KR101257447B1 - A method for preparing banking material using waste resources - Google Patents

Abstract

PURPOSE: A manufacturing method of artificial soil is provided to manufacture environmentally friendly soil by waste resource. CONSTITUTION: A manufacturing method of artificial soil comprises a step of manufacturing a first mixture by mixing sludge and water sludge; a step of manufacturing a second mixture by mixing dehydration sludge and polysilicon sludge to manufacture a second mixture; a step of manufacturing a third mixture by mixing the first and second mixtures and bottom ash; a step of manufacturing a fourth mixture by mixing incineration ash, flyash, and dust; a step of manufacturing a fifth mixture by mixing dolomite, dry plaster, or calcium oxide, and curing the same; a step of obtaining a sixth mixture by mixing waste soil and red mud; a step of mixing the sixth mixture and acid material to neutralize the mixture.

Description

A method for preparing banking material using waste resources

The present invention relates to a method for producing artificial soil by solidification of waste resources, and more specifically, the inorganic lime dewatered sludge and polysilicon sludge, bottom ash, Waste resources can be economically managed by mixing and solidifying pozzolanic materials such as incineration ash, fly ash and dust, and recycled aggregate by-products such as waste soil or red mud at a predetermined ratio to make artificial soil with the same or better quality than natural soil. The present invention relates to a method for manufacturing artificial soil that can be easily manufactured with environmentally friendly soil and can be recycled for construction and civil engineering or soil improvement that lacks soil.

Various types of construction materials are used in various construction works, among which is the most essential and consuming a large amount of landfill material (盛 土 材). Soil is currently used as a natural material in almost all construction and civil engineering fields. In general, soil includes silt, clay, sand and gravel. The soil is made in the entire construction site such as civil engineering, architecture, road, and landscaping, and the soil material used for this is used for various purposes such as roadbed, roadbed, frostbite prevention, facilities, foundation, auxiliary bases and bases, site facilities, site construction, etc. Used for the purpose. If the landfill materials required for the landfill construction are developed and used at the land pit, the civil complaints and environmental destruction problems related to the land pit are raised, and it is becoming more difficult to permit and develop the land pit. Due to the expansion of environmental regulations such as the restriction of the development of quarries, it is difficult to secure large-scale shipments, resulting in the cost increase of landfill construction costs.

In order to solve this problem, the government uses natural materials such as cutting cement, cement or hardener in the form of soil, or using cement blocks and concrete blocks in the form of soil from the outset, waste concrete, waste asphalt, steel slag and waste foundry sand. Although a method of mixing and mixing soil with a certain amount has been devised, it is difficult to supply sedimentary materials due to environmental damage, secondary environmental pollution due to dissolution of harmful substances, economic feasibility, and logistics costs. Therefore, it is urgent to develop landfill material that replaces existing natural soil material or shows equivalent physical properties.

On the other hand, waste sludge, which is mostly landfilled or incinerated, is `` Convention on the Prevention of Marine Pollution by Dumping of Wastes and Other Matter 1972, London ''. Under the Convention, the marine dumping of wastes such as dredged material and sewage sludge has been banned since 2012, and the huge amount of dumping of marine dumps is required to be landfilled on land. In this case, landfill site selection problems due to landfill reduction and secondary soil pollution may arise.

Therefore, with the development of various technologies including incineration, composting, and recycling of non-combustible or combustible sludge, it is the main research subject to recycle sludge, dredged soil, clay sediment, etc. mainly as artificial soil.

In general, purified sludge is precipitated in the process of removing the turbidity-inducing substances taken from the water supply in domestic water purification plants with Alum (sodium or potassium salt), PAC (polyaluminum chloride), alkaline hydrated lime and powdered activated carbon. It is a mud-like substance that is composed of a large amount of water, clay, sand, organic matter and flocculant. The composition ratio of the component phase is 30 to 60%, 20 to 35% for SiO ₂ and Al ₂ O ₃ , 2 to 6% for Fe ₂ O ₃ , and the organic content is about 6 to 30%. The problem of water purification sludge is that the organic matter, water content and porosity are much higher than that of ordinary clay, so it is difficult to obtain constant strength and support when recycled into soil if it is simply dehydrated. It is a poor breathability and drainage. In addition, since the phosphoric acid absorption coefficient is high, inactivation of aluminum hydroxide is necessary, so most of it was buried. However, such a treatment method may cause a problem of impairing the safety of the landfill due to the high water content and contamination of the surrounding soil and groundwater by the leachate generated. In order to solve the above problems, the development of technology for recycling purified water sludge into useful soil has been proposed one after another (Korean Patent No. 10-0242766 and Korean Patent No. 10-0274532).

However, when the soil and the purified sludge are mixed, the water content is decreased, but due to the clay property of the purified sludge, there is a problem in that the moisture is resorbed on the surface of the soil and the purified sludge particles during the rainy season.

Coal ash is defined as ash remaining after the combustion process of anthracite or bituminous coal (pulverized coal) in a thermal power plant. It is generated in the pulverized coal combustion process of most coal-fired power plants in Korea, as well as in various industrial sites such as steel mills, paper mills, waste incinerators, and cogeneration plants. The main components of coal ash depend on the type of coal, production area and combustion conditions, but SiO ₂ accounts for the largest portion, and CaO, Al ₂ O ₃ , Fe ₂ O ₃ And the like. Depending on the combustion conditions, unburnt carbon contains approximately 8-10%. Typically, coal ash varies depending on the coal burned, but occurs about 10 to 20% with respect to 100% by weight before combustion. When the average particle size of coal ash discharged is about 100 μm or less, fly ash is classified as a bottom ash. Although coal ash can be recycled as general waste, the recycling rate is very low. First, coal ash contains a large amount of chloride (salin), which causes surface corrosion of rebar when used as cement material. Second, due to the porosity of coal ash This is because not only its own strength is low but also its absorption rate is high, so it is weak in strength reduction and freeze-thawing when recycled into concrete aggregate. In addition, coal ash contains various heavy metal elements such as As, Ba, Cd, Cr, Tl, Se, Mo, and Hg derived from coal, so when it is stored or disposed of without proper treatment, it is eluted by rainwater or surface water (ground water). Can adversely affect the ecosystem. Therefore, most of the landfills with little recycling compared to the huge amount generated.

Among the ash, fly ash is used as various raw materials such as cement raw materials, clay substitutes, landfills, land improvement materials, and lightweight aggregates. Bottom ash is used to manufacture artificial aggregates or substitutes for natural aggregates and lightweight building materials in concrete products (Korea Patent No. 10-0550268, etc.).

Paper sludge incineration is a by-product of the paper mill sludge from paper mills and the process of incineration of bark. Paper sludge has a water content of 65-75%, 14% of organic matter including fibers, and 36% of inorganic matter. Paper sludge discharged from paper mills is incinerated because most of the soil contamination is caused by organic decay.

Polysilicon sludge is a by-product generated in the cutting process of polycrystalline silicon. With the development of the solar energy industry, the production of polysilicon, which is used as the main material of solar panels, and the production of sludge, which is an industrial waste, are rapidly increasing, but there is no suitable disposal and recycling method. Increasing costs are creating another environmental problem.

Waste lime is processed by processing marble, calcite, berth, ice tin, limestone, white rock, eggshell, shell, coral, etc., and made quicklime (CaO), slaked lime (Ca (OH) ₂ ), lime carbonate ( The concept of lime residue produced in the process of producing calcium carbonate, CaCO ₃ ), and soda ash (anhydrous sodium carbonate, Na ₂ CO ₃ ), etc., waste lime is close to the designated waste due to strong alkalinity, and due to high pH Since it generates ammonia gas, it has not been developed as a cover material or a fill material because of bad smell. It is also used as a part of lime fertilizer, sidewalk block, brick, and cement, but recycling technology has not been commercialized due to high water content, substandard size, and facility investment cost.

Waste gypsum is produced in large quantities by flue gas desulfurization process (from desulfurization facility in thermal power plant), phosphoric acid, hydrofluoric acid, boron, and titanium.In the case of waste gypsum, acid is strong enough to reach pH 2-3 and harmful impurities such as heavy metals and radioactive elements. If left untreated, environmental pollution, including groundwater contamination, may occur. The recycling of waste gypsum requires several steps: removal, neutralization, calcination and assembly of hazardous metals.

Red mud is a by-product of the process of producing aluminum hydroxide (Al (OH) ₃ ) and alumina (Al ₂ O ₃ ) by the Bayer process from Bauxite minerals. Bayer process dissolves Bauxite in sodium hydroxide at high temperature and then prepares Na [Al (OH) ₄ ] with Gibbsite (Al (OH) ₃ ) as the termination, and hydrolyzes and calcinates it to alumina. It is a method of manufacturing with (Al ₂ O ₃ ). Red mud occurs at more than about 2 tonnes per tonne of alumina and has an approximate particle size distribution of 5 to 20 µm. The main components are Fe ₂ O ₃ , Al ₂ O ₃ , SiO ₂ , Na ₂ O, TiO ₂ , CaO, etc. Among them, Fe ₂ O ₃ and Al ₂ O ₃ account for more than 65% of the total. Red mud is a by-product with NaOH in the alumina manufacturing process, and thus has strong alkalinity of pH 12 or more. When used as a building and civil engineering material, red mud is not treated any more and is left untreated. To recycle red mud, neutralization of sodium hydroxide (NaOH) and K ₂ O from Bauxite is required.

The waste concrete fine powder generated during the recycling of waste concrete belongs to the construction waste.Inorganic construction sludge generated during the intermediate treatment of construction wastes is dehydrated if the moisture content is less than 70% within the range that does not cause soil pollution. It can be dried and recycled for fill and cover, and is used after being mixed with more than 50% of the soil by volume. Waste concrete and construction sludge have a much higher recycling rate than other sludges, but most of them are used as land composition materials, foundation landfills, roadbeds, asphalt mixtures and cement raw materials. It does not reach the high value-added level of recycling such as concrete aggregate production and fill material.

As such, conventional methods for recycling sludge, dredged soil, clay sediment, and the like into artificial soil have the following problems. 1) When cement is used as a solidifying agent, the reaction conditions are strongly alkalinized and ammonia is generated rapidly. Accordingly, there is an inconvenience in the operation and operation of recycling treatment due to odor generation and odor generation, and 2) strong acid to suppress ammonia generation. 3) Neutralization operation is indispensable due to the addition of. 3) When only pozzolanic materials and waste resources are used, the strength of recycled artificial soil is not sufficiently developed, and the exothermic reaction of various compounds such as pozzolanic, solidifying agent and solidification accelerator is sufficient. Moisture evaporation and drying may occur.

In addition, there are many recycling technologies for developing recycled soil materials using various industrial wastes such as landfill coal, incineration ash, fly ash, inorganic sludge, construction wastes (Korea Patent No. 10-981358). It is focused on satisfying only the engineering characteristics for its purpose, and it is possible to grow ecologically recyclable soil material considering the surrounding environment, especially crops that are easy to grow and no harmful substances are polluted, and which humans can safely consume. Recycling soil material development technology of the degree is insufficient.

1. Korea Patent Registration No. 10-0242766 2. Korea Patent Registration No. 10-0274532 3. Korea Patent Registration No. 10-0550268 4. Korean Registered Patent No. 10-981358

The present inventors have made various efforts to solve odor generation by pH control and stabilization of physical properties through sufficient reduction of moisture, which is pointed out as a problem of the prior art as described above. At the same time, it is possible to evaporate the moisture contained in the waste resources through the reaction heat generated from the mixture and to effectively remove the odor by suppressing the ammonia generation, thereby recycling the waste resources to produce eco-friendly artificial soil in an economical and simple way. The present invention has been completed by knowing that it can be done.

Therefore, an object of the present invention is to provide a method for producing artificial soil economically and eco-friendly by recycling waste dredging or river dredging sludge and purified water sludge.

In addition, another object of the present invention is not only can be utilized as general land use to improve the properties of the soil is difficult to recover the original intelligence due to weakened or changed Saturn, recycled artificial soil that can be used as industrial construction and civil engineering materials To provide a method of manufacturing.

In order to solve the above problems, the present invention comprises a first mixing step of producing a first mixture by mixing one or more selected sludge and purified sludge of the sludge and stream dredging sludge in a weight ratio of 1: 0.5 ~ 1.5; A second mixing step of preparing a second mixture by mixing lime dewatered sludge and polysilicon sludge in a weight ratio of 1: 0.5 to 1.5; A third mixing step of preparing a third mixture by mixing the first mixture, the second mixture, and the bottom ash in a weight ratio of 1: (0.5 to 2) :( 3 to 5); A fourth mixing step of preparing a fourth mixture by further mixing at least one selected from an incinerator, fly ash, and dust in the third mixture in an amount of 10 to 40 parts by weight based on 100 parts by weight of the third mixture; 5th curing to prepare a fifth mixture by further mixing at least one selected from light dolomite, dry desulfurized gypsum and calcium oxide in the fourth mixture in an amount of 1 to 10 parts by weight relative to 100 parts by weight of the fourth mixture and curing for 0.5 to 1 days. step; And a sixth mixing step of mixing the fifth mixture with waste soil or red mud in a weight ratio of 1: 0.01 to 1 to obtain a sixth mixture as an artificial soil. And neutralizing the mixture by mixing one or more acidic materials selected from phosphate, titanium, gypsum, iron sulfate, iron sulfate monohydrate, alumina sulfate, and iron chloride in an amount of 1 to 50 parts by weight based on 100 parts by weight of waste soil or red mud. It provides a method for producing artificial soil by the solidification of waste resources, including.

In addition, the present invention a) the first mixture and the second mixture in which the sludge dewatering sludge and polysilicon sludge is mixed in a weight ratio of 1: 0.5 ~ 1.5 and the dredging sludge and purified sludge sludge And 100 parts by weight of the third mixture, in which the bottom ash is mixed in a weight ratio of 1: (0.5 to 2) :( 3 to 5), b) 10 to 40 parts by weight of at least one pozzolanic material selected from incineration, fly ash and dust, c A) a mixture of a) + b) + c) in which at least one curable material selected from light dolomite, dry desulfurized gypsum and calcium oxide is mixed in an amount of 1 to 10 parts by weight based on 100 parts by weight of the sum of a) and b). And waste soil or red mud are mixed at a weight ratio of 1: 0.01 to 1, and at least one acidic material selected from gypsum phosphate, titanium gypsum, phosphate gypsum, iron sulfate, iron sulfate monohydrate, alumina sulfate, and iron chloride is used. Including mixed 1 to 50 parts by weight relative to 100 parts by weight of mud Provides artificial soil.

The manufacturing method of the present invention as described above can be economically and simply produce eco-friendly artificial soil as natural soil by appropriately configuring the specific pozzolanic material and hardener composition while recycling the existing waste resources such as sludge and coal ash. will be.

In addition, the artificial soil produced according to the present invention is similar to the general soil physical properties are lacking soil soil construction site or common water surface reclamation, road and embankment construction, soft ground improvement, harbor site reclamation, industrial complex site reclamation, lowland Landfill, seabed lipid improvement, artificial tidal flat, waste mine reclaim, waste salt reclamation, coastal wetland formation, wetland topsoil, backfilling and filling materials for general civil works, sanitary landfill intermediate, daily, occasional cover or green soil raw materials, There is an effect that resources can be recycled to be recycled as a soil improver.

Hereinafter, the present invention will be described in more detail.

The present invention relates to a process for producing artificial soils with lake and dredged sludge and purified sludge, lime dewatered sludge and polysilicon sludge, bottom ash, and pozzolanic materials, curable materials and waste soil.

In order to manufacture artificial soil using waste resources, a technology for economically solidifying them while reducing the content of moisture accompanying the generation stage of waste resources is required.

Solidification treatment is a process to manufacture materials suitable for building and civil engineering parts including landfill materials by improving the soil mechanical properties such as workability of the sludge, immobilization of heavy metal elements, compressive strength, and permeability after adding solidifying agent to high water content sludge. .

In the present invention, starting from such a foundation, waste material is recovered by adding a hardening agent, a hardening aid, and a pozzolanic material to dredged soil and various types of sludge (sewage, water, lake, mine, paper, leather, plating, etc.). We propose a method for use as ash, landfill, fill, cover soil, soil improver and green soil.

In the present invention, to study the utilization of various waste resources to consider the characteristics of the waste resources to be used for artificial soil, and to study the various properties of the various additives mixed ingredients various components that can be utilized for the production of artificial soil according to the present invention In the present invention, the components used in the solidification treatment of waste resources in the present invention are classified into A, B, C, D, E, and F according to their properties, and thus, the present invention is constituted based on this.

Here, A is a waste material to be recycled.

B is a pozzolanic material mainly formed of solid solution of CaO and SiO ₂ and reacts with free water contained in A to form Ca (OH) ₂ or calcium aluminosilicate hydrate. Due to the rapid hydration reaction, water dissipation is accompanied and water content of recycled waste resources is reduced, and it reacts with SO ₄ ^{2 -} ions supplied from the D compound to form a hardened material (trisulfate or monosulfate calcium aluminosilicate compound, ettringite). When the sludge is recycled to artificial soil such as sediment, it also plays a role in the immobilization of heavy metal elements contained in the waste resources according to the strength expression and anion substitution effect.

C is mainly composed of CaO (if cement is used, SiO ₂ , Al ₂ O ₃ may be supplied) and is the most important Ca (OH) ₂ source for solidification of waste resources. Ca (OH) ₂ is produced by hydration of CaO and is cured by reaction with SO ₄ ^{2 -} supplied from D to form a solid (floor material). Unlike B, due to the high content of CaO is a major component of the hardener. C is a material that causes rapid heat generation and low water content as it is hydrated by waste water A. In addition, C rapidly stabilizes the fine waste material and immobilizes heavy metal elements.

D supplies SO ₄ ^{2 -} in the production of ettringite, an important component in the curing reaction of waste resources, and promotes the exothermic reaction of waste resources (sludge) and component B. The supply of SO4 ^{2 -} ions increases the solubility of CaO or Ca (OH) ₂ , which increases the strength of the solids (filling material) for a short period of time. However, when the Al ₂ O ₃ content is high, the solidification delay may occur.

E component is a pH adjuster for neutralizing the high pH comprised by reaction of A, B component, and C component. If the sludge is recycled, the reaction proceeds in a high alkaline state, and in this case, decomposition of organic matter contained in the sludge is promoted and odor is generated. Therefore, the pH control agent is added in order to return the pH to the neutral condition to bring the pH of the recycled artificial soil to be close to neutral to prevent odor generation, odor generation due to odor generation, and prevention of odor occurrence in the construction of the fill. E, which is classified as other component, has a different action from A, B, C, and D. It is a surfactant to prevent resorption of moisture, a deodorant to suppress odor generation, a chelating agent to prevent heavy metal leakage, Flocculants for forming flocs of sludge and the like can be used.

Based on the classification of these components, considering the characteristics of each component was applied to the manufacture of artificial soil according to the present invention.

Bottom ash and fly ash used in the present invention are each derived from coal ash.

If the manufacturing method according to the present invention is described as an embodiment, the following method may be a typical example.

First of all, one or more sludges of 20 ~ 40 wt% water content and clay dredging sludge, the main component of solids excluding water, and purified sludge with water content 40 ~ 60 wt%, which is a by-product of running water, are mixed at a weight ratio of 1: 0.5 ~ 1.5. To undergo a first mixing step of producing a first mixture.

A separate mixer is used to mix the calcium carbonate dehydration sludge with 40 to 55% by weight of water content produced in the calcium carbonate manufacturing process and the silicon sludge, a by-product generated from the polysilicon manufacturing process, in a weight ratio of 1: 0.5 to 1.5. A second mixing step is carried out to prepare the second mixture.

The bottom ash, preferably a salt-free bottom ash, which is a combustion byproduct of a coal-fired power plant in order to impart compressive strength and provide granularity to the first mixture and the second mixture that have undergone the first and second mixing steps. Mixing at a weight ratio of: (0.5 ~ 2) :( 3 ~ 5) is followed by a tertiary mixing step to produce a granulated tertiary mixture such as sand loam having good breathability, permeability and moisture retention.

In order to control the moisture of the third mixture passed through the third mixing step, at least one selected from incineration, fly ash, and dust, which are absorbent materials and pozzolanic materials, is further mixed in an amount of 10 to 40 parts by weight based on 100 parts by weight of the third mixture. Fourth mixing step to produce a fourth mixture.

As the curable material for increasing the binding force between the particles of the fourth mixture and enhancing the uniaxial compressive strength, any one or more selected from light dolomite, dry desulfurized gypsum and calcium oxide is further mixed in an amount of 1 to 10 parts by weight with respect to 100 parts by weight of the fourth mixture. By using the hydration reaction of the curable material is cured for 0.5 to 1 days to undergo a fifth curing step to prepare a fifth mixture.

Waste soil or red mud is mixed with the fifth mixture after the fifth curing step in a weight ratio of 1: 0.01 to 1, and the sixth mixing step of preparing a sixth mixture, which is a desired artificial soil, is performed. It is treated with acid.

Referring to the manufacturing method of the present invention as described above in more detail by process as follows.

The first mixing stage is typically selected from those of the lake and dredging sludges with a water content of 20 to 40% by weight in the process of restoring low water capacity, restoring rivers, repairing waterways and purifying contaminated water. 1: 0.5 to 1.5 for one or more sludges (organic content in solids except water: 10 to 20% by weight) and purified sludge (water content in solids except water: 30 to 50% by weight) with a water content of 40 to 60% by weight. Step of preparing a first mixture by mixing in a weight ratio. The first mixture thus prepared can be used as an important material for recycled artificial soils and is composed of clay and silt components. The mixture itself is poorly breathable and permeable, and if used as landfill or cover soil as it is, it causes anaerobic decomposition in the soil, causing soil pollution. The reason for using the two types of sludge is to reduce the amount of harmful gases generated from decomposition and to reduce the amount of organic matter, so that it is easy to solidify, and the water content can be easily adjusted with a small amount of aluminosilicate-based by-products and CaO. Because it can be adjusted.

The second mixing step is a calcium carbonate dehydrated sludge with a water content of 40-55 wt%, a by-product produced in the manufacturing process of high purity calcium carbonate, and silicon sludge, a by-product generated from a series of processes for producing polysilicon, a solar semiconductor device. Step 1: to prepare a second mixture by mixing in a weight ratio of 0.5 to 1.5. The second mixture thus prepared has poor water retention, high water permeability, and high shear strength. The reason for using the two kinds of sludge mixed here is to supply CaCO ₃ for the strength expression of the mixture obtained in the first mixing step.

In the third mixing step, the first mixture and the second mixture are mixed in the same weight ratio to complement the engineering characteristics of the soil, and a bottom ash having a relatively large average particle diameter, preferably salt, in order to promote compressive strength and granulation. The removed bottom ash is mixed at a ratio, that is, the first mixture: the second mixture: the bottom ash in a weight ratio of 1: (0.5 to 2): (3 to 5) to improve breathability, water permeability, moisture retention, and plasticity. And a third step of preparing a third mixture having increased compressive strength. If the second mixture is added too little or too much, there is a problem that the optimum setting time and strength cannot be reached due to the properties of CaCO ₃ . There is a possibility of acting as a coagulation accelerator or coagulation retardant. In addition, if the amount of bottom ash is too small, the time required for the development of strength is long, and there is a problem in that the amount of water decrease due to the exothermic reaction is small. If the amount is too large, rapid exotherm occurs due to rapid curing, and the transportation, transport, storage, There is a problem that mixing becomes difficult.

In the fourth mixing step, in order to control the moisture of the third mixture which has undergone the third mixing step, at least one selected from an incineration material, which is an absorbent material and a pozzolanic material, preferably paper sludge incineration material, fly ash, and dust, may contain 100 weight of the third mixture. Mixing step to prepare a fourth mixture by further mixing to 10 to 40 parts by weight relative to the part. Paper sludge ash, which is the most useful among the incineration ashes, is an incineration material generated after incineration of paper mill pulp sludge at about 800 to 1000 ° C. Al ₂ O ₃ , CaO, SiO ₂ , and Fe ₂ O ₃ are the incineration materials. Representative Pozzolanic material accounting for more than 90%. The fly ash is a by-product generated after coal combustion in coal-fired power plants and cogeneration plants that use coal as a heat source, and is a fine powder type fly ash collected in an electrostatic precipitator and accounts for about 75 to 80% of the total coal ash generation. In spite of its physical and chemical properties, it is not only possessing pozzolanic activity in the form of calcium aluminosilicate series, but also having excellent properties as a cement substitute in many aspects. The dust is generated by collecting a fly ash (dust) generated during the quarrying or stone processing and grinding process or the mineral processing and grinding process with a dust collector. In the fourth mixing step, the fourth mixture is exothermic by the hydration reaction and solidification, and the water content decreases due to vapor evaporation. Preferably, 3 to 15% by weight is preferable from the viewpoint of selecting the amount of adjusting agent for pH adjustment of the artificial soil to be manufactured and securing fluidity for mixing the individual materials.

The fifth curing step is a curable material for increasing the cohesion between the particles of the fourth mixture and enhancing the uniaxial compressive strength, and includes at least one selected from light dolomite, dry desulfurized gypsum, and calcium oxide, from 1 to 100 parts by weight of the fourth mixture. The mixture is further mixed in an amount of 10 parts by weight to cure for 0.5 to 1 days using a hydration reaction of the curable material to prepare a fifth mixture. The calcined dolomite is prepared by calcining dolomite (CaMg (CO ₃ ) ₂ ) at 700 to 1000 ° C. The constituent is at least 60% CaO and at least 32% MgO. The dry desulfurized gypsum is generated during the dry desulfurization process of the refinery fluidized bed combustion boiler exhaust gas, specifically, by the reaction between CaO and SO ₂ generated in the decomposition of calcium carbonate. The calcium oxide (CaO) is generally produced by decomposition of calcium carbonate (CaCO ₃ ), and when dissolved in water, calcium hydroxide (Ca (OH) ₂ ) is produced and the solution is basic. In the present invention, the calcium oxide content is preferably 80% or more. In the fifth curing step (S5) is a step in which the mixture is stabilized through the hydration reaction, pozzolanic reaction, absorption exothermic reaction by mixing.

The sixth mixing step is a step of preparing a sixth mixture of the desired artificial soil by mixing waste soil or red mud in a weight ratio of 1: 0.1 to 1 to the fifth mixture after the curing step. The waste soil is preferably used to neutralize the fine particulate strongly alkaline waste soil generated in the process of pulverizing the waste concrete to produce the recycled aggregate.

Waste soils are soils recycled from construction wastes, and can be used as raw materials for recycled soils. However, due to strong alkalinity, alkaline effluent can be generated when used as recycled artificial soil without proper neutralization. Red mud is also a by-product with NaOH in the alumina manufacturing process, and thus has strong alkalinity, which may cause alkaline elution water. In the case of such waste soil or red mud, it is hardly recycled due to the strong alkaline waste as described above, and it is difficult to be environmentally friendly, so applying it as an artificial soil material in terms of recycling it is very environmentally and economically beneficial. Therefore, the waste earth sand or red mud used in this step is 100% by weight of waste earth sand or red mud from any one or more selected from acidic gypsum phosphate, titanium gypsum, hydrofluoric acid gypsum, iron sulfate, iron sulfate monohydrate, alumina sulfate and iron chloride. 1 to 50 parts by weight of the mixture is preferably adjusted so that the hydrogen ion concentration (pH) in the range of 7-8.

The manufacturing method of artificial soil according to the present invention is economical and eco-friendly artificial soil no less than natural soil by optimizing by solidifying by appropriately configuring the specific pozzolanic material and hardener composition while recycling the existing waste resources such as sludge and coal ash. It can be manufactured simply.

Artificial soil prepared according to the present invention is a) at least one selected from sludge sludge and stream dredging sludge and purified water sludge 1: 0.5 ~ 1.5 mixture of the first mixture, lime dewatered sludge and polysilicon sludge 1: 0.5 100 parts by weight of the second mixture and bottom ash mixed at a weight ratio of ˜1.5 by weight ratio of 1: (0.5 to 2) :( 3 to 5), b) at least one selected from incineration ash, coal ash and dust 10 to 40 parts by weight of pozzolanic material, c) any one or more curable materials selected from light dolomite, dry desulfurized gypsum and calcium oxide mixed with 1 to 10 parts by weight based on 100 parts by weight of the sum of a) and b). b) + c) mixture and waste earth or red mud are mixed in a weight ratio of 1: 0.01 to 1, at least one selected from gypsum phosphate, titanium gypsum, fluorite gypsum, iron sulfate, iron sulfate monohydrate, alumina sulfate and iron chloride 100 parts by weight of acidic waste soil or red mud It consists in the mixing amount of 1 to 50 wt.

Artificial soil according to the present invention may be prepared in an organic content of 30 to 50% by weight, except for moisture.

The artificial soil manufactured through the above steps has similar physical properties to general soils, so that the construction site or common water reclaimed land, road and embankment construction, soft ground improvement, harbor site reclamation, industrial site reclamation, low land reclaimed material lacking soil soil To improve seabed geology, to construct artificial tidal flats, to recover waste mines, to reclaim wastewater, to construct coastal wetlands, to cover wetlands, to fill up and fill up general civil engineering works, as a medium, daily, occasional cover or green soil material of sanitary landfills, and soil improvers. And the like can be recycled.

In particular, the artificial soil thus produced in accordance with the present invention is for road foundation, road auxiliary layer, concrete and concrete products, asphalt concrete, frostbite prevention layer and barrier layer, sewage pipes aggregate, roadbed and roadbed, backfill and backfill, It can be used as an artificial soil that satisfies the circulating aggregate quality standards in the civil engineering field such as cover and fill.

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited to Examples.

Examples 1-6

Next, the artificial soil is prepared by the composition of Table 1, but the first mixture is prepared by mixing the sludge and the purified sludge in a 1: 1 weight ratio, and separately mixing the lime dewatered sludge and the polysilicon sludge in a 1: 1 weight ratio. To prepare, and the third mixture by mixing the first mixture, the second mixture, the bottom ash in a weight ratio of 1: 1: 4, respectively. A fourth mixture is prepared by mixing coal ash, which is a pozzolanic material, in a third mixture. The fourth mixture is cured by mixing calcium oxide with a curable material and curing the fourth mixture. The final artificial soil composition, which is the sixth mixture, was prepared by mixing wastewater sand or red mud treated with gypsum phosphate and iron sulfate with the fifth mixture after the curing step.

In Table 1, the unit is weight.

Composition / g Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Hososludge 100 Water sludge 100 Lime Dewatering Sludge 100 Silicone sludge 100 Bottom ash 800 Paper Sludge Incinerator 170 200 250 180 225 300 Waste soil 1100 90 500 200 150 700 Calcium oxide 25 50 30 60 70 100 Phosphate Gypsum 10 5 100 215 178 152 Iron sulfate 30 5 46 100 162 197

Comparative Examples 1 to 6

The artificial soil composition was prepared in the same ratio as in the above example, but the composition of Table 2 below, except for some components according to the composition or manufactured artificial soil for comparison under conditions outside the optimum range.

Composition / g Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Hososludge 100 Water sludge 100 Lime Dewatering Sludge 100 Silicone sludge 100 Fly ash 800 Paper Sludge Incinerator 350 100 170 0 0 0 Waste soil 1100 260 0 0 0 0 Calcium oxide 150 715 50 80 0 0 Phosphate Gypsum 0 300 150 100 100 0 Iron sulfate 30 300 0 0 100 0

Experimental Example

A physical property test was performed on the artificial soils of Examples 1 to 6, which prepared artificial soils according to the composition of Table 1. The results are shown in Tables 3 to 5, respectively.

In Table 3, the reference values are referred to the Ministry of Land, Transport and Maritime Affairs Quality Standards, Waste Management Act, and Standards of Civil Engineering Standards. In the U.S., there is a value specified in the RCRA (Resource Conversation & Recovery Act) Subtitle D for cover materials. , Installation, and Monitoring of Alternative Final Landfill Cover ALT-2, Washington, DC, 2003). In Japan, the property values of landfill materials proposed by the Ministry of Land, Infrastructure, Transport and Tourism, Urban Safety Division, have recently been applied. (Http: // www. mlit.go.jp/report/press/toshi01_hh_000002.html).

Test methods for the physical properties shown in Table 3 correspond to KS standards, ASTM standards, US SSA (Soil Science Society of America) standards, Japan JGS (Japan Geotechnical Society) and JIS standards respectively. In Table 4, PQL (practical quantitation limit) is based on U.S. EPA drinking water, which is not regulated but is defined as the lowest concentration in groundwater, and in the case of landfill and cover soil, groundwater contamination may occur due to its characteristics. for Conducting Environmental Compliance Audits of Facilities Regulated under Subtitle D of RCRA, https://www.epa.gov/compliance/resources/policies/incentives/ audit ing / apcol-rcrad.pdf). In addition, the second type of elution standard according to the Japan Soil Pollution Control Act was applied mutatis mutandis for the environmental hazard determination of the artificial soil composition according to the embodiment of the present invention (土壤 汚染 策 法 施行 規則, http: //law.e-gov.go .jp / htmldata / H14 / H14F18001000029.html). The Consensus Based Threshold Effect Concentration (CB TEC) presented in Table 5 is cited in a paper published by Burton and is the agreed value of experts for threshold effect concentrations in the quality criteria for sediments worldwide. This is applied mutatis mutandis as a reference value that can consider soil contamination when the artificial soil composition of the present invention as a fill material or cover material (GA Burton, Jr., Sediment Quality Criteria in use Around the World, Limnology, 3, 65-75 ( 2002)).

division Lower than 100 cm from the top of the stack
(Ministry of Land, Transport and Maritime Affairs, Quality Standard of Recycled Aggregate (2009.8), Waste Management Act, Standard Specification for Civil Engineering) Japan
Ministry of Land, Infrastructure and Transport US EPA (Resource Conservation & Recovery Act)
RCRA Subtitle D
(40 CFR § 258)
And the US Environmental Council of the States (ECOS)
ITRC Test Methods Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Cone index - > 400 kN // m ² - JIS A 1228 420 405 426 411 423 410 Modified CBR 2.5 or more - - KS F 2320 14.8 15.1 10.7 16.2 15.1 14.3 CBR (immersion expansion test) - <3% - KS F 2320 1.9 1.8 1.7 1.5 1.4 1.6 Dry density after compacting (t / m ³ ) 1.5 or more - - KS F 2312,
ASTM D 1557 1.61 1.52 1.6 1.7 1.6 1.52 Uniaxial Compressive Strength (MPa) 0.1 MPa or more - - KS F 2343 0.42 0.45 0.42 0.43 0.5 0.47 Liquidity limit (%) <50% - <40% KS F 2303,
ASTM D 4318 NP NP NP NP NP NP Plasticity index (%) - - 7-30% NP NP NP NP NP NP Firing limit (%) <25% - - NP NP NP NP NP NP 200 mm (0.075 mm) sieve passage rate (%) - <50% > 35% KS F 2301, 2309
ASTM D 1140 37 36 40 36 39 43 Permeability coefficient (cm / sec)
<10 ^-6
(At 45cm fill) - <10 ^-5 cm / s
(At 15cm fill) KS F 2322,
ASTM D 5084 0.2 * 10 ^-7 0.1 * 10 ^-7 0.1 * 10 ^-7 0.1 * 10 ^-7 0.1 * 10 ^-7 0.1 * 10 ^-7 Electrical conductivity - <200 mS / m - JGS 0212 92 59 25 63 81 86 pH <12.4 6 to 9 - KS F 2103,
ASTM D 4972 7.0 7.2 7.0 7.0 7.0 7.0 Water content (%) - - - KS F 2312,
ASTM D 2216 17 15 12 10 18 13 Foreign substance content (%)
(Organic foreign matter) 1.0 or less (volume) - - KS F 2576 0 0 0 0 0 0 Organic matter content (%) - - - SSSA-3 37 42 30 31.5 43 21 Ammonia Generation
(ppm, composition surface after curing) - - NIOSH
Immediately Dangerous To Life or Health Concentration
(300 ppm) - 8 2 One 7 5 4 H ₂ S generation
(ppm, composition surface after curing) - - NIOSH
Immediately Dangerous To Life or Health Concentration
(100 ppm) - 0 0 0 0 0 0 Chloride Content (mg / mg) - <1 mg / mg - JGS 0241 0 0 0 0 0 0

Test Item (Unit: mg / L) Reference value US EPA
PQL
(practical quantitation limit), mg / L Japan
Enforcement Rule of the Soil Pollution Control Act Article 24 and Schedule 4
(mg / L) Test Methods
(Waste process test standard: 2011) Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Pb 3 0.4 0.3 N.D. N.D. N.D. N.D. N.D. N.D. As 1.5 0.01 0.3 N.D. N.D. N.D. N.D. N.D. N.D. Hg 0.005 0.002 0.005 N.D. N.D. N.D. N.D. N.D. N.D. CD 0.3 0.001 0.3 0.0001 0.0004 N.D. N.D. 0.0003 0.0003 Cr ^{6 +} 1.5 0.02 1.5 N.D. N.D. N.D. N.D. N.D. N.D. CN ^- One 0.2 One N.D. N.D. N.D. N.D. N.D. N.D. Organic phosphorus One - One N.D. N.D. N.D. N.D. N.D. N.D. Tetrachlorethylene 0.3 0.0005 0.1 N.D. N.D. N.D. N.D. N.D. N.D. Trichlorethylene 0.1 0.001 0.3 N.D. N.D. N.D. N.D. N.D. N.D. Oil component (Unit:%) 5% - - 0.01 N.D. 0.02 0.05 0.03 0.01

Test Item (Unit: mg / kg) Reference value CB TEC
(Consensus Based Threshold Effect Concentration) Test Method (Second Area: Soil Pollution Test Standard: 2011) Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 CD 10 0.99 0.013 0.038 0.01 0.001 0.026 0.027 Cu 500 31.6 0.07 0.05 0.37 0.16 0.38 0.03 As 50 9.79 N.D. N.D. N.D. N.D. N.D. N.D. Hg 10 0.18 N.D. N.D. N.D. N.D. N.D. N.D. Pb 400 35.8 N.D. N.D. N.D. N.D. N.D. N.D. Cr ^{6 +} 15 43.4 N.D. N.D. N.D. N.D. N.D. N.D. Zn 600 121 N.D. N.D. N.D. N.D. N.D. N.D. Ni 200 22.7 N.D. N.D. N.D. N.D. N.D. N.D. F- 400 - N.D. N.D. N.D. N.D. N.D. N.D. Organic phosphorus 10 - N.D. N.D. N.D. N.D. N.D. N.D. PCBs 4 0.35 N.D. N.D. N.D. N.D. N.D. N.D. CN- 2 - N.D. N.D. N.D. N.D. N.D. N.D. phenol 4 - N.D. N.D. N.D. N.D. N.D. N.D. benzene One - N.D. N.D. N.D. N.D. N.D. N.D. toluene 20 - N.D. N.D. N.D. N.D. N.D. N.D. Ethylbenzene 50 - N.D. N.D. N.D. N.D. N.D. N.D. xylene 15 - N.D. N.D. N.D. N.D. N.D. N.D. Petroleum Total Hydrocarbons (TPH) 800 1.19-4.61 N.D. N.D. N.D. N.D. N.D. N.D. Trichlorethylene 8 - N.D. N.D. N.D. N.D. N.D. N.D. Tetrachlorethylene 4 - N.D. N.D. N.D. N.D. N.D. N.D.

Comparative Experimental Example

A physical property test was performed on the artificial soils of Comparative Examples 1 to 6, which prepared artificial soils with the composition of Table 2. The experiments were conducted in accordance with the circulating aggregate quality standards established by the Ministry of Land, Transport and Maritime Affairs, the effluent standards for designated hazardous substances containing wastes, and the Enforcement Rules of the Soil Environment Conservation Act. The results are shown in the following Tables 6 to 8.

division Lower than 100 cm from the top of the stack
(Ministry of Land, Transport and Maritime Affairs, Quality Standard of Recycled Aggregate (2009.8), Waste Management Act, Standard Specification for Civil Engineering) Japan
Ministry of Land, Infrastructure and Transport US EPA (Resource Conservation & Recovery Act)
RCRA Subtitle D
(40 CFR § 258)
And the US Environmental Council of the States (ECOS)
ITRC Test Methods Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Cone index - > 400 kN // m ² - JIS A 1228 375 149 227 318 382 386 Modified CBR 2.5 or more - - KS F 2320 10.1 11.1 10.0 11.3 11.9 10.8 CBR (immersion expansion test) - <3% - KS F 2320 3 5 9 6 7 5 Dry density after compacting (t / m ³ ) 1.5 or more - - KS F 2312,
ASTM D 1557 1.5 1.4 1.5 1.4 1.6 1.1 Uniaxial Compressive Strength (MPa) 0.1 MPa or more - - KS F 2343 0.22 0.15 0.32 0.10 0.12 0.11 Liquidity limit (%) <50% - <40% KS F 2303,
ASTM D 4318 NP NP NP NP NP NP Plasticity index (%) - - 7-30% NP NP NP NP NP NP Firing limit (%) <25% - - NP NP NP NP NP NP 200 mm (0.075 mm) sieve passage rate (%) - <50% > 35% KS F 2301, 2309
ASTM D 1140 37 36 40 35 39 43 Permeability coefficient (cm / sec)
<10 ^-6
(At 45cm fill) - <10 ^-5 cm / s
(At 15cm fill) KS F 2322,
ASTM D 5084 1.0 * 10 ^-4 0.5 * 10 ^-3 0.8 * 10 ^-4 0.2 * 10 ^-4 2.0 * 10 ^-2 2.7 * 10 ^-2 Electrical conductivity - <200 mS / m - JGS 0212 263 219 285 293 227 274 pH <12.4 6 to 9 - KS F 2103,
ASTM D 4972 7.0 7.0 6.5 5.3 7.0 5.0 Water content (%) - - - KS F 2312,
ASTM D 2216 7 45 42 40 48 43 Foreign substance content (%)
(Organic foreign matter) 1.0 or less (volume) - - KS F 2576 0 0 0 0 0 0 Organic matter content (%) - - - SSSA-3 30 32 35 34 25 35 Ammonia Generation
(ppm, composition surface after curing) - - NIOSH
Immediately Dangerous To Life or Health Concentration
(300 ppm) - 119 176 139 182 302 400 H ₂ S generation
(ppm, composition surface after curing) - - NIOSH
Immediately Dangerous To Life or Health Concentration
(100 ppm) - 0 0 20 15 24 150 Chloride Content (mg / mg) - <1 mg / mg - JGS 0241 0 0 0 0 0 0

Test Item (Unit: mg / L) Reference value US EPA
PQL
(practical quantitation limit), mg / L Japan
Enforcement Rule of the Soil Pollution Control Act Article 24 and Schedule 4
(mg / L) Test Methods
(Waste process test standard: 2011) Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Pb 3 0.4 0.3 0.6 0.3 0.5 0.3 0.4 0.6 As 1.5 0.01 0.3 N.D. N.D. N.D. N.D. N.D. N.D. Hg 0.005 0.002 0.005 N.D. N.D. N.D. N.D. N.D. N.D. CD 0.3 0.001 0.3 0.07 0.03 0.09 0.3 0.3 One Cr ^{6 +} 1.5 0.02 1.5 0.02 0.02 0.02 0.9 One 18 CN ^- One 0.2 One N.D. N.D. N.D. N.D. N.D. N.D. Organic phosphorus One - One N.D. N.D. N.D. N.D. N.D. N.D. Tetrachlorethylene 0.3 0.0005 0.1 N.D. N.D. N.D. N.D. N.D. N.D. Trichlorethylene 0.1 0.001 0.3 N.D. N.D. N.D. N.D. N.D. N.D. Oil component (Unit:%) 5% - - N.D. N.D. N.D. N.D. N.D. N.D.

Test Item (Unit: mg / kg) Reference value CB TEC
(Consensus Based Threshold Effect Concentration) Test Method (Second Area: Soil Pollution Test Standard: 2011) Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 CD 10 0.99 0.4 0.8 One 1.9 1.63 3.18 Cu 500 31.6 20 31 26 39 92 66 As 50 9.79 N.D. N.D. N.D. N.D. N.D. N.D. Hg 10 0.18 N.D. N.D. N.D. N.D. N.D. N.D. Pb 400 35.8 23 68 88 26 97 92 Cr6 + 15 43.4 28 37 47 30 24 82 Zn 600 121 N.D. N.D. N.D. N.D. N.D. N.D. Ni 200 22.7 N.D. N.D. N.D. N.D. N.D. N.D. F- 400 - N.D. N.D. N.D. N.D. N.D. N.D. Organic phosphorus 10 - N.D. N.D. N.D. N.D. N.D. N.D. PCBs 4 0.35 N.D. N.D. N.D. N.D. N.D. N.D. CN- 2 - N.D. N.D. N.D. N.D. N.D. N.D. phenol 4 - N.D. N.D. N.D. N.D. N.D. N.D. benzene One - N.D. N.D. N.D. N.D. N.D. N.D. toluene 20 - N.D. N.D. N.D. N.D. N.D. N.D. Ethylbenzene 50 - N.D. N.D. N.D. N.D. N.D. N.D. xylene 15 - N.D. N.D. N.D. N.D. N.D. N.D. Petroleum Total Hydrocarbons (TPH) 800 1.19-4.61 N.D. N.D. N.D. N.D. N.D. N.D. Trichlorethylene 8 - N.D. N.D. N.D. N.D. N.D. N.D. Tetrachlorethylene 4 - N.D. N.D. N.D. N.D. N.D. N.D.

Looking at the results of Tables 3 to 8, in the case of artificial soil manufactured according to an embodiment of the present invention, the quality standards of circulating aggregate (Table 3), heavy metal dissolution test (Table 4), soil pollution concern standards test (Table 5 ) The results were all within the standard and passed the US EPA's drinking water and soil pollution standards of the Ministry of Land, Infrastructure and Transport. In addition, it can be seen that the excellent properties compared to the experimental results (Table 6 to Table 8) of the comparative example.

Therefore, the artificial soil by solidification of the waste resources produced according to the method of the present invention can be preferably used for the filling of the landfill facility, in addition to the land of the limited area in the landfill facility mixed with high-quality soil in the natural state It was confirmed that it can be used as an improvement agent.

Claims (5)

A first mixing step of preparing a first mixture by mixing at least one sludge selected from the lake and the dredging sludge and the purified sludge in a weight ratio of 1: 0.5 to 1.5;
A second mixing step of preparing a second mixture by mixing lime dewatered sludge and polysilicon sludge in a weight ratio of 1: 0.5 to 1.5;
A third mixing step of preparing a third mixture by mixing the first mixture, the second mixture, and the bottom ash in a weight ratio of 1: (0.5 to 2) :( 3 to 5);
A fourth mixing step of preparing a fourth mixture by further mixing at least one selected from an incinerator, fly ash, and dust in the third mixture in an amount of 10 to 40 parts by weight based on 100 parts by weight of the third mixture;
A fifth curing step of preparing a fifth mixture by further mixing and curing any one or more selected from light dolomite, dry desulfurized gypsum and calcium oxide to 1 to 10 parts by weight relative to 100 parts by weight of the fourth mixture to the fourth mixture; And
A sixth mixing step of mixing the fifth mixture with waste soil or red mud in a weight ratio of 1: 0.01 to 1 to obtain a sixth mixture as an artificial soil; And
The waste sand or red mud is mixed with 1 to 50 parts by weight of any one or more acidic materials selected from phosphate, titanium, gypsum, iron sulfate, iron sulfate monohydrate, alumina sulfate, and iron chloride. Neutralization
Method of manufacturing artificial soil by solidification of waste resources comprising a.
The method of claim 1, wherein in the fourth mixing step, the fourth mixture begins to generate heat by the hydration reaction and the solidification, so that the water content decreases due to vapor evaporation, and the moisture content when the temperature of the solidified by the exotherm reaches 25 ° C. A method for producing artificial soil, characterized in that less than 20%.
The method of claim 1, wherein the mixing of the fifth mixture and the waste soil or red mud mixture in the sixth mixing step is carried out in the pH range of 7 to 8.
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