KR20150037175A - Solidified agent using red mud and manufacturing method of the same - Google Patents

Abstract

The present invention relates to an embankment composition using red mud and to a method for manufacturing the same and, more specifically, to an embankment composition using red mud which uses incineration residue comprising large amount of calcium oxide (CaO) having absorption and heating functions and a solidification agent comprising petrolem cokes desulfurized gypsum in order to drastically reduce moisture content of red mud, thereby being able to be utilized for landfill of low agricultural area and as an embankment. The embankment composition of the present invention comprises 10-200 parts by weight of solidification agents based on 100 parts by weight of red mud having 30-70% moisture contents. The solidification agent comprises 10-300 parts by weight of the petrolem cokes desulfurized gypsum based on 100 parts by weight of the incineration residue having 20% or more of calcium oxide (CaO) contents.

Description

TECHNICAL FIELD [0001] The present invention relates to a red mud composition,

More particularly, the present invention relates to a composition of red mud and a method for producing the same, and more particularly to a red mud composition comprising red mud The present invention relates to a composition for embankment using red mud which can be used as landfill material for underground cropland and as embankment by abruptly reducing water content, and a method for producing the embalming composition.

Red mud is a by-product of aluminum hydroxide / alumina (Al (OH) ₃ / Al ₂ O ₃ ) from bauxite. The major component of red mud is Fe ₂ O _{3, which} is reddish hue and red mud, and about 200,000 tons per year is produced as a by-product in Korea. These red muds are discharged into the sludge state with a water content of about 50% at the time of final discharge, and the industrial by-products in such a state are difficult to be recycled.

Therefore, nowadays, quicklime, cement and iron sulfate are mainly used to utilize red mud.

The above-mentioned cement can not be said to be environmentally friendly because it is produced by calcining limestone, clay, or iron ore and pyrolysis at high temperature using coal as a fuel in manufacturing cement, that is, it is a serious product of natural resources and natural damage.

Therefore, there is a demand for a new concept of high-fire firefighting without using quicklime, cement and iron sulfate, and a technology for recycling sludge using the same.

Disclosure of the Invention The present invention has been conceived in order to solve the above problems, and it is an object of the present invention to provide a method for producing a water- The present invention provides a composition for embankment using red mud that can be used as embankment of low land, landfill, and a method of manufacturing the same.

In order to solve the above-mentioned technical problems, the filler composition according to the present invention comprises 10 to 200 parts by weight of a fire-retardant, based on 100 parts by weight of red mud with a water content of 30% to 70% And 10 to 300 parts by weight of petroleum coke desulfurization gypsum based on 100 parts by weight of the incineration residue having a content of 20% or more.

The incineration residue may be any one selected from the group consisting of coal ash, paper sludge incineration residue, biomass incineration residue, sewage sludge incineration residue, RDF (Refuse Derived Fuel) incineration residue and RPF (Refuse Plastic Fuel) incineration residue .

It is preferable that the incineration residue has a particle diameter of 0.001 to 0.1 cm. The specific surface area of the incineration residue is preferably 2,000 to 6,000 cm ² / g.

In order to prevent re-slurrying of the solidified solid resulting from solidification of the red mud, at least one of the first type cement, the blast furnace slag cement or the blast furnace slag fine powder is further included, and the first type cement, the blast furnace slag cement, It is preferable that the slag fine powder further comprises 5 to 100 parts by weight based on 100 parts by weight of the incineration residue.

The anti-sticking agent may further comprise 10 to 100 parts by weight of the anti-sticking agent, based on 100 parts by weight of the incineration residue, to prevent the red mud from being adhered to the manufacturing equipment during the production or transport of the solidified product, It is preferable to incorporate additional additives.

It is preferable that the anti-adhesion agent is any one or a mixture of two or more selected from the group consisting of coal ash, calcium limestone, fine feldspar, fine silica powder and granite fine powder having a calcium oxide (CaO) content of less than 20%.

The pH reducing agent may further include an acidic powder having a pH of 4 or less by mixing directly with a sulfuric acid or a dilute sulfuric acid solution or by titrating sulfuric acid into a powder to reduce the pH of the fillet.

It is preferable that the pH-reducing agent is further mixed in an amount of 5 to 100 parts by weight based on 100 parts by weight of the incineration residue.

The method for producing a filler composition using red mud according to the present invention comprises the steps of: 1) preparing a fireproofing material as defined in any one of claims 1 to 5; 2) mixing 10 to 200 parts by weight of the fire-retardant with 100 parts by weight of red mud; And 3) curing the mixture of red mud and solid fire.

According to the present invention, there is an effect that an embankment can be obtained by using industrial by-products such as red mud, incineration residue and petro coke.

In particular, the water content of red mud can be drastically reduced by including incineration residues containing a large amount of CaO, which absorbs and exothermically acts, and petro coke desulfurization gypsum, which can be utilized as landfill and embankment for lowland farmland.

Hereinafter, the embedding composition using red mud and the method for producing embankment of the present invention will be described in detail.

First, the composition and action of the embossing material using red mud according to the present invention will be described.

Seongtojae composition using the red mud of the present invention includes water content of 30% to 70% by weight of red mud has a specific surface area of 100 2,000cm against the portion ² / g ~ 6,000cm ² / g at a high fire 10 to 200 parts by weight .

The red mud sludge includes 10 to 300 parts by weight of petroleum coke desulfurization gypsum based on 100 parts by weight of the incineration residue having a calcium oxide (CaO) content of 20% or more.

In addition, the incineration residues with a calcium oxide (CaO) content of 20% or more can be recovered from coal ash, paper sludge incineration residue, biomass incineration residue, sewage sludge incineration residue, RDF (Refuse Derived Fuel) incinerator residue and RPF (Refuse Plastic Fuel) Or a mixture of two or more thereof.

Calcium oxide, which is abundantly contained in the incineration residue, reacts with water and absorbs, exotherms and expands into calcium hydroxide. The reaction formula is as follows.

CaO + H ₂ O- > Ca (OH) ₂ + 15.6 mol ^-1

Although the incineration residue is usually recycled as a concrete admixture, incineration residues containing a large amount of calcium oxide can not be used as a concrete admixture because of its absorption, exothermic and expansion characteristics.

Therefore, the present invention utilizes incineration residues which can not be utilized as a concrete admixture material.

That is, when the red mud having a high water content and the incineration residue containing a large amount of calcium oxide are mixed, the above reaction causes the calcium hydroxide to be generated and the water content of the red mud is reduced. Also, since the heat generated by the above reaction evaporates the moisture of the red mud, it is possible to further reduce the water content of the red mud.

On the other hand, incineration residues containing 20% or more of calcium oxide are coal ash, paper sludge incineration residue, biomass incineration residue, sewage sludge incineration residue, RDF incinerator residue and RPF incinerator residue.

The specific surface area of the incineration residue is preferably 2,000 to 6,000 cm ² / g. If the specific surface area of the incineration residue is less than 2,000 cm ² / g, the effect of reducing the moisture content upon solidification of red mud is reduced due to insufficient particulate matter. If the specific surface area exceeds 6,000 cm ² / g, It is scattered during weighing and transportation, and the facility operation is degraded.

Coal materials are produced in a large number of power plants. Particularly, coal ash produced in a power plant having an in-furnace desulfurization system has a high content of calcium oxide. In the case of the in-furnace desulfurization system, since coal and limestone are mixed and burned, a large amount of Free CaO is contained in coal ash.

Petro coke desulfurization gypsum is mixed with petroleum coke and limestone in order to desulfurize the petroleum coke in the incinerator which burns petroleum coke as fuel, so ash contains a large amount of gypsum and CaO.

The petrocoke desulfurized gypsum preferably has a specific surface area of 2,000 to 6,000 cm ² / g. If the specific surface area is less than 2,000 cm ² / g, the activity is lowered due to insufficient particulate matter, and the water reducing effect is lowered. When the specific surface area exceeds 6,000 cm ² / g, the activity is raised, And the facility operation is deteriorated.

In addition, the Petro Coke desulfurization gypsum contains 10 to 300 parts by weight based on 100 parts by weight of the incineration residue. When the amount is less than 10 parts by weight, the effect of reducing the water content is insufficient due to insufficient calorific value. When the amount is more than 300 parts by weight, And it is difficult to handle in the work.

In order to prevent re-slurrying of the hardened cementitious aggregate formed by solidification of red mud, it is preferable to further include at least one of the first type cement, blast furnace slag cement and blast furnace slag fine powder.

The first type cement, the blast furnace slag cement and the blast furnace slag fine powder are preferably mixed with 5 to 100 parts by weight based on 100 parts by weight of the incineration residue. If it is mixed with less than 5 parts by weight, it can not manifest a predetermined strength. If the embankment composition comes into contact with rain, ground water and surface water, there is a danger of slurrying again. If it exceeds 100 parts by weight, But it is too hard to be used as an artificial tile or soil material, which is a soil substitute, that is, there is a possibility that the characteristics of the soil-mechanical embankment can not be satisfied.

It is also preferable that the red mud further contains a fixing agent to prevent the red mud from sticking to the manufacturing equipment during the production or transportation of the solidified product.

It is preferable that the anti-bonding agent is any one or a mixture of two or more selected from the group consisting of coal ash, calcium limestone, fine feldspar, fine silica powder and granite fine powder having a calcium oxide (CaO) content of less than 20%.

The anti-adhesion agent is preferably incorporated in an amount of 10 to 100 parts by weight based on 100 parts by weight of the incineration residue. If less than 10 parts by weight is mixed, the red mud solidification product may be adhered to the equipment during the process, resulting in a rapid deterioration of the equipotentiality of the equipment. If the amount exceeds 100 parts by weight, the water reducing effect of red mud Can be halved.

Hereinafter, a description will be given of a method for manufacturing an embankment with red mud according to the present invention.

The method for manufacturing an embankment using red mud according to the present invention comprises the steps of: 1) manufacturing the above-mentioned solidified fire; 2) mixing 10 to 200 parts by weight of the above fire-retardant with 100 parts by weight of red mud; And 3) curing the mixture of red mud and solid fire.

If the amount is less than 10 parts by weight in the second step, the water content can not be sufficiently reduced and the composition can not be used as an embankment. If the amount exceeds 200 parts by weight, the water content becomes too low, It becomes difficult to work with embankment and cover.

Hereinafter, the present invention will be described in more detail with reference to the following examples and comparative examples. It is to be understood, however, that the following examples and comparative examples are intended to illustrate the present invention and that the scope of the present invention is not limited to the scope of these examples and comparative examples.

Example  One

First, 40 parts by weight of petroleum coke desulfurization gypsum, 10 parts by weight of blast furnace slag cement to prevent sludge formation of solidified materials, and 10 parts by weight of limestone fine powder as a fixing agent were added to 100 parts by weight of high calcium coal ash with a calcium oxide content of 38% And 20 parts by weight of an acidic powder having a pH of 1.8, which was prepared by titrating sulfuric acid as a pH-reducing agent into fine silica powder, were uniformly mixed to prepare a fireproofing.

Next, 100 parts by weight of red mud having a water content of 45% was mixed with 15 parts by weight of the fire-retardant prepared as described above and cured at room temperature to prepare an embankment.

Example  2

100 parts by weight of red mud having a water content of 45% was mixed with 30 parts by weight of the same fire retardant as that of Example 1 and cured at room temperature to prepare an embankment.

Comparative Example

In the comparative example, natural soil mixed with clayey soil and sandy soil was sampled, and samples were prepared without adding a firefly.

Performance Test Methods and Results of Embankment

As shown in Table 1 below, the water content was measured by the KS F 2306 method and the compressive strength and permeability test was conducted by the method of KS F 2343 and KS F 2322.

Experiment Way Remarks Moisture content KS F 2306 How to measure water content of soil Compressive strength KS F 2343 Uniaxial compressive strength method Permeability coefficient KS F 2322 Variable Strain Test

The test results for Examples 1, 2, and Comparative Example according to Table 1 are as shown in Table 2.

division Example 1 Example 2 Comparative Example Water content (%)

Immediately after mixing 39.7 34.4 46.2 1 day 36.2 31.4 - 3 days 32.1 28.7 - Compressive strength (kgf / cm ² )
3 days 1.7 2.6 1.12 7 days a year 2.2 3.4 1.23 28 days old 3.8 4.9 1.62 Permeability Coefficient (cm / sec) 3 days 3.27 × 10 ^-4 3.38 × 10 ^-4 3.21 x 10 ^-4

(1) Change in water content

The water content of the embankment prepared by the above Examples 1 and 2 is shown in Table 2. As can be seen in Table 2, the water content of Red Mud before the fire-fighting was 45.0%, but the water content is rapidly reduced over time. As described above, the reason why the water content is greatly reduced is that the exothermic reaction occurs immediately after the high fire is mixed with the red mud and the hydration reaction proceeds at the same time. Also, as the time passes, the water content rapidly decreases due to hydrate formation and natural drying. It can be seen that all of the cases of Examples 1 and 2 were improved to be recycled immediately with embers and the like. If it is used as embankment after 3 days of natural curing, it is expected to contribute not only to easier handling but also to increase the compressive strength.

(2) Change in uniaxial compressive strength

As shown in Table 2, the unconfined compressive strength of the embankment composition produced by the present invention is larger than that of natural soil. This value is much higher than 1.0kgf / cm ² , which is the strength standard of soil and embankment materials, and shows the strength that can be used for various soil materials such as soft soil improvement material, car water material and backfill material.

This is due to the reduction of water content and the surface modification of red mud by the exothermic reaction when mixed with fire and fire, and the consolidation of particles is achieved by consolidation of the particles. Calcium silicate reaction is induced by CaO and SiO ₂ components, The solidification reaction that can be ensured occurs and the strength is enhanced. In addition, the water content of red mud is relatively low due to the absorption of the fire, and the fine particles clay and colloid components are isolated by the absorption of the fire, ion exchange, pozzolan and carbonation reaction, And the uniaxial compressive strength is increased.

(3) Permeability characteristics

As can be seen from the measurements of the permeability coefficient of Table 2, the permeability coefficient of the embankment of the third day was not significantly different from that of the natural soil of the comparative example. In the case of Middlesex country, New Jersey, USA, the permeability coefficient of the landfill cover material is 1 × 0 ^-3 cm / sec to 1 x 0 ^-7 cm / sec. It is considered that the embedding composition using the red mud prepared by the present invention has sufficient water permeability as a daily and intermediate landfill material.

Claims (8)

And 10 to 200 parts by weight of a fire retardant based on 100 parts by weight of red mud having a water content of 30% to 70%
Wherein the fireproofing comprises 10 to 300 parts by weight of petroleum gypsum desulfurization gypsum based on 100 parts by weight of incineration residue having a calcium oxide (CaO) content of 20% or more.
The method according to claim 1,
The incineration residue may be any one or a mixture of two or more selected from the group consisting of coal ash, paper sludge incineration residue, biomass incineration residue, sewage sludge incineration residue, RDF (Refuse Derived Fuel) incineration residue and RPF (Refuse Plastic Fuel) ≪ / RTI >
The method according to claim 1,
In order to prevent re-slurrying of the solidified solid resulting from solidification of the red mud, at least one of a first type cement, a blast furnace slag cement or a blast furnace slag fine powder is further included, and the first type cement, blast furnace slag cement or blast furnace slag Wherein the fine powder further comprises 5 to 100 parts by weight based on 100 parts by weight of the incineration residue.
The method according to claim 1,
The anti-sticking agent may be added in an amount of 10 to 100 parts by weight based on 100 parts by weight of the incineration residue, to prevent the red mud from being adhered to the manufacturing equipment during the production or transfer of the solidified product, Lt; RTI ID = 0.0 > 1, < / RTI >
5. The method of claim 4,
Wherein the anticaking agent is any one or a mixture of two or more selected from the group consisting of coal ash, calcium limestone powder, feldspar fine powder, fine silica powder and fine granite powder having a calcium oxide (CaO) content of less than 20%.
The method according to claim 1,
Wherein the pH reducing agent further comprises an acidic powder having a pH of 4 or less by mixing directly with a sulfuric acid or a dilute sulfuric acid solution or by titrating sulfuric acid with a powder to reduce the pH of the embryo.
The method according to claim 6,
Wherein the pH-lowering agent is further incorporated in an amount of 5 to 100 parts by weight based on 100 parts by weight of the incineration residue.
1. A method for manufacturing a fireproof product, comprising the steps of: producing a fireproofing film according to any one of claims 1 to 7;
2) blending 10 to 80 parts by weight of the fire-retardant with 100 parts by weight of red mud; And
3) curing a mixture of the red mud and the high fire.