KR100868776B1 - Coating stuff for the prevention of acid drainage and for the revegetation in acid sulfate soil material - Google Patents

Abstract

A coating agent is provided to prevent generation of the acidity drainage by the oxidation of the acid sulphate soil by suppressing pyrite from contacting with atmosphere and to accelerate vegetation coating at the acid sulphate soil by flowing out the aluminium(Al) including the acid sulphate soil. A coating agent coating acid sulphate soil for controlling acidity drainage and promoting vegetation coat is manufactured by mixing 0.01M of KH2PO4, 0.01~0.03M of H2O2 and 0.01M of Na2CO3.

Description

Coating agent for inhibiting acid drainage and promoting vegetation coating {Coating stuff for the prevention of acid drainage and for the revegetation in acid sulfate soil material}

The present invention relates to a coating for inhibiting acid drainage and promoting vegetation coating from specific acidic soils. More specifically, the specific acid soil containing pyrite is oxidized when exposed to the atmosphere to elute iron ions and sulfates to generate acidic drainage. The specific acid soil contains KH ₂ PO ₄ , H ₂ O ₂ and By coating the coating agent, which is a mixture of Na ₂ CO ₃ , prevents pyrite from coming into contact with the atmosphere, reducing the occurrence of acid drainage and promoting the vegetation coating by preventing the aluminum (Al) contained in the specific acid soil from eluting. The present invention relates to a coating agent for inhibiting acid drainage and promoting vegetation coating from specific acid soil.

Sulfide minerals are minerals that are commonly output is directly produced by precipitation or hot water and the reaction of the rock from the hot water in the rocks, sediments, soil, Argentite (Ag ₂ S) associated with diagenesis, magma activity in reducing the deposition environment, chalcocite ( Cu ₂ S), galena (PbS), sphalerite [(Zn, Fe) S], chalcopyrite (CuFeS ₂ ), covellite (CuS), cinnabar (HgS), pyrite (FeS ₂ ), arsenopyrite (FeAsS), molybdenite (MoS ₂ ) there are various kinds of sulfide minerals.

Sulfide minerals are oxidized when they are exposed to the atmosphere by stable or ground excavation, groundwater drop, drainage, dredging, etc. It contains a lot of sulfide minerals, so it is a potential acid sulfate soil that is highly likely to generate acid drainage in the future (potential acid sulfate soil). Acidic soil (actual acid sulfate soil).

Pyrite is the most common sulfide mineral and is a major source of acid drainage. Oxidation process of pyrite and production of acid drainage are as follows.

_{FeS 2 + 3.5O 2 + H 2} O --- → FeSO 4 + SO 4 2 - + 2H +

_{2FeSO 4 + 0.5O 2 + SO 4} 2 - + 2H + --- → Fe 2 (SO 4) 3 + H 2 O

FeS ₂ + Fe ₂ (SO ₄ ) ₃ --- → 3FeSO ₄ + 2S0

_{2S0 + 3O 2 + 2H 2 O} --- → 2SO 4 2 - + 4H +

Fe ^{3 +} + 3H ₂ O ----> Fe (OH) ₃ + 3H ⁺

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_{FeS 2 + 3.5O 2 + 4H 2} O --- → Fe (OH) 3 + 2SO 4 2 - + 5H +

Acid drainage is strongly acidic and contains many heavy metals eluted from sulfide minerals. Acid drainage also increases the solubility of minerals other than sulfide minerals, elevating various types of ions from rocks, sediments and soils. Therefore, acid drainage contains heavy metals, iron, aluminum and so on. Acid drainage produced by oxidation of sulfide minerals causes various problems such as acidification of soil, surface water and groundwater and heavy metal contamination, corrosion of structures, vegetation death, and landscape damage by sediment.

In addition, the problem of acid drainage occurring in the closed mine area is widely known. Due to the recent expansion of infrastructure, the ground excavation frequently occurs at the construction site, which leads to the problem of acid drainage due to the ground excavation in the latent soil. It is emerging as a new issue in our society, and it is urgent to establish and implement measures.

In Korea, rocks and sediments with high probability of generating acidic drainage are widely distributed throughout the country.The rocks are distributed in major metal mineralization zones, Pyungan Formation Group in Gangwon region, Mesozoic Cretaceous Volcanic rocks in southern region, Okcheon Formation Group in Chungcheong region, The third sedimentary rocks and volcanic rocks in Pohang area, and the fourth sedimentary deposits in Gimhae and Pyeongtaek area are representative latent soils. The damage caused by acid drainage in the abandoned mine area is widely known, and the acid drainage caused by the ground excavation and sediment at the construction site of the Okcheon Formation Group and the Baekamgi volcanic rocks is affected by crop drainage, agricultural land pollution, and river water pollution. Is occurring.

In order to reduce the damage caused by acidic drainage, various technologies to neutralize the generated acidic drainage have been developed and applied to the field. Typical neutralization techniques are chemical neutralization using alkali such as NaOH, CaO, Ca (OH) ₂ , and CaCO ₃ . , Neutralization using limestone channels and neutralization using artificial wetlands.
Recently, by using a mixture of KH ₂ PO ₄ and H ₂ O ₂ to treat the surface of pyrite causing acid drainage, the damage of acid drainage is reduced. However, when the coating agent is a mixture consisting of KH ₂ PO ₄ and H ₂ O ₂ , secondary problems such as acidification of the surrounding area and water, acidification of Al, Fe, heavy metals, etc. are caused by the generated acidic water. .

Techniques for fundamentally suppressing the generation of acidic drainage from specific acidic soils include containment and underwater storage to isolate acidic drainage material from the atmosphere. Although proven and applied in many sites, it has a disadvantage of being expensive.

The characteristic acidic soils are acidic, the plant availability of aluminum is high, and germination, rooting and growth of vegetation are poor. In particular, poor vegetation coatings in the tailings mines and the fill layers of construction sites cause problems of soil erosion and diffusion of pollutants by rain and wind.

It is urgent to develop a method for suppressing the occurrence of acidic drainage from specific acidic soil and smoothly performing vegetation coating. Various techniques are proposed as follows to suppress the occurrence of acidic drainage.

In Korean Patent Application No. 1997-0062322 (name: heavy metal removal and neutralization device of waste mine leachate), in order to block the outside air to prevent the formation of sediment and to remove and purify heavy metal contained in the leachate, iron acid A septic tank buried in the ground to prevent the formation of cargo, and a filtration member made of small particles, a filtering member made of a polymer synthetic resin passing water, adsorbing a small amount of heavy metal, and at least one activated carbon and sand in the septic tank. Or purifying means comprising a purifying member composed of a polymer synthetic resin and sand; In order to neutralize the high acidity of the leachate which has been cut off from the outside air and has passed through the above-mentioned purification means, it is arranged in at least one of the above-mentioned septic tanks, and in the soil layer so as to be introduced or discharged through the drain pipe and blocked from the outside air. A heavy metal removal and neutralization device of waste mine leachate composed of a neutralization tank buried and a neutralization means comprising a neutralizing member for neutralizing the acidity of the leachate taking up a certain space in the neutralization tank is provided.

Korean Patent Registration No. 0427774 (name: method for purifying waste mine wastewater and its apparatus) includes a first precipitation step of relieving the flow rate of leachate flowing out of the waste shaft and precipitating solids having a high soil or specific gravity in a primary precipitation tank; A primary filtration step in which the inflow water discharged from the primary sedimentation tank circulates through the filter of the primary filtration tank, while the iron oxide is naturally precipitated and adsorbed, and at the same time, precipitates the self-cleaning action and the excess sludge; A secondary filtration step of stabilizing the influent purified through the primary filtration tank to finally settle the fine suspended sludge in the secondary filtration tank; And a secondary sedimentation step in which the secondary sedimentation tank collects and discharges clean iron-free clean water discharged from the secondary filtration tank; and a method for purifying waste mine wastewater, including reducing the flow rate of the leachate flowing out of the waste shaft. A primary precipitation tank for precipitating solids having a high specific gravity; A contact filtration tank equipped with a primary filtration tank in which iron oxide is naturally precipitated and adsorbed while the inflow water discharged from the primary precipitation tank circulates through the filter, and thereafter, a secondary filtration tank for precipitating fine suspended sludge; A second mine sedimentation tank for collecting and discharging the clean clean water without iron oxide discharged from the secondary filtration tank is provided;

Korean Patent Registration No. 0493240 (name: acid drainage treatment method of the inclined slope), the first step of forming a stepped surface of a predetermined width for each predetermined section of the road or a cut slope generated during civil engineering work; A second step of forming a trench on the step surface, and mixing and applying a corrosive soil, an acid neutralizer, and a heavy metal remover at a predetermined ratio; And installing an acid neutralization and heavy metal removal layer at a predetermined position at the lower end of the inclined slope so as to treat untreated contaminants in the step surface and slope runoff immediately before the acid drainage discharged from the inclined slope reaches the water channel installed at the side of the road. It includes three steps, the mixing ratio of the caustic soil and acid neutralization and heavy metal remover in step 2 is the acid drainage treatment method of the inclined slope in which 10 to 20 parts by weight of the acid neutralization and heavy metal remover is added to 100 parts by weight of humus earth Presented.

The conventionally proposed techniques have a disadvantage in that the treatment for reducing the emission of pollutants is complicated, or various structures are installed, and the vegetation coating is not performed on specific acid soils.

An object of the present invention is to suppress the occurrence of acid drainage by oxidation of specific acid soils, and to promote vegetation coating on specific acid soils.

In order to achieve the above object, to suppress the occurrence of acidic drainage of specific acid soil and to propose a coating for promoting vegetation coating.

The present invention to achieve the above object,

To suppress acid drainage and promote vegetation coating, pyrite (sulphurized mineral) contained in specific acid soil is coated, and the coating agent is composed of KH ₂ PO ₄ , H ₂ O _2, and Na ₂ CO ₃ .

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The coating agent is made of 0.01M KH ₂ PO ₄ , 0.01 ~ 0.03MH ₂ O ₂ , 0.01M Na ₂ CO ₃ , preferably 0.01M KH ₂ PO ₄ , 0.02MH ₂ O ₂ , 0.01M Na ₂ CO ₃ .

By coating pyrite with the coating agent as described above using a spreading device and an input device to the specific acid soil, it suppresses the generation of acidic drainage from the specific acid soil and at the same time reduces the plant availability of aluminum to promote vegetation coating.

The spreading device is composed of a high-pressure pump and a sprayer, and spreads the surface to be wet 2 to 5 times enough to the specific acidic soil using the spreading device so that the specific acidic soil can be coated by the coating agent.

The dosing device is provided with perforated pipes 50 embedded in the specially acidic soil, supply pipes 40 for addressing the perforated pipes 50 and supplying a coating agent, and a valve 30 installed on the supply pipes 40. And a high pressure pump 20 supplying the coating material to the supply pipe 40 so as to have a pressure. The coating material is supplied to the supply pipe 40 using the high pressure pump 20, and the supply pipe 40 is supplied to the supply pipe 40. The coating agent is coated with the specific acid soil by the perforated pipe 50 which is embedded in the specific acid soil at regular intervals.

The H ₂ O ₂ is for oxidizing the surface of pyrite, the KH ₂ PO ₄ is for iron phosphate coating, reducing aluminum toxicity, promoting plant root growth (nutrient), Na ₂ CO ₃ is neutralized, iron hydroxide Or iron oxide coatings, to reduce aluminum toxicity.

In accordance with the present invention, by suppressing the acidic drainage discharged from the specific acidic soil and causing the precipitation of Al, Fe, heavy metals to remove harmful elements from the drainage, to prevent damage to the surrounding environment by acidic drainage and harmful elements and vegetation There is an effect of enabling the coating.
That is, when the surface of pyrite is coated with a coating agent composed of H ₂ O ₂ and KH ₂ PO ₄ , a coating of iron-phosphate mineral is formed to reduce oxidation of pyrite and occurrence of acid drainage, but iron-hydroxide and aluminum- There is a disadvantage that does not solve the problem of acidic drainage caused by hydroxides. However, when KH ₂ PO ₄ and H ₂ O ₂ and Na ₂ CO ₃ coating agents are used, the surface precipitation of not only iron-phosphate minerals, but also iron-hydroxide and aluminum-hydroxide occurs, which leads to oxidation and acidity of pyrite. The efficiency of reducing the generation of waste water can be improved.

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Oxidation of the material of the main reasons occurred acid drainage pyrite is produced by the reaction of pyrite surface contact with the oxidant iron ions (Fe ^2+, Fe ³⁺⁾ and sulfate (SO ₄ ^{2 -)} in the oxidation process has been shown to elute the the iron ion is phosphate (PO ₄ ^{3 -)} and the reaction was precipitated by low solubility stable iron phosphate mineral (vivianite, strengite), also iron ions are precipitated with iron hydroxide or iron oxide minerals in the pH 3.5 or more conditions.

The present invention oxidizes the surface of pyrite in specific acidic soils, and precipitates and coats iron ions eluted during the oxidation process on the surface of pyrite with iron phosphate, iron hydroxide or iron oxide minerals to prevent contact between the oxidant and pyrite in the medium. By blocking, the oxidation of pyrite is fundamentally prevented and acid drainage is suppressed. That is, the surface of the pyrite is oxidized for the leaching of iron and iron ions, and chemicals for the precipitation coating are added to the specific acid soil at an appropriate concentration to suppress the occurrence of acid drainage.

Aluminum (Al) exists in various forms such as water soluble, exchangeable, oxides, hydroxides, carbonates, and phosphates in the soil, and the toxicity of aluminum in the soil depends on the concentration of water solubility and exchangeability. Depends on pH and type of anion. When soil pH is neutral, water-soluble and exchangeable aluminum is converted to hydroxide, other compounds are less soluble, and aluminum phosphate minerals are known to be stable in soil and have very low plant availability.

The present invention, by adding a suitable concentration of phosphate and neutralizing agent to the acidic and highly available specific acid soils to produce a stable compound, lowering the solubility to reduce the plant availability of aluminum to promote the growth and growth of vegetation.

Phosphorus (P), the three essential nutrients of plants, promotes the growth of plant roots. In particular acid soils, the growth of plants originates from the growth and disease of roots. Therefore, the present invention promotes the rooting and growth of vegetation by supplying the soil with phosphorus essential for plant root growth.

In the present invention, H ₂ O ₂ is used to oxidize the surface of the specific acidic soil (pyrite), and KH ₂ PO ₄ is used for iron phosphate coating, reducing aluminum toxicity, and promoting plant root growth (nutrients). Na ₂ CO ₃ is used to reduce the toxicity of iron, iron hydroxides or iron oxides, and aluminum.

EXAMPLE

1. Determination of optimal treatment conditions to suppress acid drainage

Pure pyrite was pulverized to a particle size of 63 μm or less and washed with hydrochloric acid and acetone, and the solution containing various concentrations of KH ₂ PO ₄ , H ₂ O ₂ (coating agent) and pyrite was 10: 1 ratio by weight. After 24 hours of reaction, the pH, Fe and SO ₄ ^{2 -} concentrations of the solution were measured to derive the optimum coating agent conditions.

The pH, Fe and SO ₄ ^{2 -} concentrations of the solution after the reaction indicate the oxidation degree and the degree of coating formation of pyrite. The higher the pH of the solution and the lower the Fe and SO ₄ ^{2 -} concentrations, the better the coating formation and the less oxidation. have.

TABLE 1

Coating Solution after reaction PO ₄ concentration (M) H ₂ O ₂ concentration (M) pH pH Fe concentration (mg / L) SO ₄ ^{2 -} Concentration (mg / L) 0.0001 0.01 6.03 3.02 34.94 363.21 0.0001 0.02 6.08 3.06 39.19 430.18 0.0001 0.05 6.11 2.97 49.51 494.23 0.0001 0.08 6.06 2.89 62.43 579.44 0.0001 0.1 6.15 2.86 64.88 607.71 0.001 0.01 6.06 2.84 4.14 345.18 0.001 0.02 6.11 2.66 17.79 466.72 0.001 0.05 6.08 2.59 30.17 581.96 0.001 0.08 6.09 2.57 48.69 706.58 0.001 0.1 6.00 2.50 57.95 741.46 0.01 0.01 6.00 5.21 0.12 143.69 0.01 0.02 5.98 5.14 0.05 124.03 0.01 0.05 5.97 4.96 0.69 215.38 0.01 0.08 5.97 4.61 0.13 383.79 0.01 0.1 5.98 4.37 0.35 512.62

As shown in Table 1, the conditions of the highest pH of the solution after the reaction are 0.01M (mole) KH ₂ PO ₄ , 0.01M (mole) H ₂ O ₂ , Fe and SO ₄ ^{2 −} The lowest conditions were 0.01M KH ₂ PO ₄ and 0.02MH ₂ O ₂ . _{0.01M KH 2 PO 4, 0.01MH 2} O 2 and Fe SO conditions after reaction in solution ^{₄₂ -} concentration was slightly above the solution after the reaction in _{0.01M KH 2 PO 4, 0.02MH 2} O 2 conditions. Fe and SO ₄ ² in the reaction solution and then ^- considering the density of the coating is determined to be formed in _{0.01M KH 2 PO 4, 0.02MH 2} O 2 conditions are slightly superior than _{0.01M KH 2 PO 4, 0.01MH 2} O 2 conditions do. After the reaction with the acid produced during the coating, the solution was slightly acidic (lowered to pH 5.1 at pH 6). The use of 0.01 M Na ₂ CO ₃ , a commonly used neutralizing agent to neutralize the solution after the reaction, can neutralize the acid and facilitate the precipitation of iron oxide or iron hydroxide, which is more effective. Therefore, the coating agent is 0.01M KH ₂ PO ₄ , 0.02MH ₂ O ₂ , 0.01M Na ₂ CO ₃ at the optimum coating conditions.

2. Confirmation of coating formation (surface analysis)

It was confirmed that the coating was formed after reacting with a solution (coating agent) having a concentration of 0.01M KH ₂ PO ₄ , 0.02MH ₂ O ₂ without crushing pyrite having a flat surface.

1) microscopic observation

Coated pyrite and uncoated pyrite were reacted with 0.1MH ₂ O ₂ solution to oxidize and the surface was observed under a microscope. As a result of observing the surface by microscope, the surface of the coated pyrite was relatively clean and found no sign of oxidation. On the other hand, the surface of the pyrite uncoated was observed a lot of iron oxide indicating that the oxidation proceeded.

2) Surface Chemical Analysis of Coated Pyrite Using Electron Microscopy (SEM)

The chemical composition of pyrite coated was analyzed using EDX, a chemical analyzer equipped on an electron microscope. Chemical analysis confirmed that the phosphate material is present on the pyrite surface (see Fig. 1).

3) Surface analysis using X-ray photoelectron spectroscopy (XPS)

In order to identify the coating formed on the surface of the coated pyrite, the chemical composition was analyzed by depth at the surface using XPS. As a result of XPS analysis, 5Å of iron phosphate and iron oxide coating were formed on the surface of pyrite, and 25Å thick mixed layer containing iron phosphate, iron oxide, and pyrite was present below (see FIGS. 2 and 3).

3. Effect of reducing acid drainage by coating of standard pyrite

The effect of reducing acid drainage by coating treatment after coating standard pyrite with a solution having a concentration of 0.01M KH ₂ PO ₄ , 0.02MH ₂ O ₂ , 0.01M Na ₂ CO ₃ was measured. The coating standard pyrite was oxidized to test the effect of reducing acid drainage by coating.

TABLE 2

Reaction solution division H ⁺ ion concentration of solution after reaction (mM) Reduction rate of sulfuric acid generation by coating Exam conditions Distilled water  Coating 0.19 80.9% Pyrite and solution ratio of 1: 10 suspension at room temperature (20 ℃) for 24 hours  No treatment 1.01 0.0001MH ₂ O ₂ solution  Coating 0.21 80.9%  No treatment 1.10 0.001MH ₂ O ₂ solution  Coating 0.40 72.2%  No treatment 1.44 0.01MH ₂ O ₂ solution  Coating 1.08 51.8%  No treatment 2.24

4. Durability of Coating

10 g of pyrite coated with a solution (coating agent) having a concentration of 0.01 M KH ₂ PO ₄ , 0.02 MH ₂ O ₂ , 0.01 M Na ₂ CO ₃ was dissolved in pH 3-10 sulfuric acid (H ₂ SO ₄ ) or sodium hydroxide (NaOH). ) After reacting with 100 ml of solution for 24 hours, the elution amount of phosphoric acid was measured to measure the durability of the coating. In the experimental conditions, as shown in Table 3 below, more than 96% of iron phosphate was present without being eluted.

TABLE 3

Reaction condition pH 3 pH 5.8 pH 10 PO ₄ ^{3 -} Elution amount 1.12mg / g (3.20%) 0.36 mg / g (1.04%) 1.17mg / g (3.36%) PO ₄ ^{3 -} content of anodized pyrite 34.92mg / g

5. Cut off acid drainage Inhibit acid drainage on rock slopes

Acid drainage generated from the cutting slope causes various problems such as degradation of slope stability and environmental pollution.

In order to test the efficiency of the coating treatment to suppress acid drainage from cut slopes, acid drainage suppression tests were conducted on cut slopes in Boeun-gun, Chungbuk. The rock exposed to the slopes was degenerated sedimentary rocks containing pyrite. This is where strong acid drainage occurred.

Before the coating treatment, the weathered area was removed to expose fresh rock from the slope, and the 4m * 4m slope was partitioned into four sides using acrylic. Two of each of the four surfaces were used for treatment and coating. The surface to be coated was sprayed three times using a high pressure pump and a sprayer so that the slope was sufficiently wet. Immediately after rainfall, slope drainage was taken from the untreated and coated slopes, and the pH of the sample was measured to determine whether acid drainage was inhibited by the coating treatment.

The coating agent was a solution having a concentration of 0.01M KH ₂ PO ₄ , 0.02MH ₂ O ₂ , 0.01M Na ₂ CO ₃ .

The drainage of the coated slopes was similar to or slightly below the average pH 5.4 of rainwater collected near the experimental slopes. On the other hand, untreated slope drainage showed strong acidity of about pH 3. Therefore, it can be seen that the coating treatment suppresses the generation of acidic drainage from the slope (see FIG. 4).

6. Suppression of acid drainage from excavation / crushed rock fragments

Acid drainage from excavated rock at the construction site, waste rock from tailing mines and tailings causes various problems such as environmental pollution and poor vegetation cover in the surrounding area.

In order to test the efficiency of acid drainage from excavated rocks, waste rocks and tailings, the acidic drainage suppression effect was examined by treating the andesite and metamorphic sedimentary rocks containing pyrites to less than 2cm and coating them.

The coating agent was a solution having a concentration of 0.01M KH ₂ PO ₄ , 0.02MH ₂ O ₂ , 0.01M Na ₂ CO ₃ .

As a result of the experiment, the coating treatment as shown in Table 4 below reduced the occurrence of acid drainage more than 90% from the rock piece.

TABLE 4

rock process Acid generation amount (gH ₂ SO _{4 /} kg) Reduction rate of acid drainage (%) Andesite No treatment 19.23 Coating 1.60 91.7 Metamorphic sedimentary rocks No treatment 0.92 Coating 0.02 97.8

7. Suppression of acid drainage and promotion of vegetation coating: pollen test

Artificial soil was prepared by mixing the specific acidic soil collected from Pyeongtaek-si, Gyeonggi-do and the andesite powder with pyrite content of 12%. Artificial soil was filled with a diameter of 25 cm and a height of 30 cm PVC pots to a depth of 15 cm. 5 liters of untreated water and 5 liters of coating were poured on top and left for 3 days after passing through the soil layer. After standing, 80 seeds of genie barley (ryegrass) were sown in each pot, and the germination rate and growth state were observed for 2 months, and the biomass was measured. In addition, during the 2-month observation process, 10L of tap water was irrigated at a weekly interval and the pH of the leachate was measured.

The coating agent was a solution having a concentration of 0.01M KH ₂ PO ₄ , 0.02MH ₂ O ₂ , 0.01M Na ₂ CO ₃ .

During the experimental period, the leachate pH of untreated pollen was 3 ~ 5 and the pH of coated pollen was 5 ~ 6.5. The biomass was about 6 times higher in biomass (6.33 g / pot) of genie barley (ryegrass) grown in coated pots than in biomass (1.90 g / pot) of genie barley (1.90 g / pot) grown in untreated pots. Leachate pH and biomass data indicate that acidic drainage was inhibited by coating and promoted vegetation growth.

8. Vegetation coating of acid drainage rock source soil

The experiments were conducted on soils developed from degenerated sedimentary rocks of the Okcheon Formation that generate acidic drainage. The soil to be tested did not show low pH, which is a characteristic of presently specific acidic soils, but the vegetation did not grow due to high Al activity. Therefore, Al toxicity reduction and vegetation growth promotion efficiency associated with soil input of coating treatment were tested. 80 L of a solution having a concentration of 0.01 M KH ₂ PO ₄ , 0.02 MH ₂ O ₂ , and 0.01 M Na ₂ CO ₃ , which were coated in 1 m 2 of the soil, was added using a sparging device (high pressure pump and sprayer) and a soil injection device.

Untreated and coated cotton (2m * 4m) centipede (ryegrass) seeds were scattered and covered with field soil with a thickness of about 0.5cm and the vegetation growth was observed. After the soil was collected, the coating treatment was added and left for 3 days, and aluminum (Al) was extracted by the presence type (water soluble, carbonate and organic form, iron oxide form, 1M citric acid extractable form) and the change of the presence form of Al was measured.

As shown in Table 5 below, all of the water-soluble Al was converted to low plant availability by coating treatment, which means that the toxicity and plant availability of Al were reduced by the soil injection of the coating agent.

[Table 5] Change in the Form of Soil Aluminum (Al) by Treatment

Al Presence Form Untreated soil Coated soil receptivity 9.4 mg / kg 0.0 mg / kg carbonate and organic form 49.4 mg / kg 64.6 mg / kg oxide form 904.0 mg / kg 728.8 mg / kg 1M citric acid extractable form 58.0 mg / kg 51.4 mg / kg

Both germination and coating treatment showed similar germination rate (about 70%) of ryegrass, but it was observed that vegetation growth was much higher by coating treatment as shown in Table 6. The vegetation growth by coating treatment is believed to be due to the reduction of Al toxicity and fertilizer effect by the coating treatment added to the soil.

[Table 6] Vegetation Growth Status after 1 Month

division Stem numbers Leaf numbers Height No treatment One 2-4 2-5cm process 2-3 5-9 4-8cm

That is, the coating agent of the present invention can promote acid suppression of generation and suppression of vegetation coating from acid drainage generation cut and embankment of waste mines and construction sites.

In addition, by using the coating of the present invention it is possible to safely treat and recycle the acid drainage generated excavated rock and waste.

In addition, by using the coating of the present invention it is possible to cover vegetation in the soil with high toxicity of aluminum (Al).

1 is a table of EDX chemical analysis of pyrite coated with the coating of the present invention.

Figure 2 is an XPS chemical analysis result table of pyrite coated with the coating of the present invention.

Figure 3 is a schematic cross-sectional view of pyrite coated with the coating of the present invention.

Figure 4 is a table comparing the pH of the treated and untreated coating of the present invention.

Figure 5 is a schematic view of the input device for injecting the coating of the present invention into the soil.

[Explanation of symbols on the main parts of the drawings]

10: coating tank 20: high pressure pump

30: valve 40: supply pipe

50: other hole

Claims (6)

The coating agent coating the specific acid soil to suppress acid drainage generation and promote vegetation coating is characterized by being mixed with 0.01M KH ₂ PO ₄ , 0.01 ~ 0.03MH ₂ O ₂ , and 0.01M Na ₂ CO _3. Coating agent to suppress drainage and promote vegetation coating. The method of claim 1, The H ₂ O ₂ is a coating agent for inhibiting acid drainage generation and vegetation coating, characterized in that 0.02M. delete delete delete delete

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