KR100361045B1 - A new liquid type anti-rust agent containing silicate as main ingredient for metal tube and the preparation method thereof - Google Patents

Abstract

The present invention 40 to 60 parts by weight of anhydrous sodium carbonate (Na ₂ CO ₃ ), 25 to 40 parts by weight of sodium pyrophosphate, tree based on 100 parts by weight of silicate powder having a particle size of less than 300 mesh ₁₀ to 20 parts by weight of sodium tripolyphosphate (Na ₅ P ₃ O ₁₀ ) and ₃ to 15 parts by weight of sodium hexametaphosphate (NaPO ₃ ) are mixed, and the mixture is melted at a high temperature above the melting point, and then in crystalline form. It is related with a novel silicate-based liquid metal tube cleaning agent prepared by cooling a liquid obtained by cooling to obtain a crystal material, and then adding water to the crystal, putting it in a melting furnace and heating it to a temperature of 120 ° C to 200 ° C. Compared with the conventional phosphate cleaner, this agent is able to remove scale and rust formed on the metal surface by synergy of each component constituting the composition without being affected by the acidity and temperature of water. It disperses corrosion factors in water, suppresses the activity of ions, and forms a strong chemical coating on the metal surface to maintain corrosion and corrosion protection. When used after being put into the handling facility, various pipes and tanks that come into contact with water can be kept clean for a long time without rust or scale formation. In addition, the cleaning agent of the present invention minimizes the use of phosphate, which causes eutrophication of rivers, so there is no concern for water pollution, and it is colorless, odorless, and nontoxic, and does not elute metals such as lead, zinc, and copper when used. It can be used safely and sanitarily when applied to metal pipes. In addition, the cleaning agent of the present invention can reduce the cost required to maintain the cleanliness of the metal pipe because the price is low and uses a large amount of silica in the domestic buried as a main raw material.

Description

A new liquid type anti-rust agent containing silicate as main ingredient for metal tube and the preparation method

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning agent for a metal tube, and more particularly, to a scale agent as a cleaning agent for preventing corrosion of metal and scale deposition which inevitably occurs in a structure of a metal material such as a metal tube used in contact with water. It relates to a cleaning agent in liquid form containing as a main component.

Metal materials that are always in contact with water (hereinafter referred to as water supply pipes), such as various pipes or water tanks applied to commercial boilers, heat exchangers, circulation coolers, water supply facilities such as factories or apartments, are corroded by various components contained in water. As a result of the action and inevitability of scale deposition, it is common for the internal surface to be contaminated and damaged as the service period elapses.

Such metal pipe contamination causes various problems such as eluting harmful components such as heavy metals into water and acting as one of the causes of the clogging of pipes, and metal pipe cleaners or scale inhibitors have been developed to solve these problems. It is widely used.

For example, in the case of a water supply metal pipe in which tap water is transported, a scale is formed on the inner surface of the metal pipe due to the deposition of calcium carbonate components contained in the water. In the past, metasilicate, a silicate-based detergent, is used to remove and prevent this scale. Sodium (Na ₂ SiO ₂ ) is widely used.

However, the detergent made of sodium metasilicate is difficult to obtain a high-purity silicate raw material, which is relatively expensive to manufacture, and there is a limit that it is difficult to expect a sufficient metal tube cleaning effect only by the chemical action of silicate.

On the other hand, in the case of the phosphate-based cleaning agent used to remove the rust or oil film on the surface of the metal tube, the effect can be expected only in the range of neutral pH of the water, and the effect is deteriorated in the range of pH 5-6. In addition, when used in hot water, the cleaning agent is hydrolyzed and the effect is inferior. When used in copper pipes, copper pyrophosphate, which is insoluble in water, is formed, which not only shortens the life of the pipe but also uses slime when used in heat exchange. Is formed there is a problem that may interfere with the heat transfer and circulation of water.

In addition, phosphate is being regulated environmentally because it promotes eutrophication and causes water pollution when introduced into rivers.

In addition, the conventional cleaning agents, even if the purpose of the metal tube can be achieved to some extent, causing corrosion of the metal tube, there is a side effect of eluting lead harmful to the human body there is also a problem that is not suitable for use in water pipes, such as water pipes.

It is an object of the present invention to provide a technique for cleaning a metal tube using a composition of a liquid rather than a solid based on silica as a simple method for maintaining immediate and constant solubility.

In addition, another object of the present invention is to provide a multi-purpose metal tube cleaning agent that can effectively remove and prevent the scale formed in the metal tube, as well as effectively prevent corrosion of the metal tube and elution of harmful metals by the water-containing material. will be.

In addition, another object of the present invention is to show the clean, anticorrosive and anti-rusting effect of the metal tube while minimizing the use of phosphate which causes water pollution, and has colorless, odorless and odorless properties, especially used for metal pipes for drinking water. It is to provide a suitable metal tube cleaning agent as follows.

It is still another object of the present invention to provide a cleaning agent that exhibits a cleaning effect regardless of changes in temperature and acidity of water in contact with the metal tube.

40 to 60 parts by weight of anhydrous sodium carbonate (Na) based on 100 parts by weight of a silicate powder having a purity of 99.9%₂CO₃), 25-40 parts by weight sodium pyrophosphate, 10-20 parts by weight sodium tripolyphosphate (Na₅P₃O₁₀) And sodium hexametaphosphate (NaPO)₃) 3-15 parts by weight are mixed, the mixture is melted at a temperature above the melting point (preferably about 1,650 ° C), cooled to a crystalline form, and then obtained a crystalline material. The liquid rust preventive agent is obtained when it puts into a melting furnace and heats at 120 degreeC-200 degreeC, and elapses for 24 hours.

The metal tube cleaning agent of the present invention comprises the steps of uniformly mixing the silica powder, anhydrous sodium carbonate, sodium pyrophosphate, sodium tripolyphosphate and sodium hexametaphosphate by the mixing device in the above content range, the process of melting the mixture from the melting furnace into the liquid phase and It is produced by the process of molding the melt into a crystalline form by a molding machine and cooling it in a natural state. The metal tube cleaning agent of the present invention is used in the range of mortar concentration of approximately 5-20 μm with respect to water. It is preferable to use in the range of mortar concentration of 8-15 micrometers.

Silica powder (silica sand) is a main raw material of the cleaning agent of the present invention as a component for forming an anticorrosive coating on the inner surface of a metal tube by dissolving in water to form silicon dioxide (SiO ₂ ). Silica is inherently poorly soluble in water, but reacts with anhydrous sodium carbonate to become alkali silicate and becomes water-soluble. In addition, silicon silicate is decomposed by acid in water to form silicon dioxide on the metal surface to form an anticorrosive coating. To form.

Silica sand is preferably used having a purity of 99.9% in order to minimize the content of impurities, and it is preferable to grind as finely as possible in order to facilitate the melting process of the mixture. In view of the above, it is practically preferable to use a powder having a particle size in the range of 300 mesh.

Anhydrous sodium carbonate converts water-insoluble silica (silicon dioxide) into water-soluble alkaline and at the same time hydrolyzes to show strong alkalinity, reducing oxides such as iron oxide on the metal surface to remove rust and complex chemical action with silicates It acts to further increase the cleansing action. That is, Si ions in the silicate bond with the anions of the organic material contained in the water and inhibit the organic matter from acting on the metal surface and causing corrosion.

Anhydrous sodium carbonate is added to the mixture in a ratio of 40 to 60 parts by weight, preferably 50 parts by weight with respect to 100 parts by weight of the silica powder, and if the content is insufficient, the water solubility of the silica sand may be lowered, and when excessively contained, it may cause a metal hazard. .

Sodium pyrophosphate dissolved in water and showing weak alkalinity produces sodium hydrogen phosphate in aqueous solution. Sodium pyrophosphate forms a complex salt with copper, iron, magnesium ions, and the like contained in water to inhibit and block the activity of metal ions, thereby preventing corrosion of the metal tube by these ions.

Sodium pyrophosphate is used in a ratio of 25-40 parts by weight with respect to 100 parts by weight of silica sand powder _, and produces a complex salt with ions such as Cu ⁺⁺ _, Fe ⁺⁺ and Mg ⁺⁺ , and has a strong ability to inhibit the activation of anions. If the content is insufficient, the force for generating complex salts with these metal ions is weak, and when excessively contained, it is not preferable because it causes harm.

Sodium triphosphate dissolves in water and has weak alkalinity, and hydrolyzes to form hydrophilic groups with pyrophosphate to block metal ions in water and disperse corrosive minerals.

Sodium hexametaphosphate, when dissolved in water, is weakly alkaline and exhibits metal ion containment and dispersing of corrosive minerals.

Sodium tripolyphosphate and sodium hexametaphosphate are added at a ratio of 10-20 parts by weight and 3-15 parts by weight, respectively, with respect to 100 parts by weight of the silica powder, and if it falls outside the lower limit of the content range, the sodium triphosphate and hexameta It may be considered to use sodium triphosphate in place of sodium phosphate, but the trisodium phosphate maintains the sodium phosphate component at low and normal temperatures, but is changed to orthophosphoric acid at a high temperature (eg 1650 ° C.) to melt the mixture. As the blocking and dispersing action of the metal ions is reduced to about 20-30% at the same concentration, the anti-scaling and anticorrosive action is significantly reduced. On the other hand, sodium triphosphate and sodium hexametaphosphate do not change even at high temperature and form a strong rust preventive coating, so they show excellent anti-scaling and anticorrosive action despite the high temperature melting process to make silica sand water-soluble.

Next, the present invention will be described in more detail as examples and comparative examples. This example illustrates the invention in more detail, but does not limit the scope of the invention.

Examples 1 to 3

The silica powder (purity: 99.9%, 300 mesh), anhydrous sodium carbonate, sodium pyrophosphate, sodium tripolyphosphate and sodium hexamethaphosphate were mixed in a stirrer to a content (unit: kg) as shown in Table 1 below. It was left for about 2 hours and then cooled at room temperature to obtain a mixture.

Table 1 Unit: kg

division Silica powder Anhydrous sodium carbonate Sodium pyrophosphate Sodium triporiphosphate Hexametaphosphate Example 1 1,000 500 350 150 40 Example 2 1,000 600 400 200 150 Example 3 1,000 400 250 100 50

The mixture was poured into a melting furnace and heated to 1,650 ° C for 12 hours to melt. After the melting process is completed, the mixture is put into a molding press in a liquid state like molten glass and molded into a crystalline form, cooled (to stand at room temperature for about 25 hours) to prepare a transparent crystalline form, which is based on 50 kg of crystal form and 200 liters of clean water. A liquidated metal tube cleaning agent is prepared, which is composed of a silicate liquid after 24 hours of heating at a temperature of 120 ° C to 200 ° C.

1) Content: SiO ₂ 13-30% (± 2)

2) Appearance: Colorless to white liquid

3) Purity: Arsenic (As) 2 ppm or less, Lead (Pb) 15 ppm or less, Cadmium (Cd) 2 ppm or less, Mercury (HG) 0.2 ppm or less

4) pH: 10.5 to 12.0

Comparative example

65 kg of phosphoric acid (H ₃ PO ₄ : 80%), 27 kg of calcium carbonate (CaCO ₃ ) and 8 kg of sodium carbonate (Na ₂ CO ₃ ) are combined and heated in a melting furnace at 1100 ° C for 7 hours to obtain a melt, which is then cooled Obtain a crystalline coagulum. This coagulum is dissolved in water and used as a 12% (weight) solution.

Test Example

Each of the cleaning agents prepared in Examples 1 to 3 was added to tap water at a concentration of 10 ppm to prepare a clean sample of the present invention, and then copper and iron pieces were precipitated on these samples having different temperatures and pHs, respectively. The contamination was determined by visual observation of the surface. As a comparative example, the same experiment was conducted using tap water to which the same concentration of phosphate-based detergent was prepared in Comparative Example and pure tap water to which no detergent was added. The measurement results are shown in Table 2 below.

TABLE 2

division sample Sample temperature, pH Psalter result One Conventional Phosphate-Based Cleaner Room temperature pH7.5 Copper piece Blue product appeared on the surface of copper piece after 30 days. Iron piece Red rust developed after 6 months. 2 tap water Room temperature pH7.5 Copper piece Red rust developed after 6 months. Iron piece Red rust appeared on the surface after 24 hours. 3 Conventional Phosphate-Based Cleaner 60 ℃ pH5.5 Copper piece Blue product appeared on the surface of copper piece after 25 days. Iron piece Red rust appeared on the surface after 4 months. 4 Example 1 Room temperature pH7.5 Copper piece The specimen remained intact after 2 months. Iron piece The specimen remained intact after 6 months. 5 Example 2 Room temperature pH7.5 Copper piece The specimen remained intact after 2 months. Iron piece The specimen remained intact after 6 months. 6 Example 3 Room temperature pH7.5 Copper piece The specimen remained intact after 2 months. Iron piece The specimen remained intact after 6 months. 7 Example 1 60 ℃ pH6.5 Copper piece The specimen remained intact after 2 months. Iron piece The specimen remained intact after 6 months.

As confirmed in the above experimental example, the novel liquid metal tube detergent of the silicate subject of the present invention removes scale or rust formed on the metal surface by synergy of each component constituting the composition without being affected by the acidity and temperature of water. It disperses the corrosion factors included in the process, suppresses the activity of ions, and forms a strong chemical film on the metal surface to maintain the anticorrosion and anti-corrosion conditions. Therefore, it handles water such as various boilers, heat exchangers, circulating coolers, and water pipes. When used in a facility, various pipes or tanks that come in contact with water can be kept clean for a long time without rust or scale formation. In addition, the cleaning agent of the present invention minimizes the use of phosphate, which causes eutrophication of rivers, so there is no concern for water pollution, and it is colorless, odorless, and nontoxic, and does not elute metals such as lead, zinc, and copper when used. It can be used safely and sanitarily when applied to metal pipes. In addition, the cleaning agent of the present invention can reduce the cost required to maintain the cleanliness of the metal pipe by using a low cost and a large amount of silica is buried in Korea as the main raw material.

Claims (2)

40 to 60 parts by weight of anhydrous sodium carbonate (Na ₂ CO ₃ ), 25 to 40 parts by weight of sodium pyrophosphate, and sodium tripolyphosphate based on 100 parts by weight of a silicate powder having a particle size of 300 mesh or less (sodium tripolyphosphate: Na ₅ P ₃ O ₁₀ ) 10 to 20 parts by weight and sodium hexametaphosphate (NaPO ₃ ) 3 to 15 parts by weight are mixed, and the mixture is melted to a high temperature above the melting point (about 1,650 ℃) A novel silicate-based liquid metal tube cleaning agent prepared by cooling a liquid obtained by cooling to a crystal form after cooling to a crystalline form to obtain a crystal substance and adding water to the crystal in a melting furnace. 40 to 60 parts by weight of anhydrous sodium carbonate (Na ₂ CO ₃ ), 25 to 40 parts by weight of sodium pyrophosphate, and sodium tripolyphosphate based on 100 parts by weight of a silicate powder having a particle size of 300 mesh or less (sodium tripolyphosphate: Na ₅ P ₃ O ₁₀ ) 10 to 20 parts by weight and sodium hexametaphosphate (NaPO ₃ ) 3 to 15 parts by weight are mixed, and the mixture is melted to a high temperature above the melting point (about 1,650 ℃) After cooling to crystalline form to obtain a crystal substance, water is added to the crystal into a melting furnace to heat the liquid obtained by heating to 120 ℃ ~ 200 ℃ temperature to prepare a novel silicate-based liquid metal tube cleaning agent .