Aluminum-based composite desiliconizing agent and application thereof

Abstract

The application relates to the technical field of water treatment, and discloses an aluminum-based composite silicon removal agent and application thereof. The aluminum-based composite silicon removal agent comprises component A and component B; the component A is sodium metaaluminate; and the component B comprises one or more of crystalline aluminum chloride, polyaluminum chloride and polyaluminum sulfate. The two components in the aluminum-based composite silicon removal agent can form a multi-stage aluminum form distribution of'multinuclear-single nuclear-colloid' in wastewater, thereby constructing a complete silicon removal path of 'pH regulation-charge neutralization-adsorption complex-bridge flocculation-chemical precipitation', and high-efficiency removal of silicate can be realized. The composite silicon removal agent does not need to accurately adjust the pH of the system, is low in operation precision requirement, simple in operation, and low in medicament dosage.

Description

Technical Field

[0001] This invention relates to the field of water treatment technology, and in particular to an aluminum-based composite desiliconizing agent and its application. Background Technology

[0002] During coal mining, it is usually necessary to drill and grout the goaf to reinforce and support it, preventing safety accidents such as subsidence, collapse, underground water inrush, and gas outbursts. Among the grouting materials, water glass (mainly composed of sodium silicate) is often used as a quick-setting agent due to its low cost and good curing properties. This allows the grout injected into the goaf to solidify quickly, forming a curtain and preventing grout loss.

[0003] However, excessive use of sodium silicate often occurs during this process. Excessive sodium silicate entering the mine water causes numerous problems for surface mine water treatment systems. Typically, coal mine water treatment systems use aluminum or iron salts as coagulants to accelerate the coagulation and sedimentation of particulate matter such as coal dust and rock powder, thereby purifying the mine water. However, when the mine water contains a large amount of sodium silicate, its hydrolysis produces a large amount of OH-. - This causes the pH value of the water to rise, typically reaching 9-11, while the optimal pH range for commonly used coagulants is usually between 5 and 8, thus rendering the coagulants ineffective. Furthermore, the silicate ions produced when sodium silicate dissolves in water can react with metal ions in the coagulant to form insoluble silicate precipitates. This not only fails to achieve water purification but also increases sludge production, leading to poorer effluent quality from the mine water treatment system and increasing the burden on subsequent water treatment facilities. The common solution to this problem is to increase the dosage of the coagulant. Since sodium silicate increases the total negative charge density in the water after dissolving, increasing the dosage means increasing the positive charge density in the solution to neutralize the potential, which is an effective solution. However, this adds extra treatment costs to coal mining enterprises.

[0004] Traditional coagulation methods for silicon removal all have certain limitations: the magnesium method requires a large amount of reagent and introduces a significant amount of hardness, increasing the amount of reagent needed for subsequent hardening processes; the lime method has low silicon removal efficiency and generates a large amount of sludge (e.g., CN202423030375.0); sodium aluminate has a good silicon removal effect, but its precipitation requires stringent pH conditions. Therefore, finding a silicon removal agent that is effective, easy to operate, and has few limitations is of practical significance and application value for coal mining enterprises. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides an aluminum-based composite silicate remover and its application. The two components of this aluminum-based composite silicate remover can form a multi-level aluminum morphology distribution in wastewater, consisting of "multinuclear-monuclear-colloidal" forms, thereby constructing a complete silicate removal pathway of "pH regulation-charge neutralization-adsorption complexation-bridging flocculation-chemical precipitation," achieving highly efficient removal of silicate ions. This composite silicate remover does not require precise pH adjustment, thus requiring lower operational precision, is simple to operate, and requires less reagent dosage.

[0006] The specific technical solution of the present invention includes: In a first aspect, the present invention provides an aluminum-based composite silicon remover, comprising component A and component B. Component A is sodium aluminate; component B comprises one or more of crystalline aluminum chloride, polyaluminum chloride, and polyaluminum sulfate.

[0007] The composite silicate remover of this invention consists of two parts, component A and component B. Component A, when added to mine water, can generate aluminum colloids through self-hydrolysis and inhibit the hydrolysis and polymerization of silicate ions by adjusting the solution environment. After addition, component B can first generate a large number of hydrogen ions through hydrolysis to adjust the solution pH value. Then, through synergy with component A, it forms a multi-level aluminum morphology distribution of "multinucleate-mononucleate-colloidal" in wastewater. Among them, the monomeric aluminum can quickly neutralize the silicate charge, the polymerized aluminum can enhance the flocculation and sedimentation rate through bridging flocculation and net sweeping, and the colloidal aluminum can provide a large number of adsorption sites, thereby efficiently and quickly adsorbing and removing silicate ions in water.

[0008] In summary, component B and component A form a multi-level aluminum morphology distribution in water, consisting of "multinuclei-mononuclei-colloids," constructing a complete silica removal pathway of "pH regulation-charge neutralization-adsorption complexation-bridging flocculation-chemical precipitation," thus achieving highly efficient removal of silicates. The composite silica removal agent of this invention allows for adjustment of the dosage based on the amount of soluble silica in the water, eliminating the need for precise pH adjustment. This not only reduces operational precision requirements but also simplifies operation and reduces the amount of reagent used.

[0009] Preferably, the amount of component A is 0.8 to 2.5 times the mass of soluble silicon in the mine water.

[0010] As a preferred option, the dosage of component B varies depending on its composition, as follows: (1) When component B is crystalline aluminum chloride, the amount used is 1.2 to 3.75 times the mass of soluble silicon in mine water.

[0011] Crystalline aluminum chloride dissolves in water and dissociates into Al. 3+ Al 3+ The hydrolysis process releases a large amount of H + Al 3+The process involves hydrolysis to form mononuclear aluminum hydroxide ions, polynuclear aluminum hydroxide complexes, and aluminum hydroxide colloids. These colloids remove silicate ions from water through adsorption, complexation, flocculation bridging, and netting / sweeping. Simultaneously, crystalline aluminum chloride synergistically interacts with component A to generate a large amount of fine and uniform aluminum hydroxide colloids, exhibiting stronger bridging and complexing effects compared to aluminum hydroxide colloids produced by traditional processes.

[0012] (2) When component B is polyaluminum chloride, the amount used is 1.4 to 3.95 times the mass of soluble silicon in the mine water.

[0013] When polyaluminum chloride dissolves in water, its hydrolysis process releases a large amount of H₂. + Its hydrolysis produces amorphous aluminum hydroxide colloids and polynuclear aluminum hydroxide complexes, which remove silicate ions from water through adsorption, charge neutralization, and entrapment. However, due to the hydrolysis of polyaluminum chloride, H+ is produced... + Since the quantity of component B is less than that of crystalline aluminum chloride, its dosage must be higher when component B is polyaluminum chloride.

[0014] (3) When component B is polyaluminum sulfate, the amount used is 1.55 to 4.08 times the mass of soluble silicon in the mine water.

[0015] When polyaluminum sulfate dissolves in water, its hydrolysis process releases a large amount of H₂. + Its hydrolysis produces dense aluminum hydroxide colloids and sulfate-containing polynuclear aluminum hydroxide complexes, which remove silicate ions from water through adsorption, charge neutralization, flocculation bridging, and netting / sweeping. Because the hydrolysis of polyaluminum sulfate produces H₂... + The amount of component B is less than that of crystalline aluminum chloride and polyaluminum chloride. Therefore, when component B is polyaluminum sulfate, its dosage is higher than that of crystalline aluminum chloride and polyaluminum chloride.

[0016] (4) When component B is crystalline aluminum chloride and polyaluminum chloride in a mass ratio of 0.6 to 1.4:1, the amount used is 1.33 to 3.85 times the mass of soluble silicon in the mine water.

[0017] Crystalline aluminum chloride and polyaluminum chloride release a large amount of H2 during the hydrolysis process. + The mononuclear aluminum hydroxide ions, polynuclear aluminum hydroxide complexes, and aluminum hydroxide colloids produced during the hydrolysis process remove silicate ions from the water through adsorption, complexation, flocculation bridging, charge neutralization, and netting / sweeping. Because polyaluminum chloride replaces some crystalline aluminum chloride, its dosage is higher than that of crystalline aluminum chloride but lower than that of polyaluminum chloride.

[0018] (5) When component B is crystalline aluminum chloride and polyaluminum sulfate in a mass ratio of 0.75 to 1.35:1, the amount used is 1.29 to 3.95 times the mass of soluble silicon in the mine water.

[0019] Crystalline aluminum chloride and polyaluminum sulfate release a large amount of H₂ during the hydrolysis process. + The mononuclear aluminum hydroxide ions, polynuclear aluminum hydroxide complexes, sulfate-containing polynuclear aluminum hydroxide complexes, and aluminum hydroxide colloids produced during the hydrolysis process remove silicate ions from the water through adsorption, complexation, flocculation bridging, charge neutralization, and netting / sweeping. Because polyaluminum sulfate replaces part of the crystalline aluminum chloride, its dosage is higher than that of crystalline aluminum chloride but lower than that of polyaluminum sulfate.

[0020] (6) When component B is polyaluminum chloride and polyaluminum sulfate in a mass ratio of 0.85 to 1.55:1, the amount used is 1.31 to 4.01 times the mass of soluble silicon in the mine water.

[0021] Crystalline aluminum chloride and polyaluminum sulfate release a large amount of H₂ during the hydrolysis process. + The polynuclear aluminum hydroxy complexes, sulfate-containing polynuclear aluminum hydroxy complexes, and aluminum hydroxide colloids produced during the hydrolysis process remove silicate ions from the water through adsorption, complexation, flocculation bridging, charge neutralization, and netting / sweeping. Because polyaluminum sulfate replaces part of the polyaluminum chloride, its dosage is higher than that of polyaluminum chloride but lower than that of polyaluminum sulfate.

[0022] (7) When the component B is crystalline aluminum chloride, polyaluminum chloride and polyaluminum sulfate in a mass ratio of 1:(0.6~1.4):(0.75~1.2), the amount used is 1.26~3.88 times the mass of soluble silicon in the mine water.

[0023] The three substances release a large amount of H through hydrolysis. + Simultaneously, by constructing a multi-level aluminum morphology distribution of "mononuclear-multinuclear-colloidal" through the hydrolysis process, the goal of efficient and rapid removal of soluble silicon is achieved through a multi-process integration of adsorption, complexation, flocculation bridging, charge neutralization, and net capture and sweeping.

[0024] As can be seen from the above, the present invention can determine the amount of soluble silicon to be added by measuring the content of soluble silicon in water. It can achieve efficient and rapid removal of soluble silicon without the need for precise adjustment of the pH value of the system, reducing the complexity of operation and requiring less reagent.

[0025] Secondly, the present invention provides the application of the above-mentioned aluminum-based composite desiliconizing agent in removing soluble silicon from coal mine water.

[0026] Preferably, the soluble silicon is sodium silicate.

[0027] Thirdly, the present invention provides a method for removing soluble silicon from coal mine water using the above-mentioned aluminum-based composite desiliconizing agent, which includes the following steps: S1. Add component A to the mine water to cause component A to hydrolyze and form aluminum colloids. Simultaneously, adjust the pH of the water to inhibit the hydrolysis and polymerization of silicate ions. The reaction equation for this step is as follows: NaAlO2→Na + +AlO2 - AlO2 - +2H₂O→Al(OH)₃+OH - S2. Add component B to the mine water to hydrolyze component B and generate hydrogen ions, which form a multi-level aluminum distribution in the water. Among them, the monomeric aluminum rapidly neutralizes the silicate charge, the polymeric aluminum enhances the growth of flocs, and the colloidal aluminum provides a large number of adsorption sites to efficiently and rapidly remove silicate ions.

[0028] Whether it's crystalline aluminum chloride, polyaluminum chloride, or polyaluminum sulfate, their essence is Al. 3+ The hydrolysis reaction equation is as follows: (1)Al 3+ +H₂O→Al(OH) 2+ +H + (2)Al(OH) 2+ +H₂O→Al(OH)₂ + +H + (3) Al(OH)2 + +H₂O→Al(OH)₃+H + Al 3+ Aluminum hydroxide colloid is ultimately generated through multi-step hydrolysis via reaction equations (1), (2), and (3). The hydrolysis steps for generating polynuclear aluminum hydroxy complexes are more complex; simplified reaction equations are as follows: (4) 1 3Al 3+ +32H2O→[Al 13 O4(OH) 24 ] 7+ +32H + S3. Add polyacrylamide, stir, and let it stand to settle. The supernatant is the mine water with soluble silicon removed.

[0029] Preferably, in S1, the content of soluble silicon in the mine water is determined before adding component A. The quality of soluble silicon is determined using the method specified in SL 91.1-1994 "Determination of soluble silicon dioxide (silica) (silica molybdenum yellow spectrophotometric method)," and the result obtained is the content of soluble silicon in the mine water.

[0030] Preferably, in S1, component A is fully hydrolyzed by rapid stirring at a stirring rate of 250–300 r / min for a stirring time of 0.5–2 min.

[0031] Preferably, in S2, component B is thoroughly mixed by slow stirring to avoid breaking the colloidal aluminum. The stirring rate is 40-60 r / r / min and the stirring time is 3-5 min.

[0032] Preferably, in step S3, the amount of polyacrylamide added is 0.5–2 mg / L; the stirring rate is 30–40 r / r / min; the stirring time is 1–2 min; and the standing time is 20–30 min.

[0033] Fourthly, the present invention provides another method for removing soluble silicon from coal mine water using the above-mentioned aluminum-based composite desiliconizing agent, which includes the following steps: S1. Add component A to the mine water to hydrolyze component A to form aluminum colloid, while inhibiting the hydrolysis and polymerization of silicate.

[0034] S2. First, add 50-70% of component B and stir to hydrolyze component B to generate hydrogen ions, adjust the pH value, and simultaneously form a large number of fine and uniform colloidal aluminum particles in the water. These particles provide adsorption sites to remove some silicate ions. Then, add the remaining component B and stir to hydrolyze component B, further adjusting the pH value and forming a large number of monomeric and polymeric aluminum particles. The monomeric aluminum neutralizes the silicate charge, reducing the repulsion between flocs to accelerate coagulation, while the polymeric aluminum further enhances the flocculation and sedimentation process through bridging flocculation and net-like sweeping.

[0035] S3. Sedimentation. This method allows for complete settling of flocs in a short time without the need for the addition of polyacrylamide during sedimentation.

[0036] The technical principle of the above method of the present invention is as follows: according to the different pH values ​​of the solution, Al 3+ The products of ion hydrolysis also differ: when the pH is alkaline to weakly alkaline, Al 3+ The ion hydrolysis products are mainly aluminum hydroxide colloids; however, when the pH is neutral to weakly acidic, Al... 3+ The ion hydrolysis products are mainly polynuclear aluminum hydroxyl complexes. This method first involves adding 50-70% component B to adjust the solution pH to alkaline to weakly alkaline, so that Al... 3+ Ions preferentially form aluminum hydroxide colloids, thereby increasing the adsorption and complexation reaction time between colloidal aluminum and soluble silicon; then, the remaining component B is added, and the pH value is further adjusted to allow Al to... 3+Ion hydrolysis forms polynuclear aluminum hydroxyl complexes, which further enhance the coagulation and sedimentation process through flocculation bridging, netting, and sweeping, achieving the effects of aggregating colloidal particles and accelerating sedimentation. Compared with the previous method, this method controls the solution pH environment by adding component B in stages, thereby controlling the Al content in the solution. 3+ The hydrolysis products of ions enhance the removal and coagulation / precipitation effects of soluble silica. This method effectively reduces or eliminates the need for flocculants such as polyacrylamide, shortening settling time while further improving the removal of soluble silica.

[0037] Preferably, in S1, component A is fully hydrolyzed by rapid stirring at a stirring rate of 250–300 r / r / min and a stirring time of 0.5–2 min.

[0038] Preferably, in S2, the conditions for the first stirring are: stirring speed 150-200 r / r / min, stirring time 2-3 min; and the conditions for the second stirring are: stirring speed 60-100 r / min, stirring time 2-3 min.

[0039] Preferably, in S3, the settling time is 10 to 15 minutes.

[0040] Compared with the prior art, the beneficial effects of the present invention are: (1) When the composite silicate remover of this invention is added to silica-containing wastewater, it can form a multi-level aluminum morphology distribution of "multinucleate-mononucleate-colloidal", thereby constructing a complete silicate removal pathway of "pH regulation-charge neutralization-adsorption complexation-bridging flocculation-chemical precipitation", which can achieve efficient removal of silicate ions. Among them, the monomeric aluminum can quickly neutralize the silicate charge, the polymerized aluminum can enhance floc growth, and the colloidal aluminum can provide a large number of adsorption sites, thereby efficiently and quickly adsorbing and removing silicate ions in the water.

[0041] (2) The composite desiliconizing agent of the present invention does not require precise adjustment of the pH of the system, which not only has low requirements for operational precision, but also is simple to operate and requires less reagent.

[0042] (3) By further optimizing the feeding method of components A and B, this invention can further enhance the removal effect and coagulation and sedimentation effect of soluble silica. This method can effectively reduce or eliminate the use of flocculants such as polyacrylamide, reduce sedimentation time, and further improve the removal effect of soluble silica. Detailed Implementation

[0043] The present invention will be further described below with reference to embodiments.

[0044] General Implementation Examples In a first aspect, an aluminum-based composite silicon remover comprises component A and component B. Component A is sodium aluminate; component B comprises one or more of crystalline aluminum chloride, polyaluminum chloride, and polyaluminum sulfate.

[0045] Preferably, the amount of component A is 0.8 to 2.5 times the mass of soluble silicon in the mine water.

[0046] As a preferred option, the dosage of component B varies depending on its composition, as follows: (1) When component B is crystalline aluminum chloride, the amount used is 1.2 to 3.75 times the mass of soluble silicon in mine water.

[0047] (2) When component B is polyaluminum chloride, the amount used is 1.4 to 3.95 times the mass of soluble silicon in the mine water.

[0048] (3) When component B is polyaluminum sulfate, the amount used is 1.55 to 4.08 times the mass of soluble silicon in the mine water.

[0049] (4) When component B is crystalline aluminum chloride and polyaluminum chloride in a mass ratio of 0.6 to 1.4:1, the amount used is 1.33 to 3.85 times the mass of soluble silicon in the mine water.

[0050] (5) When component B is crystalline aluminum chloride and polyaluminum sulfate in a mass ratio of 0.75 to 1.35:1, the amount used is 1.29 to 3.95 times the mass of soluble silicon in the mine water.

[0051] (6) When component B is polyaluminum chloride and polyaluminum sulfate in a mass ratio of 0.85 to 1.55:1, the amount used is 1.31 to 4.01 times the mass of soluble silicon in the mine water.

[0052] (7) When the component B is crystalline aluminum chloride, polyaluminum chloride and polyaluminum sulfate in a mass ratio of 1:(0.6~1.4):(0.75~1.2), the amount used is 1.26~3.88 times the mass of soluble silicon in the mine water.

[0053] Secondly, the above-mentioned aluminum-based composite desiliconizing agent is used to remove soluble silicon from coal mine water.

[0054] Preferably, the soluble silicon is sodium silicate.

[0055] Thirdly, a method for removing soluble silicon from coal mine water using the above-mentioned aluminum-based composite desiliconizing agent includes the following steps: S1. Add component A to the mine water to hydrolyze component A to form aluminum colloid, while inhibiting the hydrolysis and polymerization of silicate.

[0056] S2. Add component B to the mine water to hydrolyze component B and generate hydrogen ions, which form a multi-level aluminum distribution in the water. Among them, the monomeric aluminum rapidly neutralizes the silicate charge, the polymeric aluminum enhances the growth of flocs, and the colloidal aluminum provides a large number of adsorption sites to efficiently and rapidly remove silicate ions.

[0057] S3. Add polyacrylamide, stir, and let it stand to settle. The supernatant is the mine water with soluble silicon removed.

[0058] Preferably, in S1, the content of soluble silicon in the mine water is determined before adding component A. The quality of soluble silicon is determined using the method specified in SL 91.1-1994 "Determination of soluble silicon dioxide (silica) (silica molybdenum yellow spectrophotometric method)," and the result obtained is the content of soluble silicon in the mine water.

[0059] Preferably, in S1, component A is fully hydrolyzed by rapid stirring at a stirring rate of 250–300 r / min for a stirring time of 0.5–2 min.

[0060] Preferably, in S2, component B is thoroughly mixed by slow stirring to avoid breaking the colloidal aluminum. The stirring rate is 40-60 r / r / min and the stirring time is 3-5 min.

[0061] Preferably, in step S3, the amount of polyacrylamide added is 0.5–2 mg / L; the stirring rate is 30–40 r / r / min; the stirring time is 1–2 min; and the standing time is 20–30 min.

[0062] Fourthly, another method for removing soluble silicon from coal mine water using the aforementioned aluminum-based composite desiliconizing agent includes the following steps: S1. Add component A to the mine water to hydrolyze component A to form aluminum colloid, while inhibiting the hydrolysis and polymerization of silicate.

[0063] S2. First, add 50-70% of component B and stir to hydrolyze component B to generate hydrogen ions, adjust the pH value, and simultaneously form a large number of fine and uniform colloidal aluminum particles in the water. These particles provide adsorption sites to remove some silicate ions. Then, add the remaining component B and stir to hydrolyze component B, further adjusting the pH value and forming a large number of monomeric and polymeric aluminum particles. The monomeric aluminum neutralizes the silicate charge, reducing the repulsion between flocs to accelerate coagulation, while the polymeric aluminum further enhances the flocculation and sedimentation process through bridging flocculation and net-like sweeping.

[0064] S3, Precipitation.

[0065] Using this method, complete sedimentation of flocs can be achieved in a short time without the addition of polyacrylamide during precipitation.

[0066] Preferably, in S1, component A is fully hydrolyzed by rapid stirring at a stirring rate of 250–300 r / r / min and a stirring time of 0.5–2 min.

[0067] Preferably, in S2, the conditions for the first stirring are: stirring speed 150-200 r / r / min, stirring time 2-3 min; and the conditions for the second stirring are: stirring speed 60-100 r / min, stirring time 2-3 min.

[0068] Preferably, in S3, the settling time is 10 to 15 minutes.

[0069] Specific embodiments and comparative examples Example 1 An aluminum-based composite silicon remover comprises component A and component B. Component A is sodium aluminate, and component B is crystalline aluminum chloride.

[0070] Example 2 An aluminum-based composite silicon remover comprises component A and component B. Component A is sodium aluminate, and component B is polyaluminum chloride.

[0071] Example 3 An aluminum-based composite silicon remover comprises component A and component B. Component A is sodium aluminate, and component B is polyaluminum sulfate.

[0072] Example 4 An aluminum-based composite silicon remover comprises component A and component B. Component A is sodium aluminate, and component B is crystalline aluminum chloride and polyaluminum chloride.

[0073] Example 5 An aluminum-based composite silicon remover comprises component A and component B. Component A is sodium aluminate, and component B is crystalline aluminum chloride and polyaluminum sulfate.

[0074] Example 6 An aluminum-based composite silicon remover comprises component A and component B. Component A is sodium aluminate, and component B is polyaluminum chloride and polyaluminum sulfate.

[0075] Example 7 An aluminum-based composite silicon remover comprises component A and component B. Component A is sodium aluminate, and component B is crystalline aluminum chloride, polyaluminum chloride, and polyaluminum sulfate.

[0076] Application Examples 1-7 A method for removing soluble silica from coal mine water, comprising the following steps: 1) First, determine the soluble silicon content in the coal mine water sample. The soluble silicon content is determined using the method specified in SL 91.1-1994 "Determination of soluble silicon dioxide (silica) (silicon molybdenum yellow spectrophotometric method)". The result obtained is the soluble silicon content in the mine water.

[0077] 2) Component A from Examples 1-7 was added to the coal mine water sample, and component A was thoroughly hydrolyzed by rapid stirring at a rate of 280 r / min for 1 min. After stirring, component A hydrolyzed to form aluminum colloid, while simultaneously inhibiting the hydrolysis and polymerization of silicate ions.

[0078] 3) Component B from Examples 1-7 was added to the coal mine water sample. Component B was thoroughly mixed by slow stirring at a rate of 50 r / min for 4 min, avoiding any breakage of the flocs. During stirring, component B hydrolyzed to generate hydrogen ions, forming a multi-level aluminum distribution in the water. Monomeric aluminum rapidly neutralized silicate charges, polymerized aluminum enhanced floc growth, and colloidal aluminum provided numerous adsorption sites for efficient and rapid removal of silicate ions.

[0079] 4) Add polyacrylamide (PAM) to the mine water at a concentration of 1 mg / L. Stir slowly and allow to settle. The stirring rate is 40 r / min, the stirring time is 2 min, and the settling time is 20 min. The supernatant after settling is the mine water with soluble silica removed.

[0080] In the above steps, the amounts of combination A and component B added in Examples 1-7 are as follows: Application Example 1: Using the aluminum-based composite silica remover of Example 1, the amount of component A added was 1 times the mass of soluble silica, and the amount of component B, which is crystalline aluminum chloride, was 2.25 times the mass of soluble silica; the final silicate removal rate was 91.93%. Application Example 2: Using the aluminum-based composite silicon remover of Example 2, the amount of component A added was 1.2 times the mass of soluble silicon, and the amount of component B, which is polyaluminum chloride, was 1.9 times the mass of soluble silicon; the final silicate removal rate was 92.75%. Application Example 3: Using the aluminum-based composite silicon remover of Example 3, the amount of component A added was 1.5 times the mass of soluble silicon, and the amount of component B, which is polyaluminum sulfate, was 2.8 times the mass of soluble silicon; the final silicate removal rate was 95.47%. Application Example 4: Using the aluminum-based composite silicon remover of Example 4, the amount of component A added was 2 times the mass of soluble silicon, and the components of component B were crystalline aluminum chloride and polyaluminum chloride, with a mass ratio of crystalline aluminum chloride to polyaluminum chloride of 0.8:1; the amount of component B added was 3.65 times the mass of soluble silicon; the final silicate removal rate was 99.18%. Application Example 5: Using the aluminum-based composite silica remover of Example 5, the amount of component A added was 1.8 times the mass of soluble silica, and component B consisted of crystalline aluminum chloride and polyaluminum sulfate, wherein the mass ratio of crystalline aluminum chloride to polyaluminum sulfate was 1.15:1, and the amount of component B added was 3.25 times the mass of soluble silica; the final silicate removal rate was 98.27%. Application Example 6: Using the aluminum-based composite silica remover of Example 6, the amount of component A added was 1.65 times the mass of soluble silica, and component B consisted of polyaluminum chloride and polyaluminum sulfate, wherein the mass ratio of polyaluminum chloride to polyaluminum sulfate was 1.3:1, and the amount of component B added was 2.88 times the mass of soluble silica; the final silicate removal rate was 96.58%. Application Example 7: Using the aluminum-based composite silica remover of Example 7, the amount of component A added was 2.5 times the mass of soluble silica, and component B consisted of crystalline aluminum chloride, polyaluminum chloride, and polyaluminum sulfate, wherein the mass ratio of crystalline aluminum chloride, polyaluminum chloride, and polyaluminum sulfate was 1:1:1.15, and the amount of component B added was 4.27 times the mass of soluble silica; the final silicate removal rate was 96.21%.

[0081] The following table shows the addition amounts of component A and component B and the silicate removal rates in each application example: Comparative Examples 1-8 As a control, sodium aluminate and other compound formulations were selected for comparison. The dosage and silicate removal rate of each agent in the comparative examples are shown in the table below: Comparison of data from various application examples and comparative examples shows that the removal rate of silicate ions in each application example can reach over 90%. In comparative examples 1-5, with the same amount of sodium aluminate added, pH value has a significant impact on the removal rate, which fluctuates between 29.73% and 98.17%. While comparative examples 6-8 also maintain a certain removal rate, the amount of reagent added is significantly higher than in the application examples. All the above results indicate that the silicate removal effect of each application example is significantly better than that of the comparative examples, and the reagent consumption is significantly reduced. This demonstrates that the composite silicate remover used in this invention not only achieves highly efficient silicate removal but also effectively reduces the reagent costs in the water treatment process.

[0082] Application Example 8-14 A method for removing soluble silica from coal mine water, comprising the following steps: 1) First, determine the soluble silicon content in the coal mine water sample. The soluble silicon content is determined using the method specified in SL 91.1-1994 "Determination of soluble silicon dioxide (silica) (silicon molybdenum yellow spectrophotometric method)". The result obtained is the soluble silicon content in the mine water.

[0083] 2) Add component A to the mine water and stir rapidly at a rate of 280 r / min for 1 min to ensure complete hydrolysis of component A. After stirring, component A hydrolyzes to form aluminum colloid, while simultaneously inhibiting the hydrolysis and polymerization of silicate ions.

[0084] 3) First, add 50-70% of component B to the mine water and stir rapidly to hydrolyze component B, generating hydrogen ions. This adjusts the pH and simultaneously forms a large amount of fine and uniform colloidal aluminum in the water, providing adsorption sites to remove some silicate ions. The stirring rate is 180 r / min, and the stirring time is 2 min. Then, add the remaining component B to the mine water and stir at a uniform speed to hydrolyze component B, further adjusting the pH and forming a large amount of monomeric and polymeric aluminum. The monomeric aluminum neutralizes the silicate charge, reducing interflocculation repulsion and accelerating coagulation, while the polymeric aluminum further enhances the flocculation and sedimentation process through bridging flocculation and net-like sweeping. The stirring rate for this step is 80 r / min, and the stirring time is 2 min.

[0085] 4) Allow the solution to stand for 10 minutes to settle, then take the supernatant and determine the mass of soluble silicon. In the above steps, the amounts of combination A and component B added in Example 8-14 are shown below: Application Example 8: Using the aluminum-based composite silica remover of Example 1, the amount of component A added was 1 times the mass of soluble silica, and the amount of component B, which is crystalline aluminum chloride, was 2.25 times the mass of soluble silica; the final silicate removal rate was 93.27%. Application Example 9: Using the aluminum-based composite silicon remover of Example 2, the amount of component A added was 1.2 times the mass of soluble silicon, and the amount of component B, which is polyaluminum chloride, was 1.9 times the mass of soluble silicon; the final silicate removal rate was 94.86%. Application Example 10: Using the aluminum-based composite silicon remover of Example 3, the amount of component A added was 1.5 times the mass of soluble silicon, and the amount of component B, which is polyaluminum sulfate, was 2.8 times the mass of soluble silicon; the final silicate removal rate was 96.87%. Application Example 11: Using the aluminum-based composite silicon remover of Example 4, the amount of component A added was 2 times the mass of soluble silicon, and the components of component B were crystalline aluminum chloride and polyaluminum chloride, with a mass ratio of crystalline aluminum chloride to polyaluminum chloride of 0.8:1; the amount of component B added was 3.65 times the mass of soluble silicon; the final silicate removal rate was 99.47%. Application Example 12: Using the aluminum-based composite silica remover of Example 5, the amount of component A added was 1.8 times the mass of soluble silica, and component B consisted of crystalline aluminum chloride and polyaluminum sulfate, wherein the mass ratio of crystalline aluminum chloride to polyaluminum sulfate was 1.15:1, and the amount of component B added was 3.25 times the mass of soluble silica; the final silicate removal rate was 99.23%. Application Example 13: Using the aluminum-based composite silica remover of Example 6, the amount of component A added was 1.65 times the mass of soluble silica, and component B consisted of polyaluminum chloride and polyaluminum sulfate, wherein the mass ratio of polyaluminum chloride to polyaluminum sulfate was 1.3:1, and the amount of component B added was 2.88 times the mass of soluble silica; the final silicate removal rate was 98.21%. Application Example 14: Using the aluminum-based composite silica remover of Example 7, the amount of component A added was 2.5 times the mass of soluble silica, and component B consisted of crystalline aluminum chloride, polyaluminum chloride, and polyaluminum sulfate, wherein the mass ratio of crystalline aluminum chloride, polyaluminum chloride, and polyaluminum sulfate was 1:1:1.15, and the amount of component B added was 4.27 times the mass of soluble silica; the final silicate removal rate was 97.92%.

[0086] The silicate removal rates for each application example are shown in the table below: As shown in the table above, under the same conditions, the removal rate of application examples 8-14 is significantly higher than that of application examples 1-7, indicating that with the same amount of reagent added, the stepwise addition of component B can improve the removal rate of silicate. Furthermore, application examples 8-14 did not add polyacrylamide (PAM) in the precipitation step; therefore, the stepwise addition of component B can also reduce the amount of flocculant used and lower treatment costs.

[0087] Unless otherwise specified, the raw materials and equipment used in this invention are all commonly used in the field; unless otherwise specified, the methods used in this invention are all conventional methods in the field.

[0088] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, alterations, and equivalent transformations made to the above embodiments based on the technical essence of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A method for removing soluble silicon from coal mine water using an aluminum-based composite desiliconizing agent, characterized in that: The aluminum-based composite silicon remover consists of component A and component B; Component A is sodium aluminate; Component B includes one or more of crystalline aluminum chloride, polyaluminum chloride, and polyaluminum sulfate; The method includes: S1. Add component A to the mine water to hydrolyze component A to form aluminum colloid, while inhibiting the hydrolysis and polymerization of silicate ions. S2. First, add 50-70% of component B and stir to hydrolyze component B to generate hydrogen ions, which form colloidal aluminum in water. This colloidal aluminum provides adsorption sites to remove some silicate ions. Then, add the remaining component B and stir to hydrolyze component B to form monomeric and polymeric aluminum. The monomeric aluminum neutralizes the silicate charge, reducing the repulsion between flocs to accelerate coagulation. The polymeric aluminum further enhances the flocculation and sedimentation process through bridging flocculation and net-like sweeping. S3, Precipitation.

2. The method according to claim 1, characterized in that: The amount of component A is 0.8 to 2.5 times the mass of soluble silicon in the mine water; and the amount of component B is crystalline aluminum chloride, which is 1.2 to 3.75 times the mass of soluble silicon in the mine water.

3. The method according to claim 1, characterized in that: The amount of component A is 0.8 to 2.5 times the mass of soluble silicon in the mine water; and the amount of component B is polyaluminum chloride, which is 1.4 to 3.95 times the mass of soluble silicon in the mine water.

4. The method according to claim 1, characterized in that: The amount of component A is 0.8 to 2.5 times the mass of soluble silicon in the mine water; and the amount of component B is polyaluminum sulfate, which is 1.55 to 4.08 times the mass of soluble silicon in the mine water.

5. The method according to claim 1, characterized in that: The amount of component A is 0.8 to 2.5 times the mass of soluble silicon in the mine water; and component B is crystalline aluminum chloride and polyaluminum chloride in a mass ratio of 0.6 to 1.4:1, and the amount is 1.33 to 3.85 times the mass of soluble silicon in the mine water.

6. The method according to claim 1, characterized in that: The amount of component A is 0.8 to 2.5 times the mass of soluble silicon in the mine water; and the amount of component B is crystalline aluminum chloride and polyaluminum sulfate in a mass ratio of 0.75 to 1.35:1, which is 1.29 to 3.95 times the mass of soluble silicon in the mine water.

7. The method according to claim 1, characterized in that: The amount of component A is 0.8 to 2.5 times the mass of soluble silicon in the mine water; and component B is polyaluminum chloride and polyaluminum sulfate in a mass ratio of 0.85 to 1.55:1, and the amount is 1.31 to 4.01 times the mass of soluble silicon in the mine water.

8. The method according to claim 1, characterized in that: The amount of component A is 0.8 to 2.5 times the mass of soluble silicon in the mine water; and component B consists of crystalline aluminum chloride, polyaluminum chloride and polyaluminum sulfate in a mass ratio of 1:(0.6 to 1.4):(0.75 to 1.2), and the amount is 1.26 to 3.88 times the mass of soluble silicon in the mine water.

9. The method according to claim 1, characterized in that: The soluble silicon is sodium silicate.

10. The method according to claim 1, characterized in that: In S1, component A is fully hydrolyzed by rapid stirring at a speed of 250-300 r / min for a duration of 0.5-2 min.

11. The method according to claim 1, characterized in that: In S2, The conditions for the first stirring are: stirring speed 150~200 r / min, stirring time 2~3 min; The conditions for the second stirring are: stirring speed 60~100 r / min, stirring time 2~3 min.

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