Copper smelting slag recleaning tailing road material and preparation method thereof

Abstract

The invention discloses a copper smelting slag recleaning tailing road material and a preparation method thereof. The material comprises the following components: 2.5-3.5% of ordinary Portland cement; 8-12% of modified copper smelting slag recleaning tailings; the modified copper smelting slag recleaning tailings are obtained through mechanical activation and chemical excitation treatment; 70%-75% of graded broken stone (4.75 mm to 19 mm); sand (the fineness modulus is 2.6 to 2.8): 10 to 15 percent; 0.8%-1.2% of a composite additive; and the optimal water content is 6-8%. According to the method, the modified copper smelting slag recleaning tailings are subjected to mechanical activation, potential gelling activity of the tailings can be fully released, then chemical excitation is carried out, added aluminum sulfate can react with active ingredients in the tailings in an alkaline environment to generate substances such as aluminate with gelling property, the volcanic ash reaction efficiency is remarkably improved, and the utilization rate of the copper smelting slag recleaning tailings is increased. The binding capacity of the tailings and other raw materials is greatly enhanced, the overall performance of the road material is improved, resource utilization of a large amount of tailings is achieved, and the environmental burden is relieved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of copper smelting slag re-concentration tailings reprocessing, and particularly relates to a copper smelting slag re-concentration tailings road material and a preparation method. BACKGROUND

[0002] At present, the production of traditional road materials is facing the double dilemma of over-consumption of natural resources and aggravation of environmental pollution. At the same time, a large amount of copper smelting slag re-concentration tailings are accumulated, which not only occupies a large amount of land resources, but also has environmental risks such as heavy metal leakage. Although the application of copper smelting slag re-concentration tailings in road materials is an effective way to realize resource recycling, the existing technology has many shortcomings.

[0003] Due to the poor activity of the tailings themselves, it is difficult for them to fully integrate with other materials, and the strength, weather resistance and other key properties of the prepared road materials are difficult to meet the needs of high-standard road construction. SUMMARY

[0004] The application proposes the following technical solutions in view of the problems in the prior art:

[0005] The copper smelting slag re-concentration tailings road material is composed of the following raw materials in mass percentage: ordinary portland cement: 2.5-3.5%;

[0006] Modified copper smelting slag re-concentration tailings: 8-12%; The modified copper smelting slag re-concentration tailings is obtained through mechanical activation and chemical activation treatment, wherein the mechanical activation is to ball mill the copper smelting slag re-concentration tailings to a specific surface area of greater than or equal to 480 m 2 / kg, so as to fully release the potential cementitious activity; the chemical activation is to use a composite activator for activation, and the composite activator is composed of sodium silicate, calcium hydroxide and aluminum sulfate in a mass ratio of 2:1:0.15, and the amount of the composite activator is 1.65% of the mass of the copper smelting slag re-concentration tailings;

[0007] Graded gravel (4.75-19 mm): 70-75%;

[0008] Sand (fineness modulus 2.6-2.8): 10-15%;

[0009] Composite admixture: 0.8-1.2%;

[0010] Optimum moisture content: 6-8%.

[0011] As a preferred embodiment of the above technical solution, the gradation of the graded gravel is designed according to the improved Fuller curve theory, the porosity is controlled at 15-18% by adjusting the proportion of gravel of different particle sizes, and the particle size distribution is further adjusted to form a tight embedded structure of coarse aggregate, thereby enhancing the skeleton stability of the road material.

[0012] As the preferred of the above technical solution, the composite admixture is composed of water reducing agent, early strength agent, air entraining agent and retarder, and the mass ratio of the water reducing agent, early strength agent, air entraining agent and retarder is 3:2:1:0.5.

[0013] The preparation method of the copper smelting slag re-concentration tailings road material comprises the following steps:

[0014] S1, mechanical activation;

[0015] The copper smelting slag re-concentration tailings is placed in an oven at 80-120 DEG C for drying until the water content is less than or equal to 5%, and then ball milling is performed on the copper smelting slag re-concentration tailings using a ball mill, and the ball milling is performed until the specific surface area is greater than or equal to 480 m 2 / kg, and the potential cementitious activity of the copper smelting slag re-concentration tailings is fully released;

[0016] S2, chemical activation;

[0017] The sodium silicate, calcium hydroxide and aluminum sulfate are mixed uniformly according to the proportion to form a composite activator, and the composite activator is mixed with the mechanically activated copper smelting slag re-concentration tailings to perform chemical activation treatment;

[0018] S3, dry mixing of materials;

[0019] In the stirring equipment, the graded gravel and sand are first added and pre-stirred for 60 s to preliminarily mix the two, and then the modified copper smelting slag re-concentration tailings, ordinary Portland cement and composite activator are added into the stirring equipment and pre-mixed for 120 s;

[0020] S4, wet mixing of materials;

[0021] In the dry-mixed materials, part of the water (60% of the total water) is first added, and the materials are stirred for 60 s to preliminarily wet the materials, and then the remaining water and composite admixture are added, and the stirring is continued for 150 s to form the road material.

[0022] As the preferred of the above technical solution, it further comprises: S5, road material forming simulation; the stirred materials are poured into a mold, and are formed by vibration compaction, the frequency of the vibration compaction is 35-45 Hz, the amplitude is 0.8-1.2 mm, and the compaction time is 3.5-4.5 min.

[0023] As the preferred of the above technical solution, it further comprises: S6, curing treatment; the formed test piece is first cured for 4 days under moisture, the humidity is greater than or equal to 98%, the moisture curing is performed by steam curing, the steam temperature is controlled to be 45-55 DEG C, and then the test piece is cured for 7 days naturally, and the 7d unconfined compressive strength, 28d compressive strength and strength loss rate after freeze-thaw cycle are detected after the curing is completed.

[0024] As the preferred technical solution of the above, in the S2 step, first, the sodium silicate and calcium hydroxide are made into a sodium silicate-calcium hydroxide activator, and then aluminum sulfate is added. The sodium silicate can hydrolyze to generate silicate ions (SiO3 2- ) in an alkaline environment, and the calcium hydroxide provides a large number of hydroxyl ions (OH - ), creating a strong alkaline reaction environment. After the addition of aluminum sulfate, aluminum ions combine with silicate ions to form a silicate-aluminate polymer precursor with a certain degree of polymerization, which can more efficiently react with the active ingredients in the tailings. The pre-dispersion of aluminum sulfate in the alkaline activator allows aluminum ions to be more uniformly distributed, ensuring that they can promote the pozzolanic reaction throughout the system during subsequent reactions with the tailings, avoiding the situation of insufficient or uneven reaction caused by uneven local aluminum ion concentration.

[0025] As the preferred technical solution of the above, in the S3 step, before the dry mixing step, the graded gravel and sand are screened, washed, and then dried to reduce the moisture content of the graded gravel and sand to less than 0.5%.

[0026] The beneficial effects of the present application are:

[0027] 1. The mechanical activation of the modified copper smelting slag and the tailings can more fully release the potential cementitious activity of the tailings, followed by chemical activation. The added aluminum sulfate can react with the active ingredients in the tailings in an alkaline environment to generate aluminate and other substances with cementitious properties, significantly improving the pozzolanic reaction efficiency and greatly enhancing the binding ability of the tailings and other raw materials, improving the overall performance of the road material, and realizing the resource utilization of a large amount of tailings and reducing the environmental burden.

[0028] 2. The aluminum ions in the aluminum sulfate combine with the silicate ions to form a silicate-aluminate polymer precursor with a certain degree of polymerization, which can more efficiently react with the active ingredients in the tailings. The pre-dispersion of aluminum sulfate in the alkaline activator allows aluminum ions to be more uniformly distributed, ensuring that they can promote the pozzolanic reaction throughout the system during subsequent reactions with the tailings, avoiding the situation of insufficient or uneven reaction caused by uneven local aluminum ion concentration. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 The process flow diagram of the embodiment is shown. DETAILED DESCRIPTION

[0030] To make the purpose, technical solution and advantages of the embodiment of the present application clearer, the technical solution of the present application will be described clearly and completely in combination with the embodiment and the drawings of the specification.

[0031] Copper smelting slag re-concentration tailings road material, characterized in that it is composed of the following raw materials in mass percentage: ordinary Portland cement: 2.5-3.5%;

[0032] Modified copper smelting slag re-concentration tailings: 8-12%; the modified copper smelting slag re-concentration tailings is obtained by mechanical activation and chemical activation treatment, wherein the mechanical activation is that the copper smelting slag re-concentration tailings is ball milled to a specific surface area ≥ 480 m 2 / kg, to fully release the potential cementitious activity; the chemical activation is that a composite activator is used for activation, the composite activator is composed of sodium silicate, calcium hydroxide and aluminum sulfate with a mass ratio of 2:1:0.15, and the amount of the composite activator is 1.65% of the mass of the copper smelting slag re-concentration tailings;

[0033] Graded gravel (4.75-19 mm): 70-75%;

[0034] Sand (fineness modulus 2.6-2.8): 10-15%;

[0035] Composite admixture: 0.8-1.2%;

[0036] Optimum moisture content: 6-8%.

[0037] The gradation of the graded gravel is designed by using the improved Fuller curve theory, by adjusting the proportion of gravel of different particle sizes, the porosity is controlled at 15-18%, and by further adjusting the particle size distribution, the coarse aggregate forms a tight embedded structure, enhancing the skeleton stability of the road material.

[0038] The composite admixture is composed of water reducing agent, early strength agent, air entraining agent and retarder, and the mass ratio of the water reducing agent, early strength agent, air entraining agent and retarder is 3:2:1:0.5.

[0039] Figure 1 In particular, the preparation method of the copper smelting slag re-concentration tailings road material comprises the following steps:

[0040] S1, mechanical activation;

[0041] The copper smelting slag re-concentration tailings is placed in an oven at 80-120°C for drying until the moisture content is ≤5%, and then it is ball milled using a ball mill, ball milled to a specific surface area ≥ 480 m 2 / kg, to fully release its potential cementitious activity;

[0042] S2, chemical activation;

[0043] Sodium silicate, calcium hydroxide and aluminum sulfate are mixed in proportion to form a composite activator, and the composite activator is mixed with the mechanically activated copper smelting slag re-concentration tailings for chemical activation treatment;

[0044] S3, dry mixing of materials;

[0045] In the stirring device, first add graded gravel and sand, and pre-stir for 60 s to preliminarily mix them uniformly, then add modified copper smelting slag re-concentration tailings, ordinary Portland cement and composite activator into the stirring device, and pre-mix for 120 s;

[0046] S4, wet mixing of materials;

[0047] To the dry-mixed materials, first add part of water (60% of the total water), stir for 60 s to preliminarily wet the materials, then add the remaining water and composite admixture, and continue to stir for 150 s to produce the road material.

[0048] The mechanical activation of the modified copper smelting slag re-concentration tailings can make it release the potential cementitious activity of the tailings more fully, and then chemical activation is performed, and the added aluminum sulfate can react with the active ingredients in the tailings under alkaline environment to generate aluminate and other substances with cementitious properties, significantly improving the pozzolanic reaction efficiency, greatly enhancing the binding ability of the tailings and other raw materials, improving the overall performance of the road material, and realizing the resource utilization of a large amount of tailings and reducing the environmental burden.

[0049] Further comprising: S5, road material forming simulation; pour the stirred materials into a mold, and use vibration compaction to form, the frequency of vibration compaction is 35-45 Hz, the amplitude is 0.8-1.2 mm, and the compaction time is 3.5-4.5 min.

[0050] Further comprising: S6, curing treatment; the formed test piece is first cured for 4 days with humidity ≥98%, the humidity curing is performed by using steam curing, and the steam temperature is controlled at 45-55℃, then the test piece is naturally cured for 7 days, and after the curing is completed, the 7d unconfined compressive strength, 28d compressive strength and strength loss rate after freeze-thaw cycle are detected.

[0051] In the S3 step, before the dry mixing step, the graded gravel and sand are screened, cleaned and then dried to make the water content of the graded gravel and sand less than 0.5%.

[0052] In the S2 step, first prepare a sodium silicate-calcium hydroxide activator from sodium silicate and calcium hydroxide, and then add aluminum sulfate, sodium silicate can produce silicate ions (SiO3 2- ) in alkaline environment, and calcium hydroxide provides a large amount of hydroxyl ions (OH -This creates a strongly alkaline reaction atmosphere. When aluminum sulfate is added, aluminum ions combine with silicate ions to form a silicate polymer precursor with a certain degree of polymerization. This precursor can react more efficiently with the active components in the tailings. The pre-dispersion of aluminum sulfate in the alkaline activator ensures that aluminum ions are distributed more evenly, ensuring that the reaction with the tailings can play its role in promoting the pozzolanic reaction throughout the entire system, and avoiding insufficient or unbalanced reactions due to uneven local aluminum ion concentrations.

[0053] Aluminum ions in aluminum sulfate combine with silicate ions to form a silicate polymer precursor with a certain degree of polymerization. This precursor can react more efficiently with the active components in the tailings. Pre-dispersing aluminum sulfate in an alkaline activator ensures that aluminum ions are distributed more evenly, guaranteeing that it can promote the pozzolanic reaction throughout the entire system during the subsequent reaction with the tailings. This avoids incomplete or unbalanced reactions caused by uneven local aluminum ion concentrations.

[0054] I. Self-reaction of composite activators

[0055] 1. Acid-base neutralization and ion release:

[0056] Calcium hydroxide (Ca(OH)2) releases OH- when dissolved in water. - This creates a strongly alkaline environment in the system (pH≈12~14), providing alkaline conditions for subsequent reactions.

[0057] Aluminum sulfate (Al2(SO4)3) dissociates into Al after dissolving in water. 3+ and SO4 2- Al 3+ With OH - The reaction produces aluminum hydroxide colloid:

[0058] Al 3+ +3OH - →Al(OH)3↓

[0059] This colloid has gelling properties and can initially fill the gaps between tailings particles.

[0060] Sodium silicate (Na₂SiO₃) dissociates into silicate ions (SiO₃⁻) under alkaline conditions. 2- ) and Na + Silicate ions combine with water to form silicic acid (H2SiO3) colloid:

[0061]

[0062] 2. Initial formation of aluminosilicate gel:

[0063] Al(OH)3 colloid reacts further with H2SiO3 colloid to form aluminosilicate hydrate gel (similar to CSH gel), whose general structural formula can be represented as:

[0064] xCaO yAl203 zSi02 wH20

[0065] This gel is the main source of early strength.

[0066] II. Reaction of activator with copper smelting slag re-concentration tailings

[0067] The main components of copper smelting slag re-concentration tailings are Si02, Al203, CaO, etc. (may contain a small amount of Fe203, MgO), and after mechanical activation, the specific surface area increases, the surface defects increase, and the active sites are exposed, so the reaction with the activator is more sufficient:

[0068] 1. Alkaline activation of active components in tailings:

[0069] Under strong alkaline conditions, the glassy Si02 and Al203 in the tailings undergoes "depolymerization-recombination" reaction:

[0070] Depolymerization: Alkaline solution destroys the network structure of Si02 and Al203, releasing Si(OH)4, Al(OH)4 - and other active ions;

[0071] Recombination: Si(OH)4 and Al(OH)4 - combine with Ca 2+ (from calcium hydroxide or CaO in tailings), Na + (from sodium silicate) to form calcium sodium aluminosilicate hydrate (such as Na-Ca-Al-Si-O-H gel):

[0072]

[0073] This gel network structure gradually densifies over time, which is the key to the 28d strength growth.

[0074] 2. Special role of aluminum sulfate:

[0075] Al 3+ In addition to participating in gel formation, it can also form complex salts (such as aluminum iron hydroxyl sulfate) with Fe 3+ , Mg 2+ and other cations in the tailings, filling pores and improving structural density;

[0076] SO4 2- can react with Ca 2+ to form gypsum (CaSO4·2H2O), which is interpenetrated in the gel network, playing a "micro-expansion" compensation role, reducing shrinkage cracks and improving frost resistance.

[0077] The aluminosilicate hydrate gel acts as a cementing phase to bind the tailings particles and aggregates (crushed stone, sand) into a whole, the 7d strength is mainly determined by the amount of early gel generated, and the 28d strength depends on the further crystallization and densification of the gel network. The gypsum crystals and complex salt filled by aluminum sulfate promote the integrity of the structure, which greatly improves the 28d compressive strength of the examples compared with the comparative examples.

[0078] Example 1

[0079] Mechanical activation: take the copper smelting slag re-concentrate, use the ball mill for mechanical activation treatment, ball mill to specific surface area of 480m 2 / kg.

[0080] Chemical activation: mix sodium silicate, calcium hydroxide and aluminum sulfate according to the mass ratio of 2:1:0.15 to make a composite activator, the amount of composite activator is 1.5% of the mass of copper smelting slag re-concentrate, mix the composite activator with the mechanically activated copper smelting slag re-concentrate, and perform chemical activation treatment.

[0081] Dry mixing of materials: first add 74% of graded crushed stone and 11% of sand in the stirring equipment, pre-stir for 60s, then add 2.8% of ordinary Portland cement, 9% of modified copper smelting slag re-concentrate, and composite activator into the stirring equipment, pre-mix for 120s.

[0082] Wet mixing of materials: first add 6.5% of total water, 60% of water, to the dry mixed materials, stir for 60s, then add the remaining 40% of water, 0.9% of composite admixture (mass ratio of water reducing agent, early strength agent and air entraining agent is 3:2:1), continue to stir for 150s.

[0083] Road material forming simulation: pour the stirred materials into the mold, use vibration compaction method for forming, the frequency of vibration compaction is 35Hz, the amplitude is 0.8mm, and the compaction time is 3.5min.

[0084] Maintenance treatment: the formed test piece is first maintained for 4 days, using steam curing method, the steam temperature is controlled at 45℃, and the humidity is ≥98%, then it is naturally cured for 7 days, and the humidity is maintained by watering every day during the natural curing period. After the curing is completed, the 7d unconfined compressive strength, 28d compressive strength and strength loss rate after freeze-thaw cycle are detected.

[0085] Example 2

[0086] Mechanical activation: mechanically activate the copper smelting slag re-concentrate, ball mill to specific surface area of 500m 2 / kg.

[0087] Chemical activation: Composite activator (sodium silicate, calcium hydroxide and aluminum sulfate with mass ratio of 2:1:0.15, dosage of 1.5% of the tailings) was prepared and mixed with the activated tailings to perform chemical activation.

[0088] Dry mixing of materials: 72% of graded gravel and 12% of sand were first mixed in a stirring device for 60 s, then 3.0% of ordinary Portland cement, 10% of modified copper smelting slag reselected tailings, and composite activator were premixed for 120 s.

[0089] Wet mixing of materials: 60% of the total water amount of 7.0% was added and stirred for 60 s, then the remaining water and 1.0% of the composite admixture were added, and stirring was continued for 150 s.

[0090] Road material molding simulation: After the materials were poured into the mold, molding was performed at a vibration compaction frequency of 40 Hz, an amplitude of 1.0 mm, and a compaction time of 4.0 min.

[0091] Curing treatment: The test piece was first moistened and cured at a steam temperature of 50℃ and a humidity of ≥98% for 4 days, then naturally cured for 7 days, during which time water was sprayed at regular intervals, and finally the relevant performance indicators were detected.

[0092] Example 3

[0093] Mechanical activation: The copper smelting slag reselected tailings were mechanically activated by ball milling to a specific surface area of 520 m 2 / kg.

[0094] Chemical activation: Composite activator (sodium silicate, calcium hydroxide and aluminum sulfate with mass ratio of 2:1:0.15, dosage of 1.5% of the tailings) was used for activation. The well-graded gravel and sand were treated.

[0095] Dry mixing of materials: 71% of well-graded gravel and 14% of sand were first stirred for 60 s, then 3.2% of ordinary Portland cement, 11% of modified copper smelting slag reselected tailings, and composite activator were premixed for 120 s.

[0096] Wet mixing of materials: 60% of the total water amount of 7.5% was added and stirred for 60 s, then the remaining water and 1.1% of the composite admixture were added, and stirring was continued for 150 s.

[0097] Road material molding simulation: The materials were molded using a vibration compaction frequency of 45 Hz, an amplitude of 1.2 mm, and a compaction time of 4.5 min.

[0098] Curing treatment: The test piece was first moistened and cured at a steam temperature of 55℃ and a humidity of ≥98% for 4 days, then naturally cured for 7 days, during which time water was sprayed at regular intervals, and finally the relevant performance indicators were detected.

[0099] Comparative Example

[0100] The copper smelting slag re-concentration tailings road material is prepared according to the similar procedure of Example 1, but without using the sodium silicate-calcium hydroxide composite activator and aluminum sulfate for chemical activation.

[0101]

[0102] Table 1: Road material forming simulation detection performance index

[0103] The copper smelting slag re-concentration tailings road material prepared through the above examples is strictly detected, and the mechanical performance indexes such as 7d unconfined compressive strength and 28d compressive strength are all better than those of the traditional road material, the strength loss rate after freeze-thaw cycle is low, 90-110kg of tailings can be absorbed per ton of material, the cement consumption is reduced by about 45%, and the economic, environmental and social benefits are significant.

[0104] The above examples are only used to illustrate the technical solutions of the present application, but not to limit it.

Claims

1. Road material for copper smelting slag tailings reprocessing, characterized in that, It is composed of the following raw materials by weight percentage: ordinary Portland cement: 2.5-3.5%; Modified copper smelting slag tailings: 8-12%; the modified copper smelting slag tailings are obtained through mechanical activation and chemical activation treatment, wherein mechanical activation involves ball milling the copper smelting slag tailings to a specific surface area ≥480m². 2 / kg, fully releasing potential gelling activity; chemical activation is carried out using a composite activator, which is composed of sodium silicate, calcium hydroxide and aluminum sulfate in a mass ratio of 2:1:0.15, and the amount of composite activator is 1.65% of the mass of copper smelting slag tailings. Graded crushed stone (4.75-19mm): 70-75%; Sand (fineness modulus 2.6-2.8): 10-15%; Composite admixture: 0.8-1.2%; Optimal moisture content: 6-8%.

2. The road material for copper smelting slag tailings reprocessing according to claim 1, characterized in that, The gradation of the graded crushed stone is designed using the improved Fuller curve theory. By adjusting the proportion of crushed stone with different particle sizes, the porosity is controlled at 15-18%, and the particle size distribution is further adjusted to make the coarse aggregate form a tightly interlocked structure, thereby enhancing the skeleton stability of the road material.

3. The road material for copper smelting slag reprocessing tailings according to claim 2, characterized in that, The composite admixture consists of a water-reducing agent, an early-strength agent, an air-entraining agent, and a retarder, with the mass ratio of the water-reducing agent, early-strength agent, air-entraining agent, and retarder being 3:2:1:0.

5.

4. A method for preparing road material for copper smelting slag reprocessing tailings as described in any one of claims 1-3, characterized in that, Includes the following steps: S1, mechanical activation; The tailings from copper smelting slag reprocessing are dried in an oven at 80-120℃ until the moisture content is ≤5%, and then ball-milled until the specific surface area is ≥480m². 2 / kg, fully releasing its potential gelling activity; S2, chemical activation; Sodium silicate, calcium hydroxide and aluminum sulfate are mixed evenly in a certain proportion to prepare a composite activator. The composite activator is then mixed with mechanically activated copper smelting slag tailings for chemical activation treatment. S3, Dry mixing of materials; First, add graded crushed stone and sand to the mixing equipment and pre-mix for 60 seconds to make the two initially mixed evenly. Then, add modified copper smelting slag tailings, ordinary silicate cement, and composite activator to the mixing equipment and pre-mix for 120 seconds. S4, wet mixing of materials; Add some water (60% of the total water volume) to the dry-mixed material and stir for 60 seconds to initially moisten the material. Then add the remaining water and compound additives and continue stirring for 150 seconds to make road material.

5. The method for preparing road materials for copper smelting slag reprocessing tailings according to claim 4, characterized in that, Also includes: S5. Road material forming simulation: Pour the mixed material into the mold and form it by vibration compaction. The vibration compaction frequency is 35-45Hz, the amplitude is 0.8-1.2mm, and the compaction time is 3.5-4.5min.

6. The method for preparing road materials for copper smelting slag reprocessing tailings according to claim 4, characterized in that, Also includes: S6. Curing treatment: After molding, the specimens are first moisturized for 4 days with a humidity of ≥98%. Moisturizing is done by steam curing with the steam temperature controlled at 45-55℃. Then, they are naturally cured for 7 days. After curing, the 7-day unconfined compressive strength, 28-day compressive strength and strength loss rate after freeze-thaw cycles are tested.

7. The method for preparing road materials for copper smelting slag reprocessing tailings according to claim 4, characterized in that, In step S2, sodium silicate and calcium hydroxide are first prepared into a sodium silicate-calcium hydroxide activator. Then, aluminum sulfate is added. Sodium silicate can hydrolyze in an alkaline environment to produce silicate ions (SiO32-), while calcium hydroxide provides a large number of hydroxide ions (OH-), creating a strongly alkaline reaction atmosphere. After the addition of aluminum sulfate, aluminum ions combine with silicate ions to form a precursor of aluminosilicate polymer with a certain degree of polymerization, which can react more efficiently with the active components in the tailings. The pre-dispersion of aluminum sulfate in the alkaline activator can make the aluminum ions more evenly distributed, ensuring that it can play its role in promoting the pozzolanic reaction in the entire system during the subsequent reaction with the tailings, and avoiding insufficient or unbalanced reaction due to uneven local aluminum ion concentration.

8. The method for preparing road materials for copper smelting slag reprocessing tailings according to claim 4, characterized in that, In step S3, before the dry mixing step, the graded crushed stone and sand are screened, washed, and then dried to ensure that the moisture content of the graded crushed stone and sand is less than 0.5%.

Images