Composite activator based on lithium slag as well as preparation method and application of composite activator

Abstract

The invention discloses a composite activator based on lithium slag as well as a preparation method and application thereof. The composite activator comprises the following raw materials in parts by weight: 30-50 parts of lithium slag, 5-10 parts of an alkali activator, 20-30 parts of slag powder, 5-10 parts of fly ash, 0.5-1.5 parts of a water reducing agent, 0.1-0.5 part of a regulator, 5-10 parts of an auxiliary admixture and 10-15 parts of water. The lithium slag composite excitant has the advantage of good excitation effect, and solves the problems that in the preparation process of an existing lithium slag composite excitant, the excitation effect on the lithium slag is poor, the performance of the lithium slag composite excitant serving as a binding material or an admixture can be directly influenced, and then negative influences are generated on engineering application and resource utilization.

Description

Technical Field

[0001] The present invention relates to the technical field of material recycling, and in particular to a composite activator based on lithium slag, a preparation method thereof, and an application thereof. Background Art

[0002] Lithium slag is an industrial waste residue generated during the production of lithium salts. It is rich in active ingredients such as SiO2 and Al2O3, but has a low calcium oxide content. Lithium slag itself has weak reaction activity under alkaline conditions, and it is difficult to fully exert its potential activity when used alone. Therefore, it is necessary to enhance its reactivity through a composite activator. The composite activator based on lithium slag is a mixed material formed by combining lithium slag with an alkaline activator, which aims to enhance the activity of lithium slag. The core goal of this activator is to activate the active ingredients in the lithium slag through chemical or physical effects, promote its reaction with substances in the alkaline environment, and generate high-value-added hydration products, thereby improving the mechanical properties and durability of the material.

[0003] During the preparation process, the existing lithium slag composite activator has a poor activating effect on lithium slag, which will directly affect its performance as a cementitious material or admixture, and thus have a negative impact on engineering applications and resource utilization. Summary of the Invention

[0004] The purpose of the present invention is to provide a composite activator based on lithium slag, a preparation method and application thereof, which has the advantage of good excitation effect and solves the problem that the existing lithium slag composite activator has poor excitation effect on lithium slag during the preparation process, which directly affects its performance as a cementitious material or admixture, and thus has a negative impact on engineering applications and resource utilization.

[0005] To achieve the above object, the present invention provides the following technical solution: a composite activator based on lithium slag, comprising the following raw materials in parts by weight:

[0006] 30-50 parts of lithium slag, 5-10 parts of alkali activator, 20-30 parts of slag powder, 5-10 parts of fly ash, 0.5-1.5 parts of water reducer, 0.1-0.5 parts of regulator, 5-10 parts of auxiliary admixture, and 10-15 parts of water.

[0007] A method for preparing a composite activator based on lithium slag comprises the following steps:

[0008] S1. Batching: weigh and mix lithium slag, alkali activator, slag powder, fly ash, water reducer, regulator, auxiliary admixtures and water according to the proportion;

[0009] S2, dry mixing, pouring lithium slag, slag powder, fly ash and auxiliary admixtures into a mixing device, stirring and mixing them, and processing them into dry materials;

[0010] S3, crushing and grinding, pouring the mixed dry material into the crushing and grinding equipment, grinding the dry material into particles, screening the dry material particles during the grinding process, screening out large particles of dry material and grinding again;

[0011] S4, preparing the exciting solvent, grinding the alkaline exciting agent into particles, and then mixing it with water to form an exciting solvent;

[0012] S5, wet mixing, pouring the ground dry material particles into the mixing equipment, during the mixing process, spraying the exciting solvent into the dry material particles through the spraying system to allow the exciting solvent to fully penetrate, after the spraying is completed, adding the water reducing agent and the regulating agent into the dry material particles, and stirring and mixing again;

[0013] S6. Material activation: pour the mixed material into the mechanical activation equipment, which grinds the material into powder. The particle size of the powder material is 5-100 μm.

[0014] As a preferred method for preparing a composite activator based on lithium slag of the present invention, the mixing equipment includes a mixing chamber, and a double-axis paddle agitator is installed inside the mixing chamber. The two parallel axes of the double-axis paddle agitator are equipped with cross-arranged blades, and three-dimensional mixing of the materials is achieved by reverse rotation. The ends of the blades are serrated to enhance the shear force and break up the agglomeration of particles.

[0015] As a preferred preparation method of a composite activator based on lithium slag of the present invention, the crushing and grinding equipment includes a crushing mechanism and a grinding mechanism. The crushing mechanism is a hydraulic double-roll crusher. The hydraulic double-roll crusher is composed of two crushing rollers rotating in opposite directions. The crushing rollers crush the material by squeezing. The grinding mechanism includes a rotating drum. The crushed material enters the rotating drum. The inside of the rotating drum is provided with grinding steel balls. During the rotation of the rotating drum, the grinding steel balls collide with the material to grind the material.

[0016] As a preferred preparation method of a composite activator based on lithium slag of the present invention, when screening the dry material particles, an analyzer is used for screening, and the ground mixture enters the analyzer through the feed port and is driven by the airflow to rise to the grading area. When the impeller rotates at high speed, a centrifugal force field is generated, and the particles are thrown to the periphery of the impeller under the action of centrifugal force. Particles with larger particle sizes have larger mass and the centrifugal force is significantly higher than the airflow drag. They are thrown to the outer wall of the impeller and slide down the shell to the coarse powder discharge port, and return to the grinding area to continue crushing. Particles with smaller particle sizes have weaker centrifugal force and cannot overcome the airflow drag. They enter the central area of ​​the impeller with the airflow and are finally discharged through the fine powder outlet.

[0017] As a preferred method for preparing a composite activator based on lithium slag of the present invention, the stirring equipment includes a horizontal stirring drum, the spraying system is installed on the top of the horizontal stirring drum, and a horizontal stirring structure is provided inside the horizontal stirring drum, and the horizontal stirring structure stirs the material.

[0018] As a preferred preparation method of a composite activator based on lithium slag of the present invention, the spraying system includes a liquid pump, which extracts the activating solvent, the liquid outlet of the liquid pump is connected to an infusion pipeline, and the liquid outlet of the infusion pipeline is connected to a fan-shaped nozzle. The activating solvent is evenly sprayed on the surface of the material inside the horizontal mixing drum through the infusion pipeline and the fan-shaped nozzle.

[0019] As a preferred preparation method of a composite activator based on lithium slag of the present invention, the mechanical activation equipment includes a stirring mill mechanism, and the driving system drives the stirring mill mechanism. The stirring mill mechanism drives the grinding balls to move at high speed inside the grinding tank through the stirring shaft to perform ultrafine grinding on the material.

[0020] As a preferred method for preparing a composite activator based on lithium slag of the present invention, a liquid cooling circulation system is provided on the grinding tank to reduce the internal temperature of the grinding tank by circulating cooling water to avoid a decrease in material activity due to high temperature.

[0021] The invention discloses an application of a composite activator based on lithium slag, and the composite activator based on lithium slag is applied to cementitious materials, soil improvement materials and building materials.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. The present invention significantly activates the activity of SiO2 and Al2O3 in lithium slag through the synergistic effect of alkaline activator and lithium slag, promotes the formation of high-strength hydration products such as CSH gel and ettringite, thereby improving the mechanical properties of cementitious materials. The composite incorporation of slag and fly ash not only compensates for the low CaO content in lithium slag, but also optimizes the pore structure through the micro-aggregate effect, reducing the risk of shrinkage cracking. At the same time, the introduction of polycarboxylate water-reducing agent and triisopropanolamine effectively improves the fluidity of the slurry, accelerates the early hydration reaction and reduces the porosity, further enhancing the density and durability of the material. In addition, this solution significantly reduces cement consumption and carbon emissions through the high-value utilization of industrial waste slag, achieving resource recycling and low-carbon environmental protection goals. It is suitable for a variety of engineering scenarios such as early-strength concrete, soil improvement and green building materials, and has both economic and sustainable advantages. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of the preparation process of the present invention. DETAILED DESCRIPTION

[0025] Example 1

[0026] A composite activator based on lithium slag comprises the following raw materials in parts by weight:

[0027] 30-50 parts of lithium slag, 5-10 parts of alkali activator, 20-30 parts of slag powder, 5-10 parts of fly ash, 0.5-1.5 parts of water reducer, 0.1-0.5 parts of regulator, 5-10 parts of auxiliary admixture, and 10-15 parts of water.

[0028] Further, one part of the alkaline activator includes 60% sodium hydroxide and 40% silicon dioxide.

[0029] Furthermore, the water reducer is a polycarboxylic acid water reducer.

[0030] Furthermore, the regulator is triisopropanolamine.

[0031] Furthermore, an auxiliary admixture includes 30% silica fume and 70% steel slag powder.

[0032] Through the synergistic effect of alkaline activators and lithium slag, the activity of SiO2 and Al2O3 in the lithium slag is significantly activated, promoting the formation of high-strength hydration products such as CSH gel and ettringite, thereby improving the mechanical properties of the cementitious material. The composite incorporation of slag and fly ash not only compensates for the low CaO content in the lithium slag, but also optimizes the pore structure through the micro-aggregate effect, reducing the risk of shrinkage cracking. At the same time, the introduction of polycarboxylate water-reducing agent and triisopropanolamine effectively improves the fluidity of the slurry, accelerates the early hydration reaction, and reduces the porosity, further enhancing the density and durability of the material. In addition, this solution significantly reduces cement consumption and carbon emissions through the high-value utilization of industrial waste slag, achieving resource recycling and low-carbon environmental protection goals. It is suitable for a variety of engineering scenarios such as early-strength concrete, soil improvement, and green building materials, and has both economic and sustainable advantages.

[0033] Example 2

[0034] See also Figure 1 , a preparation method of a composite activator based on lithium slag, comprising the following steps:

[0035] S1. Batching: weigh and mix lithium slag, alkali activator, slag powder, fly ash, water reducer, regulator, auxiliary admixtures and water according to the proportion;

[0036] S2, dry mixing, pouring lithium slag, slag powder, fly ash and auxiliary admixtures into a mixing device, stirring and mixing them, and processing them into dry materials;

[0037] S3, crushing and grinding, pouring the mixed dry material into the crushing and grinding equipment, grinding the dry material into particles, screening the dry material particles during the grinding process, screening out large particles of dry material and grinding again;

[0038] S4, preparing the exciting solvent, grinding the alkaline exciting agent into particles, and then mixing it with water to form an exciting solvent;

[0039] S5, wet mixing, pouring the ground dry material particles into the mixing equipment, during the mixing process, spraying the exciting solvent into the dry material particles through the spraying system to allow the exciting solvent to fully penetrate, after the spraying is completed, adding the water reducing agent and the regulating agent into the dry material particles, and stirring and mixing again;

[0040] S6. Material activation: pour the mixed material into the mechanical activation equipment, which grinds the material into powder. The particle size of the powder material is 5-100 μm.

[0041] Furthermore, the mixing equipment includes a mixing bin, in which a double-shaft paddle agitator is installed. The two parallel shafts of the double-shaft paddle agitator are equipped with cross-arranged blades, which realize three-dimensional mixing of materials through reverse rotation, and the ends of the blades are serrated to enhance shear force and break up particle agglomeration.

[0042] Furthermore, the crushing and grinding equipment includes a crushing mechanism and a grinding mechanism. The crushing mechanism is a hydraulic double-roll crusher, which is composed of two crushing rollers rotating in opposite directions. The crushing rollers crush the material by squeezing. The grinding mechanism includes a rotating drum. The crushed material enters the rotating drum. Grinding steel balls are provided inside the rotating drum. During the rotation of the rotating drum, the grinding steel balls collide with the material to grind the material.

[0043] Furthermore, when screening dry material particles, an analyzer is used for screening. The ground mixture enters the analyzer through the feed port and is driven by the airflow to rise to the grading area. When the impeller rotates at high speed, a centrifugal force field is generated. The particles are thrown to the periphery of the impeller under the action of centrifugal force. Particles with larger particle sizes have larger mass and the centrifugal force is significantly higher than the airflow drag. They are thrown to the outer wall of the impeller and slide down the shell to the coarse powder discharge outlet, and return to the grinding area to continue crushing. The centrifugal force of particles with smaller particle sizes is weaker and cannot overcome the airflow drag. They enter the central area of ​​the impeller with the airflow and are finally discharged through the fine powder outlet.

[0044] Furthermore, the mixing equipment includes a horizontal mixing drum, the spray system is installed on the top of the horizontal mixing drum, and a horizontal mixing structure is provided inside the horizontal mixing drum, and the horizontal mixing structure stirs the material.

[0045] Furthermore, the spraying system includes a liquid pump, which extracts the excitation solvent. The liquid outlet of the liquid pump is connected to an infusion pipeline, and the liquid outlet of the infusion pipeline is connected to a fan-shaped nozzle. The excitation solvent is evenly sprayed on the material surface inside the horizontal mixing drum through the infusion pipeline and the fan-shaped nozzle.

[0046] Furthermore, the mechanical activation equipment includes a stirring mill mechanism, and the driving system drives the stirring mill mechanism. The stirring mill mechanism drives the grinding balls to move at high speed inside the grinding tank through the stirring shaft to perform ultrafine grinding on the material.

[0047] Furthermore, a liquid cooling circulation system is provided on the grinding tank, which lowers the internal temperature of the grinding tank by circulating cooling water to avoid a decrease in material activity due to high temperature.

[0048] The synergistic effect of multi-stage mixing, crushing and grinding, and precise activator penetration significantly improves the activity and performance of the lithium slag composite activator. The serrated blade design of the dual-shaft paddle agitator enhances the shear force, breaks up the agglomeration of dry material particles, achieves uniform mixing, and provides sufficient contact conditions for subsequent activator penetration. The combination of the hydraulic roller crusher and the rotary drum grinding mechanism, combined with the dynamic screening of the air flow classifier, ensures a uniform particle size distribution of the dry material particles and improves the reaction efficiency of the lithium slag and activator. The spray system evenly sprays the alkaline activator onto the material surface through a fan-shaped nozzle. Combined with the synergistic effect of the water reducer and the regulator, it promotes the formation of CSH gel and significantly improves the density and strength of the hydration product. The stirred mill mechanism achieves 5-100μm ultrafine grinding through high-speed grinding ball impact. The liquid cooling circulation system avoids the decrease in activity caused by high temperature and ensures the maximum reaction activity of the material.

[0049] Example 3

[0050] The invention discloses an application of a composite activator based on lithium slag, and the composite activator based on lithium slag is applied to cementitious materials, soil improvement materials and building materials.

[0051] When used in cementitious materials, lithium slag can significantly improve the compressive strength of cement mortar after replacing part of the cement. Using low-cost lithium slag to replace part of the cement can significantly reduce the preparation cost of cementitious materials.

[0052] When used in soil improvement materials, it can enhance the bonding capacity between particles and significantly improve the compressive strength of soft soil. Lithium slag replaces traditional curing agents such as quicklime and cement, reducing carbon emissions during the soil improvement process.

[0053] When used in building materials, lithium slag can optimize the pore structure of recycled concrete, reduce the strength loss caused by recycled aggregates, and use low-cost lithium slag to replace high-value natural raw materials, significantly reducing the cost of concrete production.

[0054] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A composite activator based on lithium slag, characterized in that: The composition comprises the following raw materials in parts by weight: 30-50 parts of lithium slag, 5-10 parts of alkali activator, 20-30 parts of slag powder, 5-10 parts of fly ash, 0.5-1.5 parts of water reducer, 0.1-0.5 parts of regulator, 5-10 parts of auxiliary admixture, and 10-15 parts of water.

2. A method for preparing a composite activator based on lithium slag, applicable to the composite activator based on lithium slag according to claim 1, characterized in that: The following steps are involved: S1. Batching: weigh and mix lithium slag, alkali activator, slag powder, fly ash, water reducer, regulator, auxiliary admixtures and water according to the proportion; S2, dry mixing, pouring lithium slag, slag powder, fly ash and auxiliary admixtures into a mixing device, stirring and mixing them, and processing them into dry materials; S3, crushing and grinding, pouring the mixed dry materials into the crushing and grinding equipment, grinding the dry materials into particles, screening the dry material particles during the grinding process, screening out large particles of dry materials and grinding them again; S4, preparing the exciting solvent, grinding the alkaline exciting agent into particles, and then mixing it with water to form an exciting solvent; S5, wet mixing, pouring the ground dry material particles into the mixing equipment, during the mixing process, spraying the exciting solvent into the dry material particles through the spraying system to allow the exciting solvent to fully penetrate, after the spraying is completed, adding the water reducing agent and the regulating agent into the dry material particles, and stirring and mixing again; S6. Material activation: pour the mixed material into the mechanical activation equipment, which grinds the material into powder. The particle size of the powder material is 5-100 μm.

3. The method for preparing a composite activator based on lithium slag according to claim 2, characterized in that: The mixing equipment includes a mixing bin, inside which a double-shaft paddle agitator is installed. The two parallel shafts of the double-shaft paddle agitator are equipped with cross-arranged blades, which achieve three-dimensional mixing of the materials through counter-rotation. The ends of the blades are serrated to enhance shear force and break up particle agglomerations.

4. The method for preparing a composite activator based on lithium slag according to claim 3, characterized in that: The crushing and grinding equipment includes a crushing mechanism and a grinding mechanism. The crushing mechanism is a hydraulic double-roll crusher, which consists of two crushing rollers rotating in opposite directions. The crushing rollers crush the material by squeezing. The grinding mechanism includes a rotating drum. After crushing, the material enters the rotating drum. There are grinding steel balls inside the rotating drum. During the rotation of the rotating drum, the grinding steel balls collide with the material to grind the material.

5. The method for preparing a composite activator based on lithium slag according to claim 4, characterized in that: When screening dry material particles, an analyzer is used for screening. The ground mixture enters the analyzer through the feed port and is driven by the airflow to rise to the grading area. When the impeller rotates at high speed, a centrifugal force field is generated. The particles are thrown to the periphery of the impeller under the action of centrifugal force. Particles with larger particle size have larger mass and the centrifugal force is significantly higher than the airflow drag. They are thrown to the outer wall of the impeller and slide down the shell to the coarse powder discharge outlet, and return to the grinding area to continue crushing. Particles with smaller particle size have weaker centrifugal force and cannot overcome the airflow drag. They enter the center area of ​​the impeller with the airflow and are finally discharged through the fine powder outlet.

6. The method for preparing a composite activator based on lithium slag according to claim 5, characterized in that: The mixing equipment includes a horizontal mixing drum. The spray system is installed on the top of the horizontal mixing drum. A horizontal mixing structure is provided inside the horizontal mixing drum to mix the materials.

7. The method for preparing a composite activator based on lithium slag according to claim 6, characterized in that: The spraying system includes a liquid pump, which extracts the excitation solvent. The liquid outlet of the liquid pump is connected to an infusion pipeline, and the liquid outlet of the infusion pipeline is connected to a fan-shaped nozzle. The excitation solvent is evenly sprayed on the material surface inside the horizontal mixing drum through the infusion pipeline and the fan-shaped nozzle.

8. The method for preparing a composite activator based on lithium slag according to claim 7, characterized in that: The mechanical activation equipment includes a stirring mill mechanism, which is driven by a driving system. The stirring mill mechanism drives the grinding balls to move at high speed inside the grinding tank through the stirring shaft to perform ultrafine grinding on the materials.

9. The method for preparing a composite activator based on lithium slag according to claim 8, characterized in that: The grinding tank is equipped with a liquid cooling circulation system, which reduces the internal temperature of the grinding tank by circulating cooling water to avoid the decrease of material activity due to high temperature.

10. An application of a composite activator based on lithium slag, characterized in that: The composite activator based on lithium slag is used in cementitious materials, soil improvement materials and building materials.

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