WO2016169474A1 - Ground connection and resistance reduction composite padding for acid red soil and use thereof - Google Patents

Abstract

A ground connection and resistance reduction composite padding for acid red soil and the use thereof. The composite padding is prepared from a raw material comprising the following in mass ratio: 15-35% of conductive graphite, 30-60% of calcium bentonite, 15-35% of sodium bentonite, 2-5% of sodium carbonate, 1-3% of an aluminium powder and 1-3% of a zinc powder. The various components in the ratio are uniformly mixed in a drying environment, and the padding is packaged in barrels or bags and stored and transported in a sealing mode. During site construction, the resistance reduction composite padding and fresh water are blended into a viscous paste in a volume ratio of 2:1 to cover a ground connection material, increasing the effective cross section of the ground connection body; the composite padding and the ground connection body are in tight contact on one hand, and on the other hand, the composite padding and peripheral soil are reliably bonded, eliminating the contact resistance. At the same time, the ground connection body does not generate contact resistance due to corrosion because of the corrosion proof function of the padding itself so as to achieve the purposes of resistance reduction and corrosion resistance.

Description

Grounding resistance reducing composite filler for acid red soil and application thereof

This application claims priority to Chinese Patent Application No. 201510195573.9, entitled "A Kind of Acid Red Soil Grounding Resistance Reducing Composite Filler", filed on April 23, 2015, the entire contents of which are incorporated by reference. In this application.

Technical field

The invention belongs to the field of electric power grounding, and particularly relates to a grounding resistance reducing composite filler for acid red soil and application thereof.

Background technique

The soil types in the southern provinces of China are similar and have certain characteristics of acid red soil. Red soil is mainly distributed in the low hilly areas south of the Yangtze River in China, including: most of Jiangxi and Hunan provinces, southeast of Fujian and Hubei, Guangdong, northern Fujian and Guizhou, Sichuan, Zhejiang, Anhui, Jiangsu, etc. Part of it, as well as southern Tibet and other places, is characterized by the lack of alkali metals and alkaline earth metals and is rich in iron and aluminum oxides, which are acid red.

In the acid red soil area, due to the large amount of salt-based ions leaching, the soil has low conductivity and the resistivity is generally above 100 ohm·m. According to the general rule, the metal corrosion rate in this soil should be very low. But in fact, many metal materials are in the middle of corrosion, and some even reach a strong corrosion level, of which carbon steel material corrosion is the most obvious.

The corrosion of the grounding grid metal material in the soil is mainly electrochemical corrosion. Among them, chloride ion and sulfate ion are the main ions causing corrosion damage of the metal material. However, many existing grounding grid resistance reducing agents or reducing resistance materials have added chlorine. Salts and sulfates, such as sodium chloride, calcium chloride, magnesium chloride, sodium sulfate, ammonium sulfate, etc., while improving conductivity, significantly accelerate the corrosion of metal materials in the grounding grid, which will seriously endanger the safe operation of power grid equipment. .

Bentonite is a non-metallic mineral with montmorillonite as the main mineral component. The interlayer cations are easily exchanged and have a large ion exchange capacity. The bentonite is divided according to the proportion of exchangeable cations in the bentonite layer. It is sodium bentonite, calcium bentonite, magnesium bentonite and aluminum (hydrogen) based bentonite, and has excellent properties such as swelling, adsorption, cation exchange, suspension and dispersibility. Bentonite has a lower electrical resistivity because bentonite contains a large amount of metal oxides of potassium, sodium, calcium, magnesium, iron and titanium. When it meets water, it can ionize a large amount of metal ions. Contains a large amount of semiconductor elements. In addition, since bentonite has adsorption properties and ion exchange properties, it can adsorb free ions in water after exposure to water. Therefore, when the bentonite is sufficiently absorbed, the bentonite contains a large amount of ions inside, and the conductivity is good.

In order to further increase the conductivity of the bentonite, the bentonite is usually organically modified by intercalation, and the conductive mechanism after the modification is mainly based on electronic conduction. The inorganic bentonite is hydrophilic and oleophobic, and the macromolecular organic matter is introduced into the interlayer to modify it, and the hydrophilic inorganic bentonite is changed into a lipophilic organic bentonite to reduce the ion exchange capacity. However, in the preparation process, acidification, ultrasonic dispersion, heating reaction and the like are often used, which greatly increases the production cost. The original bentonite price is only a few hundred yuan / 1000kg, and the organically modified bentonite reaches 10,000 yuan / 1000kg. The modified bentonite is used for the resistance reduction of the grounding grid, and its economical efficiency is very low, which is the most important limiting factor for its difficulty in popularization and application.

Summary of the invention

In order to overcome the above disadvantages of the prior art, the present invention provides a grounding resistance reducing composite filler for acid red soil and application thereof, and the composite filler provided can inhibit acid corrosion of soil, improve protection of grounded metal materials, and significantly improve electrical conductivity. Sex, with anti-corrosion and resistance reduction.

The invention provides a grounding resistance reducing composite filler for acid red soil, characterized in that the filler is made of a raw material comprising the following mass ratio: conductive graphite 15 to 35%, calcium bentonite 30 to 60%, sodium base Bentonite 15 to 35%, sodium carbonate 2 to 5%, aluminum powder 1 to 3%, zinc powder 1 to 3%.

Preferably, the calcium bentonite has a particle size of not less than 200 mesh.

Preferably, the sodium bentonite has a particle size of not less than 200 mesh.

Preferably, the conductive graphite has a particle size of not less than 100 mesh; the sodium carbonate has a particle size of not less than 100 mesh; the aluminum powder has a particle size of not less than 100 mesh; and the zinc fine has a particle size of not Less than 100 mesh.

Preferably, the conductive graphite has a mass ratio of 15 to 24%.

Preferably, the calcium-based bentonite has a mass ratio of 30 to 45%.

Preferably, the sodium bentonite has a mass ratio of 15 to 20%.

Preferably, the filler is weakly basic.

Preferably, the filler has a pH of 9.

The invention also provides the use of a grounding resistance reducing composite filler for acid red soil, which encloses a mixture of clean water and the filler on a grounding material.

Preferably, the volume ratio of filler to fresh water in the mixture is 2:1.

The invention provides a grounding resistance reducing composite filler for acid red soil, which is prepared from raw materials including the following mass ratio: conductive graphite 15 to 35%, calcium bentonite 30 to 60%, sodium bentonite 15 to 35%, carbonic acid Sodium 2 to 5%, aluminum powder 1 to 3%, and zinc powder 1 to 3%. The invention fully considers the applicable soil environment. When the acidic substance in the soil intrudes into the drag reducing composite filler, the system composed of sodium carbonate and bentonite has a strong buffering effect on the pH value reduction, thereby inhibiting the acid corrosion of the soil. The addition of aluminum powder and zinc powder improves the electrical conductivity of the whole system. When acidic and oxidizing substances in the soil invade and react with aluminum powder and zinc powder, acidic substances and oxidizing substances are consumed, aluminum and zinc. It is converted into conductive ions and still maintains good electrical conductivity.

Further, the acid red soil grounding resistance composite filler provided by the invention is weakly alkaline, can significantly reduce the corrosion of the acidic substance, and has a protective effect on the grounded metal material; the present invention adopts the current conventional product, and the particle size of the defined component is determined. The filler is simple to prepare and convenient to use, and is beneficial to the promotion and application of the product.

When the composite filler provided by the invention is used, the reduced-resistance composite filler is mixed with clean water to form a viscous paste wrapped on the grounding material, thereby increasing the effective cross section with the grounding body, so that the composite filler is in close contact with the grounding body, thereby improving The reliability of bonding with the surrounding soil basically eliminates the contact resistance, and at the same time, due to the anti-corrosion function of the filler itself, the grounding body does not generate contact resistance due to corrosion, thereby achieving the effects of reducing resistance and anti-corrosion.

Instruction sheet

FIG. 1 is a schematic view showing changes in water content of different fillers with time according to an embodiment of the present invention.

detailed description

The invention will now be further described with reference to the embodiments and the accompanying drawings.

The invention provides a grounding resistance reducing composite filler for acid red soil, characterized in that the filler is made of a raw material comprising the following mass ratio: conductive graphite 15 to 35%, calcium bentonite 30 to 60%, sodium base Bentonite 15 to 35%, sodium carbonate 2 to 5%, aluminum powder 1 to 3%, zinc powder 1 to 3%.

The filler provided by the invention can inhibit the acid corrosion of the soil, improve the protection effect on the grounded metal material, significantly improve the conductivity, and has the functions of anti-corrosion and resistance reduction.

The filler provided by the present invention comprises 15 to 35% of conductive graphite, preferably 15 to 24% by mass. The content of the conductive graphite in the embodiment of the present application may be specifically 24% or 26%. In the present invention, the particle size of the conductive graphite is preferably not less than 100 mesh; the present invention has no particular requirement for the source of the conductive graphite, and conductive graphite well known to those skilled in the art may be used.

The filler provided by the present invention comprises 30 to 60% of calcium-based bentonite, preferably 30 to 45% by mass. The content of the calcium-based bentonite in the embodiment of the present application may be specifically 45% or 55%. In the embodiment of the present invention, the higher content ratio of the calcium-based bentonite in a limited amount range is selected to achieve the antiseptic effect on the acid red soil region with less rainfall. In the present invention, the calcium-based bentonite preferably has a particle size of not less than 200 mesh, and the present invention may be a calcium-based bentonite well known to those skilled in the art.

The filler provided by the present invention comprises, by mass ratio, 15 to 35% of sodium bentonite, preferably 20 to 35%. In the present invention, the particle size of the sodium bentonite is preferably not less than 200 mesh; the present invention has no particular requirement for the source of the sodium bentonite, and sodium bentonite known to those skilled in the art may be used.

The filler provided by the present invention comprises, in mass ratio, 2 to 5% of sodium carbonate. In the present invention, the particle size of the sodium carbonate is preferably not less than 100 mesh. The present invention employs sodium carbonate which is well known to those skilled in the art.

The filler provided by the present invention comprises, by mass ratio, 1 to 3% of aluminum powder, and the particle size of the aluminum powder is preferably not less than 100 mesh. The present invention has no special requirement for the source of the aluminum powder, and aluminum powder which is well known to those skilled in the art can be used.

The filler provided by the present invention comprises, by mass ratio, 1 to 3% of zinc powder, and the particle size of the zinc powder is preferably not less than 100 mesh. The present invention has no particular requirement for the source of the zinc powder, and zinc powder which is well known to those skilled in the art can be used.

In the embodiment of the invention, the amount of the sodium carbonate, the aluminum powder and the zinc powder are selected to be higher than the amount of the zinc powder, and the antiseptic effect on the acidic red soil region is achieved.

In the present invention, the filler is preferably weakly basic, and more preferably has a pH of 9.

The preparation method of the composite filler is not particularly limited, and the technology in the field is adopted. A technical solution for the preparation of the composition well known to the person is sufficient. In the present invention, it is preferred that the raw materials of the mass ratio described in the above aspects are uniformly mixed in a dry environment.

In order to facilitate the transportation and sale of the filler, the present invention packages the composite filler obtained by the above technical solution to achieve the purpose of sealed storage and transportation. The present invention has no special requirements for the packaging method, and the packaging method well known to those skilled in the art is adopted. In the embodiment of the present invention, it is specifically a barrel or a bag.

The invention provides the application of the composite material obtained by the above technical solution, in particular, when the on-site construction, the mixture of the clean water and the filler is wrapped on the grounding material. In the present invention, the mass ratio of the filler to the water in the mixture is preferably 2:1, and a viscous paste mixture is wrapped around the grounding material to increase the effective cross section of the grounding body.

The invention provides a grounding resistance reducing composite filler for acid red soil, which is prepared from raw materials including the following mass ratio: conductive graphite 15 to 35%, calcium bentonite 30 to 60%, sodium bentonite 15 to 35%, carbonic acid Sodium 2 to 5%, aluminum powder 1 to 3%, and zinc powder 1 to 3%. The invention fully considers the applicable soil environment. When the acidic substance in the soil intrudes into the drag reducing composite filler, the system composed of sodium carbonate and bentonite has a strong buffering effect on the pH value reduction, thereby inhibiting the acid corrosion of the soil. The addition of aluminum powder and zinc powder improves the electrical conductivity of the whole system. When acidic and oxidizing substances in the soil invade and react with aluminum powder and zinc powder, acidic substances and oxidizing substances are consumed, aluminum and zinc. It is converted into conductive ions and still maintains good electrical conductivity.

Further, the acid red soil grounding resistance composite filler provided by the invention is weakly alkaline, can significantly reduce the corrosion of the acidic substance, and has a protective effect on the grounded metal material; the present invention adopts the current conventional product, and the particle size of the defined component is determined. The filler is simple to prepare and convenient to use, and is beneficial to the promotion and application of the product.

When the composite filler provided by the invention is used, the reduced-resistance composite filler is mixed with clean water to form a viscous paste wrapped on the grounding material, thereby increasing the effective cross section with the grounding body, so that the composite filler is in close contact with the grounding body, thereby improving The reliability of bonding with the surrounding soil basically eliminates the contact resistance, and at the same time, due to the anti-corrosion function of the filler itself, the grounding body does not generate contact resistance due to corrosion, thereby achieving the effects of reducing resistance and anti-corrosion.

The grounding resistance reducing composite filler for acidic soil provided by the present invention and its application are described in detail below with reference to the embodiments, but they are not to be construed as limiting the scope of the present invention.

Example 1

The acid-resistant red soil grounding resistance-reducing composite filler is made of a raw material including the following mass ratio;

Conductive graphite: 26%;

Calcium bentonite: 55%;

Sodium bentonite: 15%;

Sodium carbonate: 2%;

Aluminum powder: 1%;

Zinc powder: 1%.

The components of the ratio are uniformly mixed in a dry environment.

During on-site construction, the resulting reduced-resistance composite filler and clean water are prepared in a 2:1 ratio to form a viscous paste wrapped on the grounding material.

Applicable to acidic red soil areas with less rainfall, the ratio increases the content of calcium bentonite.

Example 2:

The acid red soil grounding resistance reducing composite filler is made of the following mass ratio raw materials;

Conductive graphite: 24%;

Calcium bentonite: 45%;

Sodium bentonite: 20%;

Sodium carbonate: 5%;

Aluminum powder: 3%;

Zinc powder: 3%.

The components of the ratio are uniformly mixed in a dry environment.

During on-site construction, the resulting reduced-resistance composite filler and clean water are prepared in a 2:1 ratio to form a viscous paste wrapped on the grounding material.

Applicable to areas with strong acidity in red soil, the ratio of sodium carbonate, aluminum powder and zinc powder is increased.

The reduced-resistance composite filler prepared according to the embodiment 1 and the reduced-resistance composite filler prepared in the second embodiment and 100 g of acid red soil were respectively taken up to a saturated state, and then placed at room temperature, and electronic water was used every other day. The analyzer tests its water content, and the test results are shown in Figure 1. It can be seen from Fig. 1 that the water-reducing composite filler obtained in the first embodiment and the second embodiment has a significant decrease in water content with time, and the water content of the acid red soil is greatly reduced.

The reduced-resistance composite filler prepared according to the embodiment 1 and the reduced-resistance composite filler prepared in the second embodiment and 100 g of acid red soil were respectively taken up to a saturated state and placed in the same room temperature environment. After one month of storage, it was naturally air-dried and cured; it was pressed into a 3 mm thick sheet and subjected to a resistivity test by a four-probe tester. The test results are shown in Table 1.

Table 1 Resistivity of different fillers

Example 1	Example 2	Acid red soil
1.52 Ω·m	1.23 Ω·m	150.56 Ω·m

It can be seen from the data in Table 1 that the resistance of the reduced-resistance composite filler for acidic red soil obtained by the technical solution of the present invention is significantly lower than that of acid red soil, and has good electrical conductivity.

The corrosion-reducing composite fillers prepared in Example 1 and Example 2 and the acid red soil were respectively buried in different grounding materials according to conventional techniques in the art, and the corrosion weight loss rate of different grounding materials was carried out after 12 months of burying. Test, test results are shown in Table 2.

Table 2 Corrosion weight loss rate after different grounding materials are buried in different fillers for 12 months

It can be seen from the data in Table 2 that the same grounding material is etched after being immersed for 12 months by acid red soil, the reduced-resistance composite filler obtained in Example 1, and the reduced-resistance composite filler obtained in Example 2, respectively. There is a big difference in the weight loss rate. The corrosion weight loss rate of the grounding material directly buried in the acidic red soil is significantly higher than that of the grounding material buried by the reduced resistance composite filler obtained in the first embodiment or the second embodiment.

The above description of the embodiments is merely to assist in understanding the method of the present invention and its core idea. It should be noted that those skilled in the art can make various modifications and changes to the present invention without departing from the spirit and scope of the invention. Various modifications to these embodiments are obvious to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but the scope of the invention is to be accorded

Claims (11)

1. A grounding resistance reducing composite filler for acid red soil, characterized in that the filler is made of a raw material comprising the following mass ratio:

   
2. The composite filler according to claim 1, wherein the calcium-based bentonite has a particle size of not less than 200 mesh.
3. The composite filler according to claim 1 or 2, wherein the sodium bentonite has a particle size of not less than 200 mesh.
4. The composite filler according to claim 1 or 2, wherein the conductive graphite has a particle size of not less than 100 mesh; the sodium carbonate has a particle size of not less than 100 mesh; and the aluminum powder has a particle size of not Below 100 mesh; the zinc powder has a particle size of not less than 100 mesh.
5. The composite filler according to claim 1, wherein the conductive graphite has a mass ratio of 15 to 24%.
6. The composite filler according to claim 1, wherein the calcium-based bentonite has a mass ratio of 30 to 45%.
7. The composite filler according to claim 1, wherein the sodium bentonite has a mass ratio of 15 to 20%.
8. The composite filler of claim 1 wherein said filler is weakly basic.
9. The composite filler according to claim 8, wherein the filler has a pH of 9.
10. Use of the composite filler according to any one of claims 1 to 9, characterized in that a mixture of fresh water and the filler is wrapped on a grounding material.
11. The use according to claim 10, characterized in that the filler in the mixture The volume ratio to clear water is 2:1.

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