Biological enzyme catalyzed heavy metal complexing type tailings filling water reducing agent and method thereof

Abstract

The application relates to the technical field of polymer materials and building material additives, in particular to a heavy metal complex type tailing filling water reducing agent based on biological enzyme catalysis and a preparation method thereof; the preparation method comprises the steps of monomer premixing, enzymatic oxidation coupling polymerization, termination and activation; the method constructs a homogeneous aqueous phase environment by adjusting the pH of a multi-monomer system through a buffer, continuously introduces oxygen-containing gas to maintain the oxidation reaction cycle, the core is to generate a polymer skeleton containing an aromatic ring C-C bond or a C-O-C aromatic ether bond by using biological enzyme catalysis, and a heavy metal stable chemical complex structure is constructed by introducing a nitrogen heteroaromatic compound; the application solves the technical problems that a traditional water reducing agent is easy to be out of control in a heavy metal environment and has no chemical anchoring capacity, uses enzymatic polymerization, space steric hindrance and chemical complexing to solve the synthesis obstacles of complex industrial wastewater and the heavy metal leaching risk, effectively inhibits secondary pollution and improves the compressive strength of the filling body.

Description

Technical Field

[0001] This invention relates to the field of polymer materials and building material additives, specifically to a heavy metal complex-type tailings backfill water-reducing agent and its method based on bio-enzyme catalysis. Background Technology

[0002] In the cemented backfilling process of non-ferrous polymetallic tailings, polycarboxylate superplasticizers need to be added to reduce slurry viscosity and increase solid content; existing technologies face the following two main technical problems: Traditional polycarboxylate superplasticizers rely on chemical redox systems to initiate free radical polymerization of carbon-carbon double bonds. When tailings water or complex industrial wastewater is used as the synthesis medium, the large amount of free heavy metal ions present in the system will have a polymerization inhibition or chain transfer effect, leading to free radical quenching or uncontrolled polymerization, a significant increase in polydispersity index, and a decrease in product dispersion performance. Traditional polycarboxylate superplasticizers exert physical dispersion through electrostatic repulsion and steric hindrance, but have no chemical anchoring ability for heavy metal ions in tailings. During the curing and later service environment of the backfill, heavy metals are easily leached out by groundwater erosion and pH fluctuations, causing potential secondary pollution of groundwater and soil. Simply using physical compound small molecule heavy metal scavengers not only leads to deterioration of dispersion performance, but also the solidification effect is extremely unstable in long-term hydration environment. Summary of the Invention

[0003] The purpose of this invention is to provide a heavy metal complexing tailings backfill water-reducing agent based on bio-enzyme catalysis. This addresses the problems of traditional water-reducing agents in the prior art, such as easy polymerization and runaway failure in heavy metal ion environments, lack of chemical anchoring ability for heavy metals leading to secondary pollution, and the degradation of dispersion performance and unstable solidification due to physical compounding. Specifically, the technical solution of this invention is as follows: A bio-enzyme-catalyzed heavy metal complex-type tailings backfill water-reducing agent is characterized in that the effective component of the water-reducing agent is a high molecular polymer, which is prepared by an enzymatic oxidative coupling polymerization reaction of monomers containing phenolic hydroxyl groups in the presence of bio-enzymes and oxygen-containing gases; the macromolecular skeleton of the high molecular polymer contains repeating units linked by aromatic ring C-C bonds or COC aromatic ether bonds, and the raw materials for its preparation, by mass parts, include: 50-80 parts of polyethylene glycol derivatives with phenolic hydroxyl end groups modified with phenolic hydroxyl groups, 10-30 parts of aromatic sulfonates containing phenolic hydroxyl groups, 5-15 parts of nitrogen-containing heterocyclic compounds containing phenolic hydroxyl groups, and 0.5-2 parts of bio-enzymes.

[0004] Preferably, the polyethylene glycol derivative with phenolic hydroxyl groups at the end is tyramine-terminated polyethylene glycol monomethyl ether with a molecular weight of 2000-3000.

[0005] Preferably, it includes the following steps: (1) Monomer premixing: The polyethylene glycol derivative, aromatic sulfonate and nitrogen-containing aromatic ring compound are added to the solvent and stirred at 200-300 r / min for 20-30 min. The pH of the system is adjusted to 5.0-5.5 by adding buffer solution to obtain a homogeneous solution; (2) Enzymatic oxidative coupling polymerization: The homogeneous solution is heated to 35-45℃, oxygen-containing gas is continuously introduced at 50-100mL / (min·L), the biological enzyme is added, and the reaction is carried out at 150-250r / min for 4-6h to allow the monomer to undergo coupling polymerization to obtain the polymer solution. (3) Termination and activation: Heat the polymerization solution to 80-85℃ and keep it at that temperature for 20-40 minutes to deactivate the biological enzymes. After cooling to room temperature, add alkali solution to adjust the pH to 7.0-7.5 to ionize the uncoupled groups.

[0006] Preferably, the bioenzyme is laccase, and the enzyme activity of the bioenzyme is ≥50U / g.

[0007] Preferably, in step (1), the solvent is deionized water or clarified tailings water after sedimentation treatment; the buffer solution is an acetate-sodium acetate buffer solution.

[0008] Preferably, in step (2), the oxygen-containing gas is air or pure oxygen; in step (3), the temperature is maintained for 30 minutes, and the alkaline solution is NaOH solution.

[0009] Preferably, the weight-average molecular weight of the polymer is... The range is 35,000-45,000 Da, and the multi-dispersion index (PDI) is 1.3-1.5.

[0010] The beneficial effects of this invention are as follows: This invention uses biological enzymes and oxygen-containing gases to catalyze the oxidative coupling polymerization reaction of monomers containing phenolic hydroxyl groups to prepare high molecular polymers. This method can reduce the interference of free heavy metal ions on the polymerization reaction when using tailings water as a synthesis medium, and improve the synthesis stability and performance of water-reducing agents in heavy metal environments. By introducing nitrogen-containing heterocyclic compounds with phenolic hydroxyl groups into the polymer backbone, the water-reducing agent possesses a stable chemical complex structure for heavy metals. This design can capture and fix free heavy metals in tailings slurry, preventing them from leaching in the later service environment and reducing the risk of secondary pollution to groundwater and soil. This invention constructs sufficient steric hindrance and adsorption sites in the polymer by copolymerizing polyethylene glycol derivatives with phenolic hydroxyl end groups and aromatic sulfonates containing phenolic hydroxyl groups. This molecular structure enables the water-reducing agent to exhibit excellent dispersibility and flowability retention performance, which not only reduces the viscosity of the slurry, but also ensures the density and compressive strength of the filled body after curing. Attached Figure Description

[0011] Figure 1 This is a process flow diagram of the present invention. Detailed Implementation

[0012] The technical solutions in the embodiments of the present invention will be clearly and completely described below; the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0013] Example 1: Reference Figure 1 As shown, this embodiment provides a heavy metal complexing tailings backfill water-reducing agent based on bio-enzyme catalysis, specifically including the following steps: Preparation of S1 monomer A: 100.0 g of polyethylene glycol monomethyl ether with a molecular weight of 2400 was added to 250 mL of anhydrous dichloromethane. 6.5 g of triethylamine was added under ice-water bath conditions. After stirring for 10 min, 9.6 g of p-toluenesulfonyl chloride was added dropwise, controlling the system temperature to be no higher than 10 °C. After the addition was complete, the temperature was raised to 25 °C and reacted for 4 h. The reaction solution was washed with water, separated, and the solvent was removed under reduced pressure to obtain the terminal-activated product. This terminal-activated product serves as an intermediate, with its terminal hydroxyl groups activated, providing a basis for subsequent nucleophilic substitution reactions. The product was dissolved in 150 mL of anhydrous N,N-dimethylformamide, and 7.0 g of tyramine and 8.5 g of potassium carbonate were added. The mixture was reacted at 60 °C for 8 h. After the reaction was completed, the product was filtered to remove salt, and the solvent was removed under reduced pressure. The product was precipitated with diethyl ether and dried under vacuum to obtain tyramine-terminated polyethylene glycol monomethyl ether, i.e., monomer A. Monomer A serves as the core precursor in the entire technical solution, providing polyether side chains and steric hindrance of macromolecules. The phenolic hydroxyl groups introduced in monomer A enable it to participate in subsequent enzymatic oxidative coupling. Preparation of S2 reaction system: Take 65g of monomer A, 20g of sodium p-hydroxybenzenesulfonate, and 10g of 8-hydroxyquinoline, add deionized water to a total volume of 1L, and stir at 250r / min for 25min; add 0.1mol / L acetate-sodium acetate buffer to adjust the pH of the system to 5.2 to obtain a homogeneous solution. This homogeneous solution provides a uniform aqueous environment for the thorough mixing of monomer molecules and homogeneous mass transfer reaction, and provides suitable weakly acidic conditions for the catalysis of biological enzymes. S3 Enzymatic Oxidative Coupling Polymerization: The homogeneous solution obtained in step S2 was heated to 40℃, and air was continuously introduced at a flow rate of 80 mL / (min·L). 1.2 g of laccase with an enzyme activity of 60 U / g was added, and the reaction was carried out at 200 r / min for 5 h to obtain a dark brown polymer solution. This dark brown polymer solution indicates that the phenolic hydroxyl groups in the monomer have been successfully oxidized and coupled polymerized to form a polymer skeleton with a complex conjugated structure, which is the key to realizing the functions of water reduction and heavy metal curing. S4 Termination and Activation: The polymerization solution obtained in step S3 is heated to 82°C and kept at that temperature for 30 minutes to inactivate the laccase; after cooling to 25°C, a 10% NaOH solution is added to adjust the pH to 7.2 to obtain the target water-reducing agent liquid product.

[0014] Example 2: This embodiment provides a water-reducing agent, the steps of which are the same as in Embodiment 1, except that: In S1, the molecular weight of polyethylene glycol monomethyl ether is 2000, and the amounts of triethylamine, p-toluenesulfonyl chloride, tyramine and potassium carbonate are adjusted synchronously according to the same molar ratio as in Example 1. In S2, the amounts of monomer A, sodium p-hydroxybenzenesulfonate, 8-hydroxyquinoline, and laccase are 50g, 30g, 15g, and 2.0g, respectively; the solvent is clarified tailings water that has undergone sedimentation treatment; the pH is adjusted to 5.0. In S3, the reaction temperature was 35℃, the aeration rate was 50mL / (min·L), the stirring rate was 150r / min, and the reaction time was 4h. In S4, the inactivation temperature is 80℃, and the temperature is maintained for 20 minutes. After activation, the pH is adjusted to 7.0.

[0015] Example 3: This embodiment provides a water-reducing agent, the steps of which are the same as in Embodiment 1, except that: In S1, the molecular weight of polyethylene glycol monomethyl ether is 2600, and the amounts of triethylamine, p-toluenesulfonyl chloride, tyramine and potassium carbonate are adjusted synchronously according to the same molar ratio as in Example 1. In S2, the amounts of monomer A, sodium p-hydroxybenzenesulfonate, 8-hydroxyquinoline, and laccase were 70g, 15g, 8g, and 1.0g, respectively; deionized water was used as the solvent; and the pH was adjusted to 5.4. In S3, the reaction temperature was 42℃, the aeration rate was 90mL / (min·L), the stirring rate was 220r / min, and the reaction time was 5.5h. The inactivation temperature in S4 is 83℃, and the incubation period is 35 minutes. After activation, the pH is adjusted to 7.4.

[0016] Example 4: This embodiment provides a water-reducing agent, the steps of which are the same as in Embodiment 1, except that: In S1, the molecular weight of polyethylene glycol monomethyl ether is 3000, and the amounts of triethylamine, p-toluenesulfonyl chloride, tyramine and potassium carbonate are adjusted synchronously according to the same molar ratio as in Example 1. In S2, the amounts of monomer A, sodium p-hydroxybenzenesulfonate, 8-hydroxyquinoline, and laccase are 80g, 10g, 5g, and 0.5g, respectively; deionized water is used as the solvent; and the pH is adjusted to 5.5. In S3, the reaction temperature was 45℃, the aeration rate was 100mL / (min·L), the stirring rate was 250r / min, and the reaction time was 6h. In S4, the inactivation temperature is 85℃, the incubation time is 40 min, and the pH is adjusted to 7.5 after activation.

[0017] Comparative Example 1: The difference between this comparative example and Example 1 is that laccase is not added in step S3, while the other operating steps and process parameters are exactly the same as in Example 1.

[0018] Comparative Example 2: The difference between this comparative example and Example 1 is that 10g of 8-hydroxyquinoline in step S2 is replaced with an equal mass of phenol, while the other operating steps and process parameters are exactly the same as in Example 1.

[0019] Comparative Example 3: The difference between this comparative example and Example 1 is that 20g of sodium p-hydroxybenzenesulfonate in step S2 is replaced with an equal mass of sodium p-toluenesulfonate, while the other operating steps and process parameters are exactly the same as in Example 1.

[0020] Comparative Example 4: The difference between this comparative example and Example 1 is that monomer A in step S2 is replaced with an equal mass of polyethylene glycol monomethyl ether. The molecular weight of the replaced substance is 2400 and the end group does not contain phenolic hydroxyl groups. Other operating steps and process parameters are exactly the same as in Example 1.

[0021] Comparative Example 5: The difference between this comparative example and Example 1 is that the pH of the system in step S2 is adjusted from 5.2 to 7.5, while the other operating steps and process parameters are exactly the same as in Example 1.

[0022] Comparative Example 6: The difference between this comparative example and Example 1 is that the continuous air introduction in step S3 is replaced with static reaction, and no additional oxygen-containing gas is introduced. The other operating steps and process parameters are exactly the same as in Example 1.

[0023] Comparative Example 7: The difference between this comparative example and Example 1 is that: a conventional ammonium persulfate-ascorbic acid redox initiation system is used instead of the laccase / air system in step S3; the reaction temperature is 35°C; the reaction time is 5 hours; and an equimolar amount of polymerizable vinyl monomer allyl polyethylene glycol ether is added to the monomer system to form a conventional free radical polymerizable water-reducing agent. Other operating steps and process parameters are the same as in Example 1, and 500 ppm Cu is added to the reaction solution. 2+ It is used to investigate the synthesis stability under heavy metal environments.

[0024] Performance Testing and Datasheets Water reduction rate was tested according to the relevant methods in GB / T8077; slump and 2-hour slump loss were determined using tailings-cement cement-bonded backfill slurry, with the slurry solid content controlled at 72%, and the water-reducing agent dosage calculated as 0.35% of the cementitious material mass based on dry solid content; 28-day compressive strength was tested using conventional methods for cemented backfill; Cu 2+ and Zn 2+ The curing rate was calculated using a toxicity leaching procedure leaching test; the molecular weight was determined using gel permeation chromatography; the performance test data are shown in Table 1. Table 1. Performance test results of each embodiment and comparative example.

[0025] As can be seen from the comparison of the test results of Example 1 and Comparative Example 1 in Table 1, the omission of laccase resulted in the molecular weight, water reduction rate, slump retention, strength and heavy metal curing rate not meeting the benchmark performance requirements of the example. The underlying mechanism is that phenolic hydroxyl monomers are difficult to continuously generate phenolic oxygen radicals in a mild aqueous phase under enzyme-free conditions, resulting in insufficient coupling between aromatic ring C-C bonds and CO-C bonds, leading to shorter polymer chains and unstable composition; polyether side chains cannot be incorporated into the backbone at a sufficient density, reducing the thickness of the effective adsorption layer on the particle surface and decreasing the slurry dispersion ability; insufficient incorporation of 8-hydroxyquinoline reduces the number of N and O coordination sites available, thereby decreasing the heavy metal curing rate. As can be seen from the comparison of the test results of Example 1 and Comparative Example 2 in Table 1, after replacing 8-hydroxyquinoline with phenol, the molecular weight deviation is within 5%, but Cu 2+ and Zn 2+ When the curing rate drops below 60%, the 28-day compressive strength also decreases accordingly. The underlying mechanism is that although phenol can participate in oxidative coupling, it lacks the N,O bidentate coordination structure of 8-hydroxyquinoline. This means it cannot form a stable five-membered ring chelate effect by having the nitrogen atom on the quinoline ring and the oxygen atom on the phenolic hydroxyl group jointly provide lone pair electrons. Consequently, the resulting polymer skeleton lacks stable chelate sites, and free heavy metals in the slurry cannot be effectively fixed. Free Cu... 2+ and Zn2+ Continuous interference with cement hydration leads to a decrease in the density of the filling structure and a reduction in compressive strength; As can be seen from the comparison of the test results of Example 1 and Comparative Example 3 in Table 1, after replacing sodium p-hydroxybenzenesulfonate with sodium p-toluenesulfonate, the molecular weight, water reduction rate, slump and strength all decreased. The underlying mechanism is that sodium p-toluenesulfonate does not contain phenolic hydroxyl groups that can participate in enzymatic coupling, and therefore cannot enter the polymer chain as a backbone unit. As a result, the number of reactive functional groups in the system decreases, the degree of gradual polymerization decreases, the molecular weight decreases, and the distribution becomes wider. At the same time, the effective density of rigid aromatic backbones and sulfonate adsorption sites in the polymer decreases, the adsorption capacity on the surface of cement and tailings particles weakens, resulting in insufficient dispersion and increased loss over time. As can be seen from the comparison of the test results of Example 1 and Comparative Example 4 in Table 1, after replacing tyramine-terminated polyethylene glycol monomethyl ether with unterminated polyethylene glycol monomethyl ether, the molecular weight and water-reducing properties decreased significantly, and the slump retention deteriorated. The underlying mechanism is that uncapped polyethylene glycol monomethyl ether lacks phenolic hydroxyl end groups and cannot be covalently linked to the main chain through enzymatic oxidative coupling. Most polyether segments exist in a free small molecule state after the reaction, and cannot form a stable comb-shaped adsorption layer. The steric hindrance effect on the particle surface is insufficient, which leads to an increased tendency of slurry flocculation and a decrease in fluidity and its retention. As can be seen from the comparison of the test results of Example 1 and Comparative Example 5 in Table 1, after adjusting the reaction pH to 7.5, the molecular weight, water reduction rate and heavy metal curing rate all decreased. The underlying mechanism is that laccase is in the optimal catalytic activity range within the weakly acidic range. As the pH increases, the enzyme's catalytic efficiency decreases, the oxidation rate of phenolic hydroxyl groups decreases, and the coupling polymerization is insufficient. At the same time, some monomers exhibit side reactions and self-aggregation tendencies at higher pH levels, which limits chain growth and reduces the structural regularity of the resulting polymer, thus weakening both the dispersion and coordination fixation functions. As can be seen from the comparison of the test results of Example 1 and Comparative Example 6 in Table 1, the lack of continuous oxygen-containing gas introduction will lead to a decrease in molecular weight, water reduction rate and curing rate. The underlying mechanism is that the laccase catalytic cycle requires oxygen as an electron acceptor. When the oxygen supply is insufficient, the continuous generation of phenolic radicals is limited, the polymerization rate decreases, the probability of chain growth interruption increases, the resulting polymer does not reach the target degree of polymerization and the functional groups are unevenly distributed; the adsorption layer formed as a result is incomplete and the exposure of coordination sites is also reduced, which manifests as simultaneous deterioration of workability and heavy metal fixation effect. As can be seen from the comparison of the test results of Example 1 and Comparative Example 7 in Table 1, after replacing the laccase / air system with the ammonium persulfate-ascorbic acid free radical initiation system, the results were obtained at 500 ppm Cu 2+Under certain conditions, the molecular weight drops to less than 60% of its original value and the distribution becomes significantly wider, resulting in lower water-reducing performance, strength, and curing rate. Its underlying mechanism lies in Cu 2+ It has the effect of inhibiting free radical polymerization and chain transfer. After the active free radicals are consumed, the polymer chain is difficult to grow stably, resulting in insufficient molecular weight and uncontrolled structure. The polymer formed by this system is mainly based on traditional physical dispersion and lacks stable chemical anchoring sites for heavy metals. Therefore, the synthesis stability and application effect in complex ionic environments are inferior to those of Example 1. The test results from Examples 1 to 4 show that, within the scope of this invention, adjusting the molecular weight of polyethylene glycol, the ratio of the three monomers, the amount of enzyme, and the reaction conditions can all yield polymer water-reducing agents with dual functions of water reduction and heavy metal fixation. Specifically, Example 1 achieved a more balanced combination relationship between the density of polyether side chains, the density of backbone adsorption sites, and the density of 8-hydroxyquinoline coordination sites, thus reaching the optimal equilibrium state of each indicator. Compared to Example 1, Example 2 reduced the amount of monomer A to 50g and increased the amounts of sodium p-hydroxybenzenesulfonate and 8-hydroxyquinoline to 30g and 15g, respectively. This ratio adjustment within the range resulted in a higher proportion of sulfonate and 8-hydroxyquinoline, which is beneficial for adsorption and coordination. However, the proportion of polyether side chains was relatively low, which weakened the steric hindrance effect. This is reflected in the data as a slightly lower retention of the initial slump of 218 mm and a slump loss of 26 mm after 2 hours compared to Example 1. In Example 3, the reaction temperature, aeration rate, and stirring rate were all in the high-mid range, which promoted the efficiency of enzymatic oxidation. The water reduction rate was 30.4% and the copper ion curing rate was 98.0%. The overall performance was basically the same as that of Example 1, indicating that the technical solution has good stability within the intermediate parameter range. In Example 4, the amount of monomer A was increased to 80g, while sodium p-hydroxybenzenesulfonate and 8-hydroxyquinoline were reduced to 10g and 5g, respectively. The proportion of polyether segments was high and the proportion of functional monomers was low. This resulted in the polymer produced by the reaction reaching its highest molecular weight, but the density of adsorption sites and coordination sites on the backbone was significantly reduced. However, the heavy metal curing rate of copper ion curing rate was 96.8% and zinc ion curing rate was 95.4%, and the mechanical properties of 28-day compressive strength of 13.6 MPa were slightly lower than those in Example 1. It is evident that variations in raw materials and parameters within defined ranges directly affect the ratio of side chains to functional groups in the polymer microstructure, thereby leading to regular fluctuations in macroscopic water-reducing and curing properties.

[0026] The above are merely specific embodiments of the present invention and are not intended to limit the present invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments for application in other fields. However, any conventional modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the technical solution of the present invention shall still fall within the protection scope of the technical solution of the present invention.

Claims

1. A water reducing agent for heavy metal complex type tailings filling based on biocatalytic enzymes, characterized in that, The effective component of the water-reducing agent is a high molecular polymer, which is prepared by an enzymatic oxidative coupling polymerization reaction of phenolic hydroxyl groups in the presence of biological enzymes and oxygen-containing gas. The macromolecular skeleton of the high molecular polymer contains repeating units linked by aromatic ring C-C bonds or COC aromatic ether bonds. The raw materials for its preparation include, by mass parts: 50-80 parts of polyethylene glycol derivatives with phenolic hydroxyl end groups modified with phenolic hydroxyl groups, 10-30 parts of aromatic sulfonates containing phenolic hydroxyl groups, 5-15 parts of nitrogen-containing heterocyclic compounds containing phenolic hydroxyl groups, and 0.5-2 parts of biological enzymes. The polyethylene glycol derivative with phenolic hydroxyl groups at the end is tyramine-terminated polyethylene glycol monomethyl ether with a molecular weight of 2000-3000. The bioenzyme is laccase, and the enzyme activity of the bioenzyme is ≥50U / g; The aromatic sulfonate containing phenolic hydroxyl groups is sodium p-hydroxybenzenesulfonate, and the nitrogen-containing heterocyclic compound containing phenolic hydroxyl groups is 8-hydroxyquinoline.

2. A method for preparing a heavy metal complexing type tailings filling water reducer based on biocatalytic enzyme catalysis according to claim 1, characterized in that, Includes the following steps: (1) Monomer premixing: The polyethylene glycol derivative, aromatic sulfonate and nitrogen-containing aromatic ring compound are added to the solvent and stirred at 200-300 r / min for 20-30 min. The pH of the system is adjusted to 5.0-5.5 by adding buffer solution to obtain a homogeneous solution; (2) Enzymatic oxidative coupling polymerization: The homogeneous solution is heated to 35-45℃, oxygen-containing gas is continuously introduced at 50-100mL / (min·L), the biological enzyme is added, and the reaction is carried out at 150-250r / min for 4-6h to allow the monomer to undergo coupling polymerization to obtain the polymer solution. (3) Termination and activation: Heat the polymerization solution to 80-85℃ and keep it at that temperature for 20-40 minutes to deactivate the biological enzymes. After cooling to room temperature, add alkali solution to adjust the pH to 7.0-7.5 to ionize the uncoupled groups.

3. The method for preparing a heavy metal complexing type tailings filling water reducer based on biological enzyme catalysis according to claim 2, characterized in that, In step (1), the solvent is deionized water or clarified tailings water after sedimentation treatment; the buffer solution is acetate-sodium acetate buffer solution.

4. The method for preparing a heavy metal complexing type tailing filling water reducer based on biological enzyme catalysis according to claim 2, characterized in that, In step (2), the oxygen-containing gas is air or pure oxygen; in step (3), the temperature is maintained for 30 minutes, and the alkaline solution is NaOH solution.

5. The biocatalyst-based heavy metal complexing type tailings filling water reducer according to claim 1, characterized in that, The weight average molecular weight of the high molecular polymer is 35000-45000 Da, and the polydispersity index PDI is 1.3-1.5.

Images