KR20180029943A - Composition for neutralization treatment of acid waste water and for solidification of heavy metal ions from waste mine by using fly ash and bottom ash from fluidized-bed boiler and method for neutralization treatment of acid waste water and for solidification of heavy metal ions from waste mine - Google Patents

Abstract

The present invention provides a composition for neutralization treatment of acid waste water and solidification of heavy metal ions from waste mine, and a method of neutralization treatment of acid waste water and solidification of heavy metal ions from waste mine. The composition of the present invention comprises: fly ash generated in a fluidized-bed boiler; bottom ash generated in the fluidized-bed boiler; and a surfactant, wherein the fly ash and bottom ash are included in a weight ratio of 1 : 1-2, and the surfactant is included about 1-5 parts by weight based on 100 parts by weight of the fly ash.

Description

TECHNICAL FIELD The present invention relates to an acidic wastewater neutralization treatment and a heavy metal ion fixing composition for abandoned mine by using a fluidized-bed phase boiler bottom ash and fly ash, an acidic waste water neutralization treatment and a heavy metal ion immobilization technique from waste mine by using fly ash and bottom ash from fluidized-bed boiler and method for neutralization treatment of acid waste water and solidification of heavy metal ions from waste mine}

The present invention relates to an acidic waste water neutralization treatment and a composition for heavy metal ion fixation of abandoned mine by using a fluidized-bed phase boiler bottom ash and fly ash, and an acidic waste water neutralization treatment and a heavy metal ion immobilization method for a waste mine.

There are over 1,000 metal mines in Korea, and many environmental pollution problems have been raised by them. Since the mid 1990s, when the environmental pollution in the metal mine area has become a social problem, the government has been promoting the environmental pollution control policy.

Heavy metal pollution in the area around abandoned mine that is currently occurring in Korea is due to acid mine drainage, runoff of leachate, loss of mine waste, and dispersion of tailings and dust.

Acid mine drainage derived from mine drainage of abandoned mines is known as a permanent source of contamination in the surrounding area. Mining water is generated by the inflow of groundwater or surface water into the mine, and it flows out to the surface along the drain pipe or the cracked part. The amount of heavy metal elements dissolved in the mine shaft is chemically reacted with the surrounding rocks and minerals, and the amount depends on the types of minerals contained in the surrounding rocks and mineralized zones.

Sulfide minerals such as pyrite (FeS2) in the mine react with oxygen and water in the atmosphere to form acid mine drainage (AMD). Acid mine drainage from mines dissolves heavy metals and smoothes its fluidity, contaminating soil, surface water and groundwater downstream of abandoned mines.

In Korea, heavy metal contamination of soil and surface water by acidic mine drainage into the abandoned mine drainage system is serious. In such a contaminated site, the drainage of acid mine drainage should be completely controlled by shutting off the abandoned mine mouth.

However, currently, the purification methods performed in Korea are limited to the purification of contaminated soil and the surface waters flowing down to the lower part of the pollution source of acid mine drainage. Purification cases in abandoned mine polluted areas have short-term effects of several months or years, but can not permanently treat contaminants in acid mine drainage. Pollution by acid mine drainage In order to permanently purify the surface waters and soils in the area, it is required to eliminate pollution sources or establish a continuous purification system by precise analysis of pollution sources.

As the method of treating acid wastewater generated in the soil and the industrial field, the acidic wastewater described in Korean Patent Publication No. 95-008376 (Method and system for treating acidic waste water) is mixed with calcium hydroxide to adjust the pH to about 9.0 to 10.0 And the method described in JP-A No. 96-004230 (a method of neutralizing acidic wastewater using steelmaking slag), the acidic wastewater is preliminarily treated by passing the slag through a powder particle layer and neutralized by adding calcium hydroxide or caustic soda And 97-001235 (a method of treating industrial wastewater using acidic wastewater neutralizing material) discloses a method of using calcium hydroxide as an acidic wastewater neutralizing material, and Japanese Patent Application No. 97-010661 A method of treating wastewater) discloses a method using ion exchange.

Since all of these acid wastewater treatment methods use commercial lime slurry, it is not only costly, but also has the disadvantage of treating lime slurry separately.

On the other hand, the heavy metals in wastewater that are increasing due to industrialization are not easily decomposed into water or converted to stable compounds rapidly. Therefore, when heavy metal pollutants are discharged into soil, groundwater and surface water in the surrounding area, It is very likely to have an impact.

In particular, when heavy metals are absorbed into living organisms, they are not well decomposed in association with internal organisms and are difficult to be released to the outside of living body. Therefore, there is a great risk of causing a life-threatening disease.

Heavy metals are generated through various routes. In particular, acidic heavy metal wastewater generally has a high concentration of heavy metals due to the characteristics of heavy metals with increasing solubility in acidic conditions. Typical sources of acidic heavy metal wastewater include acidic wastewater from metal surface treatment companies, plating wastewater from plating companies, and electronics industry wastewater from electronics producers, acidic industrial wastewater, acidic mine drainage of dormant mine leachate and mine waters.

Since the acidic heavy metal wastewater contains various heavy metals at a high concentration, if the treatment is not performed properly, environmental damage may be caused. Therefore, appropriate measures must be provided.

Various heavy metal treatment techniques such as neutralization precipitation method, ion exchange method, oxidation and reduction method, adsorption method, solvent extraction method, filtration method and membrane separation method can be applied in order to remove heavy metals contained in acidic heavy metal wastewater. It is one of the used heavy metal treatment technologies (Eckenfelder, 2000).

The neutralization precipitation method has been evaluated as a technique which can stably obtain high heavy metal removal efficiency even in a relatively simple reaction process by using the principle of precipitation of hydroxides of a cationic heavy metal and a hydroxyl group in an alkali state. The use of an appropriate neutralizing agent is an indispensable factor in the neutralization precipitation method because the role of neutralizing agent in determining the precipitation pH range of heavy metal hydroxides is very important in the neutralization precipitation method.

(CaO), limestone (CaCO3), caustic soda (NaOH), and sodium carbonate (NaCO3) have been widely used as neutralizing agents for use in the conventional neutralization precipitation method. However, these conventional neutralizing agents, The alkali supply may not be properly performed or the pores may be blocked, and the maintenance cost is increased due to the continuous use of the chemicals. Therefore, there is a need for an economical high-performance neutralizing agent capable of continuously neutralizing industrial wastewater or mine drainage exhibiting strong acidity at a low cost for a long period of time.

In recent years, slag as a by-product, which is an industrial by-product having excellent ability to supply alkali, red mud and fly ash, which are generated in the aluminum smelting process, are attracting attention as materials that are likely to be used as neutralizing agents for acidic heavy metal wastewater .

Slag is an industrial by-product generated during the iron-making process of a steel mill. Because of the high proportion of calcium oxide (CaO) due to the influence of limestone introduced as a solvent, slag is highly soluble in acidic industrial wastewater or acid mine drainage as an alkali feed material (Simmons et al., 2002; Feng et al., 2004).

Red mud is an industrial by-product produced in the process of smelting aluminum in bauxite minerals. Iron mordant such as Fe2O3 is very high and sodium hydroxide (NaOH (Gupta et al., 2002; Nadaroglu et al., 2010), which is characterized by its ability to induce strong alkalis due to the effect of alkalinity.

In addition, fly ash is an industrial by-product generated by incineration of coal materials in a thermal power plant. Because fly ash contains a strong alkali component due to a high composition ratio of lime components, fly ash is highly valuable as a neutralizing agent for heavy metal treatment (Wang et al., 2004; Gariari et al., 2008).

However, since the above-mentioned slag, red mud and fly ash are used as industrial by-products, the alkali supply ability of the slag, red mud and fly ash can be lowered due to coating of the precipitate when used alone as a neutralizer, In the case of heavy metal wastewater mixed with various heavy metals, it is difficult to obtain effective removal efficiency with a single reaction of neutralization precipitation under a certain pH condition because the pH range of precipitated heavy metals is different due to long-term use of neutralizing agent. There is a problem.

Therefore, there is a demand for a new neutralizing treatment of abolished acid water and a method for immobilizing heavy metal ions which can solve the above-described problems.

Korean Patent Publication No. 1995-008376

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above problems of the prior art,

It is possible to effectively neutralize the acidic wastewater discharged from the abandoned mine without a secondary pollution source, effectively fix heavy metal ions contained in the abandoned mine tailings,

It is possible to carry out the removal of heavy metal ions and the acidic water neutralization treatment commonly in a mixed state of various types of heavy metals,

Since the porosity is maintained by utilizing the bubbles, the contact area with the acidic wastewater is increased, so that the neutralization of the acidic wastewater and the fixing of heavy metal ions can be performed efficiently for a long period of time,

It is an object of the present invention to provide an economical and eco-friendly abatement acidic wastewater neutralization treatment and a heavy metal ion fixing composition by recycling fly ash and bottom ash generated in a fluidized bed boiler to be buried in a fixed amount.

It is also an object of the present invention to provide an acidic waste water neutralization treatment and a heavy metal ion immobilization method of abandoned mine acid by the above composition.

The present invention

Fly ash generated in a fluidized bed phase boiler;

Bottom ash generated in a fluidized bed phase boiler; And

A surfactant,

Wherein the fly ash and bottom ash are contained in a weight ratio of 1: 1 to 2, and the surfactant is contained in an amount of 1 to 5 parts by weight based on 100 parts by weight of the fly ash. To provide a fixing composition.

In addition,

Characterized in that the acidic wastewater neutralization treatment and the heavy metal ion fixing composition of the abandoned mine are installed directly on the abandonment of the abandoned mine or on the upper part of the abandoned mine tailings or on the lower part of the abandoned mine tailings. And heavy metal ion immobilization method.

The acidic wastewater neutralization treatment and the heavy metal ion fixing composition of the present invention can effectively neutralize the acidic wastewater discharged from the abandoned mine without a secondary pollution source and also effectively neutralize the heavy metal ions contained in the abandoned mine tailings.

In addition, since it exhibits a stable and stable pH precipitation condition, removal of heavy metal ions and acidic water neutralization treatment can be performed in general, even in a mixed state of various types of heavy metals.

Also, since the fly ash and bottom ash contain a surfactant capable of generating bubbles, the contact area with the acidic wastewater is increased, so that neutralization of acidic wastewater and fixing of heavy metal ions can be performed efficiently for a long period of time.

In addition, it is very economical and environmentally friendly because it recycles fly ash and bottom ash from a fluidized bed boiler that is buried in a fixed quantity.

The acid neutral wastewater neutralization treatment and the heavy metal ion immobilization technique of the abandoned mine acid by the above composition also provide the above-mentioned effects.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a view showing a method of neutralizing an acidic waste water of a waste acid of the present invention and using a composition for fixing heavy metal ions; FIG.

Hereinafter, the present invention will be described in detail.

It will be apparent to those skilled in the art that the technical and scientific terms used herein may have other meanings as commonly understood by one of ordinary skill in the art to which the present invention belongs. Descriptions of the blurred notice function and configuration are omitted.

The present invention relates to a fly ash generated in a fluidized bed phase boiler; Bottom ash generated in a fluidized bed phase boiler; And a surfactant,

Wherein the fly ash and bottom ash are contained in a weight ratio of 1: 1 to 2, and the surfactant is contained in an amount of 1 to 5 parts by weight based on 100 parts by weight of the fly ash. ≪ / RTI >

The acidic wastewater neutralization treatment and the heavy metal ion fixing composition of the present invention are produced by efficiently recycling fly ash and bottom ash generated in a fluidized-bed-type boiler to be buried in a quantitative manner. The composition is hydrated to a fly ash having a pH of 12 to 13 The calcium oxide contained in the calcium oxide and the calcium oxide contained in the bottom ash, and the neutralized ions such as acidic water generated by the abandoned mine and the heavy metal ions contained in the abandoned mine are effectively neutralized.

In addition, it is possible to continuously supply alkaline components to acidic water or heavy metal ions including porous bottom ash and surfactant in case that the capability of supplying alkali component to the tailings decreases due to coating of precipitate or the like, Thereby maximizing the effect of the above.

In the acidic wastewater neutralization treatment and heavy metal ion fixing composition of the abandoned mine, the fly ash and bottom ash are preferably contained in a weight ratio of 1: 1 to 2, more preferably 1: 1.3 to 1.7, . When the weight ratio of the fly ash is less than 1, the porosity of the fly ash tends to be low, so that the alkali component is difficult to sufficiently react with the acidic water or the heavy metal ions of the abandoned mine. If the weight ratio is more than 2, the alkali component becomes acidic or abandoned It is difficult enough to react with the heavy metal ions of the rice.

The surfactant is preferably contained in an amount of 1 to 5 parts by weight, preferably 2 to 4 parts by weight based on 100 parts by weight of the fly ash. When the amount of the surfactant is less than 1 part by weight, the voids of the cured composition become less, and the acidic water or the heavy metal ions passing through the voids do not sufficiently react with the calcium oxide component in the fly ash, and more than 5 parts by weight , It is difficult for calcium oxide, which is an alkali component, to react sufficiently with heavy metal ions of acidic water or abandoned mines due to excess pores generated in the composition cured body.

Examples of the surfactant include anionic surfactants such as sodium lauryl sulfate and alkylbenzene sulfonate. The anionic surfactants may be used singly or in combination of two or more.

The anionic surfactant may be more preferably used in terms of reaction with cations which are acidic ions which cause heavy metal ions and acidic water.

The fluidized-bed phase boiler fly ash is generated in the fluidized-bed phase boiler, and the content of calcium oxide may be 10 to 60% by weight, preferably 30 to 60% by weight.

If the content of calcium oxide is included in the above-mentioned range, the heavy metal ions of acidic water or abandoned mine can be effectively neutralized.

The fluidized-bed phase boiler bottom ash is generated in the fluidized bed phase boiler and can be preferably used in the form of a porous aggregate having an average longitudinal length of 1 mm to 40 mm, more preferably a porous aggregate of 2 mm to 20 mm. If the bottom ash has a size of less than 1 mm, it is difficult to expect the effect of porosity. If the bottom ash is more than 40 mm, the bottom ash may be problematic because of its large permeability.

It is more preferable that the fluidized bed phase boiler bottom ash has a calcium oxide content of 10 to 60% by weight. Still more preferably from 30 to 60% by weight. When the content of calcium oxide is included in the above-mentioned range, the heavy metal ions of acidic water or abandoned mine can be more effectively neutralized.

In addition,

Characterized in that the acidic wastewater neutralization treatment and the heavy metal ion fixing composition of the abandoned mine are installed directly on the abandonment of the abandoned mine or on the upper part of the abandoned mine tailings or on the lower part of the abandoned mine tailings. And heavy metal ion immobilization method.

The contents of the acidic wastewater neutralization treatment and heavy metal ion fixing composition of the abandoned mines mentioned above can be directly applied to the immobilization technique.

Hereinafter, the present invention will be described in more detail by way of examples. However, the following examples are intended to further illustrate the present invention, and the scope of the present invention is not limited by the following examples. The following examples can be appropriately modified and changed by those skilled in the art within the scope of the present invention.

Examples 1 to 2: Acid waste water neutralization treatment of waste abandoned mine acid and preparation of heavy metal ion fixing composition

10 kg of a composition for neutralization of acidic wastewater of the abandoned mine acid of the present invention and a heavy metal ion fixing composition were prepared by mixing the components as shown in Table 1 below.

The fly ash used was one containing 40 wt% of calcium oxide, and the bottom ash having an average length of 10 mm was used. Sodium lauryl sulfate was used as a surfactant.

Example 1 (parts by weight) Example 2 (parts by weight) Bottom ash 140 160 Fly ash 100 100 Surfactants 4 2

Test Example  1: of abandoned mines Tailings  Evaluate throughput

In order to evaluate the performance of the acidic wastewater neutralization treatment and the heavy metal ion fixing composition of the abandoned mine produced in Examples 1 and 2, a cylindrical column having a diameter of 30 cm and an open top at the bottom was prepared. The abandoned maze prepared the abandoned mine of the Gogok mine in Samcheok City.

< Abandoned mine  Heavy metals and pH measurement included>

The heavy metals and pH contained in the abandoned mine of the Gamgok mine in Samcheok City were measured and are shown in Table 2 below.

<First Test>

As shown in Fig. 1 (a), acidic wastewater neutralization treatment of the abandoned mine acid produced in Example 1 or 2 and heavy metal ion fixing composition 10 were applied to two cylindrical columns 50 prepared above, And the abscissa 20 was placed thereon at a height of 10 cm. Thereafter, 50 L of ionic purified water 40 was poured down from the upper side of the column and passed downward. The passed filtered water 42 was collected and the heavy metal content and pH were measured.

&Lt; Second test >

As shown in Fig. 1 (b), the two cylindrical columns 50 prepared above were each filled with a waste lance 20 at a height of 10 cm, and then the acidity of the abandoned lance produced in Example 1 or 2 The waste water neutralization treatment and the heavy metal ion fixing composition 10 were filled to a height of 20 cm, and then 50 L of the ionized water 40 was poured down from the upper side of the column. The passed filtered water 42 was collected and the heavy metal content and pH were measured.

<Third Test>

As shown in Fig. 1 (c), the two cylindrical columns 50 prepared above were treated with the abandoned mine tailings, the acidic wastewater neutralization treatment of the abandoned mine acid produced in Example 1 or 2, and the heavy metal ion fixing composition at a ratio of 1: 1 at a volume ratio of 30 cm and then poured 50 L of ionized water 40 from the top of the column. The passed filtered water 42 was collected and the heavy metal content and pH were measured.

 * According to the Korea Institute of Construction and Environment Testing (CT16-063757)

As can be seen from the above Table 2, when the acidic waste water neutralization treatment and the heavy metal ion fixing composition of the abandoned mine acid of Examples 1 and 2 of the present invention are used, the heavy metals Cu, Pb, As and Cd Was not detected at all. In addition, it was confirmed that the amount of Zn also decreased significantly compared to the amount contained in the abandoned mine. Also, the pH of the filtered water was found to be close to neutrality from 7.15 to 8.01.

The spirit of the present invention should not be construed as being limited to the embodiments described, and all the equivalents or equivalents of the claims, as well as the following claims, fall within the scope of the present invention.

Claims (5)

Fly ash generated in a fluidized bed phase boiler;
Bottom ash generated in a fluidized bed phase boiler; And
A surfactant,
Wherein the fly ash and bottom ash are contained in a weight ratio of 1: 1 to 2, and the surfactant is contained in an amount of 1 to 5 parts by weight based on 100 parts by weight of the fly ash. &Lt; / RTI &gt; The method according to claim 1,
Wherein the fluidized bed boiler fly ash is generated in a fluidized bed boiler, and the content of calcium oxide is 10 to 60 wt%, the composition for neutralizing acidic wastewater and fixing heavy metal ions. The method according to claim 1,
Wherein the fluidized bed phase boiler bottom ash is generated in a fluidized bed boiler and has a porous aggregate form having an average longitudinal length of 1 mm to 40 mm. The method according to claim 1,
Wherein the surfactant is an anionic surfactant. Description: FIELD OF THE INVENTION The acidic wastewater of claim 1, wherein the acidic wastewater neutralization treatment and the heavy metal ion fixing composition are installed directly on the closed operation of the abandoned mine, or on the upper part of the abandoned mine tailings or on the lower part of the abandoned mine tailings. Neutralization and Heavy Metal Ion Immobilization Method.

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