阅读说明：本技术 一种循环冷却水用氯化锌复配缓蚀剂及其制备方法 (Zinc chloride compound corrosion inhibitor for circulating cooling water and preparation method thereof ) 是由 刘冬奇 刘叶姝 张炳 张华� 张荣娣 于 2021-08-26 设计创作，主要内容包括：本申请涉及缓蚀剂材料领域,具体公开了一种循环冷却水用氯化锌复配缓蚀剂及其制备方法,一种循环冷却水用氯化锌复配缓蚀剂包括缓释预膜液和缓释封闭液,所述缓释预膜液和所述缓释封闭液质量比为1：2～3,所述缓释预膜液包括下列重量份物质组成：0.5～1.0份氯化锌、6～8份壳聚糖、80～100份去离子水、所述缓释封闭液包括含硅化合物水溶液,所述含硅化合物水溶液中含硅化合物浓度为10～15％。其制备方法的制备步骤包括：S1、缓释预膜液制备；S2、缓释封闭液制备；S3、缓蚀剂复配。本申请的循环冷却水用氯化锌复配缓蚀剂,有效改善现有氯化锌缓蚀剂材料缓蚀效果差,缓蚀耐久性不佳的缺陷。(The application relates to the field of corrosion inhibitor materials, and particularly discloses a zinc chloride compound corrosion inhibitor for circulating cooling water and a preparation method thereof, wherein the zinc chloride compound corrosion inhibitor for circulating cooling water comprises a slow-release pre-filming liquid and a slow-release confining liquid, and the mass ratio of the slow-release pre-filming liquid to the slow-release confining liquid is 1: 2-3, wherein the slow-release pre-membrane liquid comprises the following substances in parts by weight: 0.5-1.0 part of zinc chloride, 6-8 parts of chitosan, 80-100 parts of deionized water, wherein the slow-release sealing liquid comprises a silicon-containing compound aqueous solution, and the concentration of the silicon-containing compound in the silicon-containing compound aqueous solution is 10-15%. The preparation method comprises the following preparation steps: s1, preparing a slow-release pre-film solution; s2, preparing a slow-release confining liquid; s3 and corrosion inhibitor. The zinc chloride compound corrosion inhibitor for circulating cooling water effectively overcomes the defects of poor corrosion inhibition effect and poor corrosion inhibition durability of the existing zinc chloride corrosion inhibitor material.)

1. The zinc chloride compound corrosion inhibitor for circulating cooling water is characterized by comprising a slow-release pre-filming liquid and a slow-release confining liquid, wherein the mass ratio of the slow-release pre-filming liquid to the slow-release confining liquid is 1: 2-3, wherein the slow-release pre-membrane liquid comprises the following substances in parts by weight:

0.5-1.0 part of zinc chloride;

6-8 parts of chitosan;

80-100 parts of deionized water;

the slow-release confining liquid comprises a silicon-containing compound aqueous solution, and the concentration of the silicon-containing compound in the silicon-containing compound aqueous solution is 10-15%.

2. The zinc chloride compound corrosion inhibitor for circulating cooling water according to claim 1, wherein the slow-release pre-membrane solution further comprises 3-5 parts by weight of a dibasic acid.

3. The zinc chloride compound corrosion inhibitor for circulating cooling water as claimed in claim 2, wherein the dibasic acid comprises any one of oxalic acid and selenic acid.

4. The zinc chloride compound corrosion inhibitor for circulating cooling water according to claim 1, wherein the slow-release pre-membrane solution further comprises 8-10 parts by weight of an organic phosphate compound.

5. The zinc chloride compound corrosion inhibitor for circulating cooling water of claim 4, wherein the organic phosphate compound comprises chitosan phosphate.

6. The zinc chloride compound corrosion inhibitor for circulating cooling water according to claim 5, wherein the chitosan phosphate is prepared by adopting the following scheme:

(1) stirring and mixing chitosan and deionized water to prepare a chitosan solution with the mass fraction of 10%, adding a phosphoric acid solution and a formaldehyde solution into the chitosan solution according to the mass ratio of 1: 2-3: 3-5, stirring and mixing, keeping the temperature, heating for reaction, standing and cooling to obtain a mixed solution;

(2) adding the mixed solution into absolute ethyl alcohol according to the mass ratio of 1:5, stirring and mixing, standing and aging for 6-8 h, filtering to obtain a filter cake, washing and drying, and grinding to obtain the chitosan phosphate particles.

7. The zinc chloride compound corrosion inhibitor for circulating cooling water of claim 1, wherein the aqueous solution of the silicon-containing compound is an aqueous solution of sodium silicate.

8. The preparation method of the zinc chloride compound corrosion inhibitor for circulating cooling water according to any one of claims 1 to 7, which is characterized by comprising the following specific preparation steps:

s1, preparing a slow-release pre-film solution: stirring and mixing zinc chloride, chitosan, deionized water, dibasic acid and chitosan phosphate according to a formula, standing at room temperature for 6-8 hours, homogenizing and filtering, and collecting filtrate to obtain a slow-release pre-membrane solution;

s2, preparing a slow-release confining liquid: adding sodium silicate into deionized water according to a formula, stirring, mixing and rotationally evaporating until the mass fraction of the slow-release pre-membrane solution is 10-15%, and preparing to obtain a slow-release confining solution;

s3, corrosion inhibitor compounding: and adding the slow-release confining liquid into the slow-release pre-membrane liquid, stirring, mixing, performing ultrasonic dispersion, standing at room temperature for swelling, homogenizing, and screening with a screen of 500-1000 meshes to obtain the zinc chloride compound corrosion inhibitor for circulating cooling water.

Technical Field

The application relates to the field of corrosion inhibitor materials, in particular to a zinc chloride compound corrosion inhibitor for circulating cooling water and a preparation method thereof.

Background

The circulating water system has an important status in industrial production, and is mainly used for cooling in the production process, so that a process medium is cooled, the process requirement is met, the circulating water control significance is more important, and when the circulating water system has the problems of deposition, scaling and the like, the circulation system is like hardening or blocking of agglomeration, and cannot be unblocked; if the circulating water system has corrosion problems, such as the blood vessel is damaged, the circulating water system is easy to break. These obstacles are sufficient to bring a plant to a complete standstill and even to suffer serious losses. Therefore, the circulating water system is a life line in industrial production and is a key control point, and because the circulating water is a key control point for production and operation of companies, corrosion inhibition treatment by adopting a corrosion inhibitor is necessary.

The corrosion inhibitor is a chemical substance capable of effectively preventing metal corrosion, and is a chemical substance capable of achieving the effect of resisting metal corrosion only by adding a very small amount of the corrosion inhibitor. Its advantages are low consumption (only 0.1-1%), and high corrosion-retarding effect. Moreover, it does not change the properties of the metal and does not affect the corrosion system. In cooling water systems, zinc salts are the most commonly used corrosion inhibitors of the cathodic type, and zinc ions play a role. Zinc ions at the cathode site, due to the increase in pH, rapidly form Zn (OH)₂Deposited on the surface of the cathode and acts as a protective film.

However, in the use process of the existing zinc chloride corrosion inhibitor material, although the zinc salt forms a film relatively quickly, the film is not durable, and when the pH value of circulating water is more than 8.3, zinc ions tend to precipitate, so the concentration addition amount of the zinc ions cannot be too high, thereby influencing the corrosion inhibition effect of the zinc ion zinc chloride corrosion inhibitor material.

Disclosure of Invention

In order to overcome the defects of poor corrosion inhibition effect and poor corrosion inhibition durability of the conventional zinc chloride corrosion inhibitor material, the application provides a zinc chloride compound corrosion inhibitor for circulating cooling water and a preparation method thereof, and the following technical scheme is adopted:

in a first aspect, the application provides a zinc chloride compound corrosion inhibitor for circulating cooling water, which adopts the following technical scheme:

the zinc chloride compound corrosion inhibitor for circulating cooling water comprises a slow-release pre-filming liquid and a slow-release confining liquid, wherein the mass ratio of the slow-release pre-filming liquid to the slow-release confining liquid is 1: 2-3, wherein the slow-release pre-membrane liquid comprises the following substances in parts by weight: 0.5-1.0 part of zinc chloride, 6-8 parts of chitosan, 80-100 parts of deionized water, wherein the slow-release sealing liquid comprises a silicon-containing compound aqueous solution, and the concentration of the silicon-containing compound in the silicon-containing compound aqueous solution is 10-15%.

By adopting the technical scheme, the slow-release pre-membrane solution and the slow-release confining liquid are adopted to perform synergistic action, and as zinc ions in zinc chloride are at the cathode part, when the pH value of cooling water rises, the zinc ions are combined with hydroxide ions to quickly form Zn (OH)₂The slow-release preservative film is deposited on the surface of a cathode, so that the chitosan loaded with zinc chloride in the slow-release pre-film solution is quickly released, after the slow-release pre-film solution acts, the silicon-containing compound in the silicon-containing compound aqueous solution in the slow-release confining liquid is used as an anode inhibition type corrosion inhibitor, and the formation of a protective film is promoted through divalent ions, so that the corrosion resistance of a corrosion inhibition film formed by the slow-release pre-film solution is further improved, and the defects of poor corrosion inhibition effect and poor corrosion inhibition durability of a zinc chloride corrosion inhibitor material are effectively overcome.

Further, the slow-release pre-membrane liquid also comprises 3-5 parts by weight of dibasic acid.

By adopting the technical scheme, the binary acid is added into the slow-release pre-membrane liquid for modification treatment, and the binary acid is combined with zinc ions and has a complexing effect, so that the corrosion inhibition synergistic effect in the slow-release pre-membrane liquid is improved, at the moment, the zinc ions mainly exist in a complexing ion form, so that the formed complexing film stably exists in cooling water, the quality of film formation in the slow-release pre-membrane liquid is effectively ensured, the adverse effect of ions in low pH (potential of hydrogen) in water on the formation of a corrosion inhibition film is avoided, the problem that the stability of the slow-release film is reduced due to the existence of high-hardness water bicarbonate ions is solved, and the corrosion inhibition durability of the zinc chloride corrosion inhibitor material is further improved.

Further, the dibasic acid includes any one of oxalic acid and selenic acid.

By adopting the technical scheme, the type of the used binary acid is optimized, and the corrosion inhibition synergistic effect between the binary acid and zinc ions is further improved, so that the corrosion inhibition durability of the zinc chloride corrosion inhibitor material is further improved.

Further, the slow-release pre-membrane liquid also comprises 8-10 parts by weight of an organic phosphate compound.

By adopting the technical scheme, the organic phosphate compound is added into the slow-release membrane preparation liquid, and the organic phosphate compound is an ester derivative of phosphoric acid and belongs to a class of phosphoric acid derivatives. The phosphate ester molecules have the advantages of low toxicity, low irritation, good biodegradability, good electrochemical stability, low surface tension, good wettability, good emulsification dispersibility and the like, particularly, hetero atoms in the phosphate ester molecules can be used as adsorption centers to be adsorbed on the metal surface, so that a good corrosion inhibition effect is achieved, and when the phosphate ester compound is used, hydrocarbon groups of the phosphate ester compound can promote the compactness and stability of a film formed by the slow-release pre-membrane solution through the interaction of van der Waals forces among molecules, so that the defects of poor corrosion inhibition effect and poor corrosion inhibition durability of the zinc chloride corrosion inhibitor material are further overcome.

Further, the organic phosphate compound includes chitosan phosphate.

By adopting the technical scheme, the prepared chitosan phosphate ester molecules contain amino (-NH) through the phosphorylation modification treatment of the chitosan molecules₂) Hydroxyl (-OH) and phosphate (-H)₂PO₄) The structural strength of a protective film formed by the corrosion inhibition pre-film liquid can be improved. Meanwhile, the chitosan phosphate molecules have good corrosion inhibition effect, so that the defects of poor corrosion inhibition effect and poor corrosion inhibition durability of the zinc chloride corrosion inhibitor material are further overcome.

Further, the chitosan phosphate is prepared by adopting the following scheme:

(1) stirring and mixing chitosan and deionized water to prepare a chitosan solution with the mass fraction of 10%, adding a phosphoric acid solution and a formaldehyde solution into the chitosan solution according to the mass ratio of 1: 2-3: 3-5, stirring and mixing, keeping the temperature, heating for reaction, standing and cooling to obtain a mixed solution;

(2) adding the mixed solution into absolute ethyl alcohol according to the mass ratio of 1:5, stirring and mixing, standing and aging for 6-8 h, filtering to obtain a filter cake, washing and drying, and grinding to obtain the chitosan phosphate particles.

By adopting the technical scheme, chitosan is used as a matrix and is subjected to phosphorylation treatment, free amino groups are in the structure of the chitosan and are easy to combine with hydrogen ions in a medium under an acidic condition, molecules become colloid macromolecules with positive charges, the chitin colloid molecules absorb and block a cathode process under the action of static electricity to form a cathode type corrosion inhibitor, and after the secondary phosphorylation modification, a phosphate compound has a good corrosion inhibition effect, so that the defects of poor corrosion inhibition effect and poor corrosion inhibition durability of a zinc chloride corrosion inhibitor material are further overcome.

Further, the aqueous solution of the silicon-containing compound is an aqueous sodium silicate solution.

By adopting the technical scheme, the sodium silicate aqueous solution is preferably used as the aqueous solution of the silicon-containing compound, and NA in the sodium silicate is dissolved by the sodium silicate in water₂O in water to form sodium hydroxide, OH^-With Zn²⁺The combination inhibits the proceeding of cathode reaction, thereby further improving the corrosion inhibition durability of the zinc chloride corrosion inhibitor material.

In a second aspect, the application provides a preparation method of a zinc chloride compound corrosion inhibitor for circulating cooling water, which adopts the following technical scheme:

a preparation method of zinc chloride compound corrosion inhibitor for circulating cooling water comprises the following specific preparation steps:

s1, preparing a slow-release pre-film solution: stirring and mixing zinc chloride, chitosan, deionized water, dibasic acid and chitosan phosphate according to a formula, standing at room temperature for 6-8 hours, homogenizing and filtering, and collecting filtrate to obtain a slow-release pre-membrane solution;

s2, preparing a slow-release confining liquid: adding sodium silicate into deionized water according to a formula, stirring, mixing and rotationally evaporating until the mass fraction of the slow-release pre-membrane solution is 10-15%, and preparing to obtain a slow-release confining solution;

s3, corrosion inhibitor compounding: and adding the slow-release confining liquid into the slow-release pre-membrane liquid, stirring, mixing, performing ultrasonic dispersion, standing at room temperature for swelling, homogenizing, and screening with a screen of 500-1000 meshes to obtain the zinc chloride compound corrosion inhibitor for circulating cooling water.

By adopting the technical scheme, the slow-release pre-filming liquid and the slow-release confining liquid are respectively prepared, and finally, the gel material is uniformly and stably formed through swelling treatment after mixing, the prepared gel corrosion inhibitor material has more excellent corrosion inhibition effect, and the formed corrosion inhibition coating film can further improve the corrosion inhibition durability of the zinc chloride corrosion inhibitor material.

In summary, the present application includes at least one of the following beneficial technical effects:

firstly, the slow-release pre-membrane solution and the slow-release confining liquid are adopted to perform a synergistic effect, zinc ions in zinc chloride are at a cathode part, and Zn (OH) 2 is rapidly formed and deposited on the surface of a cathode due to the increase of pH, so that chitosan loaded with zinc chloride in the slow-release pre-membrane solution is rapidly released, after the slow-release pre-membrane solution acts, a silicon-containing compound in a silicon-containing compound aqueous solution in the slow-release confining liquid is used as an anode inhibition type corrosion inhibitor, and the formation of a protective membrane is promoted through divalent ions, so that the corrosion resistance of a corrosion inhibition membrane formed by the slow-release pre-membrane solution is further improved, and the defects of poor corrosion inhibition effect and poor corrosion inhibition durability of a zinc chloride corrosion inhibitor material are effectively overcome.

Secondly, the binary acid is added into the slow-release pre-membrane solution for modification treatment, and the binary acid is combined with zinc ions and generates a complexing effect, so that the corrosion inhibition synergistic effect in the slow-release pre-membrane solution is improved, at the moment, the zinc ions mainly exist in a complexing ion form, so that the formed complexing film stably exists in cooling water, the quality of a formed film in the slow-release pre-membrane solution is effectively ensured, the adverse effect of ions in low pH (potential of hydrogen) in water on the formation of a corrosion inhibition film is avoided, the problem that the stability of the slow-release film is reduced due to the existence of high-hardness bicarbonate ions is solved, and the corrosion inhibition durability of the zinc chloride corrosion inhibitor material is further improved.

Thirdly, an organic phosphate compound is added into the slow-release membrane preparation liquid, and the organic phosphate compound is an ester derivative of phosphoric acid and belongs to the class of phosphoric acid derivatives. The phosphate ester molecules have the advantages of low toxicity, low irritation, good biodegradability, good electrochemical stability, low surface tension, good wettability, good emulsification dispersibility and the like, particularly, hetero atoms in the phosphate ester molecules can be used as adsorption centers to be adsorbed on the metal surface, so that a good corrosion inhibition effect is achieved, and when the phosphate ester compound is used, hydrocarbon groups of the phosphate ester compound can promote the compactness and stability of a film formed by the slow-release pre-membrane solution through the interaction of van der Waals forces among molecules, so that the defects of poor corrosion inhibition effect and poor corrosion inhibition durability of the zinc chloride corrosion inhibitor material are further overcome.

Fourthly, the slow-release pre-filming liquid and the slow-release confining liquid are respectively prepared, and finally, the gel material is uniformly and stably formed through swelling treatment after mixing, the corrosion inhibition effect of the prepared gel corrosion inhibitor material is more excellent, and the corrosion inhibition durability of the zinc chloride corrosion inhibitor material can be further improved through the formed corrosion inhibition coating film.

Detailed Description

The present application will be described in further detail with reference to examples and comparative examples.

The starting materials for the preparation examples, examples and comparative examples of the present application are commercially available unless otherwise specified.

Preparation of chitosan phosphate

Preparation example 1

(1) Taking 0.1kg of chitosan and 10kg of deionized water, stirring and mixing to prepare a chitosan solution with the mass fraction of 10%, adding 0.1kg of phosphoric acid solution with the mass fraction of 10% and 0.2kg of formaldehyde solution with the mass fraction of 10% into 0.3kg of chitosan solution with the mass fraction of 10%, stirring and mixing, and carrying out heat preservation reaction at 55 ℃ for 3 hours to obtain a mixed solution;

(2) adding 0.3kg of mixed solution into 1.5kg of absolute ethyl alcohol, stirring and mixing at 250r/min, standing and aging for 6h, filtering to obtain a filter cake, respectively and sequentially washing the filter cake for 3 times by respectively adopting the absolute ethyl alcohol, acetone and diethyl ether, drying and grinding in a 55 ℃ drying oven after washing is finished, and sieving by a 1000-mesh sieve to obtain the chitosan phosphate particles 1.

Preparation example 2

(1) Taking 0.1kg of chitosan and 10kg of deionized water, stirring and mixing to prepare a chitosan solution with the mass fraction of 10%, adding 0.1kg of phosphoric acid solution with the mass fraction of 10% and 0.25kg of formaldehyde solution with the mass fraction of 10% into 0.4kg of chitosan solution with the mass fraction of 10%, stirring and mixing, and carrying out heat preservation reaction at 57 ℃ for 4 hours to obtain a mixed solution;

(2) adding 0.3kg of mixed solution into 1.5kg of absolute ethyl alcohol, stirring and mixing at 275r/min, standing and aging for 7h, filtering to obtain a filter cake, respectively and sequentially washing the filter cake for 3 times by respectively adopting the absolute ethyl alcohol, acetone and diethyl ether, drying and grinding in an oven at 55 ℃ after washing is finished, and sieving by a 1000-mesh sieve to obtain the chitosan phosphate particles 2.

Preparation example 3

(1) Taking 0.1kg of chitosan and 10kg of deionized water, stirring and mixing to prepare a chitosan solution with the mass fraction of 10%, adding 0.1kg of phosphoric acid solution with the mass fraction of 10% and 0.3kg of formaldehyde solution with the mass fraction of 10% into 0.5kg of chitosan solution with the mass fraction of 10%, stirring and mixing, and then carrying out heat preservation reaction for 5 hours at the temperature of 60 ℃ to obtain a mixed solution;

(2) adding 0.3kg of mixed solution into 1.5kg of absolute ethyl alcohol, stirring and mixing at 300r/min, standing and aging for 8h, filtering to obtain a filter cake, respectively and sequentially washing the filter cake for 3 times by respectively adopting the absolute ethyl alcohol, acetone and diethyl ether, drying and grinding in an oven at 55 ℃ after washing is finished, and sieving by a 1000-mesh sieve to obtain the chitosan phosphate particles 3.

Examples

Example 1

S1, preparing a slow-release pre-film solution: mixing 0.5kg of zinc chloride, 6kg of chitosan and 80kg of deionized water under stirring, standing at room temperature for 6 hours, homogenizing at 4500r/min, filtering, and collecting filtrate to obtain slow-release pre-membrane solution;

s2, preparing a slow-release confining liquid: adding 1kg of sodium silicate into 10kg of deionized water, stirring and mixing, rotationally evaporating at 45 ℃, and preparing the slow-release confining liquid after rotationally evaporating until the mass fraction of the sodium silicate in the rotary evaporation liquid is 10%;

s3, corrosion inhibitor compounding: adding 1kg of slow-release confining liquid into 2kg of slow-release pre-membrane liquid, stirring, mixing, placing under 200W for ultrasonic dispersion for 10min, standing at room temperature for swelling for 24h, homogenizing at 4500r/min, and sieving with a 500-mesh sieve to obtain the zinc chloride compound corrosion inhibitor for circulating cooling water.

Example 2

S1, preparing a slow-release pre-film solution: mixing 0.75kg of zinc chloride, 7kg of chitosan and 90kg of deionized water under stirring, standing at room temperature for 7 hours, homogenizing at 5200r/min, filtering, and collecting filtrate to obtain slow-release pre-membrane solution;

s2, preparing a slow-release confining liquid: adding 1.5kg of sodium silicate into 10kg of deionized water, stirring and mixing, rotationally evaporating at 47 ℃, and preparing a slow-release confining liquid after rotationally evaporating until the mass fraction of sodium silicate in a rotary evaporation liquid is 12%;

s3, corrosion inhibitor compounding: adding 1kg of slow-release confining liquid into 2.5kg of slow-release pre-membrane liquid, stirring and mixing, placing under 250W for ultrasonic dispersion for 12min, standing and swelling at room temperature for 24h, homogenizing at 5200r/min, and sieving with a 750-mesh sieve to obtain the zinc chloride compound corrosion inhibitor for circulating cooling water.

Example 3

S1, preparing a slow-release pre-film solution: mixing 1.0kg of zinc chloride, 8kg of chitosan and 100kg of deionized water under stirring, standing at room temperature for 8 hours, homogenizing at 6000r/min, filtering, and collecting filtrate to obtain a slow-release pre-membrane solution;

s2, preparing a slow-release confining liquid: adding 2kg of sodium silicate into 10kg of deionized water, stirring and mixing, rotationally evaporating at 50 ℃, and preparing the slow-release confining liquid after rotationally evaporating until the mass fraction of the sodium silicate in the rotary evaporation liquid is 15%;

s3, corrosion inhibitor compounding: adding 1kg of slow-release confining liquid into 3kg of slow-release pre-membrane liquid, stirring, mixing, placing under 300W for ultrasonic dispersion for 15min, standing at room temperature for swelling for 24h, homogenizing at 6000r/min, and sieving with a 1000-mesh sieve to obtain the zinc chloride compound corrosion inhibitor for circulating cooling water.

Example 4: the preparation method of the zinc chloride compound corrosion inhibitor for circulating cooling water is different from the preparation method of the embodiment 1 in that 3kg of oxalic acid solution with the mass fraction of 1% is added into the slow-release pre-membrane liquid, and the rest preparation steps and preparation environment are the same as those of the embodiment 1.

Example 5: the preparation method of the zinc chloride compound corrosion inhibitor for circulating cooling water is different from the preparation method of the embodiment 1 in that 4kg of oxalic acid solution with the mass fraction of 1% is added into the slow-release pre-membrane liquid, and the rest preparation steps and preparation environment are the same as those of the embodiment 1.

Example 6: the preparation method of the zinc chloride compound corrosion inhibitor for circulating cooling water is different from the preparation method of the embodiment 1 in that 5kg of oxalic acid solution with the mass fraction of 1% is added into the slow-release pre-membrane liquid, and the rest preparation steps and preparation environment are the same as those of the embodiment 1.

Example 7: the preparation method of the zinc chloride compound corrosion inhibitor for circulating cooling water is different from that of the embodiment 1 in that 3kg of selenic acid solution with the mass fraction of 1% is added into the slow-release pre-membrane liquid, and the rest preparation steps and preparation environments are the same as those of the embodiment 1.

Example 8: the preparation method of the zinc chloride compound corrosion inhibitor for circulating cooling water is different from the preparation method of the embodiment 4 in that 8kg of chitosan phosphate 1 is also added into the slow-release pre-membrane liquid, and the rest preparation steps and preparation environment are the same as those of the embodiment 1.

Example 9: the preparation method of the zinc chloride compound corrosion inhibitor for circulating cooling water is different from the preparation method of the embodiment 4 in that 9kg of chitosan phosphate 2 is also added into the slow-release pre-membrane liquid, and the rest preparation steps and preparation environment are the same as those of the embodiment 1.

Example 10: the preparation method of the zinc chloride compound corrosion inhibitor for circulating cooling water is different from the preparation method of the embodiment 4 in that 10kg of chitosan phosphate 3 is also added into the slow-release pre-membrane liquid, and the rest preparation steps and preparation environment are the same as those of the embodiment 1.

Comparative example

Comparative example 1: the preparation method of the zinc chloride compound corrosion inhibitor for circulating cooling water is different from that of the example 1 in that no slow-release confining liquid is arranged in the comparative example 1, and the other preparation schemes and material compositions are the same as those in the example 1.

Comparative example 2: the preparation method of the zinc chloride compound corrosion inhibitor for circulating cooling water is different from the preparation method of the example 1 in that 0.5kg of aluminum chloride is adopted to replace the zinc chloride in the example 1 in the comparative example 2, and the rest preparation schemes and material compositions are the same as the example 1.

Comparative example 3: a preparation method of a zinc chloride compound corrosion inhibitor for circulating cooling water is different from that of example 4 in that 3kg of hydrochloric acid with the mass fraction of 1% is adopted in comparative example 3 to replace oxalic acid in example 4, and the rest preparation schemes and material compositions are the same as those in example 4.

Comparative example 4: the preparation method of the zinc chloride compound corrosion inhibitor for circulating cooling water is different from the preparation method of the example 8 in that 8kg of carboxymethyl chitosan is adopted to replace chitosan phosphate in the example 8 in the comparative example 4, and the other preparation schemes and material compositions are the same as those in the example 8.

Performance test

The performance tests were performed on the zinc chloride compound corrosion inhibitors for circulating cooling water prepared in examples 1 to 10 and comparative examples 1 to 4, respectively.

Detection method/test method

(1) Adding 200mL of calcium chloride standard solution into 2.5L of water to make the amount of calcium ions be 1.2g, adding 50mL of circulating cooling water, zinc chloride compound corrosion inhibitor and 200mL of borax buffer solution, and finally slowly adding 200mL of sodium bicarbonate standard solution to make the amount of bicarbonate ions be 3.66g and simultaneously using the solution as a blank test solution;

(2) and (3) placing the sample solution and the blank test solution prepared by the method into a constant-temperature water bath kettle at the temperature of 80 ℃, and heating at the constant temperature for 10 hours. Cooling to room temperature, filtering, transferring 250mL of filtrate, adding water to about 800mL, adding 50mL of potassium hydroxide and 1g of calcium-carboxylic acid indicator, finally measuring the calcium ion concentration by using an EDTA standard solution, and titrating until the solution is changed from purple red to bright blue, namely the end point. The scale inhibition performance of the water treatment agent is represented by a scale inhibition rate ŋ 1, and the calculation formula is as follows: ŋ 1= (ρ 2 — ρ 1)/(ρ 0 — ρ 1). In the formula, rho 2 is the numerical value of the calcium ion concentration after the test of the test solution added with the water treatment agent, mg/mL; rho 1 is the numerical value of the calcium ion concentration after the test of the blank test solution without the water treatment agent, mg/mL; rho 0 is the value of the concentration of calcium ions in the prepared test solution before the experiment, mg/mL.

The specific detection results are shown in the following table 1:

TABLE 1 Corrosion inhibition performance test of zinc chloride compound corrosion inhibitor for circulating cooling water

Performance analysis was performed from table 1 above:

(1) it can be seen from table 1 in combination with examples 1 to 3 and from the experimental results of examples 1 to 3 in combination with comparative example 1 that, in examples 1 to 3, the slow-release pre-membrane solution and the slow-release confining liquid are used in a synergistic effect to realize rapid release of chitosan loaded with zinc chloride in the slow-release pre-membrane solution, and after the slow-release pre-membrane solution acts, a silicon-containing compound in a silicon-containing compound aqueous solution in the slow-release confining liquid is used as an anodic inhibition type corrosion inhibitor, and formation of a protective membrane is promoted by divalent ions, so that the corrosion resistance of a corrosion inhibition membrane formed by the slow-release pre-membrane solution is further improved.

And comparing examples 1-3 with comparative example 2, the corrosion resistance of the corrosion inhibition film formed by the slow-release pre-filming liquid can be further improved by the zinc chloride due to the comparison of the zinc chloride material adopted by the application and aluminum chloride.

(2) By combining and comparing the examples 4-6 with the comparative example 3, it can be seen that the technical scheme of the application adds the dibasic acid into the slow-release pre-membrane solution for modification treatment, and the dibasic acid is combined with the zinc ions and has a complexing effect, so that the corrosion inhibition synergistic effect in the slow-release pre-membrane solution is improved, at the moment, the zinc ions mainly exist in a complex ion form, so that the formed complex film stably exists in cooling water, the quality of the formed film in the slow-release pre-membrane solution is effectively ensured, the adverse effect of ions on the formation of the corrosion inhibition film in low pH in water is avoided, the problem that the stability of the slow-release film is reduced due to the existence of high-hardness bicarbonate ions is also solved, and the corrosion inhibition durability of the zinc chloride corrosion inhibitor material is further improved.

(3) The combination of examples 8-10 and comparative example 4 and the experimental data show that the chitosan phosphate prepared by the method contains amino (-NH) in the molecule through the phosphorylation modification treatment of the chitosan molecule₂) Hydroxyl (-OH) and phosphate (-H)₂PO₄) The structural strength of a protective film formed by the corrosion inhibition pre-film liquid can be improved. Meanwhile, the chitosan phosphate molecules have good corrosion inhibition effect, so that the defects of poor corrosion inhibition effect and poor corrosion inhibition durability of the zinc chloride corrosion inhibitor material are further overcome.

The present embodiment is only for explaining the present application, and it is not limited to the present application, and those skilled in the art can make modifications of the present embodiment without inventive contribution as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present application.