Composite corrosion inhibition antisludging agent for ultralow rigidity circulation cooling water and preparation method thereof

Abstract

The invention provides a composite corrosion inhibition antisludging agent for ultralow rigidity circulation cooling water. The composite corrosion inhibition antisludging agent comprises the following raw materials in parts by weight: 5-15 parts of amino trimethylene phosphonic acid, 5-15 parts of hydroxyethylidene diphosphonic acid, 1-15 parts of diethylenetriamine pentamethylene phosphonic acid, 5-15 parts of hydrolytic polymaleic anhydride, 2-15 parts of terpolymer, 2-20 parts of heptahydrate, 0.1-2 parts of hydroxy benzotriazole and 3-79.9 parts of pure water. The hydroxy benzotriazole is added after the amino trimethylene phosphonic acid, the hydroxyethylidene diphosphonic acid, the diethylenetriamine pentamethylene phosphonic acid, the hydrolytic polymaleic anhydride and the terpolymer are stirred and mixed; and the composite corrosion inhibition antisludging agent is obtained by adding the water and the heptahydrate until the hydroxy benzotriazole is entirely dissolved. The hydrolytic polymaleic anhydride and the terpolymer used by the invention have a good diffusion effect, and can effectively prevent carbonates, phosphates and the like from being deposited and scaled. Meanwhile, the hydrolytic polymaleic anhydride and the terpolymer belong to a non-phosphate monomer, so that the agent phosphate content is reduced. Therefore, the composite corrosion inhibition antisludging agent is beneficial to environmental protection.

Description

technical field [0001] The invention belongs to the technical field of industrial circulating cooling water treatment, and in particular relates to a composite corrosion and scale inhibitor for ultra-low hardness circulating cooling water and a preparation method thereof. Background technique [0002] According to statistics, cooling water accounts for 67% to 80% of all water consumption in modern factories. my country has a vast territory, and the water quality varies greatly in different regions. For circulating water systems with high hardness, water softening and other methods can be used to solve the problem. However, in my country's South China coastal areas and other areas, the water hardness is less than 20 mg / L (calculated as CaCO 3 total alkalinity<50 mg / L, pH≈6, which belongs to ultra-low hardness and strong corrosive water quality, which is extremely corrosive to carbon steel equipment. If it is not handled properly, it will cause serious corrosion of equipme...

AI Technical Summary

Problems solved by technology

However, in areas such as the coastal areas of South my country, the water hardness is less than 20 mg / L (calculated as CaCO3, the same below), the total alkalinity is less than 50 mg / L, and pH≈6, which belongs to ultra-low hardness and strong Corrosive water quality, this type of water quality is extremely corrosive to carbon steel equipment, if not handled properly, it will cause serious corrosion of equipment

[0003]Aiming at this kind of water quality, a large number of water treatment chemicals using chromate appeared in the 1970s. Although good results have been achieved, chromate is highly toxic ,polluted environment

Molybdenum-based and phosphine-based corrosion inhibitors appeared later. For example, patent CN1990912A discloses a preparation method of a molybdenum-phosphorus composite corrosion and scale inhibitor, wherein the molybdate content is 1-20wt%, and the organic phosphorus of 1-40wt% , 1~10wt% oxidant and 30~97% excipient. On the one hand, this kind of corrosion inhibitor needs to be equipped with oxidant, which is not suitable for long-term storage. On the other hand, the cost is too high

CN1176229A discloses a composite corrosion and scale inhibitor for treating ultra-low hardness circulating cooling water, in which molybdate is discarded, 2-hydroxyphosphinoacetic acid and its salts are used as the main agent, and organic phosphine compounds, Zinc salts and phosphonic acid compounds are especially used to treat ultra-low hardness circulating cooling water with water hardness < 20 mg / L. However, the patented formula lacks polymers as dispersants. When the water concentration is too high, it needs to be combined with other agents Use it at the same time, otherwise it will be difficult to prevent the scaling of the circulating water system; CN1331050A patent discloses a composite corrosion and aftereffect inhibitor for treating low-hardness circulating water, including 1-30 parts of phosphine carboxylic acid containing sulfonic acid, hydroxyl phosphine 5-40 parts of acetic acid compound, 1-12 parts of organic phosphine carboxylic acid compound, 1-20 parts of zinc salt, 30-80 parts of water, because of the introduction of polycarboxylic acid containing phosphoric acid, it is effective in preventing scaling of the circulating water system Partially strengthened, but this formula is a high-phosphorus, high-dosage formula, which will cause environmental pollution and bring additional economic burdens to enterprises

This formula is also a high-phosphorus, high-dosage formula, which will cause environmental pollution and bring additional economic burdens to enterprises