Aluminum corrosion inhibitor and cleaning agent for alkaline descaling of converter valve radiator

Abstract

The invention discloses an aluminum corrosion inhibitor and a cleaning agent for alkaline descaling of a converter valve radiator. The aluminum corrosion inhibitor comprises the following components in weight percentage: 30% to 40% sodium alginate, 25% to 32% sodium trisilicate, 15% to 25% potassium sodium tartrate, 3% to 8% calcium hydroxide, 5.5% to 13% aminoacetic acid, and 1% to 3% dodecylphenol polyoxyethylene ether. The cleaning agent comprises: the aluminum corrosion inhibitor and an alkaline solution. The aluminum corrosion inhibitor and the cleaning agent of the invention are used for alkaline descaling of a converter valve radiator, are environmentally friendly, low in cost and easy to prepare, and have a corrosion inhibition performance of not less than 98% of the corrosion inhibition rate of pure aluminum in 1 mol / L potassium hydroxide or sodium hydroxide solution at room temperature.

Description

Technical Field

[0001] The invention relates to the technical field of power industry cleaning, and in particular to an aluminum corrosion inhibitor and a cleaning agent for alkaline descaling of a converter valve radiator. Background Art

[0002] The large amount of heat energy generated by the converter valve during normal operation needs to be released into the atmosphere through the air cooler of the external cooling system. The air cooler is exposed to the air for a long time and there is a lot of dirt, mainly oil droplets, dust, mud, sand, SO x 、NO x , CO x Inorganic and organic impurities such as grease, which are blown strongly by the fan and contact the air cooler fins, form tightly attached greasy dirt. In addition, rain also produces some salt scale, which mainly exists on the fins at the bottom of the air cooler tube bundle, that is, on the side facing the fan. The aluminum fins at the top of the tube bundle have lost their silvery white color, and a layer of hard dirt is attached to the surface. It seriously affects the heat dissipation efficiency of the air cooler and endangers the safe operation of the converter station. Conventional chemical pickling and descaling methods are not effective for dirt, and alkaline cleaning agents such as sodium hydroxide and potassium hydroxide are required. Aluminum is an active amphoteric metal that reacts with both acid and alkali to produce hydrogen. Therefore, if alkaline cleaning agents such as potassium hydroxide are used to remove dirt from the aluminum fins of the air cooler, aluminum corrosion inhibitors with strong alkaline solvents must be matched in a certain proportion.

[0003] Corrosion inhibitors for aluminum in alkaline solutions are generally divided into two types: inorganic and organic. In the early days, silicates, bismuth salts, etc. were mostly used, and later gelatin, benzaldehyde, salicylaldehyde, etc. were used as corrosion inhibitors for aluminum in alkaline solvents. The above-mentioned corrosion inhibitor solutions cannot be used in alkaline descaling agents for aluminum fins of converter valve radiators, especially strong alkaline solutions such as potassium hydroxide and sodium hydroxide, because of their low corrosion inhibition rate, environmental unfriendliness, or high cost. Therefore, the existing technology uses alkaline descaling agents to clean converter valve radiators, which is not effective and can easily cause damage to the converter valve radiator. Summary of the invention

[0004] The embodiment of the present invention provides an aluminum corrosion inhibitor and a cleaning agent for alkaline descaling of a converter valve radiator, so as to solve the problem that the alkaline descaling agent used in the prior art is not effective in cleaning the converter valve radiator and is prone to damage the converter valve radiator.

[0005] In a first aspect, an aluminum corrosion inhibitor for alkaline descaling of a converter valve radiator is provided, comprising the following ingredients in percentage by weight: 30% to 40% sodium alginate, 25% to 32% sodium trisilicate, 15% to 25% potassium sodium tartrate, 3% to 8% calcium hydroxide, 5.5% to 13% aminoacetic acid, and 1% to 3% dodecylphenol polyoxyethylene ether.

[0006] In a second aspect, a cleaning agent for alkaline descaling of a converter valve radiator is provided, comprising an aluminum corrosion inhibitor and an alkaline solution as described in the embodiment of the first aspect.

[0007] Thus, the embodiment of the present invention provides an environmentally friendly, low-cost and easy-to-prepare aluminum corrosion inhibitor and cleaning agent for alkaline descaling of converter valve radiators, and the corrosion inhibition performance reaches a corrosion inhibition rate of not less than 98% of pure aluminum in 1 mol / L potassium hydroxide or sodium hydroxide solution at room temperature. DETAILED DESCRIPTION

[0008] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0009] The embodiment of the present invention discloses an aluminum corrosion inhibitor for alkaline descaling of a converter valve radiator. Specifically, the aluminum corrosion inhibitor comprises the following components in weight percentage: 30% to 40% sodium alginate, 25% to 32% sodium trisilicate, 15% to 25% potassium sodium tartrate, 3% to 8% calcium hydroxide, 5.5% to 13% aminoacetic acid, and 1% to 3% dodecylphenol polyoxyethylene ether.

[0010] Preferably, the lower limit of the weight percentage of sodium alginate in the aluminum corrosion inhibitor is 30%, 35% or 36%, and the upper limit of the weight percentage of sodium alginate in the aluminum corrosion inhibitor is 35%, 36% or 40%.

[0011] Preferably, the lower limit of the weight percentage of sodium tripolysilicate in the aluminum corrosion inhibitor is 25%, 28%, 29%, 30% or 31%. The upper limit of the weight percentage of sodium tripolysilicate in the aluminum corrosion inhibitor is 28%, 29%, 30%, 31% or 32%.

[0012] Preferably, the lower limit of the weight percentage of potassium sodium tartrate in the aluminum corrosion inhibitor is: 15%, 20% or 22%; the upper limit of the weight percentage of potassium sodium tartrate in the aluminum corrosion inhibitor is: 20%, 22% or 25%.

[0013] Preferably, the lower limit of the weight percentage of calcium hydroxide in the aluminum corrosion inhibitor is: 3%, 5% or 5.5%; the upper limit of the weight percentage of calcium hydroxide in the aluminum corrosion inhibitor is: 5%, 5.5% or 8%.

[0014] Preferably, the lower limit of the weight percentage of aminoacetic acid in the aluminum corrosion inhibitor is 5.5%, 8% or 10%, and the upper limit of the weight percentage of aminoacetic acid in the aluminum corrosion inhibitor is 8%, 10% or 13%.

[0015] Preferably, the lower limit of the weight percentage of dodecylphenol polyoxyethylene ether in the aluminum corrosion inhibitor is: 1%, 1.5% or 2%; the upper limit of the weight percentage of dodecylphenol polyoxyethylene ether in the aluminum corrosion inhibitor is: 1.5%, 2% or 3%.

[0016] More preferably, the corrosion inhibitor comprises the following ingredients in percentage by weight: 35% to 36% sodium alginate, 28% to 30% sodium trisilicate, 20% to 22% potassium sodium tartrate, 5% to 5.5% calcium hydroxide, 5.5% to 10% aminoacetic acid, and 1% to 2% dodecylphenol polyoxyethylene ether.

[0017] Sodium trisilicate and calcium tartrate play an adsorption role on the aluminum surface. There are many empty orbitals of aluminum ions on the aluminum surface, which can combine with the lone pair of electrons of aminoacetic acid to form a chelate, adhere to the metal surface, and enhance the adsorption of sodium trisilicate and calcium ions. In addition, the diffusion of sodium alginate molecules on the aluminum metal surface increases the internal resistance of the local corrosion microbattery, blocks the cathode reaction, reduces the corrosion current, and thus enhances the corrosion inhibition efficiency. Dodecylphenol polyoxyethylene ether can not only improve the dispersibility and permeability of the corrosion inhibitor in alkaline solution, but also increase the corrosion inhibition performance of effective ingredients such as sodium trisilicate, calcium tartrate, aminoacetic acid and sodium alginate through competitive adsorption effect, play a synergistic enhancement role, and thus achieve the goal of high corrosion inhibition rate.

[0018] The embodiment of the present invention further discloses a cleaning agent for alkaline descaling of a converter valve radiator, comprising the aluminum corrosion inhibitor and alkaline solution as described in the above embodiment.

[0019] Specifically, the alkaline solution includes at least one of the following: sodium hydroxide solution and potassium hydroxide solution.

[0020] Specifically, the aluminum corrosion inhibitor is added into a 1 mol / L alkaline solution at a ratio of 3 to 5 g / L and mixed evenly to prepare the cleaning agent.

[0021] Preferably, the cleaning agent is prepared by adding the aluminum corrosion inhibitor at a ratio of 4 g / L into a 1 mol / L alkaline solution and mixing the mixture evenly.

[0022] Example 1

[0023] The aluminum corrosion inhibitor comprises the following components in percentage by weight: 36% sodium alginate, 30% sodium trisilicate, 22% potassium sodium tartrate, 5.5% calcium hydroxide, 5.5% aminoacetic acid and 1% dodecylphenol polyoxyethylene ether.

[0024] The aluminum corrosion inhibitor was added into a 1 mol / L sodium hydroxide solution at a ratio of 4 g / L and mixed evenly to prepare an alkaline cleaning agent with the aluminum corrosion inhibitor.

[0025] Example 2

[0026] The aluminum corrosion inhibitor comprises the following components in percentage by weight: 35% sodium alginate, 28% sodium trisilicate, 22% potassium sodium tartrate, 5.5% calcium hydroxide, 8% aminoacetic acid and 1.5% dodecylphenol polyoxyethylene ether.

[0027] The aluminum corrosion inhibitor was added into a 1 mol / L sodium hydroxide solution at a ratio of 4 g / L and mixed evenly to prepare an alkaline cleaning agent with the aluminum corrosion inhibitor.

[0028] Example 3

[0029] The aluminum corrosion inhibitor comprises the following components in percentage by weight: 36% sodium alginate, 29% sodium trisilicate, 20% potassium sodium tartrate, 5% calcium hydroxide, 8% aminoacetic acid and 2% dodecylphenol polyoxyethylene ether.

[0030] The aluminum corrosion inhibitor was added into a 1 mol / L sodium hydroxide solution at a ratio of 4 g / L and mixed evenly to prepare an alkaline cleaning agent with the aluminum corrosion inhibitor.

[0031] Example 4

[0032] The aluminum corrosion inhibitor comprises the following components in percentage by weight: 35% sodium alginate, 28% sodium trisilicate, 20% potassium sodium tartrate, 5% calcium hydroxide, 10% aminoacetic acid and 2% dodecylphenol polyoxyethylene ether.

[0033] The aluminum corrosion inhibitor was added into a 1 mol / L sodium hydroxide solution at a ratio of 4 g / L and mixed evenly to prepare an alkaline cleaning agent with the aluminum corrosion inhibitor.

[0034] Example 5

[0035] The aluminum corrosion inhibitor comprises the following components in percentage by weight: 30% sodium alginate, 32% sodium trisilicate, 25% potassium sodium tartrate, 3% calcium hydroxide, 8% aminoacetic acid and 2% dodecylphenol polyoxyethylene ether.

[0036] The aluminum corrosion inhibitor was added into a 1 mol / L sodium hydroxide solution at a ratio of 4 g / L and mixed evenly to prepare an alkaline cleaning agent with the aluminum corrosion inhibitor.

[0037] Example 6

[0038] The aluminum corrosion inhibitor comprises the following components in percentage by weight: 40% sodium alginate, 25% sodium trisilicate, 15% potassium sodium tartrate, 8% calcium hydroxide, 10% aminoacetic acid and 2% dodecylphenol polyoxyethylene ether.

[0039] The aluminum corrosion inhibitor was added into a 1 mol / L sodium hydroxide solution at a ratio of 4 g / L and mixed evenly to prepare an alkaline cleaning agent with the aluminum corrosion inhibitor.

[0040] Example 7

[0041] The aluminum corrosion inhibitor comprises the following components in percentage by weight: 30% sodium alginate, 31% sodium trisilicate, 20% potassium sodium tartrate, 3% calcium hydroxide, 13% aminoacetic acid and 3% dodecylphenol polyoxyethylene ether.

[0042] The aluminum corrosion inhibitor was added into a 1 mol / L sodium hydroxide solution at a ratio of 4 g / L and mixed evenly to prepare an alkaline cleaning agent with the aluminum corrosion inhibitor.

[0043] Comparative Example

[0044] As a control group, 1 mol / L sodium hydroxide solution was prepared without adding any corrosion inhibitor.

[0045] According to the "Test Method for Metal Corrosion Rate and Total Replication in Chemical Cleaning of Industrial Equipment" (GB / T25147-2010), the corrosion amount and corrosion inhibition rate of the aluminum fins were tested. At room temperature (about 25°C), the alkaline cleaning agents of Examples 1-4 of the present invention and the comparative example were soaked in the aluminum fins for 24 hours. The test results are shown in Table 1. The corrosion inhibition rate is calculated as the percentage of the difference between the corrosion amount of the comparative example and the corrosion amount of the example to the corrosion amount of the comparative example.

[0046] Table 1 Experimental data

[0047] <![CDATA[Total area of the specimen / × 10 3 mm 2 > Weight before test / g Corrosion amount / g Corrosion inhibition rate / % Example 1 2.82 7.0021 0.1166 90 Example 2 2.81 6.8513 0.0467 96 Example 3 2.78 6.8276 0.0175 98.5 Example 4 2.80 6.8355 0.014 98.8 Comparative Example 2.81 6.8604 1.1662 /

[0048] The experimental data of Example 1 and Example 2 show that simply increasing sodium alginate and sodium tripolysilicate cannot significantly improve the corrosion inhibition rate. Properly increasing the mass ratio of aminoacetic acid allows aluminum ions to combine with the lone pair electrons of aminoacetic acid to form a chelate, which adheres to the metal surface and strengthens the adsorption of sodium tripolysilicate and calcium ions, which can significantly play a synergistic role and improve the corrosion inhibition rate. The experimental data comparison of Example 2, Example 3 and Example 4 shows that the synergistic corrosion inhibition mechanism of dodecylphenol polyoxyethylene ether and aminoacetic acid is different, and the ratio of effective corrosion inhibition components and synergistic increase components needs to be optimized to achieve the best corrosion inhibition effect.

[0049] The aluminum corrosion inhibitor of the present invention is in a sodium hydroxide solution with a concentration of 1 mol / L at 25° C., and at a ratio of 4 g / L, the pure aluminum corrosion inhibition rate is as high as 98.8%.

[0050] In summary, the embodiments of the present invention provide an environmentally friendly, low-cost and easy-to-prepare aluminum corrosion inhibitor and cleaning agent for alkaline descaling of converter valve radiators, and the corrosion inhibition performance reaches a corrosion inhibition rate of pure aluminum in 1 mol / L potassium hydroxide or sodium hydroxide solution at room temperature of not less than 98%.

[0051] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. An aluminum corrosion inhibitor for alkaline descaling of a converter valve radiator, characterized in that: The invention comprises the following ingredients in percentage by weight: 35% to 36% sodium alginate, 28% to 30% sodium trisilicate, 20% to 22% potassium sodium tartrate, 5% to 5.5% calcium hydroxide, 8% to 10% aminoacetic acid and 1% to 2% dodecylphenol polyoxyethylene ether.

2. A cleaning agent for alkaline descaling of a converter valve radiator, characterized in that: It comprises the aluminum corrosion inhibitor as claimed in claim 1 and an alkaline solution.

3. The cleaning agent for alkaline descaling of converter valve radiator according to claim 2, characterized in that: The alkaline solution includes at least one of the following: a sodium hydroxide solution and a potassium hydroxide solution.