KR20090012895A - Apparatus for cover system design of waste rock file and cover layer system - Google Patents

Abstract

An apparatus for design of covering soil is provided to measure oxygen transmission rate according to covering soil material of a covering soil layer and a laminating structure. An apparatus for design of covering soil contains a main body of which a top end portion is opened, a supporting plate in which the covering soil used as covering soil material of a waste placing field(w) is laminated, a cover member in which a gas inflow port is formed in order to flow in gas inside of the main body and an oxygen sensor measuring oxygen content in air flown in to the top end portion of the main body and exhausted through the covering soil material.

Description

Apparatus for cover system design of waste rock file and Cover layer system}

The present invention relates to a cover layer for stacking on a waste stockyard to prevent oxidation by contact with air in the waste and a cover design device for designing and studying the cover layer, and in particular, a cover layer and cover design apparatus for coal mine waste yard. It is about.

The effects of acid mine drainage (AMD) have been reported to be serious in relation to the environmental pollution caused by mining activities, and various researches on the production mechanism, environmental pollution effects, and treatment methods have been conducted. In other words, as an active treatment method for preventing contamination by acid mine drainage, treatment facilities such as physicochemical treatment facilities, wet land, anodized lithium drain (ALD), and successive alkalinity producing system (SAPS) have been developed. However, these treatment facilities are mainly for treating the mine water discharged from the mine shaft, there is a problem that is not suitable for applying to the leachate generated from the waste-rock stockyard or tailings stockyard formed around the domestic abandoned mine. As a result of the recent water quality survey of the abandoned mines, as shown in the photographs shown in FIGS. 1A and 1B (such as soils reddish by acid leachate), contamination of surface water by leachate discharged from the waste-rock pile of the waste-rock deposit is, of course, Contamination of groundwater such as wells has also been confirmed, and there is an urgent need for pollution prevention and treatment of waste-rock leachate in coal mine waste-rock stockyards.

Mine waste-rock restoration technology is divided into pollution diffusion prevention technology that prevents the spread of pollutants and pollution removal technology that removes or decomposes the pollutants.

Representative pollution prevention technologies include cover, planting, and wet disposal. The cover soil artificially separates the surrounding environment from the waste-rock pile to block water (oxygen in the water) and air (oxygen) flowing into the mine waste-rock yard. This is done by isolating piles of waste-rock and then laminating cover soil on top. Planting is not only effective in suppressing ferric oxide, but also preventing the soil layer from being eroded by the wind by increasing the amount of carbon dioxide in the mine waste yard by the respiration of plant roots and the activity of heterotrophic microorganisms. . Among these pollution diffusion prevention technologies, cover and planting are very economical and highly applicable, with the advantage that they can be usefully used when resources containing a large amount of useful components such as tailings are recycled due to the depletion of resources in the future. Is required.

In Korea, however, the soil is covered only by stacking the soil in coal mine quarries, and the oxygen permeability according to the cover medium, the lamination structure of the cover medium, and the selection of the cover medium, the cover with the characteristics of coal mine There is a lack of research on design. Accordingly, the accumulation of data through a lot of research for the cover design is required. In particular, since acid mine drainage is generated when waste-rock is in contact with oxygen, it is required to accumulate data through the study of oxygen transmittance according to the cover medium and the laminated structure in the cover.

An object of the present invention is to provide a cover design device that is an experimental device for measuring oxygen transmittance according to the cover medium and the laminated structure of the cover layer in the study of the cover design.

In addition, another object of the present invention is to provide a cover layer that can effectively prevent the discharge of acidic leachate from the waste-rock storage by low oxygen permeability using the above cover design device.

The cover design apparatus according to the present invention for achieving the above object is to design a cover layer to prevent the inflow of oxygen to the waste pile is stacked in the waste stockpile, the upper end is opened, the body is installed inside the main body A support plate having a plurality of holes through which only particles having a predetermined size or less can pass therethrough, and a cover plate on which a cover medium is used as a cover material for the waste stockyard is stacked; It is detachably coupled to the upper end of the main body, and is disposed between the cover member and the lower end of the main body and the support plate formed with a gas inlet port so that gas can be introduced into the main body, and flows into the upper end of the main body. Oxygen sensor for measuring the oxygen concentration in the air discharged through the cover medium It is characterized by having a.

According to the present invention, the cover member is provided with a gas inlet port for introducing gas into the inside of the main body, the gas inlet port is preferably connected to the nitrogen tank.

In addition, according to the present invention, a gas discharge port for discharging the gas in the main body is formed between the lower end of the main body and the support plate, the discharge pipe for guiding the discharge of the gas is connected, through the discharge pipe More preferably, the end of the discharge pipe is immersed in the water tank so as to prevent outside air from entering the inside of the main body.

The cover layer according to the present invention for achieving the above another object is to be stacked in the waste stockyard to prevent oxygen from flowing into the waste pile, including the first clay layer, which is made of clay and laminated on the waste pile And a second clay layer made of a sand layer and clay stacked on the first clay layer, wherein the second clay layer is laminated on the sand layer.

According to the present invention, the sand layer is preferably a sand layer compacted by pressing at a predetermined pressure, and the sand layer includes sand and water, and a water content ratio of the weight of water to the weight of sand is 5% to 15%. The thickness of the sand layer is more preferably 4/10 or more of the total thickness of the sum of the first clay layer, the sand layer, and the second clay layer.

As described above, through the experiment using the cover design device having a simple configuration, data on the oxygen transmission rate of various cover media can be accumulated as well as data on the lamination structure that can reduce the oxygen transmission rate. The advantage is that it can provide a foundation.

 In addition, through the cover design device according to the present invention can be carried out in the field of the oxygen transmission experiments and the lamination structure of the oxygen permeability experiments on the cover medium that can be easily obtained in the surrounding environment of the waste-rock storage bar, There is an advantage that economic cover design can be performed.

The cover layer according to the present invention can effectively block oxygen while using sand and clay, which are very economical cover media, thereby preventing contamination by waste-rock deposit leachate.

Hereinafter, with reference to the accompanying drawings, it will be described in detail with respect to the cover design device according to a preferred embodiment of the present invention, the cover layer according to the present invention based on the experimental data by the cover design device.

Waste-rock or tailings generated by mining activities contain a large amount of pyrite (FeS), and acidic drainage acts as a major source of water pollution and soil pollution around the waste-rock storage by oxidation of pyrite. The oxidation of pyrite is as follows.

FeS _{2 + 3.5O 2 + H 2 O →} Fe 2 + + 2SO 4 2 - + 2H + - - - (1)

Fe ^{2 +} + 0.25 O ₂ + H ⁺ → Fe ^{3 +} + 0.5 H ₂ O---(2)

Fe ^{3 +} + 3H ₂ O → Fe (OH) _{3 (S)} + 3H ⁺ ---(3)

FeS _{2 ^{+ 14Fe 3 + + 8H 2 O}} → 15Fe 2 + + 2SO 4 2 - + 16H + - - - (4)

Looking at the reaction schemes, pyrite is oxidized Fe ^{2 +} is formed (1), Fe ^{2 +} is oxidized again to form Fe ^{3 +} (2), due to Fe ^{3 +} cross precipitates iron hydroxide (3), Fe ^{3 +} is formed (4) the Fe ^{2 +} Street and pH (acidity) again acts as an oxidizing agent. Iron or hydrogen ions generated by the above reaction is introduced into the groundwater to form an acidic drainage. In order to prevent the pyrite from being oxidized by the mechanism as described above, the pyrite and oxygen should not be in contact with each other. As shown in FIG. 2, generally, a cover method is used in which waste rocks are not exposed to oxygen in the air by forming a soil layer (c, cover layer) by covering the soil and the like on top of the mine waste stockyard w. In addition, oxygen is present in the water as well as in the air, and the cover layer (c) also serves to prevent rainwater and the like from entering the waste-rock pile.

In forming the cover layer (c) as described above, in order to improve the blocking rate of oxygen, various factors, for example, the type of cover medium, the thickness of the cover layer, the composition of the cover layer, the porosity, the permeability and the like should be considered. Economics should also be considered along with the rate of oxygen barrier. However, in the past, in the cover layer formation, the cover layer was not designed based on the specific data on these factors, and these data did not exist enough, so the cover design of the cover layer could find out the oxygen blocking rate according to various factors. Apparatus 100 is provided by the present invention.

3 is a schematic configuration diagram of a cover design apparatus according to a preferred embodiment of the present invention. Referring to FIG. 3, the cover design apparatus 100 according to the preferred embodiment of the present invention includes a body 10, a support plate 20, a cover member 30, and an oxygen sensor 40.

The main body 10 has a substantially cylindrical container shape to accommodate the cover medium (m) forming a cover layer. The main body 10 has an upper end open to allow air to flow therein. In addition, the main body 10 is made of a transparent acrylic material it is possible to visually check the cover medium (m) accommodated inside the main body 10. A discharge hole 11 for discharging gas into the main body 10 is formed at a side of the lower side of the main body 10, and a gas discharge port 12 is provided in the discharge hole 11. In addition, the valve 13 is coupled to the gas discharge port 12 to open and close the gas discharge port 12. The gas discharge port 12 is connected to a discharge pipe 14 for guiding the discharge of the gas. In order to prevent air from flowing into the main body 10 in reverse through the discharge pipe 14, the end of the discharge pipe 14 is immersed in the water contained in the water tank 19.

The support plate 20 is for supporting the cover medium m in the main body 10, and is installed above the lower end of the main body 10, more specifically above the gas discharge port 12. The support plate 20 is a mesh having a plurality of holes formed therein, and a mesh of 40 mesh to 200 mesh is used. Although the cover medium (m) is placed on the support plate (20), the air passing through the cover medium (m) is discharged to the lower part of the main body (10) through the holes of the support plate (20).

The cover member 30 is for opening and closing an open upper end of the main body 10, and is detachably coupled to the main body 10 by a bolt b or the like. When the cover member 30 is coupled to the main body 10, a predetermined space a is formed between the upper end of the main body 10 and the cover member 30. One side of the cover member 30 is formed with a gas inlet hole 31 for introducing gas into the space (a). A gas inlet port 32 is installed in the gas inlet hole 31, and the gas inlet pipe 34 connects the gas tank and the gas inlet port 32 to each other. In the present embodiment, nitrogen gas is injected into the gas inlet 31 so that the nitrogen gas tank 39 is connected. The valve 33 is installed in the gas inlet port 32 to adjust the inflow amount of nitrogen gas. On the other hand, the cover member 30 is made of a transparent acrylic material similarly to the main body 10, so that the inside of the cover member 30 can be confirmed.

The oxygen sensor 40 is disposed in the space b between the lower end of the main body 10 and the support plate 20 to measure the oxygen concentration in the air in the space b. Air in the space b between the lower end of the main body 10 and the support plate 20 is introduced through the cover medium m from the upper end of the main body 10. The oxygen sensor 40 can be used as a known member, for example, the oxygen sensor disclosed in the patent application specification No. 10-2004-0105217. The oxygen sensor 40 is electrically connected to the storage device 50 through the wire (1). The oxygen concentration measured by the oxygen sensor 40 at regular time intervals is transmitted to the storage device 50 to be recorded and displayed.

On the other hand, the cover design device 100 according to a preferred embodiment of the present invention includes a heating means and a thermal means. Since the temperature change occurs very severely depending on the season in the waste-rock pile, etc., heating means and heat-sensing means are provided in order to form the temperature conditions of the main body 10 in the same way as the actual ones.

The heating means is for increasing the temperature of the main body 10 on which the covering medium m is placed. In this embodiment, the heat transfer coil 60 is employed as the heating means, and the heat transfer coil 60 is the main body 10. It wraps around the outer circumference of.

The heat sensing means is for reducing the temperature of the main body 10 on which the covering medium m is placed. In this embodiment, a plurality of thermoelectric elements 70 are used. The plurality of thermoelectric elements 81 are mounted on the outer circumferential surface of the sealed container 10 to absorb the heat of the accommodating portion 19 to reduce the temperature. The thermoelectric element 81 may use a thermoelectric element as disclosed in Patent Publication No. 10-2006-0104687 as a known member. As is well known, each thermoelectric element 70 includes a heat generating portion and an endotherm, a Peltier semiconductor element disposed between the heat generating portion and the heat absorbing portion, and a conductor (not shown) for applying a current to the Peltier semiconductor element. . When the current is applied, the heat generating portion increases in temperature, and the heat absorbing portion decreases in temperature. Accordingly, the heat generating portion emits heat to the surroundings, and the heat absorbing portion absorbs the heat of the surroundings. The temperature of the accommodating portion 19 may be formed below zero by the thermoelectric element 70. In addition, the outer peripheral surface of the main body 10 is wrapped with a heat insulating material 80 to prevent heat transfer to the outside.

A method of using the cover design device 100 having the above-described configuration will be described. First, in the state in which the cover member 30 is opened, the cover medium m to be studied is laminated on the inner support plate 20 of the main body 10. The cover medium m may be a single medium, a mixed medium in which a single medium is mixed, or a multi-layered structure in which a plurality of mediums are layered as shown in FIG. 3. Since the particle size of the cover medium (m) is larger than the hole formed in the support plate 20, it does not flow downward through the support plate 20, but air or gas passing through the cover medium (m) passes through the support plate 20. can do. After the cover medium (m) is mounted, the cover member 30 is coupled to the main body 10 to seal the main body 10. Thereafter, nitrogen gas is introduced into the body 10 through the gas inlet port 32. Air inside the main body 10 is pushed down the main body 10 through the cover medium (m) and the support plate 20 and discharged through the gas discharge port 12 and the discharge pipe 14 at the bottom of the main body 10. do. Since the discharge pipe 14 is immersed in the water contained in the water tank 19, air is prevented from flowing into the main body 10 through the discharge pipe 14.

After injecting nitrogen gas to discharge all the air in the main body 10 as described above, the cover member 30 is opened and the oxygen concentration is measured by the oxygen sensor 40 at regular time intervals. That is, the air in the atmosphere can be introduced into the space (b) below the main body 10 through the cover medium 20 from the moment the cover member 30 is opened, and the air permeability of the cover medium 20 (oxygen) Transmittance) can be measured. The concentration of oxygen measured at regular time intervals is recorded and displayed in the storage device 50.

As described above, when using the cover design device 100 according to the present invention, when a certain cover layer is deposited in the waste-rock storage, it is possible to measure the amount of oxygen flowing through the cover layer to the waste-rock pile and the efficiency of the cover layer. Can be verified. In addition, it is possible to study the oxygen barrier ratio and the optimum cover structure of each cover medium by experimenting with various cover media. In addition, by using the heat transfer coil 60 and the thermoelectric element 70, it is also possible to measure the efficiency of the cover layer according to the temperature change by making the temperature conditions of the actual waste-rock deposit.

Experiments were conducted on various types of cover media and structures using the cover design device 100, and developed a cover layer with excellent oxygen barrier rate as shown in FIG. 9 is a schematic diagram showing a structure of a cover layer according to a preferred embodiment of the present invention.

Referring to Figure 9, the cover layer (R) according to the present invention is laminated on the waste-rock pile (w), the first clay layer (R1) is made of clay (sand sand) is laminated on the waste-rock pile and the first is made of sand A sand layer R2 stacked on the clay layer R1 and a second clay layer R3 made of clay and stacked on the sand layer R2 are provided.

The first clay layer R1 and the second clay layer R2 are formed to have the same thickness (d1 = d3), and the thickness d3 of the sand layer R2 is 1.5 times higher than that of the first and second clay layers R1 and R2. Is formed. That is, when the thickness of the entire covering layer R is 60 Cm, the thickness of the first and second clay layers is 15 Cm, respectively, and the thickness of the sand layer R2 is 30 Cm. The thickness of the sand layer R2 is preferably set to 4/10 or more with respect to the thickness of the entire covering layer, which will be described later with reference to the experimental results.

On the other hand, the clay used in the first and second clay layers R1 and R3 is a soil which is commonly available in Korea as so-called soil soil. The sand and clay are both coarse soil (soil of less than 35% sieve through 200 mesh sieve). Sand layer (R2) includes water together with sand, the water content is the ratio of the weight of water to the weight of the sand is about 5% to 15%, it is a layer made of a predetermined pressure using a roller or the like. The reason for the compaction and the moisture content will be described together when explaining the experimental results.

As described above, using the cover design device 100, the experiment on the oxygen barrier efficiency for the gravel, clay, sand frequently used as the cover medium was carried out.

The gravel, sand and clay used in this experiment are classified as gravel, sand and sandy clay according to the triangular coordinate classification developed by USDA. In addition, according to the unification classification, all three correspond to granulated soil (less than 50% of the mesh passing rate), gravel corresponds to GW (good granular gravel), sand and clay corresponds to SW (good granular sand). Finally, according to the American Road Traffic Association classification, all three are coarse soil with less than 35% of 200mesh sieve passing rate.

Pebbles, sand, and clay alone or mixed to cover the 30cm thickness experiment. Figure 4 shows the results of the oxygen concentration measurement by time progressed on them. The cover material used in the experiment was filled with no compaction and dried material containing no water was used. Prior to this experiment, in order to check the accuracy (oxygen inflow potential) of the cover design device made of acrylic itself, the oxygen inflow rate was measured after removing oxygen using only the empty cover design device. As a result, about 1.0% of oxygen was introduced for 24 hours, which is the result of the accuracy (± 1.0%) range of oxygen sensor. As a result of the 30 cm clogging test, it was determined that about 20% of oxygen was introduced into the atmosphere within 10 hours. The fastest oxygen inflow medium is only sand (porosity = 0.40), which is the most regular media. On the other hand, the inflow rate of oxygen, sand and gravel with irregular particle size (porosity = 0.28) was the slowest. This means that the oxygen permeability is lowered when a medium having an irregular particle size is mixed. This is because the small particles fill the voids between the large particles. However, the result of the non-compaction cover test shows that there is almost no effect of blocking the oxygen flowing into the mine regardless of the cover medium when the cover of about 30cm is progressed in the mine pit without making a pledge.

In the same way as the 30cm experiment, clay, sand alone, clay, sand, clay, sand, and gravel were mixed (60 cm each), and the oxygen concentration flowing in each time was measured. Figure 5 shows the results of the oxygen concentration measurement by time progressed on them. All of the experiments showed oxygen concentrations of about 20% similar to the atmosphere within 24 hours. This shows that even if 60 cm of covering is not made, it does not block oxygen flowing into the lower part at all, similar to the 30 cm thick covering result.

 Through the compaction test results, the oxygen concentration introduced into each cover soil medium after the compaction was determined using the optimum function ratio. Figure 6 shows the result of measuring the oxygen concentration introduced over time after covering the clay, clay and clay of clay, clay and sand, clay and sand and gravel mixed (each 30cm). If only gravel was used, it was excluded from the experiment because it could not be compacted. As a result, in the 30cm clay cover experiment, which was expected to have the highest oxygen blocking effect, about 20% oxygen concentration similar to the atmosphere was measured after 19 hours and 30 minutes, and the oxygen blocking effect was the lowest among the compacted cover experiments. . On the other hand, in the case of 30 cm sand cover experiment, oxygen concentration of only about 12% was measured after 19 hours and 30 minutes.

This means that the compacted sand layer has a high effect on blocking oxygen introduced into the interior. In fact, in the soil cover test using only sand, nitrogen gas did not flow into the micropressure used when filling with other media, and when the pressure was slightly increased, water dropped to the lower part (a change in moisture content of the soil medium occurred). Nitrogen was introduced. This result, unlike clay that absorbs and expands water into the particles, is caused by sand that is bound by the particles present between the particles and the particles, and air cannot be penetrated by the water present between the particles. I think it is possible.

On the other hand, when 19 hours and 30 minutes passed, about 19% of the soil cover was confirmed by mixing sand and clay, and about 18% of soil cover was determined by mixing clay, sand and gravel. This is possible because the internal pores were reduced by irregular particles as in the result of the compaction 30cm cover soil test, and the wet sand contained in the cover soil medium did not perform oxygen permeation well.

Explain the compaction of the soil. The compaction of the soil is usually carried out by mechanical methods such as rolling, tamping or vibration, reducing the voids and increasing the bulk density. Therefore, compaction reduces soil porosity and permeability coefficient, and increases shear strength and bearing capacity. In the indoor compaction test, the compaction method is largely classified according to the size of the compaction energy. There are a standard compactor test and a modified compactor test. The standard compaction test method is to divide soil into three layers in a mold of inner diameter 100mm and height 127.3mm (volume 1,000cm ³ ), and compaction by dropping 2.5kg hammer 25 times at a height of 30cm for each layer. In the modified compaction test method, soil is divided into five layers in a mold having an inner diameter of 150 mm and a height of 125 mm (volume 2,209 cm ³ ), and compacted by dropping 55 times at a height of 45 cm with a 4.5 kg hammer for each layer. In Korea Industrial Standard KS F 2312, the compaction method is divided into five methods, A, B, C, D, and E, depending on the combination of mold size and hammer weight. Compaction test used in this experiment was carried out in accordance with the KS F 2312-91 (96), ASTM D 698-91 (98), AASHTO T 79-90 test, was determined by the D method, a modified compaction test method. On the other hand, when the soil is compacted, the soil retains water, that is, the water content affects the compaction efficiency.

Clay, sand, clay and sand mixed with clay in a volume ratio of 1: 1, and soil mixed with clay, sand and gravel in a volume ratio of 1: 1: 1 The filling density / function ratio is shown in FIG. As a result of the compaction test, clay had the highest filling density at about 9.5% water content, sand at about 10% water content, about 8.5% for clay and sand mixed soil, and clay, sand and gravel mixed soil Showed the highest packing density at a water content of about 7.5%.

Based on the results of the three experiments (compact 30cm, 60cm, compaction 30cm) carried out previously, a 60cm covered soil test was performed. In the experiment, the sand layer, which had high oxygen blocking effect, was applied to the middle layer during the cover, and the concept of covering the clay using the compacted clay on the top of the sand layer was applied to minimize water penetrating into the bottom. In order to catch the water flowing out of the sand layer under the sand layer and to prevent the sand from being swept down to the lower porosity (mining waste pit), the clay was also covered with clay.

The experiments were carried out on four types of covering methods, all of which covered the plowed clay on the lower layer, the plowed sand layer on the middle layer, and the plowed clay layer on the upper sand layer. The clay method applied to the experiment was the first clay (20 cm) + sand (20 cm) + clay (20 cm), the second clay (15 cm) + sand (30 cm) + clay (15 cm), third clay (10 cm) + sand (40 cm) + Clay (10cm), fourth clay (10cm) + sand (15cm) + clay (10cm) + sand (15cm) + clay (10cm) was applied. The results are shown in FIG.

All of the four soil cover experiments with a compacted sand layer intervened with single compact and mixed media cover experiments of compaction, and compacted media and mixed media cover experiments with compacted sand. Up to about 6%) over 20 hours. The lowest oxygen inflow (approximately 2% over 20 hours) of the compacted 60cm cover experiments was achieved by applying a 40cm layer of sand sandwiched between cover media. However, the results showed that the oxygen concentrations were almost similar to those of the compacted 30 cm sand layer. On the other hand, the 20 cm sand layer introduced more oxygen by about 4% in 20 hours than the 40 cm or 30 cm sand layer.

The use of sand as a cover medium increases cover costs because it is not readily available around the abandoned mine. Therefore, it is considered economical to use sand with minimum thickness in consideration of the increase of cover cost. In the cover experiments (10cm clay + 15cm sand + 10cm sand + 15cm sand + 10cm clay), which was conducted to produce such a low-cost, high-efficiency effect, more oxygen (approximately 5% over 20 hours) was introduced when a 30 cm sand layer was applied. Appeared. This means that when the same amount of sand layer is applied separately, the oxygen blocking efficiency is lowered.

The results of measuring the oxygen concentration flowing into the interior after applying the clay of single compact and mixed media of compaction, covering the compacted single media and mixed media, and the compacted layered cover using clay, sand and gravel as simple media In addition, the oxygen barrier effect is high when the sand layer with a certain thickness is applied inside the cover medium.

That is, when comprehensively judging the experimental results, it is preferable to form a clay layer in the upper and lower layers, respectively, with the sand layer in the center as in the present invention, because the clay layer having a small permeability coefficient keeps the moisture in the sand layer. Judging. That is, the clay constituting the clay layer absorbs water and expands to block water, but the effect of blocking oxygen is low, while the sand layer has a high water permeability, but unlike clay, water exists between sand particles and particles. Because of the high oxygen blocking effect. As a result, the clay in the upper and lower layers prevents water existing between the sand particles from being discharged to the outside, and the water between the sand particles blocks the air. In addition, the capillary force acts inside the sand layer to prevent the inflow of water from flowing out.

On the other hand, the oxygen is also present in the water coming from the outside bar should also block the inflow of water, because the clay absorbs the water can also prevent the inflow of water.

1A and 1B are photographs showing an example of contamination by acidic leachate discharged from coal mine waste quarries.

2 is a schematic diagram for explaining a cover layer.

3 is a schematic configuration diagram of a cover design apparatus according to a preferred embodiment of the present invention.

Figure 4 is a graph showing the oxygen transmission rate for the cover layer to which the compacted single (mixed) cover medium 30Cm is applied.

FIG. 5 is a graph showing the oxygen permeability of the cover layer to which 60 Cm of the compacted single (mixed) cover medium is applied.

FIG. 6 is a graph showing the oxygen transmission rate for the cover layer to which 30 cm of compacted single (mixed) cover medium is applied.

7 is a table showing compaction efficiency according to the moisture content of the cover medium.

FIG. 8 is a graph showing oxygen permeability when a 60 Cm multilayered cover layer is constructed using a compacted cover medium.

9 is a schematic diagram showing a structure of a cover layer according to a preferred embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

100 ... cover design device 10 ... body

20 ... support plate 30 ... cover member

40 ... oxygen sensor 50 ... storage

60 ... Electric coil 70 ... Thermoelectric element

80 ... insulation w ... waste-rock storage

R ... cover layer R1 ... first clay layer

R2 ... sand layer R3 ... second clay layer

Claims (11)

As a cover design device for designing a cover layer stacked on the waste stockpile to prevent oxygen from entering the waste pile, A main body with an upper end open; A support plate installed inside the main body and formed of a network having a plurality of holes through which only particles having a predetermined size or less can pass therethrough, and having a cover medium stacked on the upper portion of the cover material being used as a cover material for the waste stockyard; A cover member detachably coupled to an upper end of the main body to open and close an open upper end of the main body, and a gas inlet port formed to allow gas to flow into the inner side of the main body; And And an oxygen sensor disposed between the lower end of the main body and the support plate and measuring an oxygen concentration in the air introduced into the upper end of the main body and discharged through the cover medium. The method of claim 1, Cover device is characterized in that the cover member is formed with a gas inlet port for introducing gas into the inside of the main body. The method of claim 2, And a nitrogen tank is connected to the gas inlet port so that nitrogen can be introduced into the main body. The method of claim 1, And a gas discharge port for discharging the gas in the main body between the lower end of the main body and the support plate. The method of claim 4, wherein The gas discharge port is connected to the discharge pipe for guiding the discharge of the gas, And an end portion of the discharge pipe is immersed in a water tank so as to prevent outside air from flowing into the main body through the discharge pipe. The method of claim 1, And a storage device for recording and displaying the concentration of oxygen measured by the oxygen sensor. The method of claim 1, The cover design device further comprises a heating means and a thermal reduction means for increasing or decreasing the temperature inside the main body. As a cover layer stacked on the waste stockyard to prevent oxygen from entering the waste pile, A first clay layer comprising clay and stacked on the waste pile; A sand layer including sand and stacked on the first clay layer; And A clay layer comprising clay; a second clay layer laminated on the sand layer. The method of claim 8, The sand layer is a cover layer, characterized in that the sand layer compacted by pressing at a predetermined pressure.  The method of claim 8, The sand layer is made of sand and water, A cover layer, characterized in that the water content is the ratio of the weight of water to the weight of sand is 5% to 15%. The method of claim 8, The thickness of the sand layer is a cover layer, characterized in that more than 4/10 of the total thickness of the sum of the first clay layer, the sand layer and the second clay layer.

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