CN112981413B

CN112981413B - Special corrosion inhibitor for calcium chloride

Info

Publication number: CN112981413B
Application number: CN202110198160.1A
Authority: CN
Inventors: 杨孝才
Original assignee: Cangzhou Advance Chemical Co ltd
Current assignee: Cangzhou Advance Chemical Co ltd
Priority date: 2021-02-22
Filing date: 2021-02-22
Publication date: 2022-06-17
Anticipated expiration: 2041-02-22
Also published as: CN112981413A

Abstract

The invention discloses a special corrosion inhibitor for calcium chloride, which comprises the following raw materials in percentage by weight: 30-40% of corrosion inhibition additive, 10-20% of scale inhibition additive, 5-10% of surfactant, 1-10% of defoaming agent and 30-50% of distilled water. The corrosion inhibitor special for calcium chloride is safe, non-toxic and good in chemical stability, and can greatly reduce the corrosion of calcium chloride aqueous solution to metal.

Description

Special corrosion inhibitor for calcium chloride

Technical Field

The invention relates to the technical field of calcium chloride cooling systems, in particular to a corrosion inhibitor special for calcium chloride.

Background

The calcium chloride aqueous solution is a working fluid used for transferring heat energy in a system such as refrigeration and the like to produce a heat transfer effect. At present, in various refrigerants and antifreeze, the calcium chloride aqueous solution is still widely applied to various refrigerators and equipment and occasions needing to reduce the freezing point due to the advantages of low freezing point, no pollution to the environment, nonflammability, low price and the like. However, industrial calcium chloride aqueous solution has certain corrosiveness, so that certain potential hazard is formed to safe production.

At present, due to the fact that the strong corrosivity of calcium chloride causes material damage and leakage of refrigerant, pipelines are frequently added and maintained, valves are frequently replaced, material waste is caused, even production stoppage and maintenance of enterprises are caused, production cost is greatly increased, and operation quality of the enterprises is affected.

Disclosure of Invention

The invention aims to provide a corrosion inhibitor special for calcium chloride, which is safe, nontoxic and good in chemical stability and can greatly reduce the corrosion of calcium chloride aqueous solution to metal.

In order to realize the purpose, the invention provides a special corrosion inhibitor for calcium chloride, which comprises the following raw materials in percentage by weight: 30-40% of corrosion inhibition additive, 10-20% of scale inhibition additive, 5-10% of surfactant, 1-10% of defoaming agent and 30-50% of distilled water.

Preferably, the corrosion inhibition additive comprises 20-40% of benzoic acid, 5-10% of benzotriazole, 10-20% of tungstate, 6-9% of sodium polyacrylate, 20-30% of sorbic acid, 5-15% of fumaric acid and 8-15% of styrene-maleic acid.

Preferably, the scale inhibiting additive comprises 20-50% of ethyl triamine pentamethylene phosphonic acid, 10-30% of polyaspartic acid, 20-30% of diethylene triamine pentamethylene phosphonic acid and 20-30% of zinc salt.

Preferably, the corrosion inhibitor also comprises 2-8% of borax.

Preferably, the surfactant is sodium dodecyl dimethyl benzyl dioctyl sodium sulfosuccinate, and the defoamer is polydimethylsiloxane.

Preferably, the corrosion inhibitor is prepared from the following raw materials in percentage by weight: 34% of a corrosion inhibition additive, 12% of a scale inhibition additive, 9% of sodium dodecyl dimethyl benzyl bromide dioctyl succinate, 5% of polydimethylsiloxane and 40% of distilled water;

wherein, the corrosion inhibition additive comprises 23% of benzoic acid, 6% of benzotriazole, 18% of tungstate, 7% of sodium polyacrylate, 27% of sorbic acid, 8% of fumaric acid and 11% of styrene-maleic acid;

the scale inhibiting additive comprises 38% of ethyl triamine pentamethylene phosphonic acid, 12% of polyaspartic acid, 22% of diethylene triamine pentamethylene phosphonic acid and 28% of zinc salt.

Preferably, the corrosion inhibitor is prepared from the following raw materials in percentage by weight: 38% of corrosion inhibition additive, 17% of scale inhibition additive, 6% of sodium dodecyl dimethyl benzyl dioctyl sulfosuccinate, 7% of polydimethylsiloxane, 30% of distilled water and 2% of borax;

wherein, the corrosion inhibition additive comprises 36 percent of benzoic acid, 5 percent of benzotriazole, 10 percent of tungstate, 6 percent of sodium polyacrylate, 21 percent of sorbic acid, 14 percent of fumaric acid and 8 percent of styrene-maleic acid;

the scale inhibiting additive comprises 26% of ethyl triamine pentamethylene phosphonic acid, 27% of polyaspartic acid, 24% of diethylene triamine pentamethylene phosphonic acid and 23% of zinc salt.

Therefore, the corrosion inhibitor special for calcium chloride is safe, non-toxic and good in chemical stability, and can greatly reduce the corrosion of a calcium chloride aqueous solution to metal.

The corrosion inhibition additive forms a film on the surface of metal, which prevents the invasion of harmful ions and generates synergistic effect with benzotriazole. The scale inhibiting additive prevents the scale forming ions from forming a scale layer through the effects of complexation solubilization and lattice distortion. In addition, borax, phosphate and surfactant regulate refrigerant agent to maintain stable pH value, ensure no flocculation or precipitation of solution and promote corrosion inhibition. The defoaming agent can reduce the dissolution of air in the refrigerant and slow down the oxidation-reduction process. The corrosion inhibitor reduces the possibility of forming a chemical battery by masking other metal ions, plays roles in passivating the metal surface and inhibiting corrosion, improves the anti-icing performance, and is safe, non-toxic and good in chemical stability.

The technical solution of the present invention is further described in detail by the following examples.

Detailed Description

The technical solution of the present invention is further illustrated by the following examples.

Example one

The corrosion inhibitor comprises the following raw materials in percentage by weight: 34% of corrosion inhibition additive, 12% of scale inhibition additive, 9% of sodium dodecyl dimethyl benzyl bromide dioctyl succinate, 5% of polydimethylsiloxane and 40% of distilled water;

Example two

The corrosion inhibitor comprises the following raw materials in percentage by weight: 38% of corrosion inhibition additive, 17% of scale inhibition additive, 6% of sodium dodecyl dimethyl benzyl dioctyl sulfosuccinate, 7% of polydimethylsiloxane, 30% of distilled water and 2% of borax;

EXAMPLE III

The corrosion inhibitor is prepared from the following raw materials in percentage by weight: 38% of corrosion inhibition additive, 17% of scale inhibition additive, 6% of sodium dodecyl dimethyl benzyl bromide dioctyl succinate, 7% of polydimethylsiloxane and 32% of distilled water;

wherein, the corrosion and scale inhibitor additive is the same as that in the second embodiment, and compared with the second embodiment, the components of borax are different.

Test of

(1) Corrosion inhibition performance test

And evaluating the corrosivity of different aqueous solutions on Q235 steel, aluminum alloy, copper alloy, stainless steel, rubber and tetrafluoro test pieces by adopting a static hanging piece weight loss method. The test time is 1130 hours, and the test temperature is 40-90 ℃.

The test group adopts the calcium chloride corrosion inhibitor obtained in the first to third embodiments and prepares a 28% calcium chloride aqueous solution, and the control group adopts a 28% calcium chloride aqueous solution, and the results show that the test piece surfaces of the control group are corroded to different degrees, especially the surface of the Q235 steel test piece is covered with a layer of yellow rust, and the bottom of the container is also precipitated. The surface of each test piece above the solution in the test group has no corrosion trace, the test solution is clear, and the bottom of the container has no corrosion product deposition.

According to the test, the corrosion rates of the control group and the test group are obtained, and the specific numerical values are as follows (unit mm/a):

test results show that the corrosion inhibitor has weak corrosivity when added into a calcium chloride aqueous solution, completely meets the requirements of national standard GB/T18175-2000, the corrosion rate of steel is greatly less than 0.125mm/a, the corrosion rate of copper and aluminum is greatly less than 0.005mm/a, and the corrosion rate of rubber is greatly less than 0.003 mm/a.

(2) Scale inhibition performance test

The same control and test groups of 28% calcium chloride solutions were used in a chemical plant, and samples of the corresponding aqueous solutions were collected 180 days after the operation in actual production.

Among these, the control group had a large amount of corrosion products, mainly iron oxides, Fe (OH), in a 28% calcium chloride aqueous solution₃And the refrigerant solution is turbid and is dark red or even brownish black. These substances deposit on the circulation pipes, forming a loose film of corrosion products, which on the one hand accelerates the local corrosion of the pipes, resulting in the perforation of the pipes; on the other hand, a scale layer is formed, so that the refrigeration effect of the 28 percent calcium chloride aqueous solution is reduced. Especially when the water used for preparing the 28 percent calcium chloride aqueous solution is not pure and contains some scale-forming Ca²⁺、Mg²⁺、CO₃ ^2-、SO₄ ^2-Ionic, the structural ability is stronger.

The corrosion inhibitor is added into the 28% calcium chloride aqueous solution of the test group, and the result of operation under the same condition shows that the 28% calcium chloride aqueous solution is still clear and has strong scale inhibition capability.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting the same, and although the present invention is described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that: modifications and equivalents may be made to the invention without departing from the spirit and scope of the invention.

Claims

1. The special corrosion inhibitor for calcium chloride is characterized by comprising the following raw materials in percentage by weight: 38% of corrosion inhibition additive, 17% of scale inhibition additive, 6% of sodium dodecyl dimethyl benzyl bromide dioctyl succinate, 7% of polydimethylsiloxane and 32% of distilled water;

the corrosion inhibition additive comprises 36% of benzoic acid, 5% of benzotriazole, 10% of tungstate, 6% of sodium polyacrylate, 21% of sorbic acid, 14% of fumaric acid and 8% of styrene-maleic acid;