KR101229674B1 - Particle linear for seawater resistance - Google Patents

Abstract

The present invention relates to a seawater particle orderer, the seawater particle orderer serving as a barrier layer in the water according to an embodiment of the present invention, the core 10; The core 10 surrounds the core 10 and includes a core-shell structure including a coating material 20 composed of bentonite and sepiolite.
According to the present invention, the sediolite clay having excellent chemical resistance and salt water resistance is mixed with bentonite to maintain the water repelling performance even in seawater and contaminated groundwater environments, and the high density core is used as the water repellent material. By using a simple construction method of depositing a core-shell structured particle-order material enclosed by a coating film where it is to be formed, it is possible to remarkably improve the workability of the conventional water-repellent material which is slurried and then constructed.

Description

Seawater Particle Filler {PARTICLE LINEAR FOR SEAWATER RESISTANCE}

The present invention relates to a particulate water repellent for seawater, and more particularly, to a seawater or contaminated groundwater to prevent penetration of seawater and contaminated groundwater in coastal areas or salt-contaminated areas, and furthermore, It is applied to the floating floor construction in construction and relates to the order material which can maintain seawater order performance.

In general, in order to prevent the leakage of leachate from the landfill area of pollutants such as waste or waste treatment plants, or to protect wild animals such as fish and algae from pollutants deposited on the bottom of lakes, rivers, ponds and swamps, Recession walls are embedded or artificial order layers are provided. The materials used for such underground order walls and artificial order layers are called order materials.

As the order material, in general, Montmorillonite-based clay such as bentonite is used. The bentonite is a clay made of Pyrophylite chemical structure Al ₂ Si ₄ (OH) having an expandable three-layer plate (Si-Al-Si) structure, which is expandable in water and has compactness. Therefore, it is widely used as a lining material due to such expandability and compactness.

In the method of constructing the order layer using the montmorillonite-based clay, the clay mineral and the hardening agent such as cement are mixed with the field soil or the incoming soil with water, and the clay mineral has very small particle size and plasticity index (plasticity). High) improves the orderability of the order material, and the curing agent to harden the order material to have strength and stability. Bentonite is mainly used as a clay mineral, and cement is generally used as a hardening | curing agent.

However, bentonite in powder form is inferior in workability because it has to be mixed with water and slurried as described above, and as is well known, its chemical resistance and salt water resistance are weak, so that it may come into contact with salt water such as seawater. In this case, there is a problem that the expandability is reduced.

Specifically, in an environment in which salts are dissolved, such as groundwater in areas contaminated with seawater or salts, the effects of these salts prevent the sodium ions contained in bentonite and the sodium ions contained in the brine from chemically reacting with each other. By densely filling the structure to suppress swelling and gelation, the particles of the suspension aggregate and settle, and the swelling pressure is lost and crushing occurs.

Thus, in order to use montmorillonite-based clays as seawater repellents, much larger amounts of clay must be used than those applied to normal contaminated water to maintain adequate ordering performance.

Accordingly, the development of ordered materials to replace montmorillonite-based clays such as bentonite, which have seawater resistance and chemical resistance in the marine environment, is being developed one after another, and development of ordered materials with improved order performance and excellent workability has been developed. It is a required situation.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a water repellent material that maintains sufficient water repellency even in seawater and contaminated groundwater conditions, and has excellent workability even in field applications.

The present invention is derived to solve the above problems, the seawater particle orderer serving as a barrier layer in the water according to an embodiment of the present invention, as shown in Figure 1, the core 10; The core 10 surrounds the core 10 and includes a core-shell structure including a coating material 20 composed of bentonite and sepiolite.

The particle water repellent material for seawater according to the present invention has a form in which a sepiolite is mixed with a montmorillonite-based clay such as bentonite, which is conventionally used as a repellent material, and has a core having a predetermined density and strength. and a so-called 'particulate order' structure of the form enclosed in the core). As shown in FIG. 1, the degree ordering mechanism of the seawater particle-order material according to one embodiment of the present invention is agglomerated in a form having a large number of voids in an environment without water, as shown in FIG. 1. In case of contact with sea water, it expands in the form shown on the right to close the sea water by filling the voids between the particles. That is, the deterioration of the expandability of seawater, which has been a problem in the conventional material made of bentonite clay only, can be solved by using the water repellent material of the present invention.

The size of the particle filler according to the present invention is not particularly limited, but is preferably 5 to 30 mm, more preferably 9 to 20 mm, most preferably 9.5 to 11.5 mm, and the voids between the particles and the coating material. Considering the expandability of (20), it is an appropriate range.

Here, as the core 10 used in the present invention, a material having a predetermined density and strength, such as rock, iron, slag, crushed concrete, aggregate, or the like is used. The core 10 is impervious and occupies a considerable amount in the particulate material, thereby reducing the amount of clay used. In addition, the materials applied as the material of the core 10, having a density of a predetermined level or more, and can be manufactured in the form of a filler, it is possible to settle it in water without any additional work to be applied directly as a barrier wall It is also possible to prevent the fall of workability by slurrying the clay in the form of a powder as in the prior art, thereby exhibiting the effect of significantly improving workability. In addition, the core 10 used in the present invention has a strength of a predetermined level or more, and has a characteristic that can withstand the flow of seawater.

The coating material 20 is manufactured using a clay component in which bentonite and sepiolite are mixed in a predetermined ratio. These two clays have different order principles. Bentonite fills the voids between the particles due to the expansion characteristics as described above, whereas palygorskite-based clay sepiolite, when dispersed in water, has needle-like particles in the water. Intertwined to show the degree of ordering. When bentonite is used alone in seawater or groundwater contaminated with salts, bentonite is agglomerated by salts dissolved in the solution, and its expandability is significantly lowered. Therefore, in order to compensate for this, by applying the order coating material 20 in which sepiolite clay is not affected by the salt component and mixed with bentonite, the expansion of bentonite is supplemented, and such bentonite-sepi is supplemented. The combination of allites exhibits superior order characteristics than in the case of using each clay alone.

Here, it is confirmed that the order performance depends on the content ratio of bentonite and sepiolite, and the optimum content ratio is derived. As a result, the weight ratio of bentonite and sepiolite is 75:25 to 85:15, preferably When it is configured to 80:20, it was confirmed that the order characteristics are significantly improved.

In addition, according to the particulate water repellent material for seawater according to another embodiment of the present invention, the coating material 20 further includes a gum component composed of guar gum and / or xanthan gum in addition to clay. As described above, the order mechanisms of bentonite and sepiolite, which are the clay components constituting the coating material 20 of the present invention, are different from each other, and in order to further compensate that the expandability of bentonite is reduced in the presence of a salt component, This gum component was introduced.

Kinds of gum include guar gum and xanthan gum, but there are arabic gum, tragacanth gum, karaya gum, locust bean, and the like, but the present invention has excellent resistance to salt water. As a result of examining a gum having excellent expandability with respect to water and excellent compatibility with bentonite and sepiolite clay, it was found that the guar gum and / or xanthan gum were suitable and applied.

The content ratio of clay and gum, in 100% by weight of the coating material including both clay-gum, maintains proper ordering properties when the gum is contained in 0.5 to 40% by weight, and considering the swelling properties of bentonite-sepiolite clay In the case of about 5% by weight to 10% by weight was confirmed to show more desirable properties. As a general tendency, as the content of the gum increases, the expansion properties and the degree of ordering increase, but when the amount of the gum is added in excess of 10% by weight, the viscosity of the coating material 20 increases by the amount of the increased gum. The increase causes particles to aggregate with each other. When this phenomenon occurs, cracks occur in the particle order material after drying, and the outer surface of the finished particle order material is not smooth.

The method for producing a particulate water-repellent material for seawater according to the present invention is to prepare a powder-like coating material consisting of clay and gum into a sol state or a gel state between a liquid and a solid, and to produce a particle form surrounding the core. Follow. Specifically, the sol state is near the liquid to the liquid state and the gel state is near the solid state, and the coating material having such a state is suitable for coating the core.

Water was added to the coating on the powder to create a sol and gel state. The water added here serves to bring the coating material into the sol or gel state and binds the different materials in the coating material, such as bentonite, sepiolite or gums together. Depending on the amount of water to be added, it becomes a sol or gel state, and when the coating material is dried on the core, the water evaporates and the particulate water is completed.

Herein, the content ratio of the coating material and the water is preferably mixed in a range of 1: 1 to 1: 2.5, more preferably 1: 1.5 to 1.2. If the coating material is manufactured in a gel state by reducing the water content, the amount of water used in manufacturing the coating material is reduced to reduce the cracks after drying, but the workability is lowered. The amount of water to be increased increases the cracking after drying. In order to prevent cracking of the coating material after drying and to consider the ease of operation in manufacturing, it was found that it is optimal to take the content ratio of the coating material and water.

Looking at the field of utilization of the order layer using the seawater particle orderer according to the present invention manufactured by such a manufacturing method, not only can be applied to the order work in the coastal area, as shown in FIG. It may be applied to underground dams for the groundwater supply in coastal areas where the storage effect was not good due to this, and as shown in FIG. 3, sea floor or river bottom caused by the effects of construction or dredging in seawater and river construction It can be applied as an anti-float layer to prevent the environmental pollution caused by the floating of pollutants on the floor. In the construction of the underground dam in FIG. 2, when the underground dam 100 is applied by applying the particle order material for seawater according to the present invention, it is possible to solve a problem in which seawater is invaded and the groundwater cannot be collected. By increasing the level of the groundwater due to the influence of the underground dam 100, there is an advantage that can use abundant groundwater. In addition, when applied to the floating layer 100 shown in Figure 3, to prevent the contaminants contained in the bottom of the Jonito 200, etc. laid on the bottom to prevent the floating easily, to suppress the occurrence of environmental problems in seawater or river construction Can be.

According to the present invention, the sediolite clay having excellent chemical resistance and salt water resistance is mixed with bentonite to maintain the water repelling performance even in seawater and contaminated groundwater environments, and the high density core is used as the water repellent material. By using a simple construction method of depositing a core-shell structured particle-order material enclosed by a coating film where it is to be formed, it is possible to remarkably improve the workability of the conventional water-repellent material which is slurried and then constructed.

1 is a cross-sectional view showing a particle water repellent material for seawater according to an embodiment of the present invention.
2 is a view showing an underground dam to which the seawater particle order material according to the present invention is applied.
3 is a view showing a floating prevention layer to which the seawater particle orderer according to the present invention is applied;
Figure 4 is a graph showing the permeability test results for bentonite
5 is a graph showing the results of permeability test according to the mixing ratio of bentonite and sepiolite
6 is a graph showing the dipping test results according to the ratio of guar gum and xanthan gum.
7 to 9 are graphs showing the results of permeability coefficient measurement according to the thickness change of Examples 1 to 3, respectively.

Hereinafter, through various experimental examples of the present invention, it will be described with respect to the characteristics of the seawater particle orderer according to the present invention.

Experiments conducted to examine the characteristics of the order in the present invention is as follows.

Swelling test ( KS  K 0764 / ASTM  D 5890)

The particle order member blocks the inflow of infiltrate water by filling the voids between the particle order materials after the coating material surrounding the core is hydrated and expanded. As such, the expandability of the particle order material is directly related to the permeability coefficient of the order material, and a method of measuring the expandability is the swelling test. The swelling test outlines how clay can fill the voids between the soil particles.

In the test method, the granular clay is completely dried at 105 ° C. for 24 hours, then weighed in a desiccant, and then powdered. Thereafter, 2 g of fine powder having passed through the 200 sieve is weighed. Pour 50 ml of distilled water and field water into a 100 ml mass cylinder, add 0.2 g of fine powder 10 times at 20-minute intervals, and make sure that the total amount of water is 100 ml. Leave until the clay has reacted sufficiently with water (after 24 hours) and record the volume of the hydrated clay mineral component.

Dipping test

In order to visually confirm the expansion and stability of the water repellent material, a product prepared in 50 mL of sea water and fresh water was immersed, and the change in diameter of the product over time was measured.

Permeability test ( KS  F 2322, ASTM  5084)

Permeability coefficient is a characteristic value that indicates the degree of permeability or drainage of soil and has the same units as velocity. If the permeability coefficient is large, the water penetrates well and drains well. On the contrary, if the permeability coefficient is small, the permeability is low, and if k (permeability coefficient) is smaller than 1 × 10 ⁻⁷ cm / sec, it is judged as impervious for practical use. Permeability test was performed to measure the permeability coefficient of the prepared water repellent material.

The test method is to put clay or water in the permeation tester, inject the seawater and fresh water into the tester, and pass the sample. Measure the time taken in the passage and the amount of solution passed through the burette, and then obtain the permeability coefficient from the following equation.

Here, the seawater used was a mixture of NaCl 80%, MgCl 20% and seawater with 3.5% salinity was used.

[Formula 1]

a = area of burette

= (V ₁ -V ₂ ) / d × 1000 (mm ² )

V ₁ = scale of burette after t hours

V ₂ Initial scale of water filled in burette

d = height difference between V ₁ and V ₂

ho = initial chickenpox

hf = chickenpox after t hours

t = time taken to pass

L = sample height

A = sample area

p ₁ = Injection pressure

Swelling degree test results of bentonite and sepiolite

The results of swelling test for each bentonite and sepiolite clay showed a big difference in swelling degree between bentonite and fresh water and seawater as shown in Table 1 below. It was confirmed that there is almost no.

Bentonite (mL / 2g) Sepiolite (mL / 2g) fresh water sea water fresh water sea water 16.5 8.5 6.5 6

Permeability Test Results for Bentonite

As shown in FIG. 4, the permeability test results for bentonite showed a water permeability coefficient of about 1 × 10 ⁻⁷ cm / sec, which is practically an impermeable layer under freshwater conditions, while in seawater conditions, the sample was affected by salt effects. The permeability coefficient increased rapidly.

Permeability Test Results According to the Mixing Ratio of Bentonite and Sepiolite

Permeability test results of the coating material prepared by configuring the weight ratio of bentonite and sepiolite to 100: 0, 90:10, 80:20, and 70:30, respectively, as shown in FIG. 5, the bentonite and sepiolite were 80 It was confirmed that the lowest permeability coefficient was obtained when mixed with: 20. This may be due to the fact that sepiolite having a needle-like structure is interposed between the soil particles and entangles the clay particles, thereby reducing the voids and reducing the permeability coefficient.

Dipping test results according to the ratio of guar gum and xanthan gum

As a result of measuring the diameter change rate according to the immersion test of the coating material prepared by configuring the weight ratio of guar gum and xanthan gum 1: 1, 5: 1, 15: 1, 31: 1 and 100: 0, respectively, as shown in FIG. As the amount of guar gum increases, the rate of expansion increases.

Swelling test results according to the ratio of gum and clay

Only black guar gum was used. As clay, bentonite: sepiolite = 80: 20 clay was used, and the weight ratio of gum and clay was 1: 5, with the weight ratio of water and coating material fixed at 1.5: 1. Coatings were prepared by adjusting 1:10, 1:20, 1:40, and 1:60 and swelling tests were performed for each.

As a result, as shown in Table 2, it was confirmed that the degree of swelling increased as the amount of gum increased. However, if the amount of gum is excessively large, cracking may occur. Therefore, it is preferable to select an appropriate ratio of gum.

Clay / sword ratio 10 20 40 80 100 Swelling degree
(mL / 2 g) 21 19 17 15 14

Coating materials  Swelling test according to the proportion of water

The swelling test was carried out using a coating material having a clay to gum ratio of 13.3: 1 and changing the mixing ratio of water and coating material to 1.25: 1, 2: 1, 3: 1, 8: 1 and 15: 1. It was.

As a result, as shown in Table 3, it was confirmed that the swelling degree increases as the content of water decreases. From this, it is understood that as the amount of water increases, the coating material does not expand sufficiently. Therefore, it was found that the coating material should be prepared to sufficiently expand the coating material by adding less water to the weight ratio of water and the coating material to 2: 1 or less.

Water / Coating Materials 1.25 2 3 8 15 Swelling degree
mL / 2 g 19 19 18 17.5 14.5

Based on the experimental examples thus far, black guar gum is 100%, the ratio of water and coating material is fixed at 1.5: 1, and the coating material according to the embodiment in the configuration of varying the ratio of clay and gum as shown in Table 4 below. In each embodiment, the thickness of the coating material was adjusted to 0.1cm, 0.18cm, 0.23cm, and a rigid wall permeation test was conducted to simulate the field conditions without the compaction process during construction.

Example Clay: gum compounding ratio Example 1 40: 1 (2.44% gum content) Example 2 20: 1 (4.76% gum content) Example 3 13.3: 1 (7% of gum content)

Permeability coefficient measurement results according to the thickness change of Examples 1 to 3 are shown in FIGS. As shown in Figures 7 to 9, the rigid wall permeability test results show that as the amount of gum increases, the coefficient of permeability decreases as the thickness of the coating material increases. The higher the amount of gum and clay, the tighter the voids between the particles, and the permeability coefficient is believed to decrease. It can be seen that in order to obtain a permeability coefficient of 1 × 10 ⁻⁷ cm / sec or less required for the order, the thickness of the coating material is 0.18 cm or more and the amount of guar gum is required at least 7% of the content of the coating material.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. It is clear that the present invention can be suitably modified and applied in the same manner. Accordingly, the above description does not limit the scope of the invention as defined by the limitations of the following claims.

10: core 20: coating material
100: underground dam or floating layer

Claims (6)

In order to act as a barrier layer in water,
Core 10; And
Surrounding the core 10, and made of a core-shell (core-shell) structure including a coating material 20 of the clay component consisting of bentonite and sepiolite,
The weight ratio of bentonite and sepiolite is 75:25 to 85:15, and the coating material 20 includes at least one of guar gum or xanthan gum,
In 100% by weight of the coating material, at least one of the guar gum or xanthan gum is included 5 to 10% by weight,
The coating material and water is a particle water repellent for seawater, characterized in that the mixture in a content ratio of 1: 1 to 1: 2.5.
delete delete The method of claim 1,
The core is a water repellent material for seawater, characterized in that made of at least one of rock, iron ore, slag, crushed concrete, aggregate.
The method of claim 1,
The particle size of the seawater particle repellent is 5 to 30mm, Seawater particle repellent.
In the manufacturing method of the particulate water repellent material for seawater according to claim 1,
A sol-gel preparation step of forming a sol state or a gel state by mixing a powder component of bentonite and sepiolite in a powder form and a coating material composed of gum and water in a ratio of 1: 1 to 1: 2.5;
And a core-shell manufacturing step of preparing a particle form by enclosing the mixture of the coating material and water in the sol or gel state and drying it.
In the sol-gel manufacturing step, the weight ratio of the bentonite and the sepiolite is from 75:25 to 85:15, the coating material comprises at least one of guar gum or xanthan gum, to 100% by weight of the coating material The method of claim 1, wherein at least one of the guar gum or xanthan gum is included in an amount of 5 to 10% by weight.

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