Chemical admixture for resource utilization of copper slag as well as preparation method and use method of chemical admixture

Abstract

The invention discloses a chemical admixture for resource utilization of copper slag as well as a preparation method and a use method of the chemical admixture, and belongs to the field of resource utilization of the copper slag. The chemical additive comprises isomeric alcohol amine, a cationic polymer and a slow-release polymer; the isomeric alcohol amine is a substance shown in a formula (I), m is a natural number of 1-5, and n is a natural number of 1-4; the cationic polymer is a substance shown in a formula (II), R1 and R2 are independently selected from H or CH3, W is O or-NH, Z is CH2 or CH2CH2, and X is a halogen atom; x: y represents a molar ratio of 1: (0.5-2.0); the sustained-release polymer is a substance shown in a formula (III), and R3, R4, R5 and R6 are independently selected from H or CH3; the molar ratio s: h is 1: (1.0-3.0). The chemical admixture provided by the invention can play an important role in two aspects of fluidity regulation and activity excitation of the cement-based material added with the copper slag.

Description

Technical Field

[0001] This invention relates to the resource utilization of copper slag, and in particular to a chemical additive for the resource utilization of copper slag and its preparation and application methods. Background Technology

[0002] Copper slag is an industrial waste generated during the copper smelting process, with its main chemical components being Fe2O3, SiO2, CaO, Al2O3, and MgO. Statistics show that approximately 2-3 tons of copper slag are generated for every ton of copper produced. As a major copper producer and consumer, my country generates a massive amount of copper slag annually, and the continuously growing demand for copper has led to an increasingly prominent problem of copper slag accumulation. Therefore, promoting the resource utilization of copper slag has become a research focus of considerable attention.

[0003] Generally, after sorting, the fine powder portion (particle size less than 75 micrometers) of copper slag is used as an auxiliary cementitious material, while the coarse particle portion (particle size no greater than 4.75 mm) is used as fine aggregate to replace natural sand or manufactured sand. CN108751866A uses a ball mill to crush water-quenched copper slag, and uses the coarse particle portion after crushing to prepare waste copper slag fine aggregate. It also provides a technology that uses waste copper slag as fine aggregate to completely replace natural sand / manufactured sand in translucent concrete. Compared with the use of traditional sand, the strength of translucent concrete using waste copper slag as fine aggregate is improved, reaching a maximum of 47.9 MPa. CN112608042A discloses a method for preparing ultrafine copper tailings filling cementitious material by wet grinding of water-quenched copper slag. The water-quenched copper slag is placed in a crusher and crushed to 1-10 mm. It is then dry-ground to obtain copper slag powder, and further wet-ground to obtain ultrafine copper slag powder (median particle size of 2-5 micrometers). This ultrafine copper slag powder is used as an auxiliary cementitious material. However, copper slag faces two major problems in its application. First, when used as fine aggregate, copper slag exhibits a strong adsorption effect on conventional admixtures, significantly reducing the fluidity of cementitious materials with added copper slag fine aggregate and increasing fluidity loss over time, causing inconvenience during construction. Second, when used as an auxiliary cementitious material, copper slag fine powder suffers from low activity and insufficient strength in cementitious materials. To address these two issues, CN117088652A provides an activated copper slag concrete and its preparation method, developing an activated activator composed of the reaction product of perfluorohexyl ethyl acrylate and methyl silicone oil in a specific ratio. The 28-day strength of concrete after adding the activated activator increased from 37.6 MPa to 46.2 MPa, an increase of over 20%. However, existing literature lacks targeted research on the reduced fluidity and increased fluidity loss of cementitious materials caused by copper slag fine aggregate, which remains a major challenge for the resource utilization of copper slag.

[0004] Although existing technologies disclose methods for preparing chemical admixtures that activate the activity of copper slag fine powder, which to some extent improve the activity of copper slag fine powder and increase the strength of cement-based materials with added copper slag fine powder, the disclosed activation activators have many problems such as limited activation effect, high price and poor compatibility; and there is currently no effective solution to the problem of insufficient fluidity of cement-based materials caused by copper slag fine aggregate. Summary of the Invention

[0005] Purpose of the invention: The purpose of this invention is to provide a chemical admixture for the resource utilization of copper slag that plays an important role in both fluidity control and activity activation of cement-based materials with added copper slag.

[0006] Another object of the present invention is to provide a method for preparing the above-mentioned chemical additive.

[0007] A third objective of this invention is to provide a method for using the above-mentioned chemical admixture in cement-based materials.

[0008] Technical solution: The chemical additive for the resource utilization of copper slag described in this invention includes isomeric alcoholamines, cationic polymers, and slow-release polymers; the isomeric alcoholamine is the substance described in formula (I): (I), Where m is a natural number from 1 to 5, and n is a natural number from 1 to 4; The cationic polymer is the substance described in formula (II): (II) In this process, the cationic polymer is a random copolymer, R1 and R2 are each independently selected from H or CH3, W is O or -NH, Z is CH2 or CH2CH2, and X is a halogen atom; the molar ratio x:y = 1: (0.5~2.0). The sustained-release polymer is the substance described in formula (Ⅲ): (Ⅲ), Among them, the slow-release polymer is a random copolymer, wherein R3, R4, R5, and R6 are each independently selected from H or CH3; the molar ratio s:h = 1: (1.0~3.0).

[0009] Preferably, the mass ratio of the isomeric alkanolamine, cationic polymer, and sustained-release polymer is 1:(0.2~0.5):(0.5~2.0).

[0010] Preferably, the weight-average molecular weight of the cationic polymer is 10,000 to 50,000.

[0011] Preferably, the weight-average molecular weight of the sustained-release polymer is 30,000 to 100,000.

[0012] Preferably, m is 3 and n is 2.

[0013] Preferably, R1 and R2 are both H, W is O, and Z is CH2CH2.

[0014] Preferably, R3, R4, and R6 are all CH3, and R5 is H.

[0015] The preparation method of the chemical admixture of the present invention is as follows: water, isomeric alcohol amine, cationic polymer and slow-release polymer are added to a reaction vessel and stirred evenly to obtain the chemical admixture.

[0016] The method of using the chemical admixture of the present invention is as follows: dissolve the chemical admixture in water, and add the resulting aqueous solution to copper slag fine powder and / or copper slag fine aggregate.

[0017] Preferably, the chemical admixture aqueous solution has a mass concentration of 25-35%, and the amount of aqueous solution added is 1.0-3.0% of the mass of copper slag fine powder and / or copper slag fine aggregate.

[0018] Invention Principle: The application of copper slag in cement-based materials demonstrates enormous resource utilization potential and environmental value. The core principle of this application lies in its "secondary resource" attribute, serving both as an auxiliary cementitious material and a high-quality aggregate. From a chemical perspective, although the main components of copper slag have lower reactivity than slag and fly ash, a weak pozzolanic reaction can still occur under mechanical grinding (physical activation) or an alkaline environment (chemical activation). After the glassy structure of the copper slag is disrupted, the active components can react with calcium hydroxide produced during cement hydration to generate CSH gel with cementing properties, thereby improving the later-stage strength and density of the matrix. From a physical property perspective, after crushing and screening, copper slag particles are hard, high-strength, and have good wear resistance, making it an ideal artificial aggregate. Therefore, using copper slag as an admixture or aggregate in cement-based materials such as concrete and mortar can both "turn waste into treasure," reduce environmental impact and land occupation, and improve or maintain some material properties, making it one of the effective ways to achieve green and sustainable development in the building materials industry.

[0019] To address the two major requirements of activity activation and flowability control in the resource utilization of copper slag in cement-based materials, this invention provides a chemical admixture with both activity activation and flowability control functions, as well as its preparation method. The isomeric alkanolamine component in this admixture can significantly improve the activity of copper slag fine powder; in addition, the cationic polymer part acts as an adsorption sacrifice, reducing the adsorption of water-reducing agent on the surface of copper slag fine aggregate, thus greatly improving the flowability of cement-based materials containing copper slag fine aggregate; the slow-release polymer component plays a role in delaying release and exerting a dispersion effect, greatly ensuring the flow stability of cement-based materials containing copper slag.

[0020] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: (1) The chemical admixture prepared by the present invention can increase the strength of cement-based materials mixed with copper slag fine powder by more than 30% by adding isomeric alcohol amine; (2) By adding slow-release polymer, the flow stability of cement-based materials mixed with copper slag is greatly guaranteed, and the flow loss rate after 2 hours is less than 10%. Detailed Implementation

[0021] The technical solution of the present invention will be further described below with reference to the embodiments.

[0022] The specific structural parameters of the isomeric alcoholamine used in this invention are shown in Table 1. The preparation method is based on Example 1 in the patent application document with publication number CN119841571A entitled "An Activator for Regenerated Waste Concrete Micropowder and Its Preparation Method and Application".

[0023] Table 1. Designations and chemical structural parameters of isomeric alcoholamines

[0024] The specific structural parameters of the cationic polymer used in this invention are shown in Table 2. The preparation method is based on Example 1 of the patent application document with publication number CN112979206A entitled "A sacrificial agent for improving the fluidity of concrete and its preparation method".

[0025] Table 2. Codes and chemical structural parameters of cationic polymers

[0026] Note: X represents Br.

[0027] The specific structural parameters of the sustained-release polymer used in this invention are shown in Table 3. The preparation method is based on Example 1 of the patent application document with publication number CN120574358A entitled "A polymer rheology modifier and its preparation method and application".

[0028] Table 3. Codes and chemical structural parameters of sustained-release polymers

[0029] Example 1

[0030] The preparation method of the chemical additive of the present invention is as follows: 700 kg of water, 130.4 kg of isomeric alcohol amine B, 39.1 kg of cationic polymer B, and 130.5 kg of slow-release polymer B are added to a reaction vessel and stirred evenly to obtain the chemical additive for the resource utilization of copper slag.

[0031] Example 2-15 Referring to Example 1, only the type and amount of isomeric alkanolamine, cationic polymer, and sustained-release polymer were changed to construct Examples 2-15 and Comparative Examples 1-3, with specific parameters shown in Table 4.

[0032] Table 4. Amount of each component added in different embodiments (total amount calculated based on 1000 kg). Copper slag fine aggregate and copper slag fine powder were provided by Jiangxi Wantong Environmental Protection Materials Co., Ltd. The copper slag fine aggregate meets the index requirements of the national standard GB / T 25176-2010 "Recycled Fine Aggregate for Concrete and Mortar", and the copper slag fine powder meets the fineness index Class II or above requirements in Table 5.2.2 of the China Sand and Gravel Association standard T / CAATB 004-2024 "Technical Specification for Application of Recycled Sand and Powder from Waste Concrete".

[0033] The method of using the chemical admixture of the present invention in cement-based materials is as follows: The chemical admixture prepared by the present invention is added to the copper slag modified cement mortar prepared from the above-mentioned copper slag fine aggregate and copper slag fine powder, and the proportion is as follows: cement (Helin, PO42.5) 315g, copper slag fine powder 135g, standard sand (produced by Xiamen Aisiou Standard Sand Co., Ltd.) 945g, copper slag fine aggregate 405g, water 130g, water-reducing agent (produced by Jiangsu Subote New Material Co., Ltd.) 4.50g, and chemical admixture prepared by the present invention 3.51g.

[0034] The initial fluidity (spreadability), fluidity (spreadability) after 2 hours, and compressive strength after 28 days of the above-mentioned cement mortar were tested. The test methods for the initial fluidity and fluidity after 2 hours were based on the national standard GB / T2419 "Method for Determination of Flowability of Cement Mortar", and the test method for the 28-day compressive strength was based on the national standard GB / T17671 "Test Method for Strength of Cement Mortar (ISO Method)". The specific data of the indicators are listed in Table 5.

[0035] Table 5 Performance data of cement mortar

[0036] The blank cement mortar used as a benchmark had the following mix proportions: 450g cement (Jiangsu Helin Cement Co., Ltd., PO42.5), 1350g standard sand (produced by Xiamen Aisiou Standard Sand Co., Ltd.), 130g water, and 4.50g water-reducing agent (produced by Jiangsu Subote New Material Co., Ltd.). Furthermore, Comparative Example 4 differs from other examples in that it does not contain any chemical additives prepared according to this invention.

[0037] Experimental data show that the chemical admixtures prepared by this method have a significant effect on improving the fluidity and strength of copper slag modified cement mortar.

[0038] Examples 1-3 show that, under the condition that other parameters remain unchanged, only the combination of isomeric alcohol amines was changed. The isomeric alcohol amines A, B, and C are arranged in order with the length of the polyethylene polyamine structure gradually increasing. The results show that they have a significant impact on the 28-day compressive strength. Among them, isomeric alcohol amine B has the best activation and enhancement effect. This indicates that when the polyethylene polyamine structure in the isomeric alcohol amine is tetraethylenepentamine, it has the best performance. This is mainly because when the chain length of the polyethylene polyamine structure is moderate, the adsorption and solubilization behavior of the isomeric alcohol amine on the surface of copper slag fine powder is in the optimal balance state.

[0039] Examples 4-6 show that, under the condition that other parameters remain unchanged, only the combination of cationic polymer types is changed. The cationic polymers A, B, and C are the ones in which the proportion of cationic monomers in the polymer gradually increases. The results show that the higher the proportion of cationic polymers, the better the adsorption sacrifice effect of the polymer, which means that the poor adsorption of water-reducing agents is reduced, and thus the fluidity of the mortar is significantly improved.

[0040] Examples 7-9 show combinations where only the types of slow-release polymers were changed while keeping other parameters constant. Slow-release polymers A, B, and C represent polymers with progressively increasing proportions of slow-release monomers. The results show that as the proportion of slow-release monomers increases, the polymer's ability to maintain flowability over time gradually improves.

[0041] Examples 1, 10, and 11 are combinations that change the proportion of cationic polymer in chemical admixtures. Examples 10, 1, and 11 show that the proportion of cationic polymer increases in sequence. The results show that as the proportion of cationic polymer increases, the mortar fluidity increases significantly, but the strength decreases. This is because as the proportion of cationic polymer increases, the proportion of isomeric alcohol amines decreases, thus reducing the strength.

[0042] Examples 1, 12, and 13 are combinations that change the proportion of slow-release polymers in chemical admixtures. Examples 12, 1, and 13 show that the proportion of slow-release polymers increases in sequence. The results show that as the proportion of slow-release polymers increases, the fluidity retention of mortar after 2 hours is significantly improved, but the strength decreases accordingly. This is because as the proportion of slow-release polymers increases, the proportion of isomeric alcohol amines decreases, and therefore the strength decreases.

[0043] Examples 1, 14, and 15 are combinations that change the proportion of isomeric alkanolamines in chemical admixtures. Examples 15, 1, and 14 show an increase in the proportion of isomeric alkanolamines in sequence. The results show that the 28-day strength of the mortar is significantly improved with the increase in the proportion of isomeric alkanolamines, which indicates that isomeric alkanolamines have excellent activation and enhancement effects on copper slag fine powder.

[0044] In Comparative Example 1, without the addition of isomeric alkanolamines, the mortar exhibited good fluidity and good fluidity performance after 2 hours. However, the mortar's 28-day strength was very low, approaching the strength of copper slag modified cement mortar without admixtures. This indicates that isomeric alkanolamines have an enhancing effect on the strength of cement mortar.

[0045] In Comparative Example 2, without the addition of cationic polymer, the mortar had poor fluidity, which was close to the initial fluidity of the copper slag modified cement mortar without admixtures, indicating that cationic polymer has the effect of improving the fluidity of cement mortar.

[0046] In Comparative Example 3, no slow-release polymer was added, and the mortar's ability to maintain its fluidity for 2 hours was poor. The mortar fluidity decreased by 22% after 2 hours, which was generally lower than the performance values ​​of the Example Group by less than 10%. This indicates that the corrosion-inhibiting polymer has an improving effect on the 2-hour fluidity of cement mortar.

Claims

1. A chemical additive for the resource utilization of copper slag, characterized in that, Including isomeric alcoholamines, cationic polymers, and sustained-release polymers; the isomeric alcoholamine is a substance of formula (I): （Ⅰ）， Where m is a natural number from 1 to 5, and n is a natural number from 1 to 4; The cationic polymer is the substance described in formula (II): （Ⅱ）， In this process, the cationic polymer is a random copolymer, R1 and R2 are each independently selected from H or CH3, W is O or -NH, Z is CH2 or CH2CH2, and X is a halogen atom; the molar ratio x:y = 1: (0.5~2.0). The sustained-release polymer is the substance described in formula (Ⅲ): （Ⅲ）， Among them, the slow-release polymer is a random copolymer, wherein R3, R4, R5, and R6 are each independently selected from H or CH3; the molar ratio s:h = 1: (1.0~3.0).

2. The chemical admixture according to claim 1, characterized in that, The mass ratio of the isomeric alkanolamine, cationic polymer, and sustained-release polymer is 1:(0.2~0.5):(0.5~2.0).

3. The chemical admixture according to claim 1, characterized in that, The weight-average molecular weight of the cationic polymer is 10,000 to 50,000.

4. The chemical admixture according to claim 1, characterized in that, The weight-average molecular weight of the slow-release polymer is 30,000 to 100,000.

5. The chemical admixture according to claim 1, characterized in that, The value of m is 3 and the value of n is 2.

6. The chemical admixture according to claim 1, characterized in that, R1 and R2 are both H, W is O, and Z is CH2CH2.

7. The chemical admixture according to claim 1, characterized in that, R3, R4, and R6 are all CH3, and R5 is H.

8. A method for preparing the chemical admixture according to claim 1, characterized in that, Add water, isomeric alcohol amines, cationic polymers, and slow-release polymers to a reaction vessel and stir until homogeneous to obtain the chemical additive.

9. A method of using the chemical additive as described in claim 1, characterized in that, The chemical additive is dissolved in water, and the resulting aqueous solution is added to the copper slag fine powder and / or copper slag fine aggregate.

10. A method of use according to claim 9, characterized in that, The chemical admixture aqueous solution has a mass concentration of 25-35%, and the amount of aqueous solution added is 1.0-3.0% of the mass of copper slag fine powder and / or copper slag fine aggregate.

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