Green low-carbon copper tailing-based alkali-activated concrete and preparation method thereof
By combining copper tailings powder and alkali exciter with cement, green and low-carbon copper tailings base excitation concrete is prepared, solving the problems of copper tailings accumulation and concrete production carbon emissions, and achieving resource utilization and performance improvement.
Patent Information
- Application Number
- CN202510205648.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-25
- Publication Date
- 2025-05-13
AI Technical Summary
Traditional copper tailings treatment methods cannot effectively reduce environmental pollution, and concrete production relies on a large amount of natural resources and high energy consumption to cement manufacturing processes lead to carbon emissions.
Copper tailings powder is used as raw material, combined with alkali exciter and cement, and green and low-carbon copper tailings base excitation concrete is prepared through specific ratios and preparation methods.
It effectively solves the environmental pollution problem caused by copper tailings accumulation, reduces carbon emissions from concrete production, and improves the mechanical properties of concrete.
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Figure CN119977477A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of building materials, and in particular relates to a green and low-carbon copper tailings-based alkali-activated concrete and a preparation method thereof. Background Art
[0002] With the acceleration of global industrialization, the generation and treatment of mining waste has become increasingly serious. As a ubiquitous by-product of mining, the accumulation of copper tailings not only occupies a large amount of land, but also causes serious pollution to the surrounding ecological environment. Traditional treatment methods mainly include landfill and simple physical treatment. These methods not only fail to effectively reduce the environmental impact caused by tailings, but may also induce secondary pollution of soil and water sources.
[0003] In the production process of concrete, traditional cement formulas usually rely on a large amount of natural raw materials such as sand and cement, which not only consumes huge natural resources, but also comes with significant carbon emissions. The cement manufacturing process itself is a high-energy industrial activity, and its carbon emissions account for about 8% of the world's total emissions. Although some studies have explored the use of industrial waste such as fly ash and slag as alternative raw materials for concrete, in actual applications, the supply of these materials is limited and they are often used together with traditional cement, which does not effectively reduce the overall environmental impact. In the existing alkali-activated concrete technology, although its energy consumption is relatively low, there is still room for breakthroughs in the efficiency of the use of specific solid wastes and the improvement of concrete performance.
[0004] To this end, technicians in this field have proposed a green and low-carbon copper tailings-based alkali-activated concrete and a preparation method thereof, aiming to effectively convert copper tailings into a sustainable raw material for alkali-activated concrete, which can not only solve the problem of tailings accumulation, but also reduce carbon emissions in concrete production and improve material performance. Summary of the invention
[0005] In order to solve the above technical problems, the present invention provides a green and low-carbon copper tailings-based alkali-activated concrete and a preparation method thereof to solve the problems raised in the background technology.
[0006] According to the first aspect of the present disclosure, a green and low-carbon copper tailings-based alkali-activated concrete is proposed, which is composed of the following raw materials in parts by weight: 150 to 200 parts of copper tailings powder, 450 to 600 parts of cement, 600 to 700 parts of coarse and fine aggregates, 80 to 120 parts of alkali activator, 15 to 20 parts of polycarboxylic acid water reducer, 200 to 270 parts of water, and a water-cement ratio of 0.25 to 0.35.
[0007] Preferably, the sum of the copper tailings powder, cement, Na2O and SiO2 constitutes the total cementitious material, wherein the copper tailings powder accounts for 15% to 25% of the total cementitious material, the cement is ordinary Portland cement, and its amount accounts for 60% to 70% of the total cementitious material, the Na2O accounts for 5% to 10% of the total cementitious material, and the SiO2 accounts for 4% to 6% of the total cementitious material.
[0008] Preferably, the coarse and fine aggregates are composed of crushed stone and fine sand, wherein the crushed stone particle size is 5-25 mm in continuous grading, and the amount accounts for 35%-45% of the total volume of the concrete; the fineness modulus of the fine sand is 2.3-3.0, and the amount accounts for 25%-35% of the total volume of the concrete.
[0009] Preferably, the alkali activator consists of NaOH solution, water glass and water, wherein the concentration of NaOH solution is 8% to 12%, the amount of solution accounts for 10% to 20% of the total water consumption, the modulus of water glass is 2.0 to 3.0, the amount accounts for 3% to 8% of the total cementitious material, and the amount of water meets the workability of the concrete mixture.
[0010] Preferably, it is composed of the following raw materials in parts by weight: 150 parts of copper tailings powder, 600 parts of cement, 600 parts of coarse and fine aggregates, including 450 parts of crushed stone, 150 parts of fine sand, 80 parts of alkali activator, including 20 parts of NaOH solution, 10 parts of water glass, 15 parts of polycarboxylate water reducer, 210 parts of water, and the water-cement ratio is 0.28.
[0011] According to a second aspect of the present disclosure, a method for preparing green and low-carbon copper tailings-based alkali-activated concrete is proposed, comprising the following steps:
[0012] S1, crushing, screening and grinding the copper tailings to obtain copper tailings powder, and drying it;
[0013] S2, the coarse and fine aggregates composed of crushed stone and fine sand are cleaned to remove dirt and impurities, and the dried copper tailings powder and cement are dry-mixed with the coarse and fine aggregates for 1 to 2 minutes to preliminarily mix the solid raw materials and obtain a mixed dry material;
[0014] S3, preparing an alkaline activator solution by mixing NaOH solution, water glass and water, and cooling the mixture for 24 hours;
[0015] S4, slowly add the alkali activator solution to the mixed dry materials, start the mixer to stir at the same time, so that the raw materials are fully mixed, and add the polycarboxylate water reducer during the stirring and mixing process, and continue stirring for 3 to 5 minutes to obtain a concrete mixture;
[0016] S5, pouring the mixed concrete mixture into a mold, vibrating and molding it to make it dense and free of bubbles, and obtaining a molded concrete specimen;
[0017] S6. Cover the formed concrete specimens with wet cloth or plastic film to keep them moist and perform curing for 28 days to fully solidify them and obtain the final product.
[0018] Preferably, the preparation of the alkaline activator solution comprises the following steps:
[0019] S301. According to the required concentration and amount of NaOH solution, weigh solid NaOH, slowly add solid NaOH to an appropriate amount of water in a well-ventilated environment, stirring while adding, and controlling the stirring speed at 200-300 rpm to ensure that NaOH is fully dissolved, fully cooled, and the solution temperature does not exceed 50° C. to obtain the required NaOH solution;
[0020] S302, according to the amount of water glass and the modulus requirements, in another container, add the weighed water glass to the remaining water, gently stir to make it evenly dispersed, when mixing, first slowly pour the water glass into the water, and stir at a speed of 150-250 rpm;
[0021] S303. Slowly pour the prepared NaOH solution into the water glass solution, stirring gently during the operation to obtain a combined solution, and mix the combined solution again by a stirring device with a stirring speed set to 100-150 rpm, and continue stirring for 5-8 minutes until the mixture is uniform to obtain a uniform and stable alkaline activator solution.
[0022] Preferably, the temperature of the curing conditions is maintained at 20±2° C. and the relative humidity is above 95%.
[0023] Compared with the prior art, the present invention has the following beneficial effects:
[0024] 1. The present invention uses copper tailings powder as raw material, and the copper tailings powder dosage can reach 20%, which effectively solves the environmental pollution and resource waste problems caused by the large accumulation of copper tailings, realizes the resource utilization of industrial solid waste, and conforms to the concept of sustainable development.
[0025] 2. Compared with the traditional concrete production process, the alkali-activated concrete production process of the present invention has lower carbon emissions, which helps to reduce the impact on the environment. The use of copper tailings as raw materials reduces the demand for new raw materials, thereby saving energy and energy consumption in the mining and processing of raw materials. The alkali activator can stimulate the active ingredients in the copper tailings, and work together with cement and other cementitious materials to significantly improve the compressive strength, tensile strength and other mechanical properties of concrete. BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Figure 1 This is a diagram of the preparation method of the copper tailings based alkali activated concrete of the present invention. DETAILED DESCRIPTION
[0027] The following embodiments of the present invention are described in further detail in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.
[0028] Embodiment 1: The present invention provides a green and low-carbon copper tailings-based alkali-activated concrete, which is composed of the following raw materials in parts by weight: 150 parts of copper tailings powder, 600 parts of cement, 600 parts of coarse and fine aggregates, 80 parts of alkali activator, 15 parts of polycarboxylic acid water reducer, 210 parts of water, and a water-cement ratio of 0.28. The total cementitious material is composed of the sum of copper tailings powder, cement, Na2O and SiO2, wherein the amount of copper tailings powder accounts for 20% of the total cementitious material, cement adopts ordinary silicate cement, which accounts for 70% of the total cementitious material, Na2O accounts for 6% of the total cementitious material, and SiO2 accounts for 4% of the total cementitious material; the alkali activator is composed of NaOH solution, water glass and water, wherein the concentration of NaOH solution is 10%, the amount of solution accounts for 10% of the total water consumption, the modulus of water glass is 2.0, and the proportion of water glass in the total cementitious material is 3%.
[0029] Embodiment 2: A green and low-carbon copper tailings-based alkali-activated concrete is composed of the following raw materials in parts by weight: 180 parts of copper tailings powder, 520 parts of cement, 650 parts of coarse and fine aggregates, 100 parts of alkali activator, 18 parts of polycarboxylic acid water reducer, 245 parts of water, and a water-cement ratio of 0.35. The total cementitious material is composed of the sum of copper tailings powder, cement, Na2O and SiO2, wherein the amount of copper tailings powder accounts for 15% of the total cementitious material, cement adopts ordinary silicate cement, which accounts for 70% of the total cementitious material, Na2O accounts for 10% of the total cementitious material, and SiO2 accounts for 5% of the total cementitious material; the alkali activator is composed of NaOH solution, water glass and water, wherein the concentration of NaOH solution is 10%, the amount of solution accounts for 15% of the total water consumption, the modulus of water glass is 2.0, and the proportion of water glass in the total cementitious material is 5%.
[0030] Embodiment 3: It is composed of the following raw materials in parts by weight: 200 parts of copper tailings powder, 480 parts of cement, 700 parts of coarse and fine aggregates, 120 parts of alkali activator, 20 parts of polycarboxylic acid water reducer, 170 parts of water, and the water-cement ratio is 0.25. The total cementitious material is composed of the sum of copper tailings powder, cement, Na2O and SiO2, wherein the amount of copper tailings powder accounts for 25% of the total cementitious material, cement adopts ordinary silicate cement, and its amount accounts for 60% of the total cementitious material, Na2O accounts for 10% of the total cementitious material, and SiO2 accounts for 5% of the total cementitious material; the alkali activator is composed of NaOH solution, water glass and water, wherein the concentration of NaOH solution is 10%, the amount of solution accounts for 20% of the total water consumption, the modulus of water glass is 2.0, and the proportion of water glass accounts for 8% of the total cementitious material.
[0031] Embodiment 4: The present invention provides a method for preparing green and low-carbon copper tailings-based alkali-activated concrete, comprising the following steps:
[0032] S1, crushing, screening and grinding the copper tailings to obtain copper tailings powder, and drying it;
[0033] S2, the coarse and fine aggregates composed of crushed stone and fine sand are cleaned to remove dirt and impurities, and the dried copper tailings powder and cement are dry-mixed with the coarse and fine aggregates for 1 to 2 minutes to preliminarily mix the solid raw materials and obtain a mixed dry material;
[0034] S3, preparing an alkaline activator solution by mixing NaOH solution, water glass and water, and cooling the mixture for 24 hours; the preparation of the alkaline activator solution comprises the following steps:
[0035] S301. According to the required concentration and amount of NaOH solution, weigh solid NaOH, slowly add solid NaOH to an appropriate amount of water in a well-ventilated environment, stirring while adding, and controlling the stirring speed at 200-300 rpm to ensure that NaOH is fully dissolved, fully cooled, and the solution temperature does not exceed 50° C. to obtain the required NaOH solution;
[0036] S302, according to the amount of water glass and the modulus requirements, in another container, add the weighed water glass to the remaining water, gently stir to make it evenly dispersed, when mixing, first slowly pour the water glass into the water, and stir at a speed of 150-250 rpm;
[0037] S303. Slowly pour the prepared NaOH solution into the water glass solution, stirring gently during the operation to obtain a combined solution, and mix the combined solution again by a stirring device with a stirring speed set to 100-150 rpm, and continue stirring for 5-8 minutes until the mixture is uniform to obtain a uniform and stable alkaline activator solution.
[0038] S4, slowly add the alkali activator solution to the mixed dry materials, start the mixer to stir at the same time, so that the raw materials are fully mixed, and add the polycarboxylate water reducer during the stirring and mixing process, and continue stirring for 3 to 5 minutes to obtain a concrete mixture;
[0039] S5, pouring the mixed concrete mixture into a mold, vibrating and molding it to make it dense and free of bubbles, and obtaining a molded concrete specimen;
[0040] S6. Cover the formed concrete specimens with wet cloth or plastic film to keep them moist and perform curing. The temperature of the curing conditions is maintained at 20±2°C and the relative humidity is above 95%. The curing time is 28 days to fully cure the specimens to obtain the final product.
[0041] According to the calculation method and evaluation standard of carbon emission of concrete, the content of copper tailings powder in Example 1 is 20%. Compared with ordinary concrete, the carbon emission reduction rate reaches 55.6%; compared with the benchmark sample, the carbon emission reduction rate is about 79.1%.
[0042] The mechanical properties of the concrete prepared in Examples 1 to 3 were tested, and the results are shown in the following table:
[0043]
[0044] As can be seen from the above table, Example 1 not only meets the carbon emission reduction rate requirements, but also performs best in mechanical properties, and can effectively reduce carbon emissions and increase mechanical properties during use. Using copper tailings as raw materials reduces the demand for new raw materials, thereby saving energy and energy consumption in the mining and processing of raw materials, and effectively solves the environmental pollution and resource waste problems caused by the large accumulation of copper tailings. The alkali activator can stimulate the active ingredients in the copper tailings, and the mechanical properties of the concrete such as compressive strength and tensile strength can be significantly improved under the joint action of cementitious materials such as cement.
[0045] Importantly, it should be noted that the construction and arrangement of the present application shown in a plurality of different exemplary embodiments are only exemplary. Although only several embodiments are described in detail in this disclosure, it should be easily understood by the personnel referring to this disclosure that many modifications are possible (e.g., the size, scale, structure, shape and ratio of various elements, and parameter values (e.g., temperature, pressure, etc.), installation arrangements, use of materials, color, directional changes, etc.) without departing from the scope of the present invention. Other replacements, modifications, changes and omissions can be made in the design, operating conditions and arrangement of the exemplary embodiments. Therefore, the present invention is not limited to specific embodiments, but extends to multiple modifications that still fall within the scope of the appended claims.
[0046] Additionally, in order to provide a concise description of exemplary embodiments, all features of an actual embodiment (ie, those features that are not relevant to the best mode presently contemplated for carrying out the invention or those that are not relevant to implementing the invention) may not be described.
[0047] It should be understood that in the development of any actual implementation, as in any engineering or design project, numerous implementation-specific decisions may be made. Such a development effort may be complex and time-consuming, but for those of ordinary skill having the benefit of this disclosure, without undue experimentation, the development effort will be a routine task of design, fabrication, and production.
[0048] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.
Claims
1. A green and low-carbon copper tailings-based alkali-activated concrete, characterized in that: The concrete is composed of the following raw materials in parts by weight: 150-200 parts of copper tailings powder, 450-600 parts of cement, 600-700 parts of coarse and fine aggregates, 80-120 parts of alkali activator, 15-20 parts of polycarboxylic acid water reducer, 200-270 parts of water, and a water-cement ratio of 0.25-0.
35.
2. A green and low-carbon copper tailings-based alkali-activated concrete as claimed in claim 1, characterized in that: The sum of the copper tailings powder, cement, Na2O and SiO2 constitutes the total cementitious material, wherein the copper tailings powder accounts for 15% to 25% of the total cementitious material, the cement is ordinary Portland cement, and its amount accounts for 60% to 70% of the total cementitious material, the Na2O accounts for 5% to 10% of the total cementitious material, and the SiO2 accounts for 4% to 6% of the total cementitious material.
3. A green and low-carbon copper tailings-based alkali-activated concrete as claimed in claim 1, characterized in that: The coarse and fine aggregates are composed of crushed stone and fine sand, wherein the crushed stone particle size is 5-25mm with continuous grading, and the amount accounts for 35%-45% of the total volume of concrete; the fineness modulus of the fine sand is 2.3-3.0, and the amount accounts for 25%-35% of the total volume of concrete.
4. A green and low-carbon copper tailings-based alkali-activated concrete as described in claims 1 to 2, characterized in that: The alkali activator consists of NaOH solution, water glass and water, wherein the concentration of the NaOH solution is 8% to 12%, the amount of the solution accounts for 10% to 20% of the total water consumption, the modulus of the water glass is 2.0 to 3.0, the amount of the solution accounts for 3% to 8% of the total cementitious material, and the amount of water meets the workability of the concrete mixture.
5. A green and low-carbon copper tailings-based alkali-activated concrete as claimed in claim 1, characterized in that: The invention is composed of the following raw materials in parts by weight: 150 parts of copper tailings powder, 600 parts of cement, 600 parts of coarse and fine aggregates, including 450 parts of crushed stone, 150 parts of fine sand, 80 parts of alkali activator, including 20 parts of NaOH solution, 10 parts of water glass, 15 parts of polycarboxylic acid water reducer, 210 parts of water, and the water-cement ratio is 0.
28.
6. A method for preparing green and low-carbon copper tailings-based alkali-activated concrete, characterized in that: The following steps are involved: S1, crushing, screening and grinding the copper tailings to obtain copper tailings powder, and drying it; S2, the coarse and fine aggregates composed of crushed stone and fine sand are cleaned to remove dirt and impurities, and the dried copper tailings powder and cement are dry-mixed with the coarse and fine aggregates for 1 to 2 minutes to preliminarily mix the solid raw materials and obtain a mixed dry material; S3, preparing an alkaline activator solution by mixing NaOH solution, water glass and water, and cooling the mixture for 24 hours; S4, slowly add the alkali activator solution to the mixed dry materials, start the mixer to stir at the same time, so that the raw materials are fully mixed, and add the polycarboxylate water reducer during the stirring and mixing process, and continue stirring for 3 to 5 minutes to obtain a concrete mixture; S5, pouring the mixed concrete mixture into a mold, vibrating and molding it to make it dense and free of bubbles, and obtaining a molded concrete specimen; S6. Cover the formed concrete specimens with wet cloth or plastic film to keep them moist and perform curing for 28 days to fully solidify them and obtain the final product.
7. A method for preparing a green and low-carbon copper tailings-based alkali-activated concrete as claimed in claim 6, characterized in that: The preparation of the alkaline activator solution comprises the following steps: S301. According to the required concentration and amount of NaOH solution, weigh solid NaOH, slowly add solid NaOH to an appropriate amount of water in a well-ventilated environment, stirring while adding, and controlling the stirring speed at 200-300 rpm to ensure that NaOH is fully dissolved, fully cooled, and the solution temperature does not exceed 50° C. to obtain the required NaOH solution; S302, according to the amount of water glass and the modulus requirements, in another container, add the weighed water glass to the remaining water, gently stir to make it evenly dispersed, when mixing, first slowly pour the water glass into the water, and stir at a speed of 150-250 rpm; S303. Slowly pour the prepared NaOH solution into the water glass solution, stirring gently during the operation to obtain a combined solution, and mix the combined solution again by a stirring device with a stirring speed set to 100-150 rpm, and continue stirring for 5-8 minutes until the mixture is uniform to obtain a uniform and stable alkaline activator solution.
8. A method for preparing a green and low-carbon copper tailings-based alkali-activated concrete as claimed in claim 6, characterized in that: The temperature of the curing conditions is maintained at 20±2° C. and the relative humidity is above 95%.