Solid-waste-based low-carbon cementing material

Abstract

The invention discloses a solid waste-based low-carbon cementing material, and relates to the technical field of polymer composite materials, and the solid waste-based low-carbon cementing material specifically comprises the following components: steel slag, granulated blast-furnace slag, industrial byproduct gypsum, tailing slag, a wear-resistant agent, water and an additive; the content of each component is as follows: 20-50 parts of steel slag; 30 to 60 parts of granulated blast furnace slag; 5-10 parts of industrial byproduct gypsum; 10 to 20 parts of tailing slag; 8-17 parts of a wear-resistant agent; 4 to 10 parts of water; 3-5 parts of an additive; the wear-resistant agent is of a hollow structure, and a cavity of the wear-resistant agent is filled with carbon dioxide and sealed through a sealing film. According to the solid-waste-based low-carbon cementing material, through the arrangement of the wear-resistant agent, calcium oxide and magnesium oxide in the steel slag can be in full contact with carbon dioxide in the pretreatment process of the steel slag, the influence of the diffusion speed of the carbon dioxide on carbonization maintenance of the steel slag is eliminated, and the carbonization speed of the steel slag is increased; the wear resistance of the produced cementing material can be improved, and the service life of the cementing material can be prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer composite materials, and particularly to a solid waste-based low-carbon cementitious material. Background Art

[0002] A cementitious material, also known as a binder, can turn from a slurry into a solid stone-like body under physical and chemical actions, and can cement other materials to form a composite solid with a certain mechanical strength. A solid waste-based cementitious material is a new type of low-carbon cementitious material that can replace cement in most application fields. Its production cost is about 50% of that of cement, and the carbon emissions during the production process are only 10% of that of cement. Moreover, it has excellent properties such as corrosion resistance, low shrinkage, and low heat of hydration.

[0003] In related technologies, steel slag is used as one of the production raw materials for solid waste-based low-carbon cementitious materials. However, since steel slag contains free calcium oxide and magnesium oxide, and calcium oxide reacts with water at room temperature, and magnesium oxide is prone to decomposition or deterioration under sunlight irradiation. Therefore, calcium oxide and magnesium oxide in steel slag will bring certain expansion effects and volume instability, which will affect the reliability of solid waste-based low-carbon cementitious materials. To solve this problem, in the prior art, the method of carbonating steel slag by placing it in a CO2 gas environment for carbonation curing of steel slag is usually adopted. However, during the carbonation process, affected by the diffusion rate of carbon dioxide, there are potential hazards such as a long required carbonation curing time, a low degree of carbonation inside the steel slag, and incomplete guarantee of volume stability. Moreover, the wear resistance of steel slag is poor, which affects the wear resistance of the cementitious material. Based on this, the present application proposes a solid waste-based low-carbon cementitious material. Summary of the Invention

[0004] The present invention provides a solid waste-based low-carbon cementitious material, which solves the problems in the above background art that when the method of placing steel slag in a CO2 gas environment for carbonation curing of steel slag is used for treatment, affected by the diffusion rate of carbon dioxide, there are potential hazards such as a long required carbonation curing time, a low degree of carbonation inside the steel slag, and incomplete guarantee of volume stability; and the wear resistance of the cementitious material is poor.

[0005] The present invention provides the following technical solution: A solid waste-based low-carbon cementitious material, comprising the following components: steel slag, granulated blast furnace slag, industrial by-product gypsum, tailings slag, wear-resistant agent, water, and admixture;

[0006] The content of each of the above components is: 20-50 parts of steel slag; 30-60 parts of granulated blast furnace slag; 5-10 parts of industrial by-product gypsum; 10-20 parts of tailings slag; 8-17 parts of wear-resistant agent; 4-10 parts of water; admixture: 3-5 parts;

[0007] Among them: the wear-resistant agent has a hollow structure, the cavity of the wear-resistant agent is filled with carbon dioxide, and the cavity of the wear-resistant agent is sealed by a sealing film;

[0008] The steel slag is pretreated. The specific operation of the steel slag pretreatment is as follows: after the steel slag particles are fully mixed with the wear-resistant agent and the admixture, they are mixed with water, and under a negative pressure state, carbon dioxide is released, and the steel slag is subjected to carbonation curing pretreatment in a carbonation curing environment.

[0009] Preferably, the industrial by-product gypsum is desulfurized gypsum, and the mass ratio of the industrial by-product gypsum to the steel slag is: 6.25%-6.5%:1.

[0010] Preferably, the mass ratio of the water to the steel slag is: 16%-19%:1; the mass ratio of the steel slag to the carbon dioxide is: 1000:340.

[0011] Preferably, the particle size of the wear-resistant agent is the same as that of the steel slag, and the sealing film is a water-insoluble film.

[0012] Preferably, the carbonation curing environment of the steel slag is: temperature 60-70°C; pH value is 12-13; forming pressure is 8-14 MPa; carbon dioxide pressure is: 0.4-0.5 MPa.

[0013] Preferably, there are multiple chambers in the inner cavity of the wear-resistant agent, and the thickness of the sealing film wrapped outside each chamber is different.

[0014] Preferably, the admixture includes any two of NaHCO3, Na2SiO3 and sodium carboxymethyl cellulose.

[0015] Preferably, the tailings slag is one or more of hot metal desulfurization tailings slag, high-silicon iron tailings sand, and copper tailings slag.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. For this solid waste-based low-carbon cementitious material, through the setting of the wear-resistant agent, during the pretreatment of the steel slag, calcium oxide and magnesium oxide in the steel slag can fully contact with carbon dioxide, eliminating the influence of the carbon dioxide diffusion rate on the carbonation curing of the steel slag, improving the carbonation speed of the steel slag, and the setting of the wear-resistant agent can improve the wear resistance of the produced cementitious material and extend the service life of the cementitious material.

[0018] 2. For this solid waste-based low-carbon cementitious material, by adopting the method of mixing the wear-resistant agent with the steel slag, carbon dioxide can be evenly dispersed among the steel slag, so that when the steel slag is carbonated and cured, the steel slag can fully contact with carbon dioxide, ensuring the carbonation effect of the steel slag. Description of the Drawings

[0019] Figure 1 Schematic diagram for detecting the properties of the mortar prepared in the embodiments of the present invention. Detailed implementation manners

[0020] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0021] The present invention provides a solid waste-based low-carbon cementitious material, which includes the following components: steel slag, granulated blast furnace slag, industrial by-product gypsum, tailing slag, wear-resistant agent, water and admixture;

[0022] The contents of the above components are as follows: 20-50 parts of steel slag; 30-60 parts of granulated blast furnace slag; 5-10 parts of industrial by-product gypsum; 10-20 parts of tailing slag; 8-17 parts of wear-resistant agent; 4-10 parts of water; admixture: 3-5 parts.

[0023] Among them: the industrial by-product gypsum is desulfurized gypsum, and the mass ratio of the industrial by-product gypsum to the steel slag is: 6.25%-6.5%:1. The mass ratio of water to the steel slag is: 16%-19%:1; the mass ratio of the steel slag to carbon dioxide is: 1000:340.

[0024] The admixture includes any two of NaHCO3, Na2SiO3 and sodium carboxymethyl cellulose, and the tailing slag is one or more of hot metal desulfurization tailing slag, high-silicon iron tailing sand, and copper tailing slag.

[0025] The wear-resistant agent has a hollow structure, and there are multiple chambers in the inner cavity of the wear-resistant agent. The chambers of the wear-resistant agent are filled with carbon dioxide. The chambers of the wear-resistant agent are sealed by a sealing film, and the thickness of the sealing film wrapped outside each chamber is different. In this way, the sealing films with different thicknesses need to be broken under different negative pressure environments. When the sealing film is broken, the carbon dioxide filled in the chamber can be discharged.

[0026] The particle size of the wear-resistant agent is the same as that of the steel slag. In some embodiments of the present application, the material of the wear-resistant agent is ceramic, and the sealing film is a water-insoluble film, and the sealing film can intercept carbon dioxide.

[0027] When steel slag is mixed with granulated blast furnace slag, industrial by-product gypsum and tailing slag, the steel slag is pretreated. The pretreatment operation of the steel slag is as follows: After the steel slag particles are fully mixed with wear-resistant agent and admixture, they are mixed with water, and under negative pressure, carbon dioxide is gradually released, and the steel slag is subjected to carbonation curing pretreatment in a carbonation curing environment. The carbonation curing environment of the steel slag is: temperature 60 - 70°C; pH value 12 - 13; molding pressure 8 - 14 MPa; carbon dioxide pressure: 0.4 - 0.5 MPa, and carbonation time 6 - 8 h.

[0028] The preparation method of a solid waste-based low-carbon cementitious material provided by the present invention is as follows: After the pretreated steel slag is fully and evenly mixed with granulated blast furnace slag, industrial by-product gypsum and tailing slag, it is ground until the particle size of the particulate matter is 30 - 80 μm, and then mixed evenly to obtain a solid waste-based low-carbon cementitious material provided by the present application.

[0029] It can be seen from the above description that during the pretreatment of steel slag, calcium oxide and magnesium oxide in the steel slag can be fully contacted with carbon dioxide, eliminating the influence of the carbon dioxide diffusion rate on the carbonation curing of steel slag, increasing the carbonation rate of steel slag, and the setting of the wear-resistant agent can improve the wear resistance of the produced cementitious material and extend the service life of the cementitious material.

[0030] Next, the present application will be further described through some embodiments of the present application.

[0031] Example 1

[0032] The solid waste-based low-carbon cementitious material includes the following components and contents: 20 parts of steel slag; 30 parts of granulated blast furnace slag; 5 parts of industrial by-product gypsum; 10 parts of tailing slag; 8 parts of wear-resistant agent; 4 parts of water; 3 parts of admixture. The admixture is NaHCO3 and Na2SiO3, and the tailing slag is hot metal desulfurization tailing slag.

[0033] The preparation method of the solid waste-based low-carbon cementitious material is as follows: After the steel slag particles are fully mixed with the wear-resistant agent and the admixture, they are mixed with water, and under negative pressure, carbon dioxide is gradually released, and the steel slag is subjected to carbonation curing pretreatment in a carbonation curing environment. The carbonation curing environment of the steel slag is: temperature 65°C; pH value 12.5; molding pressure 12 MPa; carbon dioxide pressure: 0.5 MPa, and carbonation time 7 h;

[0034] After the pretreated steel slag is fully and evenly mixed with granulated blast furnace slag, industrial by-product gypsum and tailing slag, it is ground until the particle size of the particulate matter is 40 μm, and then mixed evenly to obtain the solid waste-based low-carbon cementitious material.

[0035] Example 2

[0036] Solid waste-based low-carbon cementitious material, the components and their contents are as follows: 20 parts of steel slag; 30 parts of granulated blast furnace slag; 5 parts of industrial by-product gypsum; 10 parts of tailings slag; 8 parts of wear-resistant agent; 4 parts of water; 3 parts of admixture, the admixture is NaHCO3 and Na2SiO3, and the tailings slag is hot metal desulfurization tailings slag.

[0037] The preparation method of the solid waste-based low-carbon cementitious material is as follows: After fully mixing the steel slag particles with the wear-resistant agent and the admixture, mix them with water, and gradually release carbon dioxide under a negative pressure state, and carry out carbonation curing pretreatment on the steel slag in a carbonation curing environment. The carbonation curing environment of the steel slag is: temperature 65°C; pH value 12.5; molding pressure 10 MPa; carbon dioxide pressure: 0.5 MPa, and the carbonation time is 7 h;

[0038] After fully mixing and homogenizing the pretreated steel slag with granulated blast furnace slag, industrial by-product gypsum and tailings slag, carry out grinding treatment until the particle size of the particulate matter is 40 μm, and then mix evenly to obtain the solid waste-based low-carbon cementitious material.

[0039] Example 3

[0040] Solid waste-based low-carbon cementitious material, the components and their contents are as follows: 20 parts of steel slag; 30 parts of granulated blast furnace slag; 5 parts of industrial by-product gypsum; 10 parts of tailings slag; 8 parts of wear-resistant agent; 5 parts of water; 3 parts of admixture, the admixture is NaHCO3 and Na2SiO3, and the tailings slag is hot metal desulfurization tailings slag.

[0041] The preparation method of the solid waste-based low-carbon cementitious material is as follows: After fully mixing the steel slag particles with the wear-resistant agent and the admixture, mix them with water, and gradually release carbon dioxide under a negative pressure state, and carry out carbonation curing pretreatment on the steel slag in a carbonation curing environment. The carbonation curing environment of the steel slag is: temperature 65°C; pH value 12.5; molding pressure 12 MPa; carbon dioxide pressure: 0.5 MPa, and the carbonation time is 7 h;

[0042] After fully mixing and homogenizing the pretreated steel slag with granulated blast furnace slag, industrial by-product gypsum and tailings slag, carry out grinding treatment until the particle size of the particulate matter is 40 μm, and then mix evenly to obtain the solid waste-based low-carbon cementitious material.

[0043] Example 4

[0044] Solid waste-based low-carbon cementitious material, the components and their contents are as follows: 20 parts of steel slag; 30 parts of granulated blast furnace slag; 5 parts of industrial by-product gypsum; 10 parts of tailings slag; 12 parts of wear-resistant agent; 4 parts of water; 3 parts of admixture, the admixture is NaHCO3 and Na2SiO3, and the tailings slag is hot metal desulfurization tailings slag.

[0045] The preparation method of the solid waste-based low-carbon cementitious material is as follows: After fully mixing steel slag particles with wear-resistant agents and admixtures, mix them with water, and gradually release carbon dioxide under negative pressure, and perform carbonation curing pretreatment on the steel slag in a carbonation curing environment. The carbonation curing environment of the steel slag is: temperature 65°C; pH value 12.5; forming pressure 12 MPa; carbon dioxide pressure: 0.5 MPa, carbonation time 7 h;

[0046] After fully mixing and homogenizing the pretreated steel slag with granulated blast furnace slag, industrial by-product gypsum and tailings slag, perform grinding treatment until the particle size of the particulate matter is 40 μm, and then mix evenly to obtain the solid waste-based low-carbon cementitious material.

[0047] Prepare mortar using the cementitious material prepared in the example: Mix 4 parts of cement, 7 parts of cementitious material, 3 parts of fly ash, 80 parts of aggregate, and 2 parts of water reducer evenly, add water, and mix evenly to obtain the mortar. Pour the mortar into 40mm×40mm×40mm molds and vibrate to form. The specimens are cured for 1 d at room temperature and humidity ≥90%, and then demolded. Then, at room temperature and humidity ≥90%, cure until the age of 4 d, and perform compressive strength testing in accordance with GB / T 17671-1999 "Test Method for Compressive Strength of Cement Mortar (ISO Method)". The test results are as Figure 1 shown. According to Figure 1 The conclusion drawn is: The compressive performance of the specimens with a water content of 4 parts is greater than that of the specimens with a water content of 5 parts; the higher the content of the wear-resistant agent, the better the compressive performance of the specimens; when the forming pressure is 12 MPa, the compressive performance of the specimens is better than that of the specimens with a forming pressure of 10 MPa.

[0048] The content not described in detail in this specification belongs to the prior art well-known to those skilled in the art. Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A solid waste-based low-carbon cementitious material, characterized in that, It includes the following components: steel slag, granulated blast furnace slag, industrial by-product gypsum, tailing slag, wear-resistant agent, water and admixture; The contents of the above components are as follows: 20 - 50 parts of steel slag; 30 - 60 parts of granulated blast furnace slag; 5 - 10 parts of industrial by-product gypsum; 10 - 20 parts of tailing slag; 8 - 17 parts of wear-resistant agent; 4 - 10 parts of water; Admixture: 3 - 5 parts; Among them: the wear-resistant agent has a hollow structure, the cavity of the wear-resistant agent is filled with carbon dioxide, and the cavity of the wear-resistant agent is sealed by a sealing film; The steel slag is pretreated, and the specific operation of the steel slag pretreatment is: after fully mixing the steel slag particles with the wear-resistant agent and the admixture, mixing with water, and releasing carbon dioxide under a negative pressure state, carbonation curing pretreatment of the steel slag is carried out in a carbonation curing environment.

2. The low-carbon cementitious material based on solid waste according to claim 1, wherein: The industrial by-product gypsum is desulfurized gypsum, and the mass ratio of the industrial by-product gypsum to the steel slag is: 6.25% - 6.5%:

1.

3. The low-carbon cementitious material based on solid waste according to claim 1, wherein: The mass ratio of the water to the steel slag is: 16% - 19%: 1; the mass ratio of the steel slag to the carbon dioxide is: 1000:

340.

4. A solid waste-based low-carbon cementitious material according to claim 1, characterized in that: The particle size of the wear-resistant agent is the same as that of the steel slag, and the sealing film is a water-insoluble film.

5. The waste-based low-carbon cementitious material according to claim 1, characterized in that: The steel slag carbonation curing environment is: temperature 60 - 70°C; pH value is 12 - 13; forming pressure is 8 - 14 MPa; carbon dioxide pressure is: 0.4 - 0.5 MPa.

6. The low-carbon cementitious material based on solid waste according to claim 1, characterized in that: There are multiple cavities in the inner cavity of the wear-resistant agent, and the thickness of the sealing film wrapped outside each cavity is different.

7. A solid waste-based low-carbon cementitious material according to claim 1, characterized in that: The admixture includes any two of NaHCO3, Na2SiO3 and sodium carboxymethyl cellulose.

8. A solid waste-based low-carbon cementitious material according to claim 1, characterized in that: The tailing slag is one or more of hot metal desulfurization tailing slag, high-silicon iron tailing sand, and copper tailing slag.

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