Waste residue cemented composite material and preparation method thereof

Abstract

The invention relates to the field of cementing materials, and particularly discloses a waste residue cementing composite material and a preparation method thereof. The waste residue cemented composite material comprises the following raw materials in parts by weight: 30-40 parts of mineral powder, 20-30 parts of waste brick powder, 10-20 parts of tailings, 5-10 parts of an alkaline material, 1-3 parts of a water-retaining agent, 1-3 parts of an activating agent, 5-10 parts of a water-soluble organic polymer and 3-5 parts of a toughening material, the water-soluble organic polymer is prepared from the following raw materials: 2-acrylamide-2-methylpropanesulfonic acid, acrylic acid and acrylamide; the water-soluble organic polymer prepared from the 2-acrylamide-2-methylpropanesulfonic acid, the acrylic acid and the acrylamide is adopted, so that the water loss degree of the composite material is delayed, and the phenomenon that the composite material cracks due to water loss is inhibited.

Description

Technical Field

[0001] This application relates to the field of cementing materials, and in particular to a waste residue cemented composite material and its preparation method. Background Technology

[0002] In the field of building materials, with the continuous advancement of infrastructure construction and the acceleration of urbanization, the demand for various building materials is increasing daily. At the same time, the large amounts of waste generated during industrial production, such as mineral powder and tailings, not only occupy significant land resources but also cause serious environmental pollution. How to effectively utilize these wastes and transform them into building materials with practical value has become one of the current research hotspots in the field of building materials.

[0003] However, these solid waste residues currently have poor ductility and are brittle, and many cracks will appear when subjected to external forces. Summary of the Invention

[0004] In order to overcome the shortcomings of poor toughness and high brittleness of existing solid waste cementing materials, this application provides a waste residue cementing composite material and its preparation method.

[0005] In a first aspect, this application provides a waste residue cemented composite material, which adopts the following technical solution: A waste residue cemented composite material comprises the following raw materials in parts by weight: 30-40 parts mineral powder, 20-30 parts waste brick powder, 10-20 parts tailings, 5-10 parts alkaline material, 1-3 parts water-retaining agent, 1-3 parts activator, 5-10 parts water-soluble organic polymer, and 3-5 parts toughening material; wherein the water-soluble organic polymer raw material includes 2-acrylamide-2-methylpropanesulfonic acid, acrylic acid, and acrylamide.

[0006] By adopting the above technical solution, the water-soluble organic polymer made from 2-acrylamide-2-methylpropanesulfonic acid, acrylic acid, and acrylamide can be adsorbed onto the surface of waste residue particles, reducing particle agglomeration. Simultaneously, when cracks occur in the composite material after handling, the organic polymer can absorb energy, preventing the propagation of microcracks and promoting the transformation of the composite material from brittle to tough, thus improving the impact resistance and toughness of the composite material. The water-soluble organic polymer made from 2-acrylamide-2-methylpropanesulfonic acid, acrylic acid, and acrylamide can utilize its polar groups to form hydrogen bonds with water molecules, delaying water evaporation, slowing down the degree of water loss in the composite material, and inhibiting the phenomenon of cracking due to water loss.

[0007] Preferably, the water-soluble organic polymer comprises the following raw materials in parts by weight: 20-30 parts of 2-acrylamide-2-methylpropanesulfonic acid, 30-40 parts of acrylic acid, 10-20 parts of acrylamide, and 0.5-1 parts of initiator.

[0008] By adopting the above technical solution, using 2-acrylamide-2-methylpropanesulfonic acid, acrylic acid, and acrylamide as comonomers, and employing ternary copolymerization, an organic polymer with good water control and crack resistance can be produced.

[0009] Preferably, the method for preparing the water-soluble organic polymer includes the following specific steps: 2-Acrylamide-2-methylpropanesulfonic acid, acrylic acid, and acrylamide are mixed to form a mixture. The pH of the mixture is adjusted to alkaline using sodium hydroxide. After heating, an initiator is added to react and a water-soluble organic polymer is obtained.

[0010] Preferably, the heating temperature is 55-65℃.

[0011] Preferably, the alkaline material is at least one of dopamine hydrochloride and calcium formate.

[0012] By adopting the above technical solution, dopamine hydrochloride and calcium formate can be adsorbed on the surface of waste particles in the composite material, combining with calcium ions in the composite system to form calcium formate crystals, thereby improving the early strength of the composite material. Dopamine hydrochloride can form a coating effect on the particle surface, and at the same time, it undergoes a self-polymerization reaction in the weakly alkaline environment created by calcium formate, tightly weaving the inorganic gel and organic polymer in the composite system to form an organic-inorganic hybrid network structure, further improving the toughness, density, and strength of the composite material.

[0013] Preferably, the toughening material is a nano-silica-sisal fiber composite.

[0014] By adopting the above technical solution, adding nano-silica-sisal fiber to the composite material system can reduce the generation and propagation of microcracks in the composite material. When subjected to external force, the fiber and the matrix work together to bear the force, which can improve the toughness of the composite material.

[0015] Preferably, the preparation method of the nano-silica-sisal fiber composite includes the following specific steps: Sisal fibers were pretreated with acid and alkali in sequence. The pretreated sisal fibers were then mixed with a coupling agent and anhydrous ethanol to form a sisal fiber solution. Nano-silica was added to the sisal fiber solution and subjected to ultrasonic reaction to obtain a nano-silica-sisal fiber composite.

[0016] By adopting the above technical solution, the surface roughness of sisal fiber can be increased by combining silica with sisal fiber, thereby increasing the frictional resistance and increasing the energy required for fiber breakage, thus further improving the tensile strength and impact toughness of the composite material.

[0017] Preferably, the mass ratio of the sisal fiber, coupling agent and nano silica is 10:(1-3):(5-8).

[0018] Preferably, the activator is one of water glass, sodium carbonate, and sodium hydroxide, and the water-retaining agent is a cellulose ether.

[0019] Secondly, this application provides a method for preparing a waste residue cemented composite material, which adopts the following technical solution: A method for preparing a waste residue cemented composite material includes the following specific steps: The waste residue cemented composite material is prepared by mixing mineral powder, waste brick powder, tailings, alkaline materials, water-retaining agent, activator, water-soluble organic polymer and toughening material, and stirring evenly.

[0020] By adopting the above technical solution, the composite material prepared through the synergistic effect of various components has good toughness and impact resistance.

[0021] In summary, this application has the following beneficial effects: 1. Because this application uses a water-soluble organic polymer made of 2-acrylamide-2-methylpropanesulfonic acid, acrylic acid and acrylamide to add to the composite material, it can prevent the propagation of microcracks, transform the composite material from brittle to tough, and improve the impact resistance and toughness of the composite material.

[0022] 2. In this application, dopamine hydrochloride and calcium formate are used as alkaline materials added to the composite material system to improve the early strength of the composite material and form an organic-inorganic hybrid network structure in the composite material system, further improving the toughness, density, and strength of the composite material. The nano-silica-sisal fiber composite, as a toughening material, can reduce the generation and propagation of microcracks in the composite material. When subjected to external force, the fiber and the matrix work together to bear the force, improving the toughness of the composite material. Detailed Implementation

[0023] The present application will be further described in detail below with reference to the embodiments.

[0024] All raw materials used in the examples are commercially available. Example Example 1

[0025] This embodiment provides a waste residue cemented composite material, comprising the following raw materials in parts by weight: 35 kg of mineral powder, 25 kg of waste brick powder, 15 kg of tailings, 8 kg of alkaline material, 2 kg of water-retaining agent, 2 kg of activator, 8 kg of water-soluble organic polymer, and 4 kg of toughening material. The activator is water glass, the water-retaining agent is hydroxypropyl methylcellulose, the alkaline material is calcium formate, and the toughening material is sisal fiber with an average length of 10 mm.

[0026] The water-soluble organic polymer comprises the following raw materials in parts by weight: 25 kg of 2-acrylamide-2-methylpropanesulfonic acid, 35 kg of acrylic acid, 15 kg of acrylamide, and 0.8 kg of initiator. The initiator is ammonium persulfate.

[0027] The preparation method of waste residue cemented composite material includes the following specific steps: S1: Mix 2-acrylamide-2-methylpropanesulfonic acid, acrylic acid, and acrylamide to form a mixture. Adjust the pH of the mixture to 10 using sodium hydroxide. Heat to 60°C and add an initiator to react for 4 hours to obtain a water-soluble organic polymer.

[0028] S2: Mix mineral powder, waste brick powder, tailings, alkaline materials, water-retaining agent, activator, water-soluble organic polymer and toughening material, and stir evenly to obtain waste residue cemented composite material. Example 2

[0029] The difference between Example 2 and Example 1 is that the amount of mineral powder used in the raw materials of the waste residue cemented composite material is 30 kg, the amount of waste brick powder is 20 kg, the amount of tailings is 20 kg, the amount of alkaline material is 10 kg, the amount of water-retaining agent is 1 kg, the amount of activator is 1 kg, the amount of water-soluble organic polymer is 5 kg, and the amount of toughening material is 3 kg. Example 3

[0030] The difference between Example 3 and Example 1 is that the amount of mineral powder used in the raw materials of the waste residue cemented composite material is 40 kg, the amount of waste brick powder is 30 kg, the amount of tailings is 10 kg, the amount of alkaline material is 5 kg, the amount of water-retaining agent is 3 kg, the amount of activator is 3 kg, the amount of water-soluble organic polymer is 10 kg, and the amount of toughening material is 5 kg. Example 4

[0031] The difference between Example 4 and Example 1 is that the amount of 2-acrylamide-2-methylpropanesulfonic acid used in the water-soluble organic polymer raw material is 20 kg, the amount of acrylic acid is 40 kg, the amount of acrylamide is 10 kg, and the amount of initiator is 0.5 kg. Example 5

[0032] The difference between Example 5 and Example 1 is that the amount of 2-acrylamide-2-methylpropanesulfonic acid used in the water-soluble organic polymer raw material is 30 kg, the amount of acrylic acid is 30 kg, the amount of acrylamide is 20 kg, and the amount of initiator is 1 kg. Example 6

[0033] The difference between Example 6 and Example 1 is that the alkaline material in the waste residue cemented composite material is a mixture of dopamine hydrochloride and calcium formate, with a mass ratio of 1:1. Example 7

[0034] The difference between Example 7 and Example 1 is that the toughening material in the waste residue cemented composite material is a nano-silica-sisal fiber composite.

[0035] The preparation method of waste residue cemented composite material includes the following specific steps: S1: Sisal fibers were pre-soaked in 5% sulfuric acid and sodium hydroxide solutions for 20 hours each, then washed with water until neutral and dried. The pre-treated sisal fibers were mixed with coupling agent KH560 and anhydrous ethanol to form a 2% sisal fiber solution. Nano-silica was added to the sisal fiber solution. The mass ratio of sisal fiber, coupling agent and nano-silica was 10:1:8. The mixture was reacted under ultrasound for 1 hour to obtain the nano-silica-sisal fiber composite.

[0036] S2: Mix 2-acrylamide-2-methylpropanesulfonic acid, acrylic acid, and acrylamide to form a mixture. Adjust the pH of the mixture to 10 using sodium hydroxide. Heat to 60°C and add an initiator to react for 4 hours to obtain a water-soluble organic polymer.

[0037] S3: Mix mineral powder, waste brick powder, tailings, alkaline materials, water-retaining agent, activator, water-soluble organic polymer and toughening material, and stir evenly to obtain waste residue cemented composite material. Example 8

[0038] The difference between Example 8 and Example 7 is that the mass ratio of sisal fiber, coupling agent and nano silica in the nano silica-sisal fiber composite raw material is 10:3:5.

[0039] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that the water-soluble organic polymer in the raw material of the waste residue cemented composite material is polyacrylamide, and the number-average molecular weight of polyacrylamide is 12 million.

[0040] The preparation method of waste residue cemented composite material includes the following specific steps: The waste residue cemented composite material is prepared by mixing mineral powder, waste brick powder, tailings, alkaline materials, water-retaining agent, activator, water-soluble organic polymer and toughening material, and stirring evenly.

[0041] The waste residue cemented composite materials provided in Examples 1-8 and Comparative Example 1 of this application were subjected to the following performance tests, and the test results are shown in Table 1.

[0042] I. Flexural strength and compressive strength Using the strength testing instrument, a TYE200B compressive and flexural strength tester (Wuxi Jianyi Instrument Machinery Co., Ltd.), the compressive and flexural strengths of the waste residue cemented composite material samples prepared in this application were tested at 7 days. Six test blocks were prepared for each group of experiments, and the arithmetic mean of the strengths of the six groups of test blocks was taken as the flexural and compressive strength of that group of test blocks.

[0043] II. Crack Resistance The waste residue cemented composite material prepared in this application was placed in a constant temperature and humidity test chamber for high and low temperature tests. It was placed in an environment with a temperature of -20℃ and a humidity of 0% for 24 hours, and the structural changes of the composite material were observed. Then it was placed in an environment with a temperature of 120℃ and a humidity of 50% for 24 hours, and the structural changes of the composite material were observed.

[0044] Table 1: Performance Test Results Data Table

[0045] The performance test results show that the waste residue cemented composite material prepared in this application has good compressive strength and flexural toughness. A comparison between Comparative Example 1 and Example 1 shows that, although Comparative Example 1 uses conventional polyacrylamide instead of the water-soluble organic polymer used in this application, it still maintains a certain degree of water loss resistance, but the toughness of the composite material is reduced. Contamination effectively prevents crack propagation, thereby reducing the flexural and compressive strength of the composite material.

[0046] A comparison of Example 6 and Example 1 shows that in Example 6, a mixture of dopamine hydrochloride and calcium formate was used as an alkaline material. The performance test results show that the strength and toughness of the composite material were further improved. This further illustrates that in the weakly alkaline environment created by calcium formate, dopamine hydrochloride can tightly weave the inorganic gel and organic polymer in the composite material system to form an organic-inorganic hybrid network structure, thereby further improving the toughness, density and strength of the composite material.

[0047] A comparison of Examples 7-8 and Example 1 shows that using nano-silica-sisal fiber composite as a toughening material in the waste residue cemented composite material significantly improves the overall performance of the prepared composite material, as indicated by performance testing results. This further demonstrates that the combination of silica and sisal fiber increases the surface roughness of the sisal fiber, increases frictional resistance, and consequently increases the energy required for fiber breakage, thereby further improving the tensile strength and impact toughness of the composite material.

[0048] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A waste residue cemented composite material, characterized in that, The raw materials include the following parts by weight: 30-40 parts mineral powder, 20-30 parts waste brick powder, 10-20 parts tailings, 5-10 parts alkaline material, 1-3 parts water-retaining agent, 1-3 parts activator, 5-10 parts water-soluble organic polymer, and 3-5 parts toughening material; the water-soluble organic polymer raw material includes 2-acrylamide-2-methylpropanesulfonic acid, acrylic acid, and acrylamide.

2. The waste residue cemented composite material according to claim 1, characterized in that, The water-soluble organic polymer comprises the following raw materials in parts by weight: 20-30 parts of 2-acrylamide-2-methylpropanesulfonic acid, 30-40 parts of acrylic acid, 10-20 parts of acrylamide, and 0.5-1 parts of initiator.

3. The waste residue cemented composite material according to claim 2, characterized in that, The preparation method of the water-soluble organic polymer includes the following specific steps: 2-Acrylamide-2-methylpropanesulfonic acid, acrylic acid, and acrylamide are mixed to form a mixture. The pH of the mixture is adjusted to alkaline using sodium hydroxide. After heating, an initiator is added to react and a water-soluble organic polymer is obtained.

4. The waste residue cemented composite material according to claim 3, characterized in that, The heating temperature is 55-65℃.

5. The waste residue cemented composite material according to claim 1, characterized in that, The alkaline material is at least one of dopamine hydrochloride and calcium formate.

6. The waste residue cemented composite material according to claim 1, characterized in that, The toughening material is a nano-silica-sisal fiber composite.

7. The waste residue cemented composite material according to claim 6, characterized in that, The preparation method of the nano-silica-sisal fiber composite includes the following specific steps: Sisal fibers were pretreated with acid and alkali in sequence. The pretreated sisal fibers were then mixed with a coupling agent and anhydrous ethanol to form a sisal fiber solution. Nano-silica was added to the sisal fiber solution and subjected to ultrasonic reaction to obtain a nano-silica-sisal fiber composite.

8. The waste residue cemented composite material according to claim 7, characterized in that, The mass ratio of the sisal fiber, coupling agent and nano silica is 10:(1-3):(5-8).

9. The waste residue cemented composite material according to claim 1, characterized in that, The activator is one of water glass, sodium carbonate, and sodium hydroxide, and the water-retaining agent is a cellulose ether.

10. A method for preparing a waste residue cemented composite material as described in any one of claims 1-9, characterized in that, The specific steps include the following: The waste residue cemented composite material is prepared by mixing mineral powder, waste brick powder, tailings, alkaline materials, water-retaining agent, activator, water-soluble organic polymer and toughening material, and stirring evenly.

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