Copper tailings recycled cement admixture and method for preparing the same

Abstract

The application discloses copper tailing recycled cement admixture and a preparation method thereof, and the method comprises the following steps: S1, drying treatment; S2, grinding treatment; S3, adding a dispersing agent; polyacrylamide is used as the dispersing agent to prepare a polyacrylamide aqueous solution, the polyacrylamide aqueous solution is added into copper tailing powder and uniformly stirred; S4, configuring a composite activator; S5, copper tailing activation; S6, lead-zinc slag compounding. When the copper tailing and the sodium silicate-calcium hydroxide composite activator react to generate C-S-H gel, the physical entanglement of the polyacrylamide can enhance the toughness of the gel network, and the crack resistance of the cement stone is improved, so that, under the mechanical-chemical synergistic use, the activity of the broken copper tailing is released, the copper tailing content is increased to 60%, the cement clinker consumption is greatly reduced, and the strength of the admixture is increased.

Description

Technical Field

[0001] This invention belongs to the field of copper tailings recycling technology, and particularly relates to copper tailings recycled cementitious materials and methods for preparing copper tailings recycled cementitious materials. Background Technology

[0002] With the large-scale development and utilization of mineral resources, a large amount of tailings waste has been generated. Copper tailings, as a typical type of metal tailings, not only occupy a large amount of land resources when stored for a long time, but may also cause pollution to the surrounding environment. Copper tailings are the main solid waste after copper ore beneficiation. Currently, they are mainly treated by landfilling or simply by being mixed into cement-based materials. Using industrial waste such as copper tailings to prepare cement admixtures can reduce the environmental problems caused by tailings accumulation and alleviate the dependence of cement production on natural resources, which has important economic and environmental benefits.

[0003] Because the active components such as SiO2 and Al2O3 in copper tailings exist in the form of inert crystals, they are difficult to react with cement hydration products. Traditional activation methods have a low degree of activation for copper tailings, and their mineral admixture is usually less than 30%. Furthermore, the admixtures produced by traditional activation methods require a high amount of water, which can easily affect the workability of concrete and lead to a significant decrease in cement strength. Summary of the Invention

[0004] To address the problems in the prior art, the present invention proposes the following technical solution:

[0005] A method for preparing recycled copper tailings cementitious admixture includes the following steps:

[0006] S1. Drying treatment;

[0007] Copper tailings (58-62%wt) were dried in an oven at 80-120℃ until the moisture content was ≤5% to break the adsorbed water film on the particle surface.

[0008] S2, grinding process;

[0009] A vertical mill was used to grind (8-10%wt) lead-zinc slag and dried copper tailings respectively. The lead-zinc slag was ground into powder and the copper tailings were ground to a specific surface area of ​​400-500 m² / kg to increase the exposure of active sites in the copper tailings.

[0010] S3. Add dispersant;

[0011] Polyacrylamide (0.5-1.2wt%) was used as a dispersant to prepare an aqueous solution of polyacrylamide, which was then added to copper tailings powder and stirred evenly. The polymer chains of polyacrylamide were adsorbed onto the surface of copper tailings particles through hydrogen bonds or electrostatic adsorption, forming a physical coating layer and enhancing the physical entanglement between particles.

[0012] S4. Prepare a composite activator;

[0013] Sodium silicate-calcium hydroxide composite activator (3-5 wt%) is dissolved in water to prepare an aqueous solution of composite activator. Sodium silicate provides an alkaline environment (OH⁻) and an active silicon source (SiO3²⁻), while calcium hydroxide increases the alkalinity of the solution, provides Ca²⁺ ions, and combines with (SiO3²⁻) in sodium silicate to form calcium silicate hydrate (CSH gel).

[0014] S5, copper tailings activation;

[0015] The mixed composite activator solution was added to the copper tailings mixture and stirred. Under alkaline conditions, the SiO2, KAlSi3O8 and other sites in the copper tailings were eroded, releasing SiO3²⁻ and Al³⁺, which reacted with Ca²⁺ to form CSH and CAH gels.

[0016] S6, a compound of lead-zinc slag;

[0017] The remaining lead-zinc slag (28-34%wt) is then added and mixed, and the active ingredients released by the lead-zinc slag work synergistically to form a continuous cementitious network. Ball milling is then performed to homogenize the mixture and promote contact between the unreacted active ingredients. After drying, the finished cement blend is obtained.

[0018] As a preferred embodiment of the above technical solution, step S4 further includes enhancing alkaline activation;

[0019] Add lead-zinc slag powder to the composite activator solution, stir evenly, and age for 0.5 to 1 hour for pre-hydration treatment. The alkaline solution dissolves the glass phase on the surface of the lead-zinc slag, destroys its inert structure, and releases active SiO2 and Al2O3, allowing the lead-zinc slag to fully absorb water, expand, and release active ions, ensuring that alkaline activation is fully carried out.

[0020] As a preferred embodiment of the above technical solution, step S5 further includes a pre-coordinated reaction;

[0021] When the CSH gel and other products generated by the reaction of lead-zinc slag with the activator are mixed with copper tailings, they act as "nuclei" to promote the dissolution and recrystallization of active components in the copper tailings.

[0022] As a preferred embodiment of the above technical solution, step S1 further includes introducing hot air;

[0023] During the grinding process, hot air at a temperature of 40-60℃ and a flow rate of 5-10m³ / min is introduced into the vertical mill. The hot air can further dry the copper tailings particles, remove the grinding heat, and improve the grinding efficiency, resulting in a more uniform particle size distribution.

[0024] As a preferred embodiment of the above technical solution, step S6 further includes humidity determination;

[0025] Before ball milling, the moisture content of the mixture is tested. If the moisture content is too high, the mixture is dried to meet the requirements for ball milling.

[0026] As a preferred embodiment of the above technical solution, in step S3, the concentration of the polyacrylamide aqueous solution is 1-3%. By controlling the concentration of the aqueous solution, the adsorption amount and encapsulation effect of polyacrylamide on the surface of copper tailings particles can be precisely controlled.

[0027] As a preferred embodiment of the above technical solution, in step S6, the drying process adopts a segmented drying process, first drying at 60-80℃ to a moisture content of 10-15%, and then raising the temperature to 100-120℃ to dry to the required moisture standard of the finished product, so as to avoid structural damage to the mixed material due to excessive drying.

[0028] The copper tailings recycled cement blend and its preparation method are made from the following raw materials by weight percentage: 58-62% copper tailings, 38-42% lead-zinc slag, 0.5-1.2 wt% polyacrylamide, and 3-5 wt% sodium silicate-calcium hydroxide composite activator.

[0029] The beneficial effects of this invention are as follows:

[0030] 1. Polyacrylamide is used as a dispersant in conjunction with sodium silicate-calcium hydroxide composite activator. The steric hindrance effect of the polymer chain of polyacrylamide ensures that the copper tailings particles are uniformly dispersed after grinding, and the active sites are fully exposed. In addition, its polymer chain is adsorbed on the particle surface through hydrogen bonds to form a flexible coating layer. When the copper tailings react with the sodium silicate-calcium hydroxide mixed activator to generate CSH gel, the physical entanglement of polyacrylamide can enhance the toughness of the gel network and improve the crack resistance of cement stone. Thus, under the synergistic use of mechanical and chemical methods, the active release of copper tailings is activated, which increases the copper tailings content to 60%, significantly reduces the amount of cement clinker used, and increases the strength of the composite material.

[0031] 2. Lead-zinc slag powder is pre-added to the composite activator solution. The glassy phase on its surface is dissolved by alkaline solution, releasing active SiO2 and Al2O3. OH⁻ destroys the inert aluminosilicate structure of the lead-zinc slag, causing it to absorb water, swell, and release ions, providing more reaction sites for subsequent copper tailings activation. Furthermore, the CSH gel generated by the pre-reaction of lead-zinc slag and activator acts as a "crystal nucleus" when mixed with copper tailings, reducing the activation energy of SiO2 and Al³⁺ recrystallization in copper tailings, increasing the rate of cement product formation by 20-25%, and shortening the cement setting time. Attached Figure Description

[0032] Figure 1The diagram shown is a schematic representation of the workflow of an embodiment; Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments and the accompanying drawings.

[0034] Figure 1 The method for preparing copper tailings recycled cementitious admixture includes the following steps:

[0035] S1. Drying treatment;

[0036] Copper tailings (58-62%wt) were dried in an oven at 80-120℃ until the moisture content was ≤5% to break the adsorbed water film on the particle surface.

[0037] S2, grinding process;

[0038] A vertical mill was used to grind (8-10%wt) lead-zinc slag and dried copper tailings respectively. The lead-zinc slag was ground into powder and the copper tailings were ground to a specific surface area of ​​400-500 m² / kg to increase the exposure of active sites in the copper tailings.

[0039] S3. Add dispersant;

[0040] Polyacrylamide (0.5-1.2 wt%) was used as a dispersant to prepare an aqueous solution with a concentration of 1-3%. By controlling the concentration of the aqueous solution, the adsorption amount and coating effect of polyacrylamide on the surface of copper tailings particles were precisely controlled. When added to copper tailings powder and stirred evenly, the polymer chains of polyacrylamide adhered to the surface of the copper tailings particles through hydrogen bonds or electrostatic adsorption, forming a physical coating layer and enhancing the physical entanglement between particles.

[0041] S4. Prepare a composite activator;

[0042] Sodium silicate-calcium hydroxide composite activator (3-5 wt%) is dissolved in water to prepare an aqueous solution of composite activator. Sodium silicate provides an alkaline environment (OH⁻) and an active silicon source (SiO3²⁻), while calcium hydroxide increases the alkalinity of the solution, provides Ca²⁺ ions, and combines with (SiO3²⁻) in sodium silicate to form calcium silicate hydrate (CSH gel).

[0043] S5, copper tailings activation;

[0044] The mixed composite activator solution was added to the copper tailings mixture and stirred. Under alkaline conditions, the SiO2, KAlSi3O8 and other sites in the copper tailings were eroded, releasing SiO3²⁻ and Al³⁺, which reacted with Ca²⁺ to form CSH and CAH gels.

[0045] S6, a compound of lead-zinc slag;

[0046] The remaining lead-zinc slag (28-34%wt) is then added and mixed, and the active ingredients released by the lead-zinc slag work synergistically to form a continuous cementitious network. Ball milling is then performed to homogenize the mixture and promote contact between the unreacted active ingredients. After drying, the finished cement blend is obtained.

[0047] When polyacrylamide aqueous solution is added to copper tailings powder, the steric hindrance effect of the polyacrylamide polymer chain prevents the copper tailings from agglomerating due to van der Waals forces, ensuring that the copper tailings particles are uniformly dispersed after grinding and that the active sites are fully exposed. Furthermore, its polymer chains are adsorbed onto the particle surface through hydrogen bonds, forming a flexible coating layer. When the copper tailings react with sodium silicate-calcium hydroxide mixed activator to generate CSH gel, the physical entanglement of polyacrylamide can enhance the toughness of the gel network and improve the crack resistance of cement stone.

[0048] When preparing the aqueous solution of the composite activator, sodium silicate reacts with calcium hydroxide to produce calcium silicate (CaSiO3) and NaOH. NaOH provides a strongly alkaline environment (OH⁻). CaSiO3 further reacts with water to form calcium silicate hydrate (CSH gel). The reaction equation is as follows:

[0049]

[0050]

[0051] The sodium silicate-calcium hydroxide composite activator destroys the aluminosilicate structure of copper tailings particles through chemical action (alkaline dissolution), causing them to depolymerize into nanoscale active particles; polyacrylamide prevents the depolymerized particles from re-aggregating through electrostatic repulsion and steric hindrance, keeping the active particles in a highly dispersed state, thereby increasing the contact area with the activator and accelerating the reaction process.

[0052] When lead-zinc slag powder is added to the aqueous solution of the composite activator, the main component of the lead-zinc slag is vitreous (containing SiO2, Al2O3, CaO, etc.). In a strongly alkaline solution, OH⁻ breaks the Si-O-Si and Al-O-Si bonds, promoting the dissolution of the vitreous. The released active SiO3²⁻ and Al(OH)4⁻ react with Ca²⁺ in the solution to generate hydrated calcium silicate (CSH) and hydrated calcium aluminate (CAH) gels, enhancing the gelling properties of the system. The reaction equation is as follows:

[0053]

[0054]

[0055] When a mixture of composite activator aqueous solution and lead-zinc slag powder is added to copper tailings, the copper tailings undergo alkaline activation. Quartz (SiO2) and feldspar (KAlSi3O8, etc.) in the copper tailings are eroded under alkaline conditions, releasing SiO3²⁻ and Al³⁺, which react with Ca²⁺ to form CSH and CAH gels. At the same time, they synergistically act with the active components released from the lead-zinc slag to form a continuous cementitious network. During the compound ball milling process, the active sites (such as broken Si-O and Al-O groups) already formed on the surface of the pre-activated lead-zinc slag powder can directly react with the active SiO2 / Al2O3 in the copper tailings, shortening the "induction period".

[0056] Polyacrylamide is used as a dispersant in conjunction with sodium silicate-calcium hydroxide composite activator. The steric hindrance effect of the polymer chain of polyacrylamide ensures that the copper tailings particles are uniformly dispersed after grinding, and the active sites are fully exposed. Furthermore, its polymer chains are adsorbed onto the particle surface through hydrogen bonds, forming a flexible coating layer. When the copper tailings react with the sodium silicate-calcium hydroxide mixed activator to generate CSH gel, the physical entanglement of polyacrylamide can enhance the toughness of the gel network and improve the crack resistance of cement stone. Thus, under the synergistic use of mechanical and chemical methods, the active release of copper tailings is activated, increasing the copper tailings content to 60%, significantly reducing the amount of cement clinker used while increasing the strength of the composite material.

[0057] The S4 step also includes enhancing alkaline activation;

[0058] Add lead-zinc slag powder to the composite activator solution, stir evenly, and age for 0.5 to 1 hour for pre-hydration treatment. The alkaline solution dissolves the glass phase on the surface of the lead-zinc slag, destroys its inert structure, and releases active SiO2 and Al2O3, allowing the lead-zinc slag to fully absorb water, expand, and release active ions, ensuring that alkaline activation is fully carried out.

[0059] The S5 step also includes a pre-coordinated reaction;

[0060] When the CSH gel and other products generated by the reaction of lead-zinc slag with the activator are mixed with copper tailings, they act as "nuclei" to promote the dissolution and recrystallization of active components in the copper tailings.

[0061] Lead-zinc slag powder is pre-added to the composite activator solution. The glassy phase on its surface is dissolved by alkaline solution, releasing active SiO2 and Al2O3. OH⁻ destroys the inert aluminosilicate structure of the lead-zinc slag, causing it to absorb water, swell, and release ions, providing more reaction sites for subsequent copper tailings activation. Furthermore, the CSH gel generated by the pre-reaction of lead-zinc slag and activator acts as a "nucleus" when mixed with copper tailings, reducing the activation energy of SiO2 and Al³⁺ recrystallization in copper tailings, increasing the rate of cementitious product formation by 20-25%, and shortening the cement setting time.

[0062] Step S1 also includes introducing hot air;

[0063] During the grinding process, hot air at a temperature of 40-60℃ and a flow rate of 5-10m³ / min is introduced into the vertical mill. The hot air can further dry the copper tailings particles, remove the grinding heat, and improve the grinding efficiency, resulting in a more uniform particle size distribution.

[0064] Step S6 also includes humidity determination;

[0065] Before ball milling, the moisture content of the mixture is tested. If the moisture content is too high, the mixture is dried to meet the requirements for ball milling.

[0066] In step S6, the drying process adopts a segmented drying process. First, it is dried at 60-80℃ to a moisture content of 10-15%, and then the temperature is raised to 100-120℃ to dry to the required moisture content of the finished product, so as to avoid structural damage to the mixed material due to excessive drying.

[0067] The copper tailings recycled cement blend and its preparation method are made from the following raw materials by weight percentage: 58-62% copper tailings, 38-42% lead-zinc slag, 0.5-1.2 wt% polyacrylamide, and 3-5 wt% sodium silicate-calcium hydroxide composite activator. Example

[0068] Raw material preparation: Weigh out 60%wt of copper tailings, 40%wt of lead-zinc slag (of which 8%wt is used for grinding together with copper tailings and 32%wt is used for subsequent compounding), 0.8wt of polyacrylamide, and 4wt of sodium silicate-calcium hydroxide composite activator.

[0069] Drying treatment: The copper tailings are placed in an oven at 100℃ and dried until the moisture content is ≤5%. During the grinding process, hot air at 50℃ and a flow rate of 8m³ / min is introduced into the vertical mill.

[0070] Grinding process: 8%wt lead-zinc slag and dried copper tailings were ground separately using a vertical mill. The lead-zinc slag was ground into powder and the copper tailings were ground to a specific surface area of ​​450m² / kg.

[0071] Add dispersant: Prepare a 2% aqueous solution of 0.8 wt% polyacrylamide and add it to the copper tailings powder and stir evenly.

[0072] Preparation of composite activator: Dissolve 4wt% sodium silicate-calcium hydroxide composite activator in water to prepare an aqueous solution, add lead-zinc slag powder, stir evenly and age for 0.8 hours for pre-hydration treatment.

[0073] Copper tailings activation: Add the composite activator solution to the copper tailings mixture and stir to allow the active components in the copper tailings to fully react with the activator.

[0074] Lead-zinc slag blending: The remaining 32% wt of lead-zinc slag is added and mixed, then homogenized by ball milling. The moisture content is tested before ball milling; if too high, it is dried. A segmented drying process is used: first, drying at 70℃ to a moisture content of 12%, then raising the temperature to 110℃ and drying to the required moisture content standard for the finished product, yielding the cementitious blend. Testing shows that the blend has a 28-day activity index of 75% and a water requirement ratio of 103%. Example

[0075] Raw material preparation: Weigh out 58%wt of copper tailings, 42%wt of lead-zinc slag (of which 10%wt is used for grinding together with copper tailings and 32%wt is used for subsequent compounding), 0.5wt of polyacrylamide, and 3wt of sodium silicate-calcium hydroxide composite activator.

[0076] Drying treatment: The copper tailings are placed in an oven at 80℃ and dried until the moisture content is ≤5%. During the grinding process, hot air at 40℃ and a flow rate of 5m³ / min is introduced into the vertical mill.

[0077] Grinding process: 10%wt lead-zinc slag and dried copper tailings were ground separately using a vertical mill. The lead-zinc slag was ground into powder and the copper tailings were ground to a specific surface area of ​​400m² / kg.

[0078] Add dispersant: Prepare a 1% aqueous solution of 0.5wt% polyacrylamide and add it to the copper tailings powder and stir evenly.

[0079] Preparation of composite activator: Dissolve 3wt% sodium silicate-calcium hydroxide composite activator in water to prepare an aqueous solution, add lead-zinc slag powder, stir evenly and age for 0.5 hours for pre-hydration treatment.

[0080] Copper tailings activation: Add the composite activator solution to the copper tailings mixture and stir to allow the active components in the copper tailings to fully react with the activator.

[0081] Lead-zinc slag blending: The remaining 32% wt of lead-zinc slag is added and mixed, then homogenized by ball milling. The moisture content is tested before ball milling; if too high, it is dried. A segmented drying process is used: first, drying at 60℃ to a moisture content of 10%, then raising the temperature to 100℃ and drying to the required moisture content standard for the finished product, yielding the cementitious blend. Testing shows that the blend has a 28-day activity index of 72% and a water requirement ratio of 105%. Example

[0082] Raw material preparation: Weigh out 62%wt of copper tailings, 38%wt of lead-zinc slag (of which 8%wt is used for grinding together with copper tailings and 30%wt is used for subsequent compounding), 1.2wt of polyacrylamide, and 5wt of sodium silicate-calcium hydroxide composite activator.

[0083] Drying treatment: The copper tailings are placed in an oven at 120℃ and dried until the moisture content is ≤5%. During the grinding process, hot air at 60℃ and a flow rate of 10m³ / min is introduced into the vertical mill.

[0084] Grinding process: 8%wt lead-zinc slag and dried copper tailings were ground separately using a vertical mill. The lead-zinc slag was ground into powder and the copper tailings were ground to a specific surface area of ​​500m² / kg.

[0085] Add dispersant: Prepare a 3% aqueous solution of 1.2 wt% polyacrylamide and add it to the copper tailings powder and stir evenly.

[0086] Preparation of composite activator: Dissolve 5wt% sodium silicate-calcium hydroxide composite activator in water to prepare an aqueous solution, add lead-zinc slag powder, stir evenly and age for 1 hour for pre-hydration treatment.

[0087] Copper tailings activation: Add the composite activator solution to the copper tailings mixture and stir to allow the active components in the copper tailings to fully react with the activator.

[0088] Lead-zinc slag blending: The remaining 30% wt of lead-zinc slag is added and mixed, then homogenized by ball milling. The moisture content is tested before ball milling; if too high, it is dried. A segmented drying process is used: first, drying at 80℃ to a moisture content of 15%, then raising the temperature to 120℃ and drying to the required moisture content standard for the finished product, yielding the cementitious blend. Testing shows that the blend has a 28-day activity index of 78% and a water requirement ratio of 102%.

[0089] Comparative Example

[0090] The cementitious material was prepared following similar steps to Example 1, but without the use of the sodium silicate-calcium hydroxide composite activator. Testing revealed that the 28-day activity index of this material was only 58%, and the water requirement ratio was 112%. Comparison shows that the preparation method of this invention significantly improves the performance of the copper tailings recycled cementitious material.

[0091] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it.

Claims

1. A method for preparing recycled cementitious materials from copper tailings, characterized in that, Includes the following steps: S1. Drying treatment; 58-62wt% of copper tailings were dried in an oven at 80-120℃ until the moisture content was ≤5% to break the adsorbed water film on the particle surface. S2, grinding process; A vertical mill was used to grind 8-10 wt% lead-zinc slag and dried copper tailings separately. The lead-zinc slag was ground into powder, and the copper tailings were ground to a specific surface area of ​​400-500 m². 2 / kg to increase the exposure of active sites in copper tailings; S3. Add dispersant; A polyacrylamide aqueous solution was prepared by using 0.5-1.2 wt% polyacrylamide as a dispersant. This solution was then added to copper tailings powder and stirred until homogeneous. The polymer chains of polyacrylamide adhered to the surface of the copper tailings particles through hydrogen bonds or electrostatic adsorption, forming a physical coating layer that enhanced the physical entanglement between the particles. S4. Prepare a composite activator; A sodium silicate-calcium hydroxide composite activator solution is prepared by dissolving 3-5 wt% of the composite activator in water. Sodium silicate provides the alkaline environment (OH-). - and active silicon source SiO3 2- Calcium hydroxide increases the alkalinity of the solution and provides Ca. 2+ Ions and SiO3 in sodium silicate 2- Combined to form calcium silicate hydrate CSH gel; Add lead-zinc slag powder to the composite activator solution, stir evenly and age for 0.5-1 hours for pre-hydration treatment. The alkaline solution dissolves the glass phase on the surface of the lead-zinc slag, destroys its inert structure, and releases active SiO2 and Al2O3, allowing the lead-zinc slag to fully absorb water, expand and release active ions, ensuring that alkaline activation is fully carried out. S5, copper tailings activation; The mixed composite activator solution was added to the copper tailings mixture and stirred. Under alkaline conditions, the SiO2 and KAlSi3O8 sites in the copper tailings were eroded, releasing SiO3. 2- And Al 3+ , with Ca 2+ The reaction produces CSH and CAH gels; S6, a compound of lead-zinc slag; Subsequently, the remaining 28-34 wt% of lead-zinc slag is added and mixed, and it works synergistically with the active ingredients released by the lead-zinc slag to form a continuous cementitious network. Ball milling is then performed to homogenize the mixture and promote the contact of the unreacted active ingredients. After drying, the finished cement blend is obtained.

2. The method for preparing copper tailings recycled cementitious admixture according to claim 1, characterized in that, Step S1 also includes introducing hot air; During the grinding process, a gas with a temperature of 40-60℃ and a flow rate of 5-10 m³ / h is introduced into the vertical mill. 3 The hot air at a rate of / min can further dry the copper tailings particles, remove the grinding heat, and improve grinding efficiency, resulting in a more uniform particle size distribution.

3. The method for preparing copper tailings recycled cementitious admixture according to claim 1, characterized in that, The S5 step also includes a pre-coordinated reaction; When the CSH gel product generated by the reaction of lead-zinc slag powder with the composite activator is mixed with copper tailings, it acts as a "nucleus" to promote the dissolution and recrystallization of active components in the copper tailings.

4. The method for preparing copper tailings recycled cementitious admixture according to claim 1, characterized in that, In step S3, the concentration of the polyacrylamide aqueous solution is 1-3%. By controlling the concentration of the aqueous solution, the adsorption amount and coating effect of polyacrylamide on the surface of copper tailings particles can be precisely controlled.

5. The method for preparing copper tailings recycled cementitious admixture according to claim 1, characterized in that, Step S6 also includes humidity determination; Before ball milling, the moisture content of the mixture is tested. If the moisture content is too high, the mixture is dried to meet the requirements for ball milling.

6. The method for preparing copper tailings recycled cementitious admixture according to claim 1, characterized in that, In step S6, the drying process adopts a segmented drying process. First, it is dried at 60-80℃ to a moisture content of 10-15%, and then the temperature is raised to 100-120℃ to dry to the required moisture content of the finished product, so as to avoid structural damage to the mixed material due to excessive drying.

7. The copper tailings recycled cementitious material prepared by the method for preparing copper tailings recycled cementitious material according to any one of claims 1-6, characterized in that, The copper tailings recycled cement blend is made from the following raw materials by weight percentage: 58-62 wt% copper tailings, 38-42 wt% lead-zinc slag, 0.5-1.2 wt% polyacrylamide, and 3-5 wt% sodium silicate-calcium hydroxide composite activator, with the total of the above components being 100%.

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