Cementing material prepared by using multiple solid wastes, and preparation method and application thereof

Abstract

The present application relates to solid waste cementing material preparation technical field, specifically is the cementing material prepared by using multiple solid wastes, and its preparation method and application. The cementing material prepared by using multiple solid wastes includes the following components by mass fraction: coal gangue 40-56 parts, red mud 4-10 parts, desulfurization gypsum 3-5 parts, fly ash 15-25 parts, silicate cement 28-42 parts, and composite reinforcing material 15-25 parts. The cementing material prepared by the present application can be effectively applied in the preparation of building materials, reducing the use of cement, and at the same time, the chitosan is loaded on the biochar in the material, then combined with copper oxide and zinc oxide through gas, and carried into the slurry, which has a better strength promoting effect on the solidified building materials.

Description

Technical Field

[0001] This invention relates to the field of solid waste cementitious material preparation technology, specifically to cementitious materials prepared from multi-component solid waste, their preparation methods, and applications. Background Technology

[0002] Building materials are the various materials used in construction projects. Building materials are diverse and can be broadly categorized as follows: Inorganic materials, which include metallic materials (including ferrous and non-ferrous metals) and non-metallic materials (such as natural stone, calcined clay products, cement, concrete, and silicate products); Organic materials, which include plant-based materials, synthetic polymer materials (including plastics, coatings, and adhesives), and asphalt materials; and Composite materials, which include asphalt concrete and polymer concrete, generally composed of inorganic non-metallic materials and organic materials.

[0003] In the use of building materials such as concrete, curing agents such as cementitious materials are needed to allow the materials to harden. Currently, the most common curing cementitious material is cement. However, the production of cement consumes a lot of resources and also releases a large amount of harmful gases, thus polluting the environment.

[0004] Therefore, to reduce the amount of cement used, solid waste is sometimes used in cementitious materials. Common solid wastes include coal gangue, fly ash, and slag. These solid wastes have a pozzolanic effect, making them suitable not only as cementitious materials but also reducing cement usage and benefiting the environment. Furthermore, during the solidification of building materials, other additives, such as biochar and metal oxide particles, are sometimes incorporated into the cementitious materials. These particles can further promote the strength development of building materials. However, in existing technologies, these materials are directly incorporated into the cementitious materials. Metal oxide particles, in particular, often have small particle sizes, resulting in weak dispersion in the slurry and limited promotion of building material strength. Therefore, addressing the problems mentioned in the background, those skilled in the art propose a cementitious material prepared using multiple solid wastes, its preparation method, and its application. Summary of the Invention

[0005] The purpose of this invention is to provide a cementitious material prepared from multi-component solid waste, its preparation method, and its application, in order to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] The cementitious material prepared from multi-component solid waste comprises the following raw materials by weight:

[0008] 40-56 parts coal gangue, 4-10 parts red mud, 3-5 parts desulfurized gypsum, 15-25 parts fly ash, 28-42 parts silicate cement, and 15-25 parts composite reinforcing material;

[0009] The method for preparing the composite reinforced material includes the following steps:

[0010] S101. Take rice husk biochar and grind it;

[0011] S102. The rice husk biochar treated in step S101 is placed in nitric acid for 10-30 minutes, then filtered. The filtered product is washed with sufficient deionized water and then dried at room temperature to constant weight.

[0012] S103. The rice husk biochar treated in step S102 is placed in hydrogen peroxide for 1-3 hours, then filtered. The filtered product is washed with sufficient deionized water and then dried at room temperature to constant weight.

[0013] S104. Add the rice husk biochar treated in step S103 to the chitosan solution, add sodium hydroxide solution to adjust the pH to 12-13, let it stand for 30-60 minutes, then filter, wash the filtered product with sufficient deionized water and dry it at room temperature to constant weight.

[0014] S105. The rice husk biochar treated in step S104 is placed into a mixed solution of copper chloride and zinc chloride, allowed to stand for 1-3 hours, and then filtered to obtain the filtered product.

[0015] S106. Place the filtered product from step S105 into deionized water, add sodium hydroxide solution to adjust the pH to 10-11, perform hydrothermal reaction for 4-6 hours, then filter, wash the filtered product with sufficient deionized water and dry it at room temperature to constant weight to obtain the composite reinforced material.

[0016] Furthermore, in step S102, the concentration of nitric acid is 10-30 wt%, and the mass ratio between nitric acid and rice husk biochar added to the nitric acid is 10:1.

[0017] Furthermore, in step S103, the concentration of hydrogen peroxide is 20-25 wt%, and the mass ratio between hydrogen peroxide and rice husk biochar added to hydrogen peroxide is 15:1.

[0018] Furthermore, in step S104, the concentration of the chitosan solution is 3-6 wt%, and the mass ratio between the chitosan solution and the rice husk chitosan added to the chitosan solution is (8-12):1.

[0019] Furthermore, in step S105, the concentrations of copper chloride and zinc chloride in the mixed solution of copper chloride and zinc chloride are 0.1-0.2 mol / L and 0.5-1 mol / L, respectively, and the mass ratio between the mixed solution of copper chloride and zinc chloride and the rice husk chitosan added to the mixed solution of copper chloride and zinc chloride is (15-20):1.

[0020] Furthermore, the temperature of the hydrothermal reaction in step S106 is 120-140℃.

[0021] The above-mentioned method for preparing cementitious materials using multi-component solid waste includes the following steps:

[0022] S1. Calcine coal gangue, red mud, desulfurized gypsum and fly ash at 500-700℃ for 1-4 hours according to the mass fraction;

[0023] S2. The gangue, red mud, desulfurized gypsum and fly ash treated in step S1 are put into a mixer. Then, silicate cement and composite reinforcing materials are added to the mixer and mixed evenly to obtain a cementitious material.

[0024] The above-mentioned cementitious materials prepared from multi-component solid wastes are applied in the field of building materials preparation.

[0025] Furthermore, the following methods are specifically used to prepare building materials:

[0026] Z1. Add coarse and fine aggregates to water, then add water-reducing agent, and stir at 250 r / min for 30 min to obtain a mixture;

[0027] Z2. Maintain the stirring speed in step Z1, continue to add cementitious material to the mixture, and then sonicate the mixture for 90 minutes at a frequency of 30 kHz. After sonication, a slurry is obtained.

[0028] Z3. Pour the slurry obtained in step Z2 into a mold, cure it at 22°C, and then demold it to obtain the building material.

[0029] Furthermore, the mass ratio of the cementitious material, coarse aggregate, fine aggregate, water, and water-reducing agent is 3:2:1:1.2:0.05; crushed stone is used as the coarse aggregate; river sand is used as the fine aggregate; and polycarboxylate superplasticizer is used as the water-reducing agent.

[0030] Compared with the prior art, the beneficial effects of the present invention are:

[0031] 1. The composite reinforcing material in this invention uses rice husk biochar as a carrier. Rice husk biochar itself has the function of improving the overall strength of the material. Then, chitosan is loaded on the biochar. Chitosan can adsorb a large number of copper and zinc ions by utilizing the porous structure of biochar. By adjusting the pH and hydrothermal reaction, the copper oxide and zinc oxide particles produced are attached to the chitosan. These materials enter the building material along with the larger biochar particles, which is conducive to their dispersion.

[0032] 2. In the process of preparing building materials, the slurry is treated with ultrasound. During the ultrasound process, chitosan is degraded, and the oxide particles attached to its surface are gradually dispersed into the slurry during the stirring process. This can largely avoid the problem of small metal oxide particles being dispersed in the slurry, and the strength-promoting effect of the building materials is improved. Attached Figure Description

[0033] Figure 1 This is a process flow diagram for preparing building materials in this invention;

[0034] Figure 2 This is a process flow diagram for preparing the cementitious material in this invention;

[0035] Figure 3 This is a process flow diagram for preparing composite reinforced materials in this invention. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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 skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] Please see Figures 1 to 3 The present invention provides:

[0038] Example 1

[0039] The preparation method of cementitious materials using multi-component solid waste includes the following steps:

[0040] S1. Calcine 55g of coal gangue, 6g of red mud, 4g of desulfurized gypsum and 20g of fly ash at 650℃ for 2h.

[0041] S2. Put the gangue, red mud, desulfurized gypsum and fly ash treated in step S1 into a mixer, and then add 35g of silicate cement and 21g of composite reinforcing material into the mixer. Mix them evenly to obtain the cementitious material.

[0042] The preparation method of the above-mentioned composite reinforced material includes the following steps:

[0043] S101. Take rice husk biochar and grind it;

[0044] S102. 35g of rice husk biochar treated in step S101 is placed in 350g of 25wt% nitric acid and treated for 20min. After that, it is filtered, and the filtered product is washed with sufficient deionized water and then dried at room temperature to constant weight.

[0045] S103. 30g of rice husk biochar treated in step S102 is placed in 450g of hydrogen peroxide with a concentration of 22wt% and treated for 2.2h. After that, it is filtered, and the filtered product is washed with sufficient deionized water and then dried at room temperature to constant weight.

[0046] S104. Add 25g of rice husk biochar treated in step S103 to 250g of chitosan solution with a concentration of 5wt%, add 1mol / L sodium hydroxide solution to adjust the pH to 12.5, let stand for 40min, then filter, wash the filtered product with sufficient deionized water and dry it at room temperature to constant weight.

[0047] S105. 25g of rice husk biochar treated in step S104 is placed into a mixed solution of copper chloride and zinc chloride. The amount of the mixed solution of copper chloride and zinc chloride is 420g. The concentrations of copper chloride and zinc chloride in the mixed solution are 0.15mol / L and 0.6mol / L, respectively. The mixture is allowed to stand for 2 hours, and then filtered to obtain the filtered product.

[0048] S106. The filtered product from step S105 is placed in 400g of deionized water, and 1mol / L sodium hydroxide solution is added dropwise to adjust the pH to 10.5. The hydrothermal reaction is carried out for 5 hours at a temperature of 130℃. After filtration, the filtered product is washed with sufficient deionized water and dried at room temperature to constant weight to obtain the composite reinforced material.

[0049] Example 2

[0050] The preparation method of cementitious materials using multi-component solid waste includes the following steps:

[0051] S1. Calcine 40g of coal gangue, 4g of red mud, 3g of desulfurized gypsum and 15g of fly ash at 500℃ for 1 hour;

[0052] S2. Put the gangue, red mud, desulfurized gypsum and fly ash treated in step S1 into a mixer, and then add 28g of silicate cement and 15g of composite reinforcing material into the mixer. Mix them evenly to obtain the cementitious material.

[0053] The preparation method of the above-mentioned composite reinforced material includes the following steps:

[0054] S101. Take rice husk biochar and grind it;

[0055] S102. 35g of rice husk biochar treated in step S101 is placed in 350g of 10wt% nitric acid and treated for 10min. After that, it is filtered, and the filtered product is washed with sufficient deionized water and then dried at room temperature to constant weight.

[0056] S103. 30g of rice husk biochar treated in step S102 is placed in 450g of 20wt% hydrogen peroxide and treated for 1h. After that, it is filtered, and the filtered product is washed with sufficient deionized water and then dried at room temperature to constant weight.

[0057] S104. Add 25g of rice husk biochar treated in step S103 to 200g of chitosan solution with a concentration of 3wt%, add 1mol / L sodium hydroxide solution to adjust the pH to 12, let stand for 30min, then filter, wash the filtered product with sufficient deionized water and dry it at room temperature to constant weight.

[0058] S105. 25g of rice husk biochar treated in step S104 is placed into a mixed solution of copper chloride and zinc chloride. The amount of the mixed solution of copper chloride and zinc chloride is 375g, and the concentrations of copper chloride and zinc chloride are 0.1mol / L and 0.5mol / L, respectively. The mixture is allowed to stand for 1 hour, and then filtered to obtain the filtered product.

[0059] S106. The filtered product from step S105 is placed in 400g of deionized water, and 1mol / L sodium hydroxide solution is added dropwise to adjust the pH to 10. The hydrothermal reaction is carried out for 4 hours at a temperature of 120℃. After filtration, the filtered product is washed with sufficient deionized water and dried at room temperature to constant weight to obtain the composite reinforced material.

[0060] Example 3

[0061] The preparation method of cementitious materials using multi-component solid waste includes the following steps:

[0062] S1. Calcine 56g of coal gangue, 10g of red mud, 5g of desulfurized gypsum and 25g of fly ash at 700℃ for 4h.

[0063] S2. Put the gangue, red mud, desulfurized gypsum and fly ash treated in step S1 into a mixer, and then add 42g of silicate cement and 25g of composite reinforcing material into the mixer. Mix them evenly to obtain the cementitious material.

[0064] The preparation method of the above-mentioned composite reinforced material includes the following steps:

[0065] S101. Take rice husk biochar and grind it;

[0066] S102. 35g of rice husk biochar treated in step S101 is placed in 350g of 30wt% nitric acid and treated for 30min. After that, it is filtered, and the filtered product is washed with sufficient deionized water and then dried at room temperature to constant weight.

[0067] S103. 30g of rice husk biochar treated in step S102 is placed in 450g of 25wt% hydrogen peroxide and treated for 3h. After that, it is filtered, and the filtered product is washed with sufficient deionized water and then dried at room temperature to constant weight.

[0068] S104. Add 25g of rice husk biochar treated in step S103 to 300g of chitosan solution with a concentration of 6wt%, add 1mol / L sodium hydroxide solution to adjust the pH to 13, let stand for 60min, then filter, wash the filtered product with sufficient deionized water and dry it at room temperature to constant weight.

[0069] S105. 25g of rice husk biochar treated in step S104 is placed into a mixed solution of copper chloride and zinc chloride. The amount of the mixed solution of copper chloride and zinc chloride is 500g. The concentrations of copper chloride and zinc chloride in the mixed solution are 0.2mol / L and 1mol / L, respectively. The mixture is allowed to stand for 3 hours, and then filtered to obtain the filtered product.

[0070] S106. The filtered product from step S105 is placed in 400g of deionized water, and 1mol / L sodium hydroxide solution is added dropwise to adjust the pH to 11. The hydrothermal reaction is carried out for 6 hours at a temperature of 140℃. After filtration, the filtered product is washed with sufficient deionized water and dried at room temperature to constant weight to obtain the composite reinforced material.

[0071] Example 4

[0072] The preparation method of cementitious materials using multi-component solid waste includes the following steps:

[0073] S1. Calcine 52g of coal gangue, 8g of red mud, 4g of desulfurized gypsum and 22g of fly ash at 650℃ for 3.5h;

[0074] S2. Put the gangue, red mud, desulfurized gypsum and fly ash treated in step S1 into a mixer, and then add 36g of silicate cement and 18g of composite reinforcing material into the mixer. Mix them evenly to obtain the cementitious material.

[0075] The preparation method of the above-mentioned composite reinforced material includes the following steps:

[0076] S101. Take rice husk biochar and grind it;

[0077] S102. 35g of rice husk biochar treated in step S101 is placed in 350g of 25wt% nitric acid and treated for 22min. After that, it is filtered, and the filtered product is washed with sufficient deionized water and then dried at room temperature to constant weight.

[0078] S103. 30g of rice husk biochar treated in step S102 is placed in 450g of hydrogen peroxide with a concentration of 20wt% and treated for 2.5h. After that, it is filtered, and the filtered product is washed with sufficient deionized water and then dried at room temperature to constant weight.

[0079] S104. Add 25g of rice husk biochar treated in step S103 to 220g of chitosan solution with a concentration of 4wt%, add 1mol / L sodium hydroxide solution to adjust the pH to 12, let stand for 45min, then filter, wash the filtered product with sufficient deionized water and dry it at room temperature to constant weight.

[0080] S105. 25g of rice husk biochar treated in step S104 is placed into a mixed solution of copper chloride and zinc chloride. The amount of the mixed solution of copper chloride and zinc chloride is 450g. The concentrations of copper chloride and zinc chloride in the mixed solution are 0.1mol / L and 1mol / L, respectively. The mixture is allowed to stand for 2.5h, and then filtered to obtain the filtered product.

[0081] S106. The filtered product from step S105 is placed in 400g of deionized water, and 1mol / L sodium hydroxide solution is added dropwise to adjust the pH to 11. The hydrothermal reaction is carried out for 5 hours at a temperature of 140℃. After filtration, the filtered product is washed with sufficient deionized water and dried at room temperature to constant weight to obtain the composite reinforced material.

[0082] The coal gangue in this application has a particle size between 20-60 μm, the red mud and fly ash have a particle size between 0.5-2 μm, the desulfurized gypsum has a particle size between 30-40 μm, and the ground rice husk biochar needs to pass through a 100-mesh sieve.

[0083] Examples 1-4 yielded four sets of cementitious materials that can be used to prepare building materials. The four sets of cementitious materials were respectively mixed with coarse aggregate, fine aggregate, water, and a water-reducing agent. The mass ratio of the cementitious materials, coarse aggregate, fine aggregate, water, and water-reducing agent was 3:2:1:1.2:0.05. Crushed stone with a particle size of 10-20 mm was used as the coarse aggregate; river sand with a particle size of 1-5 mm was used as the fine aggregate; and polycarboxylate superplasticizer was used. The specific usage method is as follows:

[0084] Z1. Add coarse and fine aggregates to water, then add water-reducing agent, and stir at 250 r / min for 30 min to obtain a mixture;

[0085] Z2. Maintain the stirring speed in step Z1, continue to add cementitious material to the mixture, and then sonicate the mixture for 90 minutes at a frequency of 30 kHz. After sonication, a slurry is obtained.

[0086] Z3. Pour the slurry obtained in step Z2 into a mold, cure it at 22°C, and then demold it to obtain the building material.

[0087] The present invention includes the following comparative examples. The cementitious materials prepared in the comparative examples are used to prepare building materials in the same way as in the examples (the preparation process of building materials in Comparative Example 4 is different).

[0088] Comparative Example 1

[0089] The difference between Comparative Example 1 and Example 1 is that steps S102 and S103 are omitted, while the remaining steps are exactly the same as in Example 1.

[0090] Comparative Example 2

[0091] The difference between Comparative Example 2 and Example 1 is that step S104 is omitted, while the remaining steps are exactly the same as in Example 1.

[0092] Comparative Example 3

[0093] The difference between Comparative Example 3 and Example 1 is that steps S105 and S106 were omitted in the prepared gelling material, while the remaining steps were exactly the same as in Example 1.

[0094] Comparative Example 4

[0095] The difference between Comparative Example 4 and Example 1 is that the ultrasonic treatment in step Z2 was omitted, while the remaining steps are exactly the same as in Example 1.

[0096] Comparative Example 5

[0097] The difference between Comparative Example 5 and Comparative Example 3 is that 2g of copper oxide and 8g of zinc oxide particles were added simultaneously in step Z2. The particle size of both copper oxide and zinc oxide particles was between 50-200nm. The remaining steps were exactly the same as those in Comparative Example 3.

[0098] Comparative Example 6

[0099] The difference between Comparative Example 6 and Comparative Example 3 is that 0.8g of copper oxide and 3.2g of zinc oxide particles were added simultaneously in step Z2. The particle size of both copper oxide and zinc oxide particles was between 50-200nm. The remaining steps were exactly the same as those in Comparative Example 3.

[0100] Comparative Example 7

[0101] The difference between Comparative Example 7 and Comparative Example 3 is that 0.32g of copper oxide and 1.28g of zinc oxide particles were added simultaneously in step Z2. The particle size of both copper oxide and zinc oxide particles was between 50-200nm. The remaining steps were exactly the same as those in Comparative Example 3.

[0102] The prepared building materials were tested for 7-day flexural and compressive strength and 28-day flexural and compressive strength according to GB / T 50081-2019 "Standard for Test Methods of Mechanical Properties of Ordinary Concrete". The test results are shown in Table 1 below:

[0103] Table 1: Test results of building materials prepared in Examples 1-4 and Comparative Examples 1-7

[0104]

[0105] The building materials obtained in Comparative Example 1 (Table 1) showed a decrease in strength compared to Example 1. This was due to the lack of surface oxidation treatment on the rice husk biochar, which not only reduced the binding capacity between the rice husk biochar and chitosan but also reduced its binding capacity with copper and zinc ions, thus decreasing the amount of copper and zinc oxide carried and reducing the overall strength of the building materials. The building materials obtained in Comparative Example 2 also showed a decrease in strength compared to Example 1. Comparative Example 2 lacked the attachment of chitosan to the rice husk biochar, directly using rice husk biochar for loading. Chitosan has a strong adsorption capacity for copper and zinc ions, and its structure is easily damaged during the preparation of building materials due to ultrasonic impact, making it easier for the copper and zinc oxide adhering to its surface to penetrate. Adding them to the slurry has a better effect on promoting the strength of the prepared building materials; in Comparative Example 3, the binding of copper oxide and zinc oxide on rice husk biochar was completely eliminated, and its strength was also weaker than that of Example 1; in Comparative Example 4, the ultrasonic treatment in step Z2 was omitted, and the strength of the building materials also decreased; in addition, Comparative Examples 5-6 added different weights of copper oxide and zinc oxide particles respectively. The strength of Comparative Examples 5 and 6 was similar, and both were higher than that of Comparative Example 7. Since the amount added in Comparative Example 7 was too small, the promoting effect was weak. Comparative Examples 5-6 were weaker than Example 1, which proves that the present invention uses biochar and chitosan to bind copper oxide and zinc oxide and disperse them in the building materials, which has a better promoting effect on the building materials.

[0106] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A cementitious material prepared from multiple solid wastes, characterized in that, Raw materials comprising the following components by weight: 40-56 parts coal gangue, 4-10 parts red mud, 3-5 parts desulfurized gypsum, 15-25 parts fly ash, 28-42 parts silicate cement, and 15-25 parts composite reinforcing material; The method for preparing the composite reinforced material includes the following steps: S101. Take rice husk biochar and grind it; S102. The rice husk biochar treated in step S101 is placed in nitric acid for 10-30 minutes, then filtered. The filtered product is washed with sufficient deionized water and then dried at room temperature to constant weight. S103. The rice husk biochar treated in step S102 is placed in hydrogen peroxide for 1-3 hours, then filtered. The filtered product is washed with sufficient deionized water and then dried at room temperature to constant weight. S104. Add the rice husk biochar treated in step S103 to the chitosan solution, add sodium hydroxide solution to adjust the pH to 12-13, let it stand for 30-60 minutes, then filter, wash the filtered product with sufficient deionized water and dry it at room temperature to constant weight. S105. The rice husk biochar treated in step S104 is placed into a mixed solution of copper chloride and zinc chloride, allowed to stand for 1-3 hours, and then filtered to obtain the filtered product. S106. Place the filtered product from step S105 into deionized water, add sodium hydroxide solution to adjust the pH to 10-11, perform hydrothermal reaction for 4-6 hours, then filter, wash the filtered product with sufficient deionized water and dry it at room temperature to constant weight to obtain the composite reinforced material.

2. The cementitious material prepared from multi-component solid waste according to claim 1, characterized in that, In step S102, the concentration of nitric acid is 10-30 wt%, and the mass ratio of nitric acid to rice husk biochar added to the nitric acid is 10:

1.

3. The cementitious material prepared from multi-component solid waste according to claim 1, characterized in that, In step S103, the concentration of hydrogen peroxide is 20-25 wt%, and the mass ratio of hydrogen peroxide to rice husk biochar added to hydrogen peroxide is 15:

1.

4. The cementitious material prepared from multi-component solid waste according to claim 1, characterized in that, In step S104, the concentration of the chitosan solution is 3-6 wt%, and the mass ratio between the chitosan solution and the rice husk biochar added to the chitosan solution is (8-12):

1.

5. The cementitious material prepared from multi-component solid waste according to claim 1, characterized in that, In step S105, the concentrations of copper chloride and zinc chloride in the mixed solution are 0.1-0.2 mol / L and 0.5-1 mol / L, respectively, and the mass ratio of the mixed solution of copper chloride and zinc chloride to the rice husk biochar added to the mixed solution of copper chloride and zinc chloride is (15-20):

1.

6. The cementitious material prepared from multi-component solid waste according to claim 1, characterized in that, The temperature of the hydrothermal reaction in step S106 is 120-140℃.

7. A method for preparing a cementitious material based on any one of claims 1-6 using multi-component solid waste, characterized in that, Includes the following steps: S1. Calcine coal gangue, red mud, desulfurized gypsum and fly ash at 500-700℃ for 1-4 hours according to the mass fraction; S2. The coal gangue, red mud, desulfurized gypsum and fly ash treated in step S1 are put into a mixer. Then, silicate cement and composite reinforcing materials are added to the mixer and mixed evenly to obtain a cementitious material.

8. The application of the cementitious material prepared from multi-component solid waste as described in any one of claims 1-6 in the field of building materials.

9. The application of the cementitious material prepared from multi-component solid waste according to claim 8 in building materials, characterized in that, The application method specifically includes the following steps: Z1. Add coarse and fine aggregates to water, then add water-reducing agent, and stir at 250 r / min for 30 min to obtain a mixture; Z2. Maintain the stirring speed in step Z1, continue to add cementitious material to the mixture, and then sonicate the mixture for 90 minutes at a frequency of 30 kHz. After sonication, a slurry is obtained. Z3. Pour the slurry obtained in step Z2 into a mold, cure it at 22°C, and then demold it to obtain the building material.

10. The application of the cementitious material prepared from multi-component solid waste according to claim 9 in the field of building material preparation, characterized in that, The mass ratio of the cementitious material, coarse aggregate, fine aggregate, water and water-reducing agent is 3:2:1:1.2:0.05; crushed stone is used as coarse aggregate; river sand is used as fine aggregate; and polycarboxylate superplasticizer is used as water-reducing agent.

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