KR101016789B1 - Method for manufacturing functional soil material using the sludge of a coal mine - Google Patents

Abstract

The present invention relates to a method for producing a functional soil material using coal mine sludge, which is to manufacture the cover material and the order material that meets the respective selection criteria for soil cover and stabilization using coal mine sludge. To this end, the present invention, the sludge powderization step (S10) for powdering the coal mine sludge obtained in the coal mine; Mixing step (S20) of mixing the coal mine sludge powder obtained through the sludge powder forming step (S10) with the solidified material; to prepare a cover material, and to obtain the coal mine sludge powder obtained through the sludge powder forming step (S10) Fly ash (Bly ash) and bentonite (Bentonite) mixing step (S30); characterized in that the manufacturing of the filler material through, characterized in that it is possible to manufacture the cover material and the filler material that meets the requirements.

Cover material, liner, fly ash, bentonite, coal mine sludge

Description

Method for manufacturing functional soil material using coal mine sludge {METHOD FOR MANUFACTURING FUNCTIONAL SOIL MATERIAL USING THE SLUDGE OF A COAL MINE}

The present invention relates to a method for manufacturing functional soil material using coal mine sludge, and more specifically, to manufacture cover material and order material in accordance with the current selection criteria by using sludge obtainable from coal mine as cover material and order material. It relates to a functional soil material manufacturing method using coal mine sludge for.

In general, cover soils play an important role in the preservation of the surrounding environment, such as preventing the emission of odors, minimizing the release of meteorological pollutants, preventing the scattering and spillage of garbage, preventing the reproduction of pests and wildlife, preventing direct contact with humans, preventing fires, and improving the landscape. . In addition, it is very important in the operation of landfills such as reducing the amount of leachate generated, and improving work efficiency such as improving the ease of entering vehicles, unfolding and compacting, and reducing the penetration of rainwater.

 Applying a large amount of cover will reduce the landfill capacity in the future, reduce air permeability, and reduce the decomposition rate of organic matter. Therefore, in the case of covering the soil, the covering method should be selected in consideration of the purpose of the covering and the type of landfill waste, and the appropriate covering material should be used according to the exposure time and function of the covering point. According to the type of cover soil, the desirable soil characteristics are soils of permeability and air permeability, which are suitable for daily cover materials, such as uneven spreading, compacting, securing the stability of the waste layer, and preventing decomposition of the waste. In the case of intermediate cover material, low-permeability clay-based soil is mainly used to prevent gas emission and rainwater penetration, and gravel-mixed soil is preferable for the point to be used as roads in landfills. Loam soils with strong humus resistance, small permeability and adequate humus are suitable. In particular, intermediate cover is designed to reduce the occurrence of leachate by continually preventing the exposure of landfilled wastes to induce the scattering and odor reduction of wastes, as well as to provide the access roads of transport vehicles and quickly exclude rainwater during rainfall. Waste management legislation states that when landfill operations are interrupted for more than seven days on the exposed part of the landfill layer, they must be covered with a thickness of 30 cm or more.

The above classification of soil depends on the particle size and clay content, and the density and permeability of the soil vary depending on the particle size and water content. Soil is classified as shown in Table 1 according to the particle diameter and as shown in Figure 1 according to the composition ratio of sand-silt-clay.

Table 1-Classification of soil by particle size

The general criteria for the selection of cover materials include soils with extremely high acidity or alkalinity, soils containing harmful substances, soils that exacerbate the leachate or give vegetation, and are not suitable as cover materials. In terms of soil mechanics in consideration of the stability of the

On the other hand, since various contaminants accumulated in places such as waste landfills and metal mines can be directly or indirectly transferred to the surrounding environment and humans, damages are expected to prevent such contaminants from being transferred underground or above the ground. It is legally stipulated to lay down ordering materials such as clay and bentonite to a predetermined thickness.

However, it is difficult to secure raw materials by selecting the appropriate cover material and the order material according to the purpose of covering and ordering, and therefore, there is a problem that the cost consumption of covering material and the order material purchase is large.

The present invention has been made to solve the above problems of the prior art, by using a sludge obtainable from coal mining as a material for the cover material and the order material by using a method for producing a functional soil material using coal mine sludge suitable for cover and order purposes. The purpose is to provide.

In order to achieve the above object, the present invention comprises a sludge powdering step of powdering coal mine sludge obtained in coal mining; And a mixing step of mixing the coal mine sludge powder obtained through the sludge powdering step with the solidified material.

In addition, in the sludge powdering step, the coal mine drainage is reacted with Ca (OH) ₂ and slaked lime in a neutralization tank, and then concentrated by dehydration of the coal mine sludge obtained by solid-liquid separation in the precipitation tank, or the coal mine drainage is electropurified. It is characterized in that the coal mine sludge obtained by solid-liquid separation in the precipitation tank after the reaction tank is concentrated and dehydrated.

In addition, the solidifying agent is formed by mixing the hydrated lime, cement and fly ash in a weight ratio of 0.3: 0.3: 0.4, the mixing step is characterized in that the coal mine sludge powder and the solidified material is mixed in a weight ratio of 1: 0.4.

On the other hand, the present invention comprises a sludge powdering step of powdering coal mine sludge obtained from coal mining; Characterized in that consisting of; mixing the coal mine sludge powder obtained through the sludge powdering step with fly ash (Fly ash) and bentonite (Bentonite).

In addition, in the blending step, the coal mine sludge powder, fly ash and bentonite are characterized in that the mixture in a weight ratio of 1: 0.5: 0.1.

As described above, the method for producing a functional soil material using coal mine sludge according to the present invention makes it possible to manufacture a cover material by pulverizing the sludge obtainable from coal mine and mixing it with solidified material, and the coal mine sludge powder and ply By mixing the ash and the bentonite, it is possible to prepare the filler.

Hereinafter, a functional soil material manufacturing method using coal mine sludge according to the present invention will be described with reference to the drawings.

Figure 2 is a sequential diagram showing a method for manufacturing a cover material using coal mine sludge according to the present invention, Figure 3 is a coal mine sludge powder produced through the neutralization reaction tank of the functional soil material manufacturing method using coal mine sludge according to the present invention. 4 is a flowchart illustrating a process of manufacturing coal mine sludge powder through an electropurification tank in a functional soil ash production method using coal mine sludge according to the present invention.

In the method for manufacturing cover material using coal mine sludge according to the present invention, the coal mine sludge powder obtained through the sludge powder forming step (S10) and the sludge powder forming step (S10) are mixed with the solidified material. It consists of a mixing step (S20).

Item pH SiO ₂ Al ₂ O ₃ Fe ₂ O ₃ CaO MgO Na ₂ O K ₂ O TiO ₂ MnO P ₂ O ₅ Coal mine sludge 8.3 6.65 0.52 64.74 8.60 0.32 0.13 0.08 0.02 0.38 0.11

Table 2-Chemical Properties of Coal Mine Sludge Powder (Unit: wt%)

In general, in the sludge powdering step (S10) for powdering coal mine sludge having the chemical properties as shown in Table 2, the coal mine sludge is naturally dried, and then, it is filtered through a sieve to remove coal mine sludge powder of a certain size. Although it can be obtained, the coal mine drainage is reacted with Ca (OH) ₂ and slaked lime in a neutralization reactor and then solid-liquid separated in the precipitation tank to concentrate and powder the coal mine sludge, or to convert the coal mine drainage into an electropurification tank. After the process, the coal mine sludge obtained by solid-liquid separation in a sedimentation tank may be concentrated and dehydrated to obtain coal mine sludge powder.

The mixing step (S20) is a step of mixing the coal mining sludge powder obtained through the sludge powdering step (S10) and the solidifying agent formed by mixing the hydrated lime, cement and fly ash in a weight ratio of 0.3: 0.3: 0.4, coal mining Sludge powder and solidified material are mixed in a weight ratio of 1: 0.4.

Requirements Standard Permeability coefficient 5 × 10 ^-5 Cm / sec (Data for public hearing of metropolitan landfill infrastructure development project in 1995) Hazardous Ingredients Elution Below elution standard Water content Equipment will not stick less than 35% Compressive strength Equipment capable of driving 0.5kgf / cm ² or more smell No smell like ammonia color  If possible, the earth color is fine

Table 3-Requirements for Korean Intermediate Cover Material

Requirements U.S. EPA Regulations Liquid Limit (LL) 50% less than Plasticity Index (PI) 25% less than Dry density 1.5 t / m ³ or more Porosity 42% less than Organoclay content handful

 Table 4-Regulations on Covered Ash in accordance with US EPA

The requirements and regulations for Korean and US cover materials are shown in Tables 3 and 4, respectively, and the results of examining the harmful components of general coal mine sludge are shown below the specified standard values or not detected as shown in Table 5. have.

Test items unit The specified baseline result As mg / kg 1.5 or less 0.05 Pb mg / kg 3.0 or less 0.071 CD mg / kg 0.3 or less none Cr ^{6 +} mg / kg 1.5 or less none Cu mg / kg 3.0 or less none CN ^- mg / kg 1.0 or less none Hg mg / kg 0.005 or less 0.002 Organic phosphors mg / kg 1 or less none Tri. C. E mg / kg 0.1 or less none Tetra. C. E mg / kg 0.3 or less none Oil ingredients mg / kg 0.5 or less 5% less than

Table 5-Heavy Metal Containing Components of Coal Mine Sludge Tested by Rural Development Administration

 The selection of the solidifying agent and coal mine sludge mixture ratio used to stabilize the coal mine sludge is very important for controlling the odor in consideration of the occurrence of complaints due to the control of moisture content through exothermic reaction and the odor (ammonia) caused by the pH rise. The basic requirements of intermediate cover should also be met.

Accordingly, in order to calculate the optimum ratio of coal mine sludge and solidifying agent, the weight ratio of solidifying agent and coal mine sludge having a weight ratio of 0.3: 0.3: 0.4 of slaked lime: cement: fly ash is 1: 1, 1: 0.8, 1: The experiment to calculate the optimum compounding ratio by 0.6 and 1: 0.4 was carried out as follows. In this experiment, the compaction method according to KS F 2312 was used to analyze the compaction characteristics according to the compounding ratio. In addition, one of the B, E compaction method or the A, D compaction method can be selected according to the soil size, and after selecting the compaction method, the maximum dry density of the mixed soil from the compaction curve representing the relationship between dry density and water content And optimum moisture content (OMC). Since the sanitary landfill in metropolitan area generally uses the A compaction method, the experiment was also carried out using the A compaction method.The mass of the rammer, the inner diameter of the mold, the number of compactions, and the maximum allowable particle diameters were determined according to the compaction test method. same.

Title of the method Rammer mass (KG) Mold inside diameter (Cm) Compaction floors Number of compactions per floor Permissible particle diameter A 2.5 10 3 25 19 B 2.5 15 3 55 37.5 C 4.5 10 5 25 19 D 4.5 15 5 55 19 E 4.5 15 3 92 37.5

Table 6-Kinds of compaction methods according to KS F 2312

Table 7 shows the optimum water content and dry density according to the mixing ratio of A compaction test method.

Compaction method A Compounding cost 1: 1 1: 0.8 1: 0.6 1: 0.4 Optimal Function Rate (%) 38.8 41.3 43.3 46.5 Optimum dry density (g / cm ³ ) 1.296 1.275 1.240 1.196

Table 7-A Optimum Water Content and Dry Density according to Mixing Ratio of Compaction Method

After changing the compounding ratio of the cover material, the specimens were subjected to the standard A compaction of KS F 2314 having a diameter of 70 mm and a height of 150 mm at the four mixing ratios described above, and then placed in a constant temperature and humidity chamber at a temperature of 25 ° C. and a humidity of 95%. After curing, the uniaxial compressive strength of the specimens was analyzed using a compressive strength digital uniaxial compressive strength tester. Curing period was 1 day, 3 days, 7 days of wet curing was performed and the data are as shown in Figs.

Compaction method A Compounding cost 1: 1 1: 0.8 1: 0.6 1: 0.4 Curing date Strength (kg / cm ² ) 1 day 1.13 1.27 0.82 1.00 3 days 1.64 1.74 1.73 1.24 7 days 2.64 1.99 2.40 1.89

Table 8-Test results of uniaxial compressive strength

 The permeability coefficient test was carried out according to the compaction type with 8 different mixing ratios, and the triaxial compression permeability test method using ASTM D 5084 was adopted. According to the compaction test results, the permeability coefficient was calculated according to one compounding ratio and curing period, and the rest permeability coefficient was calculated based on the daily curing period.

Compaction Method A Compounding cost 1: 1 1: 0.8 1: 0.6 1: 0.4 Curing date Repair Conductivity (cm / sec) 1 day 5.7 × 0 ^-6 1.8 × 0 ^-6 2.7 × 0 ^-6 1.6 × 0 ^-6 3 days 3.2 × 0 ^-6 1.3 × 0 ^-6 2.2 × 0 ^-6 9.5 × 0 ^-7 7 days 1.7 × 0 ^-6 6.5 × 0 ^-7 1.3 × 0 ^-6 4.2 × 0 ^-7

    Table 9-Triaxial Permeability Experiment Results

Coarse mine sludge production method using a coal mine sludge according to the present invention is a coal mine sludge powder obtained by the sludge powderization step (S10) and the sludge powderization step (S10) to powder coal mining sludge obtained in coal mining. It is composed of a compounding step (S30) of mixing with fly ash (Fly ash) and bentonite (Bentonite).

In the sludge powdering step (S10), it is possible to take the powder of coal mine sludge in the same manner as in the powdering step of the cover material manufacturing method described previously.

In the blending step (S30), coal mine sludge powder, fly ash and bentonite are mixed at a weight ratio of 1: 0.5: 0.1, respectively.

As shown in Table 2, the pH of coal mine sludge is 8.3, which is slightly alkaline, and its main component is SiO ₂ , Al ₂ O ₃ , Fe ₂ O ₃ was the dominant species. In addition, since CaO, MgO, K ₂ O, and Na ₂ O, which are pH-raising substances, are included, it is judged that coal mine sludge exhibits a slightly alkaline state due to 2 mole of OH ⁻ generated by their hydrolysis.

_{M x O + H 2 O →} M (OH) y ↔ M ion + 2OH -

 Where M: Ca, Mg, K, Na

contents Guideline Repair conductivity <1 × 0 ^-7 cm / s Fine chimneys and clays of particulate size   > 20% Plasticity Index (PI) 10-30% ^* Gravel size pieces   <10% % Rock content or soil content of 1-2 inches or more in diameter   0

Table 10-U.S. EPA Requirements for Graded Materials (Difficult to Install in the Field Due to the Sticky Properties of Clay at PIs Above 30-40)

Specific gravity is a value necessary to determine soil clearance ratio, saturation degree, dry saturation and weight in water. The test method is specified in KS F 2308. The specific gravity of coal mine sludge is average 2.6821 g / cm ³ It belongs to the specific gravity range of ordinary soil. As a result of measuring the natural water content, the average natural water content was 19.73%.

The liquid limit (LL) test is a test to determine the water content at the instant of the change from the plastic state to the liquid state during the liquefied limit test. In general, the larger the liquid limit, the greater the expansion and contractility. In addition, the plastic limit (PL) test is a test for determining the water content when indicating the limits of the plastic state and the semi-solid state of soil. The plastic limit is a major factor in determining the suitability of roadbed materials, and is an important factor in determining the engineering properties of the soil as well as the classification of the soil. Here LL-PL becomes the plastic index (PI), and the soil can be classified using this result. The grains of fine-grained soil are classified into plastic charts that show the LL-PI relationship in six areas, which Casagrande proposed in 1948. The results and the Unified Soil Classification System (USCS) are used. Understand the nature of the soil. Liquid / baking limit tests for coal mine sludge were carried out using KS F2303 and KS F2304 methods. As shown in Table 11, the liquid limit (LL) was 42.38%, the calcined limit (PL) was 21.64%, the plasticity index (PI) was 20.74%, and the natural function ratio was 19.73%. In addition, the plasticity index was high at 20.74%, which satisfies the US Environmental Protection Agency (EPA) standard of 10% or more and the Italian standard of 10% or more. In addition, the Wisconsin state threshold of 15% or more was satisfied. The soil classification using Atterberg's limit was classified as clay (CL), and the plasticity index was 20.74%.

Table 11-Liquid and plastic limit test of coal mine sludge

As the compaction method for the compaction test, the A compaction method was selected as described above. As a result of compaction experiments with coal mine sludge itself, the optimum water content was 57.9% and the maximum dry density was 1.11 g / cm ^3, as shown in FIG. 13.

Drying density is shown in Table 12.

Compaction method A Mixing ratio (soil: fly ash: bentonite) 1: 0: 0 1: 0.3: 0.3 1: 0.3: 0.05 1: 0.3: 0.07 1: 0.5: 0.1 Optimal moisture content (%) 47.9 37.5 33.5 31.9 29.9 Optimum dry density (g / cm ³ ) 1.110 1.156 1.195 1.236 1.278

 Table 12-Optimum Water Content and Dry Density According to Mixing Ratio

As a result of fabrication and test of the specimen by applying 95% compaction degree of the maximum dry density obtained from the compounding compact as described above, the uniaxial compressive strength according to the age is as shown in FIGS. 14 to 21. Table 13 shows the results of uniaxial compressive strength test after wet curing for 1 day, 3 days and 7 days for each compounding ratio. All compounding ratios were mixed by weight. In Korea, there is no clear regulation on the strength of ordered materials, but the US EPA regulations require more than 2.5 kg / cm ² . As a result, when the mixing ratio of sludge, fly ash and bentonite was 1: 0.5: 0.1, the uniaxial compressive strength could satisfy 2.5 kgf / cm ² or more. This can be summarized as a result of the pozzolanic reaction with increasing fly ash.

Compaction method A commitment Mixing ratio
(Sludge: Fly Ash: Bentonite) One 1: 0.3: 0.03 1: 0.3: 0.05 1: 0.3: 0.07 1: 0.5: 0.1 Curing date Strength (kg / cm ² ) 1 day 0.55 3.16 5.81 5.61 7.34 3 days 1.60 5.20 7.75 7.34 9.39 7 days 1.82 8.16 10.81 9.38 11.5

   Table 13-Compressive strength test using coal mine sludge, fly ash and bentonite

Permeability test results of only coal mine sludge itself, the permeability was found not satisfied in the case of 7 days curing 5.5 × 10 ^-5 cm / sec appear to landfill liner criteria 1 × 10 ^-7 or less. However, coal mine sludge, with an increase in the blend ratio: fly ash: the proportion of bentonite from 1: 0.5: 0.1 days for, 8.50 × 10 at the time of curing hayeoteul 1 ^- could meet the liner reference by ^eight. This is due to the phenomenon that the pozzolanic reaction is actively caused by the increase of the fly ash to fill the pores. Permeability experiments were carried out using KS F 2322 variable offense, and the results are shown in Table 14.

Compaction method A commitment Mixing ratio
(Sludge: Fly Ash: Bentonite) One 1: 0.3: 0.03 1: 0.3: 0.05 1: 0.3: 0.07 1: 0.5: 0.1 Curing date Repair Conductivity (cm / sec) 1 day 8.3 × 0 ^-5 6.1 × 0 ^-6 1.4 × 0 ^-6 9.4 × 0 ^-7 8.50 × 0 ^-8 3 days 6.2 × 0 ^-5 5.4 × 0 ^-6 1.2 × 0 ^-6 3.3 × 0 ^-7 6.78 × 0 ^-8 7 days 5.5 × 0 ^-5 2.8 × 0 ^-6 9.9 × 0 ^-7 2.4 × 0 ^-7 4.20 × 0 ^-8

 Table 14-Permeation Experiments with Bare Mine Sludge and Fly Ash Bentonite

As demonstrated by the above experiments, according to the method of manufacturing the cover material using coal mine sludge according to the present invention, when the mixing ratio of coal mine sludge and solidified material is 1: 0.4 by weight ratio, the optimum moisture content ratio is 46.5%, and the maximum dry density is 1.196. g / cm ³ , uniaxial compressive strength of 1 kg / cm ² and permeability coefficient of 1.6 × 10 ^-6 cm / sec at 1 day of loading, with a liquid limit of 47.8%, firing limit of 20.52%, and firing index of 19.4. In addition, it is possible to manufacture a cover material that can satisfy the cover material standard proposed by the US EPA.

According to the method of manufacturing the order material using coal mine sludge according to the present invention, when the mixing ratio of coal mine sludge, fly ash and bentonite is 1: 0.5: 0.1 by weight, the average specific gravity is 2.6821 g / cm3 and the natural water content ratio is 19.73%. The liquidity, plasticity limit and plasticity index were 42.38%, 21.64% and 20.74, respectively. Further compaction results and optimum water content is 29.9%, the optimal dry density of 1.278 g / cm ^3, uniaxial compressive strength test results, and 7.34 kgf / cm2, the permeability test results permeability've found as 8.5 × 10 ^-8 cm / sec In addition, it becomes possible to recycle coal mine sludge as a grade material.

1 is a view showing the soil classification according to the composition ratio of sand-mass-clay.

Figure 2 is a sequential diagram showing a method for manufacturing cover material using coal mine sludge according to the present invention.

Figure 3 is a flow chart illustrating a process for producing coal mine sludge powder through a neutralization tank of the functional soil ash production method using coal mine sludge according to the present invention.

Figure 4 is a flow chart illustrating a process for producing coal mine sludge powder through an electropurification reactor of the functional soil ash production method using coal mine sludge according to the present invention.

5 is a graph showing the compressive strength test results for the mixing ratio of coal mine sludge and solidified material 1: 1.

Figure 6 is a graph showing the compressive strength test results for the 1: 1 ratio of coal mine sludge and solidified material.

7 is a graph showing the compressive strength test results for the mixing ratio of coal mine sludge and solidified material 1: 0.6.

8 is a graph showing the results of compressive strength test for the mixing ratio of coal mine sludge and solidified material 1: 0.4.

9 is a graph showing the strength comparison at the age of age according to the blending ratio of coal mine sludge and solidified material.

10 is a graph showing the strength comparison at 3 days of age according to the blending ratio of coal mine sludge and solidified material.

11 is a graph showing the strength comparison at 7 days of age according to the blending ratio of coal mine sludge and solidified material.

12 is a sequential diagram illustrating a method for manufacturing a material using coal mine sludge according to the present invention.

13 is a graph showing the compaction test results of coal mine sludge.

14 is a graph showing the compressive strength test results for the mixing ratio 1: 0: 0 of coal mine sludge, fly ash and bentonite.

15 is a graph showing the results of compressive strength experiments for the mixing ratio 1: 0.3: 0.3 of coal mine sludge, fly ash and bentonite.

16 is a graph showing the results of compressive strength experiments for the mixing ratio 1: 0.3: 0.05 of coal mine sludge, fly ash and bentonite.

17 is a graph showing the results of compressive strength experiments for the combination ratio of coal mine sludge, fly ash and bentonite 1: 0.3: 0.07.

18 is a graph showing the results of compressive strength experiments for the combination ratio 1: 0.5: 0.1 of coal mine sludge, fly ash and bentonite.

19 is a graph showing the strength comparison at 1 day of age according to the blending ratio of coal mine sludge, fly ash and bentonite.

20 is a graph showing the strength comparison at 3 days of age according to the blending ratio of coal mine sludge, fly ash and bentonite.

21 is a graph showing the strength comparison at 7 days of age according to the blending ratio of coal mine sludge, fly ash and bentonite.

Claims (7)

delete Sludge powdering step (S10) for powdering the coal mine sludge obtained in the coal mine; Composed of the coal mine sludge powder obtained through the sludge powderization step (S10) and the solidified material mixing step (S20); In the sludge powdering step (S10), the coal mine drainage is reacted with Ca (OH) ₂ and slaked lime in a neutralization tank, and then concentrated by dehydration of coal mine sludge obtained by solid-liquid separation in a precipitation tank, and powdered. The solidifying agent is formed by mixing hydrated lime, cement and fly ash in a weight ratio of 0.3: 0.3: 0.4, In the mixing step (S20), the coal mine sludge powder and the solidified material is a method for producing a functional soil material using coal mine sludge, characterized in that the mixture in a weight ratio of 1: 0.4. Sludge powdering step (S10) for powdering the coal mine sludge obtained in the coal mine; Composed of the coal mine sludge powder obtained through the sludge powderization step (S10) and the solidified material mixing step (S20); In the sludge powdering step (S10), the coal mine wastewater obtained by solid-liquid separation from the sedimentation tank after the coal mine drainage is subjected to an electropurification tank, and concentrated to powder The solidifying agent is formed by mixing hydrated lime, cement and fly ash in a weight ratio of 0.3: 0.3: 0.4, In the mixing step (S20), the coal mine sludge powder and the solidified material is a method for producing a functional soil material using coal mine sludge, characterized in that the mixture in a weight ratio of 1: 0.4. delete delete delete Sludge powdering step (S10) for powdering the coal mine sludge obtained in the coal mine; Constituent step (S30) of mixing the coal mine sludge powder obtained through the sludge powder (S10) with fly ash and bentonite (B30); In the blending step (S30), the coal mine sludge powder, fly ash and bentonite are mixed in a weight ratio of 1: 0.5: 0.1, functional soil material manufacturing method using coal mine sludge.

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