Cementitious material, method for preparing same and use thereof
By mixing copper tailings, red mud, phosphogypsum, cement, mineral powder, and additives to prepare cementitious materials, the problems of low activity of industrial solid waste and environmental pollution have been solved, and the preparation and low-cost production of high-performance cementitious materials have been realized.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHUXIONG DIANZHONG NON FERROUS METALS LLC
- Filing Date
- 2026-02-09
- Publication Date
- 2026-05-29
AI Technical Summary
In existing technologies, industrial solid wastes such as copper tailings, red mud, and phosphogypsum are difficult to use directly as cementing materials, resulting in problems such as low activity, high energy consumption, high cost, and environmental pollution. Furthermore, simple mixing makes it difficult to balance mechanical properties and environmental safety.
A cementitious material is prepared by mixing copper tailings, red mud, phosphogypsum, cement, mineral powder and admixtures in a certain proportion and then curing it after homogenization. The admixtures consist of water-reducing agent, sodium aluminate and sodium silicate. The water-to-material ratio is controlled at 1:(0.18-0.22)g/ml, the stirring speed is 400-600r/min, and the curing methods include standard, steam, drying or soaking curing.
It achieves high compressive strength and low heavy metal leaching in cementitious materials, with excellent performance, meeting GB18599-2020 Class I standards, and reducing production costs and environmental pollution.
Abstract
Description
Technical Field
[0001] This invention belongs to the field of waste recycling, specifically relating to a cementitious material, its preparation method, and its application. Background Technology
[0002] my country's annual copper tailings emissions are about 25 million tons, with Yunnan Province having a stockpile of over 150 million tons. Its activity index is only 60%-65%, making it difficult to use directly as a cementitious material. The annual emissions of red mud (pH>12) and phosphogypsum (containing soluble phosphorus / fluorine) are 6 million tons and 5 million tons, respectively. The stockpiling of these three wastes occupies land and pollutes groundwater. Currently, the single use or simple mixing has the following drawbacks: (1) Copper tailings have low activity and require high-temperature activation or a large amount of cement clinker, resulting in high energy consumption and high cost; (2) Red mud is strongly alkaline, limiting the amount that can be added, and excessive amounts can cause the slurry to crack; (3) Phosphorus and fluorine in phosphogypsum are easily leached out, causing steel reinforcement corrosion and efflorescence; (4) Simple mixing of the three results in dispersed particle size distribution, making it difficult to balance mechanical properties and environmental safety.
[0003] Therefore, in order to solve the above problems, it is urgent to develop a "room temperature, synergistic, green, and low cost" cementitious material and its preparation method. Summary of the Invention
[0004] To address or partially address the problems existing in the related technologies, this application provides a cementitious material composed of copper tailings, red mud, phosphogypsum, cement, mineral powder, and additives.
[0005] Furthermore, the cementitious material is composed of 55-75 parts by weight of copper tailings, 6-12 parts of red mud, 6-12 parts of phosphogypsum, 8-12 parts of cement, 8-12 parts of mineral powder, and 1.5-5 parts of admixtures.
[0006] Furthermore, the admixture is composed of a water-reducing agent, sodium aluminate, and sodium silicate.
[0007] Furthermore, the mass ratio of the water-reducing agent, sodium aluminate, and sodium silicate is (1.5-2.0):(0.3-0.7):(2-3).
[0008] On the other hand, this application also provides a method for preparing the above-mentioned cementitious material, which involves mixing copper tailings, red mud, phosphogypsum, cement, mineral powder and admixtures in a certain mass ratio, adding water, stirring and homogenizing, and then curing to obtain the target cementitious material; wherein the certain mass ratio is 55-75 parts copper tailings, 6-12 parts red mud, 6-12 parts phosphogypsum, 8-12 parts cement, 8-12 parts mineral powder and 1.5-5 parts admixtures.
[0009] Furthermore, the water-to-material ratio is 1:(0.18-0.22) (g / ml).
[0010] Furthermore, the stirring and homogenization is carried out under stirring conditions of 400-600 r / min for 2-4 min.
[0011] Furthermore, the maintenance mentioned refers to standard maintenance, steam maintenance, dry maintenance, or water immersion maintenance.
[0012] On the other hand, this application also provides an application of the above-mentioned cementitious material, which is the application of the cementitious material in the preparation of cementitious material products.
[0013] Beneficial effects The gel material provided in this application has excellent properties, and its compressive strength, water resistance coefficient, and heavy metal content are all lower than the Class I limit of GB18599-2020. Detailed Implementation
[0014] The present invention will be further described below with reference to embodiments, but this is not intended to limit the present invention in any way. Any modifications or substitutions made based on the teachings of the present invention shall fall within the protection scope of the present invention.
[0015] The cementitious material provided by this invention is composed of copper tailings, red mud, phosphogypsum, cement, mineral powder, and additives in parts by weight. Copper tailings: magnetic separation to remove iron, sieved through a 0.075 mm screen, moisture content ≤8%; Red mud: aged to reduce alkali to pH 10.5-11.5; Phosphogypsum: washed with water to remove free acid and SO3. 2- ≤40%.
[0016] The cementitious material is composed of 55-75 parts by weight of copper tailings, 6-12 parts of red mud, 6-12 parts of phosphogypsum, 8-12 parts of cement, 8-12 parts of mineral powder, and 1.5-5 parts of admixtures.
[0017] The additives consist of a water-reducing agent, sodium aluminate, and sodium silicate.
[0018] The mass ratio of the water-reducing agent, sodium aluminate and sodium silicate is (1.5-2.0):(0.3-0.7):(2-3).
[0019] Water-reducing agent: dosage is 1.5%-2.0% of the total amount of cement and mineral powder; sodium aluminate: dosage is 0.3%-0.7% of the total amount of cement and mineral powder; sodium silicate: dosage is 2%-3% of the total amount of cement and mineral powder; sodium aluminate and sodium silicate can be used alone or in combination.
[0020] The method for preparing the cementitious material provided by the present invention involves adding water to a mixture of copper tailings, red mud, phosphogypsum, cement, mineral powder and admixtures in a specified ratio, stirring and homogenizing the mixture, and then curing it to obtain the target cementitious material.
[0021] The water-to-material ratio is 1:(0.18-0.22) (g / ml).
[0022] The homogenization process involves using a planetary mixer at 400-600 rpm for 2-4 minutes. The specimens are then vibrated or pressed into shape, with dimensions customized to meet specific requirements.
[0023] The maintenance methods mentioned include standard maintenance, steam maintenance, dry maintenance, or water immersion maintenance.
[0024] Standard curing: 20±2℃, humidity ≥95%, age 7-28 days; or steam curing: 60-80℃, 3-7 days; or dry curing: 20±2℃, RH 50%-70%, 7-28 days; or water curing: 20±2℃ in water, 7-28 days; choose one or a combination according to project requirements and site conditions.
[0025] Performance testing and environmental assessment of the gel material provided in this application: Compressive strength shall be determined according to GB / T 17671-2021; leaching toxicity of heavy metals, fluorine, and phosphorus shall be determined according to GB 5085.3-2007; activity index shall be determined according to GB / T 18046-2017.
[0026] Red mud and phosphogypsum are both major industrial solid wastes, containing highly alkaline components and CaSO4·2H2O respectively, which can produce a synergistic activating effect with copper tailings.
[0027] The invention will be further illustrated below with specific implementation examples: Example 1 64 kg copper tailings, 8 kg red mud, 8 kg phosphogypsum, 10 kg cement, 10 kg mineral powder; water-reducing agent dosage is 1.75% (0.35 kg) of the total cement and mineral powder content; sodium aluminate 0.5% (0.10 kg); sodium silicate 2.5% (0.50 kg); water-to-material ratio 0.19 (g / ml); homogenization in a planetary mixer at 500 r / min for 3 min; standard curing for 28 days.
[0028] Results: 7-day compressive strength 37.2 MPa, 28-day compressive strength 53.8 MPa; water resistance coefficient 0.94; As leaching 0.0038 mg / L, F - The leaching concentration was 0.58 mg / L, which is lower than the Class I limit of GB 18599-2020.
[0029] Example 2 68 kg copper tailings, 7 kg red mud, 7 kg phosphogypsum, 9 kg cement, 9 kg mineral powder; 1.8% water-reducing agent (0.324 kg); 0.4% sodium aluminate (0.072 kg); 2.2% sodium silicate (0.396 kg); water-to-material ratio 0.20 (g / ml); homogenization in a planetary mixer at 450 r / min for 4 min; steam curing at 70℃ for 5 days.
[0030] Results: 3-day compressive strength 42.1 MPa, 28-day compressive strength 51.6 MPa; drying shrinkage 0.025%; As leaching 0.0041 mg / L, F - Leaching concentration: 0.62 mg / L.
[0031] Example 3 70 kg copper tailings, 6 kg red mud, 6 kg phosphogypsum, 9 kg cement, 9 kg mineral powder; 1.6% water-reducing agent (0.288 kg); only 2.5% sodium silicate (0.45 kg); water-to-material ratio 0.20 (g / ml); homogenization in a planetary mixer at 550 r / min for 2 min; drying and curing for 28 days.
[0032] Results: 7-day compressive strength was 31.5 MPa, and 28-day compressive strength was 45.9 MPa; the 7-day strength was 18% higher than that of standard curing, and the 28-day strength was 88% of that of standard curing; As leaching was 0.0052 mg / L, F - Leaching concentration: 0.65 mg / L.
[0033] Comparative Example 1 80kg copper tailings, 10kg cement, 10kg mineral powder; 1.75% water-reducing agent (0.35kg); water-to-material ratio 0.19 (g / ml); standard curing 28 days.
[0034] Results: 7-day compressive strength 8.7 MPa, 28-day compressive strength 28.0 MPa; activity index 62.4%; As leaching 0.0052 mg / L, F - The leaching concentration was 0.63 mg / L. All indicators were lower than those in Examples 1-3 of this invention.
[0035] The above description is exemplary and not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.
Claims
1. A cementitious material, characterized in that, The cementing material is composed of copper tailings, red mud, phosphogypsum, cement, mineral powder, and additives.
2. The cementitious material according to claim 1, characterized in that, The cementitious material is composed of 55-75 parts by weight of copper tailings, 6-12 parts of red mud, 6-12 parts of phosphogypsum, 8-12 parts of cement, 8-12 parts of mineral powder, and 1.5-5 parts of admixtures.
3. The cementitious material according to claim 1, characterized in that, The additives consist of a water-reducing agent, sodium aluminate, and sodium silicate.
4. The cementitious material according to claim 3, characterized in that, The mass ratio of the water-reducing agent, sodium aluminate and sodium silicate is (1.5-2.0):(0.3-0.7):(2-3).
5. A method for preparing a cementitious material as described in any one of claims 1-4, characterized in that, The target cementitious material is obtained by mixing copper tailings, red mud, phosphogypsum, cement, mineral powder and admixtures in a certain mass ratio, adding water, stirring and homogenizing, and then curing. The certain mass ratio is 55-75 parts copper tailings, 6-12 parts red mud, 6-12 parts phosphogypsum, 8-12 parts cement, 8-12 parts mineral powder and 1.5-5 parts admixtures.
6. The preparation method according to claim 5, characterized in that, The water-to-material ratio is 1:(0.18-0.22)(g / ml).
7. The preparation method according to claim 5, characterized in that, The homogenization process is carried out under a stirring speed of 400-600 r / min for 2-4 min.
8. The preparation method according to claim 5, characterized in that, The maintenance methods mentioned include standard maintenance, steam maintenance, dry maintenance, or water immersion maintenance.
9. An application of the cementitious material as described in any one of claims 1-4, characterized in that, The application is the use of cementitious materials in the preparation of cementitious material products.