High-activity mineral admixture based on copper tailings and preparation method of high-activity mineral admixture

Abstract

The invention provides a high-activity mineral admixture based on copper tailings and a preparation method of the high-activity mineral admixture, and relates to the technical field of solid waste resourceful treatment. The invention discloses a high-activity mineral admixture. The high-strength and high-wear-resistance copper tailings are prepared from 80-90 parts of copper tailings, 5-10 parts of mineral powder, 5-10 parts of desulfurized gypsum, 0.01-0.02 part of a chemical activating agent and 0.01-0.02 part of a grinding aid. The high-activity mineral admixture has the advantages that the activity is high, the high additional value of the copper tailing slag is realized, the cost is saved, the problem of accumulation of the copper tailing powder can be effectively solved, and the environmental pollution is reduced.

Description

Technical Field

[0001] This invention relates to the field of solid waste resource utilization, and in particular to a highly active mineral admixture based on copper tailings slag and its preparation method. Background Technology

[0002] Due to multiple factors, including the complex mineral composition of copper tailings, the low proportion of usable components, the presence of harmful components, the excessively fine and powdery content of the tailings slag, and the low added value of the remaining slag after recovering useful metal mineral components, most copper tailings are discharged into tailings ponds, resulting in large-scale stockpiling. This not only causes serious waste of resources and restricts the normal production of mineral processing enterprises but also poses safety hazards. Given the sluggish real estate economy and declining cement prices, there is an urgent need to find new active mineral admixtures to replace cement and reduce costs. Therefore, this paper proposes a highly active mineral admixture based on copper tailings slag and its preparation method. Summary of the Invention

[0003] This invention addresses the problems existing in the application of existing active mineral admixtures by providing a highly active mineral admixture based on copper tailings slag and its preparation method.

[0004] Implementation of this invention:

[0005] A highly active mineral admixture based on copper tailings slag, comprising, by weight: 80-90 parts copper tailings, 5-10 parts mineral powder, 5-10 parts desulfurized gypsum, 0.01-0.02 parts chemical activator, and 0.01-0.02 parts grinding aid.

[0006] Preferably, the fineness of the copper tailings is 200 mesh.

[0007] Preferably, the mineral powder is S95 grade mineral powder.

[0008] Preferably, the chemical activator is one or both of sodium silicate and sodium hydroxide. NaOH, when dissolved in water, can provide OH-. - Ions, strongly alkaline OH - An ionic environment can disrupt the original silicon-oxygen network structure of copper tailings, causing the Si-O-Si, Si-O-Al, and Al-O-Al bonds to break, leading to the dissolution of the glassy structure and the dissociation of Ca in the copper tailings. 2+ Mg 2+ (AlO4) 5- (SiO4) 4- Plasma is released. Free Ca in the solution... 2+ Mg 2+ (SiO4) 4- (AlO4) 5-Plasma recombines to form hydrated calcium silicate (CSH) and ettringite, among other hydration products. These substances adhere to the surface of the tailings particles. With increasing age, the cementing products and hydrated products like ettringite interlock to form a framework, solidifying the tailings sand particles into a cohesive whole, thus continuously increasing compressive strength. Sodium silicate, when added to copper tailings, hydrolyzes to generate OH-. - and [SiO2(OH)2] 2- ions, OH 2 It acts as a catalyst in the stirred slurry, causing the glassy silica network of copper tailings to break down and dissolve, forming Ca. 2+ Al 3+ Plasma reacts with [SiO2(OH)2] in an alkaline environment 2- The ions react to form CSH gel and hydrated calcium aluminosilicate. The abundant formation of CSH gel tightly binds the tailings particles together, while the ettringite produced by the hydration reaction of the curing agent acts as a framework, thus improving the curing strength. Furthermore, the hydrated silica gel formed after the hydrolysis of sodium silicate has a polymerization effect, polymerizing the tailings and hydration products into a three-dimensional structure. This contributes to the formation of a denser microstructure and higher compressive strength. When using sodium silicate, it is observed that the interfacial porosity between aggregates is low, resulting in excellent interfacial properties and improved strength.

[0009] Preferably, the grinding aid is one or both of diethanolamine and triethanolamine. Diethanolamine, as a grinding aid, is gradually adsorbed onto the surface of copper tailings particles through balanced valence bonds, forming an adsorption film on the particle surface. Due to the presence of this film, the van der Waals forces and electrostatic attraction between copper tailings particles are reduced, and the contact area between the particles is also relatively reduced. This facilitates relative sliding between powder particles, thereby improving powder flowability and reducing the angle of repose. Triethanolamine is a strongly polar small molecule that neutralizes unsaturated charges through adsorption, reducing the surface energy of powder particles and preventing particle agglomeration and cross-sectional healing, thus achieving a grinding aid effect.

[0010] The above-mentioned method for preparing highly active mineral admixtures based on copper tailings slag includes the following steps: Step 1, drying the copper tailings at 100-110℃ to constant weight; drying the desulfurized gypsum at 40-50℃ to constant weight; Step 2, stirring the copper tailings, mineral powder, desulfurized gypsum, chemical activator, and grinding aid in a mixer for 1-2 minutes to obtain a mixture; Step 3, mechanically pulverizing the mixture obtained in Step 2 in a vibratory mill for 30-60 minutes to obtain a specific surface area of ​​600 m². 2 Highly active mineral admixtures of 1 kg or more.

[0011] The beneficial effects of this invention are as follows: (1) This invention uses copper tailings, mineral powder, desulfurized gypsum and other solid wastes as the main raw materials, which is conducive to the comprehensive treatment and resource utilization of waste. (2) The chemical activator of this invention chemically activates the copper tailings, fully stimulates the potential activity of the copper tailings, greatly improves the activity of the copper tailings, and the physical and mechanical properties after replacing cement and concrete in equal amounts are comparable to those of pure cement. (3) The highly active mineral admixture prepared by this invention has excellent properties such as high activity, high added value of copper tailings slag, and cost saving. Detailed Implementation

[0012] The specific embodiments of the present invention will be described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments.

[0013] Example 1

[0014] A highly active mineral admixture based on copper tailings slag, comprising, by weight: 80 parts of 200-mesh copper tailings, 10 parts of S95 grade mineral powder, 10 parts of desulfurized gypsum, 0.01 parts of chemical activator, and 0.01 parts of grinding aid. The chemical activator is sodium silicate; the grinding aid is diethanol monoisopropanolamine.

[0015] The above-mentioned method for preparing highly active mineral admixtures based on copper tailings slag is characterized by the following steps: Step 1, drying copper tailings at 100°C to constant weight; Step 2, drying desulfurized gypsum at 40°C to constant weight; Step 3, stirring copper tailings, mineral powder, desulfurized gypsum, chemical activator, and grinding aid in a mixer for 1 min; Step 4, mechanically pulverizing the obtained mixture in a vibratory mill for 30 min to obtain highly active mineral admixtures.

[0016] Example 2

[0017] A highly active mineral admixture based on copper tailings slag, comprising, by weight: 80 parts of 200-mesh copper tailings, 8 parts of S95 grade mineral powder, 10 parts of desulfurized gypsum, 0.01 parts of chemical activator, and 0.015 parts of grinding aid. The chemical activator is sodium hydroxide; the grinding aid is diethanol monoisopropanolamine.

[0018] The above-mentioned method for preparing highly active mineral admixtures based on copper tailings slag is characterized by the following steps: Step 1, drying copper tailings at 110℃ to constant weight; Step 2, drying desulfurized gypsum at 40℃ to constant weight; Step 3, stirring copper tailings, mineral powder, desulfurized gypsum, chemical activator, and grinding aid in a mixer for 1 min; Step 4, mechanically pulverizing the obtained mixture in a vibratory mill for 30 min to obtain highly active mineral admixtures.

[0019] Example 3

[0020] A highly active mineral admixture based on copper tailings slag, comprising, by weight: 80 parts of 200-mesh copper tailings, 10 parts of S95 grade mineral powder, 7 parts of desulfurized gypsum, 0.015 parts of chemical activator, and 0.01 parts of grinding aid. The chemical activator is sodium silicate; the grinding aid is triethanolamine.

[0021] The above-mentioned method for preparing highly active mineral admixtures based on copper tailings slag is characterized by the following steps: Step 1, drying copper tailings at 105℃ to constant weight; Step 2, drying desulfurized gypsum at 50℃ to constant weight; Step 3, stirring copper tailings, mineral powder, desulfurized gypsum, chemical activator, and grinding aid in a mixer for 1.5 min; Step 4, mechanically pulverizing the obtained mixture in a vibratory mill for 45 min to obtain highly active mineral admixtures.

[0022] Example 4

[0023] A highly active mineral admixture based on copper tailings slag, comprising, by weight: 85 parts 200-mesh copper tailings, 10 parts S95 grade mineral powder, 5 parts desulfurized gypsum, 0.01 parts chemical activator, and 0.02 parts grinding aid. The chemical activator is sodium hydroxide; the grinding aid is triethanolamine.

[0024] The above-mentioned method for preparing highly active mineral admixtures based on copper tailings slag is characterized by the following steps: Step 1, drying copper tailings at 110°C to constant weight; Step 2, drying desulfurized gypsum at 50°C to constant weight; Step 3, stirring copper tailings, mineral powder, desulfurized gypsum, chemical activator, and grinding aid in a mixer for 2 minutes; Step 4, mechanically pulverizing the obtained mixture in a vibratory mill for 60 minutes to obtain highly active mineral admixtures.

[0025] Example 5

[0026] A highly active mineral admixture based on copper tailings slag, comprising, by weight: 85 parts 200-mesh copper tailings, 5 parts S95 grade mineral powder, 10 parts desulfurized gypsum, 0.02 parts chemical activator, and 0.01 parts grinding aid. The chemical activator is sodium hydroxide; the grinding aid is triethanolamine.

[0027] The above-mentioned method for preparing highly active mineral admixtures based on copper tailings slag is characterized by the following steps: Step 1, drying copper tailings at 105℃ to constant weight; Step 2, drying desulfurized gypsum at 45℃ to constant weight; Step 3, stirring copper tailings, mineral powder, desulfurized gypsum, chemical activator, and grinding aid in a mixer for 2 minutes; Step 4, mechanically pulverizing the obtained mixture in a vibratory mill for 40 minutes to obtain highly active mineral admixtures.

[0028] Example 6

[0029] A highly active mineral admixture based on copper tailings slag, comprising, by weight: 90 parts 200-mesh copper tailings, 5 parts S95 grade mineral powder, 5 parts desulfurized gypsum, 0.02 parts chemical activator, and 0.015 parts grinding aid. The chemical activator is a mixture of sodium hydroxide and sodium silicate in a 1:1 weight ratio; the grinding aid is a mixture of triethanolamine and diethanolmonoisopropanolamine in a 1:1 weight ratio.

[0030] The above-mentioned method for preparing highly active mineral admixtures based on copper tailings slag is characterized by the following steps: Step 1, drying copper tailings at 110℃ to constant weight; Step 2, drying desulfurized gypsum at 45℃ to constant weight; Step 3, stirring copper tailings, mineral powder, desulfurized gypsum, chemical activator, and grinding aid in a mixer for 1.5 min; Step 4, mechanically pulverizing the obtained mixture in a vibratory mill for 50 min to obtain highly active mineral admixtures.

[0031] The highly active mineral admixtures based on copper tailings obtained in Examples 1-6 were subjected to performance tests in terms of flexural strength, compressive strength, activity ratio, fluidity ratio, and specific surface area according to the national standard GB / T 51003-2014 "Technical Specification for Application of Mineral Admixtures". The performance test results are shown in Table 1. As can be seen from the results in Table 1, the highly active mineral admixtures based on copper tailings obtained in this invention achieved good overall performance in terms of flexural strength and compressive strength at 7d and 28d. The highest activity ratio at 7d reached 80.15, while the highest at 28d reached 87.47, demonstrating excellent high activity.

[0032] Table 1 Performance testing of high-activity mineral admixtures prepared from copper tailings slag

[0033] No. 45 pm square control screen residue (%) Specific surface area (m 2 / kg) 7d flexural strength (MPa) 7d compressive strength (MPa) 7d activity ratio 28d flexural strength (MPa) 28d compressive strength (MPa) 28d activity ratio fluidity ratio Example 1 5 650 4.3 22 76.34 6.3 35.4 80.64 105 Example 2 5 655 4.3 23.1 80.15 6.4 38.4 87.47 102 Example 3 8 620 5.1 21.1 73.21 5.9 36.4 82.92 102 Example 4 8 610 4.3 22.4 77.72 5.3 37.7 85.88 105 Example 5 8 610 3.7 22.1 76.68 6.3 37.8 86.10 105 Example 6 5 670 4.0 20.5 71.13 5.6 34.2 77.90 105

Claims

1. A highly active mineral admixture based on copper tailings slag, characterized in that, By weight, its components are: 80-90 parts copper tailings, 5-10 parts mineral powder, 5-10 parts desulfurized gypsum, 0.01-0.02 parts chemical activator, and 0.01-0.02 parts grinding aid.

2. The highly active mineral admixture based on copper tailings slag according to claim 1, characterized in that, The fineness of the copper tailings is 200 mesh.

3. The highly active mineral admixture based on copper tailings slag according to claim 1, characterized in that, The mineral powder is S95 grade mineral powder.

4. The highly active mineral admixture based on copper tailings slag according to claim 1, characterized in that, The chemical activator is one or both of sodium silicate and sodium hydroxide.

5. The highly active mineral admixture based on copper tailings slag according to claim 1, characterized in that, The grinding aid is one or both of diethanol monoisopropanolamine and triethanolamine.

6. A method for preparing a highly active mineral admixture based on copper tailings slag as described in any one of claims 1-5, characterized in that, The process includes the following steps: Step 1, drying copper tailings at 100-110℃ to constant weight, and drying desulfurized gypsum at 40-50℃ to constant weight; Step 2, mixing copper tailings, mineral powder, desulfurized gypsum, chemical activator, and grinding aid in a mixer for 1-2 minutes to obtain a mixture; Step 3, mechanically pulverizing the mixture obtained in Step 2 in a vibratory mill for 30-60 minutes to obtain a material with a specific surface area of ​​600 m². 2 Highly active mineral admixtures of 1 kg or more.