A phosphorus-free, nitrogen-free, recyclable boiler water treatment agent and its preparation method.

Abstract

This invention belongs to the field of boiler water treatment technology, specifically a phosphorus-free, nitrogen-free, and recyclable boiler water treatment agent and its preparation method. The agent, by weight, contains the following raw materials: acrylic polymer@TiO2: 10-25 parts, polyepoxysuccinic acid@TiO2: 5-20 parts, sodium dodecylbenzenesulfonate@TiO2: 1-5 parts, zinc polysilicate: 1-5 parts, ferrous sulfate: 1-10 parts, and sodium tetraborate: 1-3 parts. This invention uses a phosphorus-free and nitrogen-free environmentally friendly water treatment agent that can prevent calcium, magnesium, and iron ions in water from reacting with other ions or from depositing and scaling on the surface of boilers and other equipment due to decreased solubility caused by temperature increases. The shell-core structured magnetic nanocomposite material in the water treatment agent can chelate cations in water and form a protective film on the boiler surface, slowing down equipment corrosion, extending service life, and the material is not easily decomposed and is recyclable, making it widely applicable.

Description

Technical Field

[0001] This invention belongs to the field of boiler water treatment technology, specifically a phosphorus-free, nitrogen-free, recyclable boiler water treatment agent and its preparation method. Background Technology

[0002] In daily use of boiler water, it is usually necessary to add scale inhibitors, flocculants and other ingredients. The addition of these agents can, on the one hand, reduce the formation of scale on the surface of the boiler and equipment due to the adhesion of sediment in the water, thereby reducing heat transfer loss during the boiler heating process; on the other hand, it can reduce the corrosion of the boiler inner wall by various ionic impurities in the water, thus extending the service life of the boiler equipment.

[0003] Currently, most boiler water treatment agents are ineffective in boiler applications, failing to achieve proper scale inhibition. Secondly, most boiler water treatment agents cannot form a protective film on the boiler's inner walls, thus failing to mitigate corrosion. Furthermore, boiler water treatment agents are consumables, easily decomposed at high temperatures, and the agents in the discharged boiler wastewater cannot be recovered, causing environmental pollution. Most boiler water treatment agent formulations contain phosphorus and nitrogen, and the wastewater generated after boiler use often needs to be discharged into the environment, where the presence of phosphorus and nitrogen can cause environmental damage. Current wastewater treatment methods suffer from high costs, poor treatment effects, and the inability to recover wastewater after use, further increasing subsequent treatment costs.

[0004] Patent CN 113354107A discloses a composite scale inhibitor, which is prepared by using components such as ethylenediaminetetraacetic acid salt, fatty alcohol polyoxyethylene ether sulfonate, and hydrolyzed maleic anhydride. It effectively avoids the deposition of scale on the inner wall of equipment. However, the formula contains a lot of organic amines and other components that can volatilize into the atmosphere and cause environmental pollution. In addition, during use, the organic acids and other components in the formula can corrode the inner wall of the boiler when removing scale and inhibiting scale. Moreover, the wastewater generated after using the agent is more difficult to treat and causes greater damage to the environment. Patent CN 113045096A discloses a crystallization inhibitor prepared using ferric ammonium citrate, acrylamide-2-methylpropanesulfonic acid, polyhexamethylene guanidine, and other components. When added to a boiler, it effectively inhibits the accumulation of large amounts of salt deposits on the boiler's inner wall. However, the formula contains polyethers and amines, which volatilize significantly into the environment during use, causing pollution. Scale continues to adhere to the inner surface during use, and the raw materials are easily decomposed at high temperatures, exhibiting poor high-temperature resistance. Patent CN 114477477A discloses a water treatment descaling agent and its application method, effectively removing hard salt scale generated in various high-temperature pipelines, high-temperature tower walls, chemical plants, and industrial production processes. However, the formula contains organic amines, organic acids, and their organic acid salts. These substances have limited high-temperature resistance and decompose when used in high-temperature, high-pressure boilers. Furthermore, these organic compounds are easily volatilized during use, causing pollution and are difficult to treat after use.

[0005] In summary, the organic components contained in the above products are easily volatile, pollute the environment, and have limited high-temperature resistance. They are prone to high-temperature decomposition when used in high-temperature and high-pressure boilers. Furthermore, the chemical components can corrode the boiler body during descaling and scale inhibition. The chemicals cannot be recycled after use, the wastewater generated is highly harmful to the environment, and the cost of wastewater treatment is high. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a phosphorus-free, nitrogen-free, and recyclable boiler water treatment agent and its preparation method. This water treatment agent can prevent scale formation on the inner wall of the boiler and form a protective film on the boiler surface, thereby slowing down scaling and corrosion and extending the service life of the equipment. The water treatment agent does not contain phosphorus or nitrogen, is heat-resistant and does not easily decompose, and the wastewater generated after boiler use can be directly discharged into the external environment without causing environmental damage. The used product can also be recycled.

[0007] The technical solution of the present invention is as follows:

[0008] A phosphorus-free, nitrogen-free, and recyclable boiler water treatment agent, by weight, contains the following raw materials: acrylic polymer@TiO2: 10-25 parts, polyepoxysuccinic acid@TiO2: 5-20 parts, sodium dodecylbenzenesulfonate@TiO2: 1-5 parts, zinc polysilicate: 1-5 parts, ferrous sulfate: 1-10 parts, and sodium tetraborate: 1-3 parts.

[0009] Preferably, the acrylic polymer @TiO2 is one or more of the following: acrylic acid-sodium vinyl sulfonate copolymer @TiO2, maleic acid-acrylic acid copolymer @TiO2, and itaconic acid-acrylic acid copolymer @TiO2.

[0010] Acrylic acid-sodium vinyl sulfonate copolymer@TiO2: Acrylic acid-sodium vinyl sulfonate copolymer is prepared by copolymerizing acrylic acid and sodium vinyl sulfonate. The weight average molecular weight of the acrylic acid-sodium vinyl sulfonate copolymer is 2000-6000, which is at the nanoscale. It is coated on the outer surface of magnetic nano-TiO2 using chemical deposition to form a magnetic nanocomposite material with a shell@core structure. The acrylic acid-sodium vinyl sulfonate copolymer, as the shell, can chelate calcium, magnesium and other ions in water. Maleic acid-acrylic acid copolymer@TiO2: Maleic acid-acrylic acid copolymer is prepared by copolymerizing maleic acid and acrylic acid. The weight average molecular weight of the maleic acid-acrylic acid copolymer is 2500-5500. At the nanoscale, a magnetic nanocomposite material with a shell@core structure is formed by chemically depositing it onto the outer surface of magnetic TiO2 nanoparticles. The maleic acid-acrylic acid copolymer, acting as the outer shell, can inhibit the formation of phosphate scale. Itaconic acid-acrylic acid copolymer@TiO2: Itaconic acid-acrylic acid copolymer is obtained by copolymerizing itaconic acid and acrylic acid. The weight average molecular weight of itaconic acid-acrylic acid copolymer is 2200-6500. At the nanoscale, it is also formed by chemically depositing it onto the outer surface of magnetic TiO2 nanoparticles to create a magnetic nanocomposite material with a shell@core structure. The itaconic acid-acrylic acid copolymer, acting as the outer shell, can inhibit the formation of phosphate scale.

[0011] Preferably, the raw materials contain 15-24 parts of acrylic polymer@TiO2, 10-15 parts of polyepoxysuccinic acid@TiO2, 2-5 parts of sodium dodecylbenzenesulfonate@TiO2, 2-4 parts of zinc polysilicate, 1.5-4 parts of ferrous sulfate, and 1-2 parts of sodium tetraborate.

[0012] Preferably, the particle size of acrylic polymers @TiO2, polyepoxysuccinic acid @TiO2, and sodium dodecylbenzenesulfonate @TiO2 is less than 100 nm.

[0013] More preferably, the particle size of acrylic polymer@TiO2 is greater than that of polyepoxysuccinic acid@TiO2, which is greater than that of sodium dodecylbenzenesulfonate@TiO2.

[0014] Preferably, the TiO2 is magnetic nano-TiO2.

[0015] Preferably, the raw material also contains 3 to 7 parts of polymaleic acid@TiO2 with a particle size of less than 100 nm and a weight-average molecular weight of 400 to 1000, which is at the nanoscale. The carboxyl and carbonyl groups contained in the outer shell of polymaleic acid can chelate calcium, magnesium and other ions in water. In addition, the decomposition temperature of polymaleic acid@TiO2 is above 330°C, and it has good corrosion inhibition ability. When combined with zinc polysilicate, it can achieve a better corrosion inhibition effect.

[0016] More preferably, the particle size of acrylic polymer@TiO2 is greater than that of polymaleic acid@TiO2, which is greater than that of sodium dodecylbenzenesulfonate@TiO2.

[0017] A method for preparing a phosphorus-free, nitrogen-free, and recyclable boiler water treatment agent includes the following steps:

[0018] (1) Weigh the above-mentioned raw materials;

[0019] (2) Add the raw materials to water in sequence and mix well to form the original medicine solution;

[0020] (3) Allow the original drug solution to settle and stand, and filter the upper layer of homogeneous clear liquid.

[0021] (4) The filtered medicine solution is bottled, sealed, and stored in a cool, dark place.

[0022] Preferably, the weight ratio of raw materials to water is 1:3-5.

[0023] Preferably, a 5-micron filter is used for filtration.

[0024] Preferably, the water is ultrapure water.

[0025] In this invention, the acrylic acid-ethylene sulfonate copolymer@TiO2, maleic acid-acrylic acid copolymer@TiO2, and itaconic acid-acrylic acid copolymer@TiO2 share the same propylene groups, exhibiting good compatibility and easily achieving compatibilization. When two or three of them are adsorbed onto a boiler or pipeline, they can co-form a film without mutual incompatibility. Furthermore, in the formed protective film, the particle size of polyepoxysuccinic acid@TiO2 is smaller than that of acrylic acid copolymer@TiO2, and the particle size of sodium dodecylbenzene sulfonate@TiO2 is smaller than that of polyepoxysuccinic acid@TiO2. This allows them to effectively fill the pores of the formed protective film, creating a very dense protective film that can be used for corrosion prevention.

[0026] Polyepoxysuccinic acid@TiO2: Polyepoxysuccinic acid has a weight-average molecular weight of 400-1500, placing it at the nanoscale. It is chemically deposited onto the outer surface of magnetic nano-TiO2, forming a shell-and-core structured magnetic nanocomposite material. The polyepoxysuccinic acid, acting as the shell, disperses calcium, strontium, and silicate ions in the water. The acrylic polymer@TiO2 enhances the adsorption and chelation of cations in the water, preventing scale formation. The magnetic nano-TiO2, possessing magnetic properties, adheres to the inner surface of boiler steel. The shell-and-core structured magnetic nanocomposite material forms a filled nanocomposite material, creating a protective film that protects the steel from corrosion. This nanocomposite material also has a self-cleaning function, reducing the frequency of boiler cleaning. After use, the shell-and-core structured magnetic nanocomposite material can be recycled and cleaned under an external magnetic field for repeated use. Sodium dodecylbenzenesulfonate@TiO2: Sodium dodecylbenzenesulfonate in the outer shell acts as a dispersant, reducing the interfacial tension between water and the shell-core magnetic nanocomposite material, allowing the agent to be uniformly dispersed in the water, which is more conducive to uniform film formation. Furthermore, the formed sodium dodecylbenzenesulfonate@TiO2 has a particle size of 25-35 nanometers, smaller than other shell-core structures, allowing for better filling of the nanocomposite material with other shell-core magnetic nanocomposite materials. Zinc polysilicate: Zinc polysilicate acts as a flocculant, adsorbing calcium, magnesium, and iron ions in the water to form softer flocculent scale that does not adhere to the inner surface of the boiler. Ferrous sulfate: It can adsorb iron, sulfate, and phosphate ions in the water, and the resulting flocculent precipitate will not corrode the boiler steel. Sodium tetraborate: As a buffer solution and corrosion inhibitor, it can regulate and stabilize the pH of the boiler water, while also slowing down the corrosion of the boiler steel.

[0027] This invention employs a phosphorus-free, nitrogen-free, and recyclable boiler water treatment agent. It prevents calcium, magnesium, and iron ions in water from reacting with other ions or from depositing and forming scale on the surface of boilers and other equipment due to decreased solubility caused by temperature increases. The shell-core structured magnetic nanocomposite material in the formula chelates cations in the water and forms a dense, filled protective film on the boiler surface, slowing down equipment corrosion, extending service life, and exhibiting high-temperature resistance, non-decomposition, and recyclability. This boiler water treatment agent is not only suitable for boiler water but can also be combined with other ingredients for applications in industrial wastewater treatment, medical wastewater treatment, and other fields, demonstrating a wide range of applications.

[0028] This invention provides a phosphorus-free, nitrogen-free, and recyclable boiler water treatment agent and its preparation method. This water treatment agent can prevent scale formation on the inner wall of the boiler and does not contain phosphorus or nitrogen elements. The wastewater generated after boiler use can be directly discharged into the external environment without causing pollution. It is also heat-resistant and not easily decomposed. Various shell-core structure magnetic nanocomposites form a dense protective film on the surface of boilers and other equipment, protecting the equipment from corrosion and extending its service life. The magnetic nanocomposites also have a self-cleaning function, reducing the frequency of boiler cleaning. After use, the shell-core structure nanomaterials can be recycled and cleaned under the action of an external magnetic field and reused repeatedly. Attached Figure Description

[0029] Figure 1 This is a picture of a standard corrosion test piece before chemical treatment;

[0030] Figure 2 This is a picture of the standard corrosion test piece after chemical treatment.

[0031] Figure 3 This is a comparison image of the standard corrosion test piece after chemical treatment in Experiment 1;

[0032] Figure 4 These are before-and-after comparison images of the chemically treated standard corrosion test pieces in experimental groups 2.

[0033] Figure 5 These are before-and-after comparison images of the chemically treated standard corrosion test pieces in the three experimental groups.

[0034] Figure 6 These are before-and-after comparison images of the chemically treated standard corrosion test pieces in the four experimental groups.

[0035] Figure 7 The images show a comparison of the chemically treated standard corrosion test pieces before and after the test in the five experimental groups. Detailed Implementation

[0036] The technical solutions in this embodiment will be described in detail below, but the described embodiments are only some embodiments of the present invention and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this application.

[0037] The following substances, including polymaleic acid (Guangzhou Desheng Chemical Co., Ltd., weight-average molecular weight 600), polyepoxysuccinic acid (Shandong Taihe Technology Co., Ltd., weight-average molecular weight 1300), acrylic acid-sodium vinyl sulfonate copolymer (Dow Chemical, molar ratio of acrylic acid to sodium vinyl sulfonate 1:1, weight-average molecular weight 4000), maleic acid-acrylic acid copolymer (Jinan Jinbang Environmental Protection Technology Co., Ltd., molar ratio of maleic acid to acrylic acid 1:1, weight-average molecular weight 4000), itaconic acid-acrylic acid copolymer (Shandong Jinshengtai Chemical Co., Ltd., molar ratio of itaconic acid to acrylic acid 1:1, weight-average molecular weight 4500), sodium dodecylbenzenesulfonate (Shandong Yulongsheng Biotechnology Co., Ltd.), magnetic nano-TiO2 (Shanghai Huijingya Nanomaterials Co., Ltd., particle size 10-25nm), ferrous sulfate (Tianjin Kaitong Chemical Reagent Co., Ltd.), and sodium tetraborate (Sinopharm Chemical Reagent Co., Ltd.), can be purchased or prepared using existing technologies.

[0038] The preparation method of polyzinc silicate in this invention is as follows: Add 5.8g of sodium silicate and 120mL of water to a 250mL beaker, stir to dissolve, and reserve 10mL of sodium silicate solution. Add 2-3mL of 3mol / L sulfuric acid to the remaining 110mL solution under stirring to adjust the pH to 2-3. Aging the solution for 1 hour, then add the reserved sodium silicate solution dropwise to the solution to adjust the pH to 4-5. Weigh 11.6g of zinc sulfate heptahydrate and add it directly to the solution, stirring until completely dissolved. Continue stirring for 0.5 hours, add 1.4g of aluminum chloride stabilizer, and stir until dissolved. Add a small amount of sulfuric acid to adjust the pH back to 2-3. Activate for 7 days to obtain polyzinc silicate. Ultrapure water can be used. This preparation method is derived from the technical solution of Example 3 in application number 2009100037895.

[0039] The ultrapure water used in this invention has a conductivity of 0.064 μS / cm, and its quality meets production requirements.

[0040] Preparation method of acrylate-vinyl sulfonate copolymer@TiO2: 20g of magnetic nano-TiO2 was dissolved in 2000g of ultrapure water, and 100g of acrylate-vinyl sulfonate copolymer was added while stirring to form a hydrogel. The hydrogel was stirred at 90℃ for 10h and dried to obtain acrylate-vinyl sulfonate copolymer@TiO2, forming a magnetic nanocomposite material with a shell@core structure and a particle size of 60-75nm.

[0041] Preparation method of maleic acid-acrylic acid copolymer@TiO2: Add 2000g of ultrapure water to 100g of maleic acid-acrylic acid copolymer and stir to dissolve evenly. Then heat to 35℃ and stir for 3h. Add 20g of magnetic nano-TiO2 and stir at 60℃ for 6h. After drying, a magnetic nanocomposite material with a shell@core structure is obtained with a particle size of 50-65nm.

[0042] Preparation method of itaconic acid-acrylic acid copolymer@TiO2: 20g of magnetic nano-TiO2 is dissolved in 2000g of ultrapure water, and 150g of itaconic acid-acrylic acid copolymer is added while stirring to form a hydrogel. The hydrogel is stirred at 80℃ for 12h, and the product is dried by cold air. After drying, itaconic acid-acrylic acid copolymer@TiO2 is obtained, forming a magnetic nanocomposite material with a shell@core structure and a particle size of 75-90nm.

[0043] Preparation method of polyepoxysuccinic acid@TiO2: Dissolve 20g of magnetic nano-TiO2 in 2000g of ultrapure water, and add 60g of polyepoxysuccinic acid while stirring to form a hydrogel. Stir the hydrogel at 80℃ for 12h to coat the surface of the magnetic nano-TiO2 with polyepoxysuccinic acid. After drying, polyepoxysuccinic acid@TiO2 is obtained, forming a magnetic nanocomposite material with a shell@core structure and a particle size of 45-55nm.

[0044] Preparation method of polymaleic acid@TiO2: 50g of polymaleic acid is mixed with 2000g of ultrapure water and stirred until dissolved. The mixture is then heated to 65℃ and stirred for 5h. 15g of magnetic nano-TiO2 is added and stirred at 80℃ for 6h. After drying, a magnetic nanocomposite material with a shell@core structure is obtained with a particle size of 35-50nm.

[0045] Preparation method of sodium dodecylbenzenesulfonate@TiO2: Dissolve 10g of magnetic nano-TiO2 in 500g of ultrapure water, and add 20g of sodium dodecylbenzenesulfonate while stirring to form a hydrogel. Stir the hydrogel at 60℃ for 24h to coat the surface of the magnetic nano-TiO2 with sodium dodecylbenzenesulfonate. After drying, sodium dodecylbenzenesulfonate@TiO2 is obtained, forming a magnetic nanocomposite material with a shell@core structure and a particle size of 25-35nm.

[0046] Example 1

[0047] A phosphorus-free, nitrogen-free, and recyclable boiler water treatment agent formulation: Polyepoxysuccinic acid@TiO2: 80g, acrylic acid-sodium vinyl sulfonate copolymer@TiO2: 70g, maleic acid-acrylic acid copolymer@TiO2: 60g, itaconic acid-acrylic acid copolymer@TiO2: 70g, sodium dodecylbenzene sulfonate@TiO2: 20g, zinc polysilicate: 30g, ferrous sulfate: 40g, sodium tetraborate: 20g;

[0048] The preparation method includes the following steps.

[0049] (1) Weigh the corresponding raw materials according to the above formula;

[0050] (2) Add 1170g of ultrapure water to the reactor, and add the raw materials to the reactor in sequence and stir for 3 hours to form the original drug solution;

[0051] (3) Transfer the original drug solution to a sedimentation tank for sedimentation, let it stand for 10 hours, take the upper layer of homogeneous clear liquid, and filter it through a 5-micron filter screen.

[0052] (4) The filtered medicine solution is bottled, sealed, and stored in a cool, dark place.

[0053] Example 2

[0054] A phosphorus-free, nitrogen-free, and recyclable boiler water treatment agent formulation: Polyepoxysuccinic acid@TiO2: 120g, acrylic acid-sodium ethylene sulfonate copolymer@TiO2: 90g, maleic acid-acrylic acid copolymer@TiO2: 55g, itaconic acid-acrylic acid copolymer@TiO2: 95g, sodium dodecylbenzene sulfonate@TiO2: 30g, zinc polysilicate: 40g, ferrous sulfate: 50g, sodium tetraborate: 20g;

[0055] The preparation method includes the following steps.

[0056] (1) Weigh the corresponding raw materials according to the above formula;

[0057] (2) Add 2000g of ultrapure water to the reactor, and add the raw materials to the reactor in sequence and stir for 5 hours to form the original drug solution;

[0058] (3) Transfer the original drug solution to the sedimentation tank for sedimentation, let it stand for 15 hours, take the upper layer of homogeneous clear liquid, and filter it through a 5-micron filter screen.

[0059] (4) The filtered medicine solution is bottled, sealed, and stored in a cool, dark place.

[0060] Example 3

[0061] A phosphorus-free, nitrogen-free, and recyclable boiler water treatment agent formulation: polyepoxysuccinic acid@TiO2: 100g, acrylic acid-sodium vinyl sulfonate copolymer@TiO2: 70g, maleic acid-acrylic acid copolymer@TiO2: 60g, itaconic acid-acrylic acid copolymer@TiO2: 110g, sodium dodecylbenzene sulfonate@TiO2: 20g, zinc polysilicate: 20g, ferrous sulfate: 15g, sodium tetraborate: 10g;

[0062] The preparation method includes the following steps.

[0063] (1) Weigh the corresponding raw materials according to the above formula;

[0064] (2) Add 1620g of ultrapure water to the reactor, and add the raw materials to the reactor in sequence and stir for 4 hours to form the original drug solution;

[0065] (3) Transfer the original drug solution to the sedimentation tank for sedimentation, let it stand for 14 hours, take the upper layer of homogeneous clear liquid, and filter it through a 5-micron filter screen.

[0066] (4) The filtered medicine solution is bottled, sealed, and stored in a cool, dark place.

[0067] Example 4

[0068] A phosphorus-free, nitrogen-free, and recyclable boiler water treatment agent formulation: Polyepoxysuccinic acid @TiO2: 150g, acrylic acid-sodium vinyl sulfonate copolymer @TiO2: 110g, maleic acid-acrylic acid copolymer @TiO2: 60g, itaconic acid-acrylic acid copolymer @TiO2: 50g, sodium dodecylbenzene sulfonate @TiO2: 15g, zinc polysilicate: 15g, ferrous sulfate: 10g, sodium tetraborate: 10g, polymaleic acid @TiO2: 40g

[0069] The preparation method includes the following steps.

[0070] (1) Weigh the corresponding raw materials according to the above formula;

[0071] (2) Add 2310g of ultrapure water to the reactor, and add the raw materials to the reactor in sequence and stir for 3 hours to form the original drug solution;

[0072] (3) Transfer the original drug solution to a sedimentation tank for sedimentation, let it stand for 10 hours, take the upper layer of homogeneous clear liquid, and filter it through a 5-micron filter screen.

[0073] (4) The filtered medicine solution is bottled, sealed, and stored in a cool, dark place.

[0074] Test case

[0075] The chemically treated standard corrosion test piece (stainless steel sample) used in this invention is made of stainless steel and manufactured by Gaoyou Sanchuang Petrochemical Equipment Factory (General Partnership). The anhydrous ethanol used is manufactured by Tianjin Yongda Chemical Reagent Co., Ltd. The turbidimeter used is manufactured by Shanghai Xinrui Instrument Co., Ltd. (model WGZ-200). The electronic balance used is manufactured by Sartorius Scientific Instruments (Beijing) Co., Ltd. (model BSA224S). The absorbent cotton used is manufactured by Changde Bickman Biotechnology Co., Ltd. The nitric acid used is manufactured by Laiyang Kangde Chemical Co., Ltd., and the sodium hydroxide used is manufactured by Xilong Scientific Co., Ltd.

[0076] The simulated boiler water configuration conforms to national standards. The main parameters of the simulated boiler water are shown in the table below.

[0077] Table 1

[0078]

[0079] The 10 chemically treated standard corrosion test pieces were numbered as follows: 4171, 4172, 4173, 4174, 4175, 4176, 4177, 4178, 4179, and 4180. The cleaning procedure for the chemically treated standard corrosion test pieces is as follows:

[0080] (1) Wipe the anti-rust grease off the chemically treated standard corrosion test piece with clean filter paper;

[0081] (2) Place the chemically treated standard corrosion test piece in ultrapure water, wipe it once with degreased cotton, and then rinse it with ultrapure water for 15 seconds;

[0082] (3) Place the chemically treated standard corrosion test piece in anhydrous ethanol and wipe it twice with degreased cotton, then rinse it with anhydrous ethanol for 15 seconds, and place it on dry filter paper to dry it with cold air.

[0083] (4) The standard corrosion test piece was wrapped in filter paper and placed in a desiccator for more than 24 hours. Before the experiment, the initial weight was weighed and measured to an accuracy of 0.0001g.

[0084] After the chemically treated standard corrosion test piece has undergone the above treatment, observe the following: Figure 1 As shown, the surface condition was then observed under a metallographic microscope. Under conditions of consistent light source intensity and 100x magnification, the surface of the 10 chemically treated standard corrosion specimens was observed. The surface conditions were basically consistent, with no signs of oxidation or corrosion. See details... Figure 3-7 .

[0085] Before the experiment, the inner walls of the five high-temperature and high-pressure reactors were thoroughly cleaned. Ultrapure water was then continuously injected into the reactors, and the temperature was adjusted to 200°C for 12 hours of circulating cleaning. After cleaning, the ultrapure water was discharged. The cleaned chemically treated standard corrosion test pieces were placed into the five identical high-temperature and high-pressure reactors according to their numbers: 4171 and 4172 were test group 1; 4173 and 4174 were test group 2; 4175 and 4176 were test group 3; 4177 and 4178 were test group 4; and 4179 and 4180 were test group 5. Treatment agent No. 1 (prepared according to Example 3 of patent CN 113354107 A), treatment agent No. 2 (prepared according to Example 3 of patent CN 113045096 A), treatment agent No. 3 (prepared according to Example 4 of patent CN 114477477A), and treatment agent No. 4 (prepared according to Example 3 of this invention) were divided into four groups. The simulated boilers were configured as follows: Group 1 without any treatment agent; Group 2 with treatment agent No. 1; Group 3 with treatment agent No. 2; Group 4 with treatment agent No. 3; and Group 5 with treatment agent No. 4. Each high-temperature, high-pressure reactor contained 10L of simulated boiler water. Treatment agents No. 1-4 were added in equal weight to the 10L simulated boiler water in each of the five reactors, maintaining a concentration of 40.5 μg / mL. The reactors were operated at 310℃ and 9.81 MPa for 40 hours. After cooling to below 100℃, the water was drained from the reactors, and the chemically treated standard corrosion test pieces were removed, dried, and observed. Figure 2 As shown, the surface condition was then observed under a metallographic microscope. The light source intensity was adjusted to be the same, and the magnification was 100x before focusing and observation. See details below. Figure 3-7 Different treatment methods were applied to standard corrosion test pieces with different corrosion deposit states, and the samples were weighed after treatment. The treatment methods are as follows:

[0086] (1) For chemically treated standard corrosion test pieces with inconspicuous corrosion deposition, wipe them with an eraser to expose the metal color, then immerse them in anhydrous ethanol and wipe them twice with degreased cotton. Then immerse them in clean anhydrous ethanol for 30 seconds, rinse them with flowing anhydrous ethanol for 15 seconds, take them out and place them on clean filter paper, and dry them with cold air. Wrap the chemically treated standard corrosion test pieces with filter paper and place them in a desiccator for more than 24 hours. Weigh and measure the final weight, accurate to 0.0001g.

[0087] (2) For chemically treated standard corrosion test pieces with a large amount of corrosion deposits, use a chemical cleaning agent to remove corrosion products. The chemical cleaning agent is a 10% nitric acid solution. Soak the chemically treated standard corrosion test piece in the 10% nitric acid solution for 30 seconds, then wipe off the oxides on the surface with degreased cotton. Immediately after chemical cleaning, put the chemically treated standard corrosion test piece into a 5 mol / L sodium hydroxide solution for passivation for 15 seconds. After taking it out, immerse it in anhydrous ethanol, wipe it dry with filter paper, and then wipe it with an eraser to expose the metal color. Then immerse it in anhydrous ethanol and wipe it twice with degreased cotton. Then immerse it in clean anhydrous ethanol for 30 seconds, and then rinse it with flowing anhydrous ethanol for 15 seconds. After taking it out, place it on clean filter paper and dry it with cold air. Wrap the chemically treated standard corrosion test piece with filter paper and place it in a desiccator for more than 24 hours. Weigh and measure the final weight, accurate to 0.0001g.

[0088] Among them, the chemically treated standard corrosion test pieces in test groups 1, 2, 3 and 4, which have more corrosion deposits, are cleaned with chemical cleaning agents to remove corrosion and deposits, which is the method in (2) above; the chemically treated standard corrosion test pieces in test group 5, which have less obvious corrosion deposits, are wiped with an eraser, which is the method in (1) above.

[0089] Determination of corrosion rate: The annual corrosion rate of the chemically treated standard corrosion test piece is calculated using the following formula based on the total area of ​​the test piece, the density of the test piece, the test time, and the weight loss of the chemically treated standard corrosion test piece:

[0090]

[0091] In the formula:

[0092] v—Annual corrosion rate of chemically treated standard corrosion test piece, mm / a;

[0093] m—mass of the chemically treated standard corrosion test piece after cleaning, in grams;

[0094] m0—Initial mass of the chemically treated standard corrosion test piece after cleaning before testing, in grams;

[0095] S—Surface area of ​​the chemically treated standard corrosion test piece, in cm² 2 ;

[0096] ρ — Density of the chemically treated standard corrosion test piece, g / cm³ 3 ;

[0097] T—Test time, in hours;

[0098] 8760 – the number of hours equivalent to one year, h / a;

[0099] 10 – the number of millimeters equivalent to 1 cm, mm / cm;

[0100] Among them, the above-mentioned chemically treated standard corrosion test piece is Type I, with a surface area S of 28 cm². 2 The density ρ is 7.92 g / cm³. 3 The test lasted for 40 hours.

[0101] Table 2 below shows the weight and annual corrosion rate of the standard corrosion test pieces before and after chemical treatment:

[0102] Table 2 Weight data of standard corrosion test pieces after chemical treatment

[0103]

[0104] Based on the data in the table above and calculations, the average annual corrosion rate of the chemically treated standard corrosion test pieces in Experiment 1 was 1.2600 mm / a, in Experiment 2 it was 0.8705 mm / a, in Experiment 3 it was 0.6612 mm / a, in Experiment 4 it was 0.7402 mm / a, and in Experiment 5 it was 0.0114 mm / a. Compared to other water treatment agents and the blank test, the annual corrosion rate of the chemically treated standard corrosion test pieces was significantly reduced when using the water treatment agent of this invention.

[0105] like Figure 2-3 As shown, the boiler water, without any additives, lacked scale inhibition capabilities, resulting in significant scale deposition on the surface of the chemically treated standard corrosion test pieces. Furthermore, yellow oxidative corrosion was observed in some areas of the surface, and the chemically treated standard corrosion test pieces lost their original metallic luster. Without additives, the purpose of scale inhibition and corrosion prevention could not be achieved. Under a metallographic microscope at 100x magnification, it was observed that the surface of the chemically treated standard corrosion test pieces contained deposits, and the original uneven metallic texture had been smoothed out by scale deposition. Most of the texture was covered by scale, with only a small amount still observable. Additionally, obvious black pitting corrosion appeared in some areas of the surface. The annual corrosion rate of the first group of chemically treated standard corrosion test pieces in this experiment was relatively high.

[0106] like Figure 2 , Figure 4As shown, in Experiment 2, where treatment agent No. 1 was added, the scale inhibition effect was not obvious. A large amount of scale deposited on the surface of the chemically treated standard corrosion test piece, indicating limited scale inhibition capability. Furthermore, yellow oxides appeared locally on the chemically treated standard corrosion test piece, failing to achieve complete scale inhibition and corrosion prevention, and unable to form a protective film. Under a metallographic microscope at 100x magnification, it was observed that the surface of the chemically treated standard corrosion test piece was covered with deposits, and the original uneven metallic texture had been flattened by scale deposits, covering most of the original metallic texture, with less visible covered metallic texture. Compared to Experiment 1, which did not add any agent, although the annual corrosion rate of Experiment 2 was reduced, the reduction was small.

[0107] like Figure 2 , Figure 5 As shown, in Experiment 3, where treatment agent No. 2 was added, a small amount of scale deposited on the surface of the chemically treated standard corrosion test pieces, indicating a certain scale inhibition effect. However, the small amount of scale deposited on the surface of the chemically treated standard corrosion test pieces did not achieve a complete scale removal and inhibition effect, and a protective film could not be formed on the surface of the chemically treated standard corrosion test pieces. Under a metallographic microscope at 100x magnification, a thin layer of deposit was observed on the surface of the chemically treated standard corrosion test pieces. The original uneven metal texture on the surface had been smoothed out by the scale deposit, and the original uneven metal texture was not obvious, but the overall metal texture could still be observed. Compared with Experiment 1, which did not add any agent, the annual corrosion rate of Experiment 3 was reduced.

[0108] like Figure 2 , Figure 6 As shown, in Experiment 4, where treatment agent No. 3 was added, a relatively thick protective film formed in localized areas on the surface of the chemically treated standard corrosion test pieces. However, the thickness of the protective film was uneven, the area covered by the film was small, and the distribution was uneven. Scale deposits appeared on the surface, indicating a certain scale inhibition effect. A small amount of pitting and oxidation were observed on the surface of the chemically treated standard corrosion test pieces. Under a metallographic microscope at 100x magnification, scale deposits were observed in some areas of the surface of the chemically treated standard corrosion test pieces. The uneven metallic texture in some areas appeared smooth after being covered by the scale deposits, while in other areas, the metallic texture appeared smooth after being covered by the deposits. Compared to Experiment 1, which did not add any agents, although the annual corrosion rate of Experiment 4 was reduced, the reduction was small.

[0109] like Figure 2 , Figure 7As shown, in test group 5, which added treatment agent No. 4, no scaling occurred on the surface of the chemically treated standard corrosion test pieces. Furthermore, an extremely thin micron-sized protective film formed on the surface of the chemically treated standard corrosion test pieces, effectively preventing scaling deposition. No corrosion occurred on the surface of the chemically treated standard corrosion test pieces. Under a metallographic microscope at 100x magnification, no oxidative corrosion was observed on the surface of the chemically treated standard corrosion test pieces, demonstrating its anti-corrosion effect. No scaling deposition was observed on the surface, and the uneven metallic texture of the surface remained largely unchanged compared to before, without any smoothing due to scaling deposition. Compared to test group 1, which did not add any agents, the annual corrosion rate of test group 5 was significantly reduced, and it also showed a very significant reduction compared to test groups that added other treatment agents. After using the reagent of this invention, not only can it prevent scaling on the surface of the chemically treated standard corrosion test piece, but it also forms an extremely thin protective film on the surface of the chemically treated standard corrosion test piece. The protective film is evenly distributed on the surface of the chemically treated standard corrosion test piece, which can effectively prevent oxidation corrosion and other electrochemical corrosion of the chemically treated standard corrosion test piece, and achieve the purpose of corrosion prevention.

[0110] In addition, to determine the recovery rate and adsorption rate of the reagent after addition in Example 3 of the present invention, during the above 5 sets of experiments, the concentration of various polymers @TiO2 with different structures in the boiler water was sampled and detected at the beginning of the addition of the reagent. After the experiment, the concentration of polymers @TiO2 in the boiler water was measured after recovery by an external magnetic field. The specific results are shown in Table 2.

[0111] The calculation formula is as follows:

[0112]

[0113] In the formula:

[0114] C0—Concentration of polymer@TiO2 in boiler water after dosing begins, in mg / mL;

[0115] C e —The concentration of polymer@TiO2 in the boiler water at the end of the experiment, mg / mL;

[0116]

[0117] In the formula:

[0118] C e —The concentration of polymer@TiO2 in the boiler water at the end of the experiment, mg / mL;

[0119] C r —Concentration of polymer@TiO2 in boiler water after magnetic field recovery, mg / mL;

[0120] Table 2

[0121]

[0122] The results above show that the scale inhibition effect of the formulation of this invention is better than that of other existing treatment agents. Furthermore, the treatment agent in this invention can prevent the corrosion of chemically treated standard corrosion test pieces, and different shell-core structure magnetic nanocomposites will adsorb onto the surface of the chemically treated standard corrosion test pieces to form a dense, filled protective film. After use, the agent, under the action of an external magnetic field, recovers polymers @TiO2 of different structures from the water. The recovery rate of different polymers @TiO2 is greater than 95%, proving that the different polymers @TiO2 in the formulation of this invention can be recovered with a high recovery rate, which can reduce the environmental damage caused by wastewater discharge.

[0123] The embodiments described are intended to illustrate the invention only and not to limit its scope. They are merely examples of formulation inventions, and the proportions are for reference only. Furthermore, it should be understood that various modifications or alterations made within the technical solutions of this invention also fall within the scope of protection of this invention. The molecular weight and particle size of the nanoshell@core structure magnetic nanocomposite material described in this invention are merely illustrative and should be understood as all nanoscale shell@core structure magnetic nanocomposite materials appearing in the formulation falling within the scope of protection of this invention.

Claims

1. A phosphorus-free, nitrogen-free, and recyclable boiler water treatment agent, characterized in that, By weight, the raw materials contain acrylic polymers@TiO2: 10-25 parts, polyepoxysuccinic acid@TiO2: 5-20 parts, sodium dodecylbenzenesulfonate@TiO2: 1-5 parts, zinc polysilicate: 1-5 parts, ferrous sulfate: 1-10 parts, and sodium tetraborate: 1-3 parts. The acrylic polymer @TiO2 is one or more of the following: acrylate-sodium vinyl sulfonate copolymer @TiO2, maleic acid-acrylic acid copolymer @TiO2, itaconic acid-acrylic acid copolymer @TiO2; The particle sizes of the acrylic polymers @TiO2, polyepoxysuccinic acid @TiO2, and sodium dodecylbenzenesulfonate @TiO2 are all less than 100 nm. The particle size of the acrylic polymer@TiO2 is greater than that of polyepoxysuccinic acid@TiO2, which is greater than that of sodium dodecylbenzenesulfonate@TiO2. The TiO2 is magnetic nano-TiO2; The raw material also contains 3 to 7 parts of polymaleic acid@TiO2 with a particle size of less than 100 nm.

2. The phosphorus-free, nitrogen-free, and recyclable boiler water treatment agent according to claim 1, characterized in that, The raw materials contain acrylic polymers@TiO2: 15-24 parts, polyepoxysuccinic acid@TiO2: 10-15 parts, sodium dodecylbenzenesulfonate@TiO2: 2-5 parts, zinc polysilicate: 2-4 parts, ferrous sulfate: 1.5-4 parts, and sodium tetraborate: 1-2 parts.

3. The phosphorus-free, nitrogen-free, and recyclable boiler water treatment agent according to claim 1, characterized in that, The particle size of the acrylic polymer@TiO2 is greater than that of polymaleic acid@TiO2, which is greater than that of sodium dodecylbenzenesulfonate@TiO2.

4. A method for preparing a phosphorus-free, nitrogen-free, and recyclable boiler water treatment agent according to any one of claims 1-3, characterized in that, Includes the following steps: (1) The raw materials for boiler water treatment agents; (2) Add the raw materials to water in sequence and mix well to form the original medicine solution; (3) Allow the original drug solution to settle and stand, and filter the clear liquid at the top layer; (4) The filtered medicine liquid is bottled, sealed, and stored in a cool, dark place.

5. The method for preparing a phosphorus-free, nitrogen-free, and recyclable boiler water treatment agent according to claim 4, characterized in that, The weight ratio of the raw material to water is 1:3-5.

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