CN-121976195-A - Corrosion inhibition protective agent, preparation method thereof and application thereof in airtight reclaimed water system

Abstract

The invention discloses a corrosion inhibition protective agent, a preparation method thereof and application thereof in a closed reclaimed water system, and belongs to the technical field of industrial water treatment. The corrosion inhibition protective agent is prepared by taking 2,2' - ((1H-benzo [ d ] [1,2,3] triazole-1-yl) methyl) azodicarbonic acid as a core functional component and compounding a copper corrosion inhibition auxiliary agent and deionized water. The invention synthesizes the core functional components with corrosion inhibition and iron ion chelating dispersion through one-step aqueous phase Mannich condensation reaction, abandons the physical compounding mode in the prior art, has simple preparation process, easily obtained raw materials and high product conversion rate and purity. The product has no nitrite, no phosphorus and no molybdenum, has excellent high-temperature stability, can form a compact protective film on the surfaces of carbon steel and copper alloy, can realize high-efficiency corrosion inhibition by adding 80-150mg/L, and is suitable for a closed circulating cooling water system in the steel industry.

Inventors

• SUN HUI
• CAI YIMING
• HU ZHIREN
• TANG YU
• QU LIWEI
• WANG KUNPENG
• LI HONG
• ZHANG YU
• WANG XUE
• CHEN QI
• SUN LU

Assignees

• 鞍钢栗田(鞍山)水处理有限公司

Dates

Publication Date

20260505

Application Date

20260409

Claims (10)

1. 1. A corrosion inhibition protective agent is characterized by comprising the following components, by weight, 10-20 parts of 2,2' - ((1H-benzo [ d ] [1,2,3] triazol-1-yl) methyl) azodicarbonic acid, 0.1-0.5 part of copper corrosion inhibition auxiliary agent and 80-90 parts of deionized water; the chemical structural formula of the 2,2' - ((1H-benzo [ d ] [1,2,3] triazol-1-yl) methyl) azoxydiacetic acid is as follows: The preparation method comprises the following steps: (1) Adding sodium hydroxide into deionized water, controlling the temperature to be 30-40 ℃, and stirring until the sodium hydroxide is dissolved to obtain alkali liquor; (2) Adding benzotriazole and iminodiacetic acid into alkali liquor, stirring until the mixture is dissolved, dropwise adding 37wt% of formaldehyde aqueous solution for 1.5-3h, controlling the temperature of a system to be not more than 50 ℃ in the dropwise adding process, heating to 80-90 ℃ after the dropwise adding is completed, and reacting for 4-6h; (3) Cooling the reaction solution to room temperature, dropwise adding a dilute hydrochloric acid solution under stirring until the pH of the system is 1.5-2, standing for 1-2h, filtering the obtained precipitate, washing with a glacial acetic acid aqueous solution with pH=2, and drying to obtain a crude product; (4) Adding the crude product into deionized water, heating to 60-70 ℃, stirring until the crude product is dissolved, adding active carbon, stirring for 5-10min, filtering while the obtained filtrate is hot, cooling the obtained filtrate to room temperature, standing for 8-12H, filtering, collecting precipitated solid, and drying to obtain 2,2' - ((1H-benzo [ d ] [1,2,3] triazol-1-yl) methyl) azodiacetic acid.
2. 2. The corrosion inhibitor according to claim 1, wherein the copper corrosion inhibitor is methylbenzotriazole.
3. 3. The corrosion inhibition protector according to claim 1, wherein the mass concentration of sodium hydroxide in the alkali liquor in (1) is 10-15%.
4. 4. The corrosion inhibition protective agent according to claim 1, wherein the molar ratio of the benzotriazole to the iminodiacetic acid in the component (2) is 1:1.02-1.05, and the weight ratio of the benzotriazole, the alkali liquor and the 37wt% aqueous formaldehyde solution is 1:10-15:0.72-0.8.
5. 5. The corrosion inhibitor according to claim 1, wherein the concentration of the dilute hydrochloric acid solution in (3) is 1-5mol/L.
6. 6. The corrosion inhibition protector according to claim 1, wherein the weight ratio of the crude product, deionized water and activated carbon in (4) is 1:8-15:0.008-0.012.
7. 7. The method for preparing a corrosion inhibitor according to any one of claims 1 to 6, comprising the steps of: adding 2,2' - ((1H-benzo [ d ] [1,2,3] triazole-1-yl) methyl) azodicarbonic acid and copper corrosion inhibition auxiliary agent into deionized water, adding pH regulator under stirring, regulating pH of the system to 7.5-9.0, and continuously stirring until the solution is dissolved to obtain the corrosion inhibition protective agent.
8. 8. The method for preparing corrosion inhibitor according to claim 7, wherein the pH adjustor is one of sodium hydroxide or potassium hydroxide.
9. 9. The use of the corrosion inhibition protective agent according to any one of claims 1 to 6 in a closed reclaimed water system, wherein the closed reclaimed water system is a closed circulating cooling water system which takes soft water or desalted water as a medium and has an operation temperature of 40 to 120 ℃ in the steel industry, and the corrosion inhibition protective agent is added at a concentration of 80 to 150mg/L according to the water content of the system.
10. 10. The use of the corrosion inhibitor according to claim 9 in a closed reclaimed water system, wherein the equipment material of the closed reclaimed water system comprises at least one of carbon steel, brass and red copper.

Description

Corrosion inhibition protective agent, preparation method thereof and application thereof in airtight reclaimed water system Technical Field The invention relates to the technical field of industrial water treatment, in particular to a corrosion inhibition protective agent, a preparation method thereof and application thereof in a closed reclaimed water system. Background The steel industry is an important pillar industry for national economy development, and the closed circulating reclaimed water system is used as a cooling matching system of a core in a steel production flow, is widely applied to cooling of process equipment and hydraulic systems of key procedures such as a blast furnace, a converter, continuous casting, hot rolling and the like, and directly determines continuous and stable operation of a steel production main line. The closed circulating water system uses soft water and desalted water as cooling medium, so that the scaling risk in the running process of circulating water is fundamentally avoided, but the new industry pain point is brought, the water quality buffering capacity of the soft water and the desalted water is weak, the annual running temperature of the system is stabilized above 40 ℃, part of the high-temperature section is even more than 100 ℃, the core equipment material covers various metals such as carbon steel, brass, red copper and the like, and the natural passivation film on the metal surface is extremely easy to break under the water environment with high temperature, low hardness and low alkalinity, so that the electrochemical corrosion problem is particularly prominent. The corrosion not only can cause the thinning and perforation leakage of the pipe wall of the equipment, cause the unplanned shutdown of the production line and greatly improve the maintenance and replacement cost of the equipment, but also can deposit and form loose corrosion product scale on the surface of the equipment, form anoxic local corrosion environment under the scale, cause more serious local corrosion such as pitting corrosion, crevice corrosion and the like, and become a core difficult problem for restricting the long-period, safe and stable operation of a closed circulating water system in the steel industry. Aiming at the corrosion prevention and control requirements of a closed circulating water system, the most mainstream and most economical technical means in the industry at present is a chemical corrosion inhibitor adding technology, and a plurality of relatively mature corrosion inhibitor formula systems are formed in the industry after decades of technical development, and are widely applied to industrial sites. The nitrite compound formula system is a mainstream scheme with highest application proportion in the steel industry at present, a compact passivation film is formed on the surfaces of carbon steel and copper alloy through the oxidation of nitrite, the corrosion inhibition effect is remarkable, the corrosion inhibition effect can be achieved without depending on dissolved oxygen in water, the corrosion inhibition effect is perfectly adapted to the low-oxygen operation environment of a closed system, the molybdate and tungstate compound formula system is used as an environment-friendly alternative scheme, corrosion inhibition is achieved through forming a metal oxide passivation film on the surface of metal, toxicity is far lower than that of nitrite, the corrosion inhibition effect is achieved in a part of environment-friendly severe scenes, the phosphorus compound formula system adopts organic phosphonic acid and polyphosphate as core functional components, the corrosion inhibition and scale inhibition dual-performance are achieved, the corrosion inhibition and scale inhibition effect is a general technical scheme in the field of industrial circulating water treatment, in addition, environment-friendly technologies such as silicate systems, organic amine/imidazoline systems and azole compound systems are explored and optimized in sequence in the industry, and the corrosion inhibition and optimization are developed aiming at specific working conditions. Although the conventional various corrosion inhibitor formula systems can solve the corrosion problem of the closed circulating water system to a certain extent, the conventional corrosion inhibitor formula systems have technical defects which cannot be overcome, and the core requirements of the iron and steel industry on 'high-efficiency corrosion inhibition, high-temperature stability, environmental protection, low cost and long-term operation reliability' of the corrosion inhibitor cannot be met. The existing mainstream system firstly faces the core contradiction that performance and environmental protection cannot be considered, the nitrite system is excellent in corrosion inhibition effect, nitrite belongs to a highly-carcinogenic and highly-toxic chemical, the reagent adding, equipment overhauling and wastewater disc