3d printed cementitious material containing copper tailings and method of manufacture
By using copper tailings instead of river sand in 3D printed cement-based materials, and combining ordinary silicate cement with a high water-cement ratio and low mortar ratio, the problems of high cost and difficult copper tailings treatment in existing technologies have been solved. This has enabled the preparation of low-cost and environmentally friendly 3D printed cement-based materials with good printing performance and strength.
Patent Information
- Application Number
- CN202411807277.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-10
- Publication Date
- 2026-06-12
AI Technical Summary
Existing 3D printed cement-based materials are expensive, mainly due to the large amount of high-quality cementitious materials used, which leads to high preparation costs, and the difficulty in disposing of solid waste such as copper tailings.
By replacing some river sand with copper tailings and combining them with ordinary silicate cement and a high water-cement ratio and low mortar ratio, 3D printing cement-based materials are prepared, reducing the amount of cementitious materials and improving the disposal efficiency of copper tailings.
It reduces the preparation cost of 3D printed cement-based materials, improves the disposal efficiency of copper tailings, has environmental benefits, and maintains sufficient printing strength and fluidity, making it suitable for large-scale production.
Smart Images
Figure CN122187431A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of 3D printing technology, specifically to a 3D printing cement-based material containing copper tailings and its preparation method. Background Technology
[0002] 3D printing, also known as additive manufacturing or layer-by-layer manufacturing, is a technology that uses digital model files as a basis and employs powdered metals or plastics and other bondable materials to construct objects layer by layer. 3D printing materials are an indispensable and crucial component of 3D printing technology, directly affecting the feasibility, print quality, printing speed, cost, and the physical and chemical properties of the final product.
[0003] In the construction industry, 3D printing cement-based materials are widely used due to their high design freedom, fast construction speed, and eco-friendliness. Existing 3D printing cement-based materials achieve high early stiffness by incorporating high-quality cementitious materials such as silica fume and fly ash, and improve early strength by using quick-setting cements such as sulfoaluminate cement. Furthermore, the mortar mix in these materials should be free of coarse aggregates and have a high paste content. While general 3D printing cement-based materials can be used, the high cost of high-quality cementitious materials and quick-setting cement, coupled with the need for a low water-cement ratio and a high binder-mortar ratio to meet printing requirements, results in an excessively high cementitious material content, thus increasing usage costs.
[0004] Therefore, the development of low-cost 3D printing cement-based materials has become a market need. Summary of the Invention
[0005] In view of this, the purpose of this application is to provide a 3D printing cement-based material containing copper tailings and a preparation method thereof. The 3D printing cement-based material uses ordinary silicate cement as a cementing material, copper tailings replace part of the river sand in the mortar, and a high water-cement ratio and low binder-mortar ratio is used to prepare the 3D printing cement-based material, thereby reducing the amount of cementing material in the mortar of the 3D printing cement-based material and thus reducing the preparation cost of the 3D printing cement-based material. The 3D printing cement-based material can be used for 3D printing and has sufficient printing strength.
[0006] To achieve, or at least partially achieve, the above objectives, this application provides the following technical solution:
[0007] In a first aspect, this application provides a 3D printing cement-based material containing copper tailings, comprising, by weight:
[0008] The mixture contains 100 parts cement, 30-150 parts copper tailings, 150-270 parts river sand, 50-60 parts water, and 0.68-3 parts water-reducing agent, of which the total mass of copper tailings and river sand is 300 parts.
[0009] Secondly, this application provides a method for preparing the aforementioned 3D-printed cement-based material containing copper tailings, comprising the following steps:
[0010] (1) Prepare cement, copper tailings, river sand, water, and water-reducing agent according to the mass ratio;
[0011] (2) Mix the cement, copper tailings and river sand components evenly to obtain a dry mixture;
[0012] (3) Dissolve the water-reducing agent in water to obtain a water-reducing agent solution;
[0013] (4) Mix the dry material mixture with the water-reducing agent solution evenly to obtain a 3D printed cement-based material containing copper tailings.
[0014] This application provides a 3D printing cement-based material containing copper tailings and its preparation method, which, compared with the prior art, has at least the following advantages:
[0015] 1. This application uses copper tailings as the main material to design a 3D printing cement-based material with a low binder-to-mortar ratio and a mix proportion suitable for 3D printing. The mix proportion of this 3D printing cement-based material supports 3D printing, and the strength of the printed mortar can reach 94.2% of that of the mortar prepared by the mold.
[0016] 2. The copper tailings content in the 3D printing cement-based material provided in this application is 22.5%, which improves the efficiency of copper tailings disposal in 3D printing and can alleviate the adverse environmental impact of copper tailings accumulation.
[0017] 3. The 3D printing cement-based material provided in this application can use ordinary silicate cement and does not contain high-quality cementitious materials such as silica fume and fly ash, which reduces the cost of mortar preparation.
[0018] 4. The method for preparing 3D printed cement-based materials provided in this application is simple to operate, suitable for large-scale production, and improves the disposal efficiency of copper tailings solid waste, thus having environmental benefits. Attached Figure Description
[0019] Figure 1 This is a photograph of the copper tailings raw material collected in the embodiments of this application.
[0020] Figure 2 The open time test results of the copper tailings-containing 3D printing cement-based materials C1 to C5 prepared for the embodiments of this application.
[0021] Figure 3 These are the setting parameters for the 3D printer in the embodiments of this application.
[0022] Figure 4 This is an image of a 3D printer printing mortar in an embodiment of this application.
[0023] Figure 5 This is a photograph of the in-situ curing of a 3D-printed component sample from an embodiment of this application.
[0024] Figure 6 This is a photograph of a 3D-printed component sample from an embodiment of this application, after being sprayed with water and coated with a film, undergoing standard curing.
[0025] Figure 7 The image shows a physical sample of a component with a cutting dimension of 70.7mm × 70.7mm × 70.7mm, as described in an embodiment of this application.
[0026] Figure 8 This is a physical image of a component with a cutting size of 40mm×40mm×160mm, as shown in the embodiment of this application. Detailed Implementation
[0027] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.
[0028] Those skilled in the art will understand that, unless otherwise stated, the terms "the," "the," and "the foregoing" used in this application may also include plural forms. It should be further understood that the word "comprising" as used in the specification of this application means the presence of the stated features, steps, or operations, but does not exclude the presence or addition of one or more other features, integers, or steps.
[0029] Those skilled in the art will understand that, where specific experimental steps or conditions are not specified in the embodiments, they can be performed according to the conventional experimental steps or conditions described in the literature in this field; and where the manufacturers of the raw materials or instruments and equipment used are not specified, they are all conventional products that can be obtained commercially.
[0030] Those skilled in the art will understand that, unless otherwise stated in this application, when numerical ranges are given in the embodiments, both endpoints of each numerical range and any value between the two endpoints may be selected. Unless otherwise defined, all technical and scientific terms used in this application, as well as the prior art known to those skilled in the art and the descriptions in this application, can be implemented using any prior art methods, devices, and materials similar to or equivalent to those described, used, or made by means of methods, devices, and materials in the embodiments of this application.
[0031] The term "mortar" refers to a building material primarily used for laying bricks and stones, plastering walls and floors, and repairing cracks. It is made by mixing cementitious materials (such as cement), fine aggregates (such as sand), and water in a certain proportion, and sometimes additives are added to improve its properties.
[0032] The term "mixing ratio" refers to the mass ratio. In this application, "mixing ratio" refers to the mass ratio of various raw materials mixed in a certain proportion in order to meet the printing performance of the 3D printing cement-based material.
[0033] Existing 3D printing cement-based materials employ a low water-cement ratio and a high binder-mortar ratio to meet 3D printing requirements. These materials contain a high content of high-quality cementitious materials (such as silica fume, fly ash, and sulfoaluminate cement), resulting in high production costs. Copper tailings are powdery or gravelly solid waste generated from the crushing, sorting, and beneficiation of natural copper ore. Through research, the applicant has discovered that copper tailings can replace some river sand or cement components in the preparation of 3D printing cement-based materials. This reduces the mass proportion of cement, silica fume, and other cementitious materials, forming a new type of 3D printing cement-based material with 3D printing performance. Simultaneously, it improves the disposal efficiency of copper tailings solid waste, thus providing environmental benefits.
[0034] Based on this, this application provides a 3D printing cement-based material containing copper tailings, which, by mass, includes: 100 parts cement, 30-150 parts copper tailings, 150-270 parts river sand, 50-60 parts water, and 0.68-3 parts water-reducing agent, wherein the total mass of copper tailings and river sand is 300 parts.
[0035] The aforementioned 3D printing cement-based material containing copper tailings has a high water-cement ratio of 0.5 to 0.6 and a fixed mortar-bond ratio of 1 / 3, which is low.
[0036] In some embodiments, the above-mentioned 3D printing cement-based material containing copper tailings includes, by weight, 100 parts cement, 30 parts copper tailings, 270 parts river sand, 55 parts water, and 0.68 parts water-reducing agent.
[0037] In some embodiments, the above-mentioned 3D printing cement-based material containing copper tailings comprises, by weight: 100 parts cement, 60 parts copper tailings, 240 parts river sand, 55 parts water, and 1.56 parts water-reducing agent.
[0038] In some embodiments, the above-mentioned 3D printing cement-based material containing copper tailings comprises, by weight, 100 parts cement, 90 parts copper tailings, 210 parts river water, 55 parts water, and 2.36 parts water-reducing agent.
[0039] In some embodiments, the above-mentioned 3D printing cement-based material containing copper tailings includes, by weight, 100 parts cement, 120 parts copper tailings, 180 parts river sand, 55 parts water, and 2.74 parts water-reducing agent.
[0040] In some embodiments, the above-mentioned 3D printing cement-based material containing copper tailings includes, by weight, 100 parts cement, 150 parts copper tailings, 150 parts river sand, 55 parts water, and 3 parts water-reducing agent.
[0041] In some embodiments, the cement is PO 42.5 ordinary Portland cement.
[0042] In the embodiments of the application, the water-reducing agent is not specifically limited. Its main function is to reduce the amount of water required for mixing during the preparation of 3D printed cement-based materials, and to maintain or improve the fluidity, strength and other processability properties of 3D printed cement-based materials.
[0043] In some embodiments, the water-reducing agent is at least one of naphthalene-based high-efficiency water-reducing agent, aliphatic high-efficiency water-reducing agent, polycarboxylic acid high-performance water-reducing agent, lignin sulfonate water-reducing agent, phosphate ester water-reducing agent, and naphthalene sulfonate formaldehyde polymer water-reducing agent, wherein the water-reducing agent has a water reduction rate of 25% to 35%.
[0044] In some preferred embodiments, the water-reducing agent is a polycarboxylate high-performance water-reducing agent with a water reduction rate of 30%.
[0045] In some embodiments, the aforementioned copper-containing tailings 3D printing cement-based material further includes 1.5 to 2.5 parts by weight of sodium tetraborate, wherein the purity of sodium tetraborate is above 99%. The main function of sodium tetraborate in the 3D printing cement-based material is as a retarder to control the setting time of the material. Simultaneously, sodium tetraborate also ensures that the material has good adhesion.
[0046] Based on this, the present application provides a method for preparing the aforementioned 3D printing cement-based material containing copper tailings, including the following steps: (1) preparing cement, copper tailings, river sand, water, and water-reducing agent according to the mass ratio; (2) mixing the cement, copper tailings, and river sand components evenly to obtain a dry mixture; (3) dissolving the water-reducing agent in water to obtain a water-reducing agent solution; (4) mixing the dry mixture and the water-reducing agent solution evenly to obtain a 3D printing cement-based material containing copper tailings.
[0047] The technical solution of this application and the technical effects achieved will be described in detail below through more specific embodiments.
[0048] The copper tailings used in the following examples were taken from a tailings dam in Huangshi City, Hubei Province. Liquid limit and plastic limit tests determined its liquid limit to be 32.01%, plastic limit to be 19.43%, and plasticity index to be 12.5. According to the soil classification in my country's "Code for Design of Building Foundations" GB50007-2022, this copper tailings belongs to silty clay, with an optimum moisture content of 16.1% and a maximum dry density of 1.897 g / cm³. 3 Copper tailings particles with a diameter of less than 0.075 mm are selected and used after crushing, drying, screening, and grinding. Figure 1 The image shows a sample of copper tailings, which is the main raw material for preparing 3D printed cement-based materials in this embodiment. As can be seen from the image, the copper tailings is fine aggregate.
[0049] The water-reducing agent used in the following examples is a polycarboxylate high-performance water-reducing agent with a water reduction rate of 30%.
[0050] The cement used in the following examples is PO 42.5 ordinary Portland cement.
[0051] Example 1
[0052] This embodiment provides a method for preparing a 3D-printed cement-based material containing copper tailings, the steps of which are as follows:
[0053] Prepare the raw materials according to the following mass ratio: 100 parts cement, 30 parts copper tailings, 270 parts river sand, 55 parts water, and 0.68 parts water-reducing agent. Mix the cement, copper tailings, and river sand components for more than 2 minutes to obtain a dry mixture. Dissolve the water-reducing agent in water to obtain a water-reducing agent solution. Mix the dry mixture and the water-reducing agent solution for 3 minutes to obtain 3D printing cement-based material C1 containing copper tailings.
[0054] Example 2
[0055] This embodiment provides a method for preparing a 3D-printed cement-based material containing copper tailings, the steps of which are as follows:
[0056] Prepare the raw materials according to the following mass ratio: 100 parts cement, 60 parts copper tailings, 240 parts river sand, 55 parts water, and 1.56 parts water-reducing agent. Mix the cement, copper tailings, and river sand components for more than 2 minutes to obtain a dry mixture. Dissolve the water-reducing agent in water to obtain a water-reducing agent solution. Mix the dry mixture and the water-reducing agent solution for 3 minutes to obtain 3D printing cement-based material C2 containing copper tailings.
[0057] Example 3
[0058] This embodiment provides a method for preparing a 3D-printed cement-based material containing copper tailings, the steps of which are as follows:
[0059] Prepare the raw materials according to the following mass ratio: 100 parts cement, 90 parts copper tailings, 210 parts river sand, 55 parts water, and 2.36 parts water-reducing agent. Mix the cement, copper tailings, and river sand components for more than 2 minutes to obtain a dry mixture. Dissolve the water-reducing agent in water to obtain a water-reducing agent solution. Mix the dry mixture and the water-reducing agent solution for 3 minutes to obtain 3D printing cement-based material C3 containing copper tailings.
[0060] Example 4
[0061] This embodiment provides a method for preparing a 3D-printed cement-based material containing copper tailings, the steps of which are as follows:
[0062] Prepare the raw materials according to the following mass ratio: 100 parts cement, 120 parts copper tailings, 180 parts river sand, 55 parts water, and 2.74 parts water-reducing agent. Mix the cement, copper tailings, and river sand components for more than 2 minutes to obtain a dry mixture. Dissolve the water-reducing agent in water to obtain a water-reducing agent solution. Mix the dry mixture and the water-reducing agent solution for 3 minutes to obtain C4, a 3D printing cement-based material containing copper tailings.
[0063] Example 5
[0064] This embodiment provides a method for preparing a 3D-printed cement-based material containing copper tailings, the steps of which are as follows:
[0065] Prepare the raw materials according to the following mass ratio: 100 parts cement, 150 parts copper tailings, 150 parts river sand, 55 parts water, and 3 parts water-reducing agent. Mix the cement, copper tailings, and river sand components for more than 2 minutes to obtain a dry mixture. Dissolve the water-reducing agent in water to obtain a water-reducing agent solution. Mix the dry mixture and the water-reducing agent solution for 3 minutes to obtain C5, a 3D printing cement-based material containing copper tailings.
[0066] The 3D printing performance of the copper tailings-containing cement-based materials C1 to C5 prepared in the above embodiments was tested, including flowability test, constructability test, open time test and mechanical property test.
[0067] (1) Flowability test: The table test shall be carried out in accordance with GB / T2419-2005, and the flowability shall be between 180 and 200 mm.
[0068] (2) Constructability test: Stack printing with 20mm printing nozzles, and the number of printing layers must be more than 10 before structural printing can be carried out.
[0069] (3) Open time test: The time taken for the mortar to gradually solidify to a fluidity of 180 mm after the mortar mixing is completed is the open time (also known as the printable time).
[0070] According to the test results, the fluidity and constructability of the 3D printing cement-based materials C1 to C5 containing copper tailings all meet the requirements.
[0071] Figure 2 The results of open time tests for 3D printed cement-based materials C1 to C5 containing copper tailings are shown. As can be seen from the figure, the open time gradually shortens as the mass proportion of copper tailings in the mixed components increases.
[0072] (4) Mechanical property testing
[0073] C3 was selected from the copper-containing tailings-based 3D printing cementitious material prepared above. The mortar was then printed using a 3D printer, and its strength performance was tested.
[0074] Printing equipment selection: The 3D printer used is the HC 1009 3D concrete printer, with a 20mm nozzle. The printing model is set to a 150mm×150mm×150mm cube and a 100mm×100mm×400mm cube. The layer height is 10mm based on the nozzle selection, with the first layer height set to 7mm for printing. Figure 3 (As shown); Before dispensing, the printer rotates for 1 minute to expel air from the bottom of the printing chamber, preventing air bubbles from forming during printing. During printing, a spatula is used to squeeze the mortar, simulating a mechanical pump delivery of the mortar, ensuring full and uniform mortar output from the nozzle. Figure 4 This is a picture of a 3D printer printing mortar on site.
[0075] The printed component sample was cured in situ for 1 day (e.g.) Figure 5 As shown), after spraying water and covering with a membrane, standard curing is carried out for 28 days (e.g. Figure 6 (As shown).
[0076] After curing the printed component samples for 7 days, the printed surface was cut, retaining the printed bottom surface, and cut into cubes with dimensions of 70.7mm×70.7mm×70.7mm and 40mm×40mm×160mm (e.g., Figure 7 , Figure 8 As shown in the figure, the component samples were cured under standard conditions for 28 days before being tested for compressive and flexural strength.
[0077] The results showed that the standard components printed and cut using 3D-printed cement-based material C3 had compressive strength and flexural strength of 36.47 MPa and 7.66 MPa, respectively, meeting the building requirements.
[0078] Mortar test blocks were prepared using a mold from 3D-printed cement-based material C3, and their compressive and flexural strengths were tested. The compressive strength was 38.72 MPa and the flexural strength was 8.40 MPa. The results show that the mortar components produced by 3D printing from the 3D-printed cement-based material prepared in this application can achieve 94.2% and 91.2% of the strength of the mortar test blocks prepared by the mold, respectively. This indicates that the copper tailings-containing 3D-printed cement-based material provided in this application can be used for 3D printing of building materials.
[0079] The present application has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of the present application. The descriptions of the embodiments above are only for the purpose of helping to understand the present application and its core ideas. It should be noted that those skilled in the art can make several improvements and modifications to the present application without departing from the principles of the present application, and these improvements and modifications also fall within the protection scope of the claims of the present application.
Claims
1. A 3D printing cement-based material containing copper tailings, characterized in that, By weight, it includes: The mixture contains 100 parts cement, 30-150 parts copper tailings, 150-270 parts river sand, 50-60 parts water, and 0.68-3 parts water-reducing agent, of which the total mass of copper tailings and river sand is 300 parts.
2. The 3D printing cement-based material containing copper tailings according to claim 1, characterized in that, By mass parts, including any one of (a) to (e): (a) 100 parts cement, 30 parts copper tailings, 270 parts river sand, 55 parts water, and 0.68 parts water-reducing agent; (b) 100 parts cement, 60 parts copper tailings, 240 parts river sand, 55 parts water, and 1.56 parts water-reducing agent; (c) 100 parts cement, 90 parts copper tailings, 210 parts river water, 55 parts water, and 2.36 parts water-reducing agent; (d) 100 parts cement, 120 parts copper tailings, 180 parts river sand, 55 parts water, and 2.74 parts water-reducing agent; (e) 100 parts cement, 150 parts copper tailings, 150 parts river sand, 55 parts water, and 3 parts water-reducing agent.
3. The 3D printing cement-based material containing copper tailings according to claim 1, characterized in that, The cement is PO42.5 ordinary Portland cement.
4. The 3D printing cement-based material containing copper tailings according to claim 1, characterized in that, The water-reducing agent is at least one of naphthalene-based high-efficiency water-reducing agent, aliphatic high-efficiency water-reducing agent, polycarboxylate high-performance water-reducing agent, lignin sulfonate water-reducing agent, phosphate ester water-reducing agent, and naphthalene sulfonate formaldehyde polymer water-reducing agent, and the water reduction rate of the water-reducing agent is 25% to 35%.
5. The 3D printing cement-based material containing copper tailings according to claim 4, characterized in that, The water-reducing agent is a polycarboxylate high-performance water-reducing agent with a water reduction rate of 30%.
6. The 3D printing cement-based material containing copper tailings according to claim 1, characterized in that, It also includes 1.5 to 2.5 parts by weight of sodium tetraborate, wherein the purity of sodium tetraborate is above 99%.
7. The method for preparing the 3D printing cement-based material containing copper tailings as described in claim 1, characterized in that, Includes the following steps: Prepare cement, copper tailings, river sand, water, and water-reducing agent according to the specified weight ratio; The cement, copper tailings, and river sand components are mixed evenly to obtain a dry mixture. Dissolve the water-reducing agent in water to obtain a water-reducing agent solution; The dry material mixture is mixed evenly with the water-reducing agent solution to obtain a 3D-printed cement-based material containing copper tailings.