water mass of the foam stabilizer, stir well, and pour the resulting slurry into the mold, and vibrate the mold for 60~120s; Concrete curing: The mixture slurry poured into the mold is subjected to aeration, static curing, pre-curing, green body cutting and high-temperature autoclaving to obtain ceramsite aerated concrete.

2. The preparation method according to claim 1, wherein, The preparation method of the powder 1 is as follows: The lithium tailings were sieved in a vibrating screen, and the sieved lithium tailings were dried at 100~110℃ to constant weight, and then ground to a specific surface area of ​​350~450m². 2 / kg, yielding powder 1.

3. The preparation method according to claim 1, wherein, The preparation method of the powder 2 is as follows: Carbide slag and papermaking causticized mud were dried separately at 100-110℃ to constant weight. The dried carbide slag and papermaking causticized mud were then mixed evenly at a mass ratio of (1-3):1 and stirred for 60-120 seconds. Water, accounting for 8-10% of the total mass of the dry powder of carbide slag and papermaking causticized mud, was added and stirred for 120-180 seconds. The mixture was then transferred to a mold and pressed into cakes with a thickness of 1-3 cm and a diameter of 5-8 cm. The cakes were dried at 95-105℃ for 15-25 minutes. The dried cakes were then calcined, cooled, and ground to a specific surface area of ​​400-500 m². 2 / kg, yielding powder 2; The calcination of the material cake is carried out by raising the temperature from room temperature to 200°C at a rate of 4°C / min, holding at 200°C for 20-30 minutes; then raising the temperature from 200°C to 700°C-800°C at a rate of 10°C / min, and holding at 700°C-800°C for 30-40 minutes.

4. The preparation method according to claim 1, wherein, The preparation method of the powder 3 is as follows: Particles 11 (≤2mm) and 12 (>2mm) with diameters greater than 2mm were screened out of the vanadium-titanium ore slag. Particles 21 (≤2mm) and 22 (>2mm) with diameters greater than 2mm were also screened out. Particles 12 and 22 were crushed to a particle size ≤2mm to obtain particles 13 and 14 respectively. Particles 11 and 13 were mixed and dried at 100~110℃ to constant weight to obtain particle 1. Particles 21 and 23 were mixed and dried at 100~110℃ to constant weight to obtain particle 2. The dried particles 1 and 2 were mixed at a mass ratio of (2~4):1 and ground to a specific surface area of ​​400~500 m². 2 / kg, yielding 3g of powder.

5. The preparation method according to claim 1, wherein, The preparation method of the low-carbon powder 4 is as follows: Clean the waste photovoltaic panels, let them air dry, then crush them into pieces ≤25mm. Grind the pieces to a specific surface area of ​​250~350m². 2 / kg, yielding 41g of powder; Particles 4 with a diameter > 2 mm and particles 5 with a diameter ≤ 2 mm are screened out from the coal gangue. Particles 4 are crushed to a diameter ≤ 2 mm to obtain particles 6. Particles 5 and 6 are mixed and dried at 100~110℃ to constant weight to obtain coal gangue powder. Coal slime is dried at 100~110℃ to constant weight to obtain coal slime powder. Coal gangue powder and coal slime powder are ball-milled and mixed at a mass ratio of 1:(1~3) to obtain powder 42 with a diameter ≤ 2 mm. Mix powder 1, powder 2, powder 41, powder 42 and powder 3 evenly, and grind them to a specific surface area of ​​400~500m². 2 / kg, then stir for 60-120s to obtain a mixture, then add 8-10% water by mass of the mixture and stir for 120-180s, transfer to a mold, press into cakes with a thickness of 1-3cm and a diameter of 5-8cm, dry the cakes at 95-105℃ for 15-25min, then calcine at high temperature, air-cool, crush to a particle size ≤2mm, and grind to a specific surface area of ​​400-500m². 2 / kg, yielding 4g of low-carbon powder.

6. The preparation method according to claim 5, wherein, In the preparation steps of the low-carbon powder 4, the high-temperature calcination is to raise the temperature from room temperature to 300°C at a rate of 3°C / min, hold at 300°C for 20-30 minutes, raise the temperature from 300°C to 1150-1250°C at a rate of 5°C / min, and then hold for 30-40 minutes. The air cooling process involves first cooling to 1000°C at a rate of 18-20°C / min, and then cooling to room temperature at a rate of ≥100°C / min.

7. The preparation method according to claim 1, wherein, The preparation method of the powder 5 is as follows: Phosphogypsum and lithium slag were sieved separately using a vibrating screen, and then dried at 100~110℃ to constant weight. The dried phosphogypsum and lithium slag were mixed evenly at a mass ratio of (2~4):(1~2) and ground to a specific surface area of ​​350~450m². 2 / kg, yielding 5g of powder; The preparation method of the powder 6 is as follows: The deactivated ZSM-5 was screened using a vibrating screen, then dried at 100-110℃ to constant weight, and finally ground to a specific surface area of ​​350-450 m². 2 / kg, yielding 6g of powder.

8. The preparation method according to claim 1, wherein, The foam stabilizer is prepared from 86-94 wt% distilled water, 4-9 wt% oleic acid and 2-6 wt% sodium stearoyl lactylate.

9. The preparation method according to claim 1, wherein, The high-temperature autoclaving treatment in the concrete curing process includes three stages: heating and pressurizing, maintaining constant temperature and pressure, and cooling and depressurizing. The heating and pressurizing process involves heating to 175-195℃ and pressurizing to a saturated vapor pressure of 1.1-1.3 MPa over 2-3 hours. The maintaining constant temperature and pressure process involves curing at 175-195℃ and a saturated vapor pressure of 1.1-1.3 MPa for 6-8 hours. The cooling and depressurizing process involves reducing the temperature and pressure to normal within 1-2 hours.

10. An aerated concrete for wall materials, characterized in that, The aerated concrete is prepared using the preparation method described in any one of claims 1-9.

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