Composite non-phosphorus scale inhibitor and preparation method thereof

Abstract

The present application relates to a kind of composite phosphorus-free scale inhibitor and its preparation method, including 800-1200 parts by weight of desalted water, 1-3 parts by weight of modified lignin sulfonate, 2-4 parts by weight of calcium magnesium acetate, 0.5-1.5 parts by weight of azole, 400-600 parts by weight of soluble inorganic zinc salt and 50-150 parts by weight of copolymer A.The composite phosphorus-free scale inhibitor provided by the present application is clear and transparent concentrate, after the above concentrate is added to circulating water, the effective ingredient in it can form soluble chelate with Ca 2+ , Mg 2+ Forming, increase the saturation solubility of ion, hinder micro-fouling lattice formation, distort crystal growth, so that microcrystalline will not accumulate into scale, and can make old scale loose, gradually shed old scale;At the same time, the special corrosion inhibitor and other corrosion inhibitor produce synergistic effect, which can effectively control the pitting of stainless steel, achieve the purpose of preventing scale, and fundamentally reduce the efficiency of corrosion and scale inhibition.

Description

Technical Field

[0001] This invention belongs to the field of water treatment, specifically relating to a composite phosphorus-free scale inhibitor and its preparation method. Background Technology

[0002] Water treatment chemicals began to be used in industry in the early 1920s, and circulating cooling water treatment technology has been developing for nearly 100 years, resulting in relatively mature phosphorus-based scale inhibitor water treatment technology. However, with the increasing prominence of environmental problems and increasingly stringent national standards for phosphorus emissions, the phosphorus-free transformation of water treatment scale inhibitors has become an inevitable trend. Water treatment formulations using molybdates, tungstates, novel synthetic agents, and silicates as primary corrosion inhibitors have made some progress, but due to the high cost of these agents or their applicability only to specific conditions, most of these technologies have not achieved large-scale application.

[0003] Modern industries in China, such as steel mills, power plants, petrochemical plants, fertilizer plants, and paper mills, all rely heavily on the treatment of cooling water, process water, and wastewater. The treatment of circulating cooling water is receiving increasing attention in industry, as circulating cooling water accompanies the entire production process, accounting for 70-80% of total water consumption. In industrial production, circulating water is frequently used for equipment cooling or heat transfer. However, due to evaporation within the system, the salt concentration increases. High-concentration saline water easily leads to scaling or corrosion in equipment and pipelines primarily constructed of steel and copper. Scale buildup can have serious consequences for production, reducing heat exchange efficiency and even causing shutdowns, resulting in significant economic losses for industrial production.

[0004] Scale inhibitors are a class of agents that can disperse sparingly soluble inorganic salts in water, prevent or interfere with the precipitation and scaling of sparingly soluble inorganic salts on metal surfaces, and maintain good heat transfer properties in metal equipment.

[0005] Therefore, the development of low-cost, high-efficiency, phosphorus-free scale inhibitors for water treatment has become an urgent need for research institutes and application enterprises to slow down scaling and enable cooling water systems to operate effectively and stably. Summary of the Invention

[0006] The purpose of this invention is to propose a composite phosphorus-free scale inhibitor and its preparation method, which can reduce phosphorus pollution in the environment when used in circulating cooling water systems. It can decompose and slow down the scaling, corrosion and heat exchange efficiency reduction of equipment caused by cooling water concentration, and ensure the effective and stable operation of the cooling water system.

[0007] To achieve the above objectives, the present invention provides a composite phosphorus-free scale inhibitor comprising 600-800 parts by weight of demineralized water, 1-3 parts by weight of modified lignin sulfonate, 2-4 parts by weight of calcium magnesium salt, 0.5-1.5 parts by weight of azole, 400-600 parts by weight of water-soluble inorganic zinc salt, and 50-150 parts by weight of copolymer A.

[0008] Copolymer A is a sulfonated terpolymer, including one or two of the following: acrylic acid-2-acrylamide-2-methylbenzenesulfonic acid copolymer, 2-acrylamide-2-methylpropylsulfonic acid copolymer, and acrylic acid-acrylate-sulfonate copolymer, with an effective content of 30%.

[0009] Preferably, the azole is benzotriazole, methylbenzotriazole, mercaptobenzothiazole, or an azole derivative.

[0010] Preferably, the composite phosphorus-free scale inhibitor comprises 1000 parts by weight of water, 2 parts by weight of modified lignin sulfonate, 3 parts by weight of calcium magnesium acetate, 1 part by weight of azole, 500 parts by weight of water-soluble inorganic zinc salt, and 100 parts by weight of copolymer A.

[0011] Another object of the present invention is to provide a method for preparing a composite phosphorus-free scale inhibitor, comprising the following steps:

[0012] A. Mix 400-600 parts by weight of deionized water with 1-3 parts by weight of modified lignin sulfonate, stir evenly, and filter through a 200-mesh filter cloth to obtain liquid A.

[0013] B. Mix 400-600 parts by weight of deionized water with 2-4 parts by weight of calcium magnesium acetate, stir well to obtain liquid B;

[0014] C. Mix 0.5 to 1.5 parts by weight of azoles with 400 to 600 parts by weight of water-soluble inorganic zinc salt and heat to 50 degrees Celsius. Then add 50 to 150 parts by weight of copolymer A and mix. Stir until homogeneous to obtain liquid C.

[0015] D. Mix liquid C with liquid B, stir until homogeneous, then add liquid A, mix until homogeneous, and filter to obtain a composite phosphorus-free scale inhibitor.

[0016] Preferably, the azole is benzotriazole, methylbenzotriazole, mercaptobenzothiazole, or an azole derivative.

[0017] Preferably, the preparation method of the composite phosphorus-free scale inhibitor includes the following steps:

[0018] A. Mix 500 parts by weight of deionized water with 2 parts by weight of modified lignin sulfonate, stir evenly, and filter through a 200-mesh filter cloth to obtain liquid A.

[0019] B. Mix 500 parts by weight of deionized water with 3 parts by weight of calcium magnesium acetate, stir well, and obtain liquid B.

[0020] C. Mix 1 part by weight of azole with 500 parts by weight of deionized water-soluble inorganic zinc salt and heat to 50 degrees Celsius. Then add 100 parts by weight of copolymer A and mix. Stir until homogeneous to obtain liquid C.

[0021] D. Mix liquid C with liquid B, stir until homogeneous, then add liquid A, mix until homogeneous, and filter to obtain a composite phosphorus-free scale inhibitor.

[0022] Based on the above technical solution, the advantages of the present invention are:

[0023] The composite phosphorus-free scale inhibitor provided by this invention is a clarified concentrate. After using the above-mentioned scale inhibitor, the amount of scale inhibitor and slow-release agent used can be effectively reduced without affecting the treatment effect, which greatly saves costs. Moreover, the copolymer and water-soluble inorganic zinc salt contained in this formula can also work synergistically to reduce operating costs. At the same time, this formula is a phosphorus-free system formula, which avoids eutrophication of the receiving water body caused by the addition of phosphorus.

[0024] By adding a compound phosphorus-free scale inhibitor to the circulating cooling water, the corrosion, scaling, and sludge formation caused by the circulating cooling water can be effectively controlled, ensuring the normal operation of the equipment and saving water. This reduces the impact of scaling, corrosion, and sludge formation on the heat exchange efficiency of the heat exchange equipment and extends its service life. Detailed Implementation

[0025] The technical solution of the present invention will be further described in detail below through embodiments.

[0026] This invention provides a composite phosphorus-free scale inhibitor for use in circulating cooling water. It can effectively control corrosion, scaling, and sludge formation in equipment caused by circulating cooling water, ensuring normal operation of the equipment and saving water.

[0027] Specifically, the composite phosphorus-free scale inhibitor comprises 800-1200 parts by weight of deionized water, 1-3 parts by weight of modified lignin sulfonate, 2-4 parts by weight of calcium magnesium acetate, 0.5-1.5 parts by weight of azoles, 400-600 parts by weight of water-soluble inorganic zinc salt, and 50-150 parts by weight of copolymer A.

[0028] Copolymer A is a sulfonated terpolymer, including one or two of the following: acrylic acid-2-acrylamide-2-methylbenzenesulfonic acid copolymer, 2-acrylamide-2-methylpropylsulfonic acid copolymer, and acrylic acid-acrylate-sulfonate copolymer, with an effective content of 30%.

[0029] Preferably, the azole is benzotriazole or sodium dodecylbenzenesulfonate.

[0030] Preferably, the composite phosphorus-free scale inhibitor comprises 1000 parts by weight of deionized water, 2 parts by weight of modified lignin sulfonate, 3 parts by weight of calcium magnesium acetate, 1 part by weight of azole, 500 parts by weight of water-soluble inorganic zinc salt, and 100 parts by weight of copolymer A.

[0031] The composite phosphorus-free scale inhibitor provided by this invention is a clear and transparent concentrated solution. When this concentrated solution is added to circulating water in a continuous manner, its effective components can react with scaling-causing calcium... 2+ Mg 2+ It forms soluble chelates, increases the saturated solubility of ions, hinders the formation of micro-scale lattice, distorts crystal growth, prevents microcrystals from accumulating into scale, and loosens old scale, allowing it to gradually fall off. At the same time, the special corrosion inhibitors work synergistically with other corrosion inhibitors to effectively control pitting corrosion of stainless steel, thereby preventing scale formation and fundamentally reducing the efficiency of corrosion prevention and scale inhibition.

[0032] The composite phosphorus-free scale inhibitor provided by this invention is a clarified concentrate. After using the above-mentioned scale inhibitor, the amount of scale inhibitor and slow-release agent used can be effectively reduced without affecting the treatment effect, which greatly saves costs. Moreover, the copolymer and water-soluble inorganic zinc salt contained in this formula can also work synergistically to reduce operating costs. At the same time, this formula is a phosphorus-free system formula, which avoids eutrophication of the receiving water body caused by the addition of phosphorus.

[0033] By adding a compound phosphorus-free scale inhibitor to the circulating cooling water, the corrosion, scaling, and sludge formation caused by the circulating cooling water can be effectively controlled, ensuring the normal operation of the equipment and saving water. This reduces the impact of scaling, corrosion, and sludge formation on the heat exchange efficiency of the heat exchange equipment and extends its service life.

[0034] The present invention also provides a method for preparing a composite phosphorus-free scale inhibitor, comprising the following steps:

[0035] A. Mix 400-600 parts by weight of deionized water with 1-3 parts by weight of modified lignin sulfonate, stir evenly, and filter through a 200-mesh filter cloth to obtain liquid A.

[0036] B. Mix 400-600 parts by weight of deionized water with 2-4 parts by weight of calcium magnesium acetate, stir well to obtain liquid B;

[0037] C. Mix 0.5 to 1.5 parts by weight of azole with 400 to 600 parts by weight of water-soluble inorganic zinc salt and heat to 50 degrees Celsius. Then add 50 to 150 parts by weight of copolymer A and mix. Stir until homogeneous to obtain liquid C. Preferably, the azole is benzotriazole or sodium dodecylbenzenesulfonate.

[0038] D. Mix liquid C with liquid B, stir until homogeneous, then add liquid A, mix until homogeneous, and filter to obtain a composite phosphorus-free scale inhibitor.

[0039] Since the aforementioned phosphorus-free scale inhibitor needs to form a clear and transparent concentrated liquid complex to function, it needs to be divided into liquid A, liquid B, and liquid C. Only after the different substances are distributed, mixed, and complexed can a special clear and transparent concentrated liquid complex structure be formed. If it is not divided into three liquids, liquid A, liquid B, and liquid C, it is difficult to form a complex structure.

[0040] More preferably, the preparation method of the composite phosphorus-free scale inhibitor includes the following steps:

[0041] A. Mix 500 parts by weight of water with 2 parts by weight of modified lignin sulfonate, stir evenly, and filter through a 200-mesh filter cloth to obtain liquid A.

[0042] B. Mix 500 parts by weight of deionized water with 3 parts by weight of calcium magnesium acetate, stir well, and obtain liquid B.

[0043] C. Mix 1 part by weight of azole with 500 parts by weight of water-soluble inorganic zinc salt and heat to 50 degrees Celsius. Then add 100 parts by weight of copolymer A and mix. Stir until homogeneous to obtain liquid C.

[0044] D. Mix liquid C with liquid B, stir until homogeneous, then add liquid A, mix until homogeneous, and filter to obtain a composite phosphorus-free scale inhibitor.

[0045] Example 1

[0046] A. Mix 1 ton of demineralized water with 4 kg of modified lignin sulfonate evenly, filter through a 200-mesh filter cloth to obtain liquid A. Separately, stir 1 ton of water and 6 kg of calcium magnesium acetate evenly to obtain liquid B.

[0047] B. Mix 2 kg of benzotriazole (a type of azole) with 1 ton of water-soluble inorganic zinc salt and heat to 50 degrees Celsius. Then add 200 kg of copolymer acrylic acid-2-acrylamide-2-methylbenzenesulfonic acid multi-component copolymer and 2-acrylamide-2-methylpropylsulfonic acid and mix. Stir until homogeneous to obtain liquid C.

[0048] C. Mix liquid C with liquid B, then add liquid A, mix thoroughly, and filter to obtain a composite phosphorus-free scale inhibitor.

[0049] Example 2

[0050] A. Mix 1 ton of demineralized water with 2.5 kg of modified lignin sulfonate evenly, filter through a 200-mesh filter cloth to obtain liquid A. In addition, stir 1 ton of demineralized water with 5 kg of calcium magnesium acetate evenly to obtain liquid B.

[0051] B. Mix 1.25 kg of benzotriazole (a type of azole) with 1 ton of water-soluble inorganic zinc salt and heat to 50 degrees Celsius. Then add 500 kg of acrylic acid-acrylate-sulfonate copolymer and mix thoroughly to obtain liquid C. C. Mix liquid C with liquid B, then add liquid A, mix thoroughly, and filter to obtain a composite phosphorus-free scale inhibitor.

[0052] Example 3

[0053] A. Mix 1 ton of demineralized water with 5 kg of modified lignin sulfonate evenly, and filter through a 200-mesh filter cloth to obtain liquid A. Separately, stir 1 ton of water and 6.6 kg of calcium magnesium acetate evenly to obtain liquid B.

[0054] B. Mix 3 kg of benzotriazole (a type of azole) with 1 ton of water-soluble inorganic zinc salt and heat to 50 degrees Celsius. Then add 250 kg of copolymers 2-acrylamide-2-methylpropylsulfonic acid copolymer and acrylic acid-acrylate-sulfonate copolymer and mix and stir evenly to obtain liquid C. Mix 250 kg of copolymer A to obtain liquid C.

[0055] C. Mix liquid C with liquid B, then add liquid A, mix thoroughly, and filter to obtain a composite phosphorus-free scale inhibitor.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of the present invention or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the scope of the technical solutions claimed in the present invention.

Claims

1. A composite phosphorus-free scale inhibitor, characterized in that: The mixture comprises 800-1200 parts by weight of demineralized water, 1-3 parts by weight of modified lignin sulfonate, 2-4 parts by weight of calcium magnesium acetate, 0.5-1.5 parts by weight of azoles, 400-600 parts by weight of water-soluble inorganic zinc salt, and 50-150 parts by weight of copolymer A, wherein copolymer A comprises one or two of acrylic acid-2-acrylamide-2-methylbenzenesulfonic acid multi-component copolymer, 2-acrylamide-2-methylpropylsulfonic acid copolymer, and acrylic acid-acrylate-sulfonate copolymer. The process involves mixing demineralized water with modified lignin sulfonate to obtain liquid A; mixing demineralized water with calcium magnesium acetate to obtain liquid B; mixing azoles with water-soluble inorganic zinc salts and heating the mixture before adding copolymer A to obtain liquid C; mixing liquid C with liquid B, stirring until homogeneous, then adding liquid A, mixing until homogeneous, and finally filtering to form a clarified concentrated complex, thus obtaining a composite phosphorus-free scale inhibitor.

2. The composite phosphorus-free scale inhibitor according to claim 1, characterized in that: The azole is benzotriazole.

3. The composite phosphorus-free scale inhibitor according to claim 2, characterized in that: It includes 1000 parts by weight of demineralized water, 2 parts by weight of modified lignin sulfonate, 3 parts by weight of calcium magnesium acetate, 1 part by weight of azoles, 500 parts by weight of water-soluble inorganic zinc salt, and 100 parts by weight of copolymer A.

4. A method for preparing the composite phosphorus-free scale inhibitor as described in any one of claims 1 to 3, characterized in that: Includes the following steps: A. Mix 400-600 parts by weight of deionized water with 1-3 parts by weight of modified lignin sulfonate, and filter through a 200-mesh filter cloth to obtain liquid A; B. Mix 400-600 parts by weight of deionized water with 2-4 parts by weight of calcium magnesium acetate, stir well to obtain liquid B; C. Mix 0.5-1.5 parts by weight of azoles with 400-600 parts by weight of water-soluble inorganic zinc salt and heat to 50 degrees Celsius. Then add 50-150 parts by weight of copolymer A and mix and stir evenly to obtain liquid C. D. Mix liquid C with liquid B, stir evenly, then add liquid A, mix evenly, and filter to form a clear concentrated liquid complex, thus obtaining a composite phosphorus-free scale inhibitor.

5. The method for preparing the composite phosphorus-free scale inhibitor according to claim 4, characterized in that: The azole is benzotriazole.

6. The method for preparing the composite phosphorus-free scale inhibitor according to claim 4, characterized in that: Includes the following steps: A. Mix 500 parts by weight of demineralized water with 2 parts by weight of modified lignin sulfonate, and filter through a 200-mesh filter cloth to obtain liquid A. B. Mix 500 parts by weight of deionized water with 3 parts by weight of calcium magnesium acetate, stir well, and obtain liquid B. C. Mix 1 part by weight of azole with 500 parts by weight of water-soluble inorganic zinc salt and heat to 50 degrees Celsius. Then add 100 parts by weight of copolymer A and mix and stir evenly to obtain liquid C. D. Mix liquid C with liquid B, stir evenly, then add liquid A, mix evenly, and filter to form a clear concentrated liquid complex, thus obtaining a composite phosphorus-free scale inhibitor.