KR101535909B1 - Mamufacturing method for soil solidified agent - Google Patents

Abstract

The present invention relates to a dirt fire composition using red mud, and more particularly, to a dirt fire composition using red mud which can recycle industrial by-products such as red mud, incineration residue and desulfurization dust.
(CaO) content of not less than 20% by weight and an oxidant ferrous (Fe ₂ O ₃ ) content of not less than 5% by weight based on 100 parts by weight of red mud with a water content of 30% by weight to 70% And 5 to 200 parts by weight of a desulfurizing dust having a calcium oxide (CaO) content of 20% by weight or more and a ferric oxide (Fe ₂ O ₃ ) content of 5% by weight or more.

Description

TECHNICAL FIELD [0001] The present invention relates to a method for manufacturing a fire-retardant composition using red mud,

The present invention relates to a dirt fire composition using red mud, and more particularly, to a dirt fire composition using red mud which can recycle industrial by-products such as red mud, incineration residue and desulfurization dust.

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. Such red mud is discharged into the sludge state having a moisture content of about 50% by weight at the final discharge, and such a functional by-product is difficult to recycle.

Therefore, in order to utilize Red Mud nowadays, Red Mud is put into a rotary dryer and is heated and dehydrated, and powdered and then used as a pigment of building materials.

In order to completely dry the red mud having a water content of about 50 wt% by using the rotary dryer, it is uneconomical because it requires a fuel cost of about 40,000 KRW or more per 1 ton of red mud, It is used as pigment of building material and its application is extremely limited.

Therefore, in order to effectively and efficiently recycle Red Mud as an industrial byproduct, it is urgently required to develop a technology for expanding the capacity to utilize it as a civil engineering fire to secure the economical efficiency through the efficiency of the drying process and to solidify the soil.

Japanese Patent Application Laid-Open No. 10-2013-0046775

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and it is an object of the present invention to provide a pretreatment step of reducing the water content of red mud by mixing red mud with a small amount of CaO- And then drying it after roughly using powdered red mud as a raw material.

In order to solve the above-mentioned technical problems, the present invention provides a method for producing a red mud which comprises 20 parts by weight or more of calcium oxide (CaO) and 20 parts by weight or more of ferric oxide (Fe ₂ O ₃ ) 5 to 200 parts by weight of an incineration residue having a content of 5% by weight or more and 5 to 200 parts by weight of a desulfurization dust having a calcium oxide (CaO) content of 20% by weight or more and an oxidizing agent ferrous (Fe ₂ O ₃ ) content of 5% .

In addition, the incineration residues include coal ash, paper sludge incineration residues, biomass incineration residues, sewage sludge incineration residues, incineration residues from incinerators burning petro coke, refuse derived fuel (RDF) incinerator residues, and RPF (Refuse Plastic Fuel) And an incinerator residue, or a mixture of two or more thereof.

It is preferable that the desulfurized dust is discharged from a steel making and steelmaking process of a steel mill.

And further comprising 5 to 100 parts by weight of a strength development agent based on 100 parts by weight of the red mud dry powder, wherein the strength development agent is at least one of portland cement, blast furnace slag cement, fly ash cement and ternary cement And the ternary cement is preferably mixed with the portland cement with the slag fine powder and the fly ash.

Also, 10 to 50 parts by weight of a pozzolan activator is further incorporated into 100 parts by weight of the red mud dry powder, and the pozzolan activator is preferably a coal ash or blast furnace slag powder having a calcium oxide (CaO) content of less than 10% by weight.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to recycle industrial byproducts such as incineration residue, desulfurized dust, and red mud containing a large amount of CaO.

Hereinafter, the composition of the soil fire using the red mud according to the present invention and the manufacturing method thereof will be described in detail.

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

Heulgo smoke composition using the red mud of the present invention is the water content with respect to the red mud 100 30% by weight to 70% by weight of parts by weight of calcium oxide (CaO) content is at least 20% by weight, ferric oxide (Fe ₂ O ₃ ) Of 5 wt% or more, and 5 to 200 parts by weight of desulfurizing dust.

In addition, the incineration residues include refuse derived gypsum, refuse derived fuel (RDF), and refuse plastic fuel (RPF), which are generated from coal ash, paper sludge incineration residues, biomass incineration residues, incineration residues of sewage sludge, incinerators that burn petro coke, And an incinerator residue, or a mixture of two or more thereof.

The desulfurization dust is a slag dust or a KR slag dust as a desulfurization by-product generated in a steelmaking and steelmaking process.

It is preferable that the incineration residue and the desulfurization dust have 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 maintain the reddish color of the red mud mixed dried product, the oxidizing agent (Fe ₂ O ₃ ) component of the incineration residue and the desulfurization dust should be not less than 5% by weight. The color of the incineration residue and the desulfurization dust is determined by the content of oxidizing agent (Fe ₂ O ₃ ) in the raw material. As the content of ferric oxide (Fe ₂ O ₃ ) is lower, the color of the raw material becomes white and whitish, and the color of brown becomes more as the content of ferric oxide (Fe ₂ O ₃ ) is higher. Therefore, in order to keep the color of brown fire from red to brown due to the characteristic of dirt fire, oxidizing agent (Fe ₂ O ₃ ) component of incineration residue and desulfurization dust should be 5 wt% or more.

Calcium oxide, which is contained in large amounts in incineration residue and desulfurization dust, reacts with water and absorbs, exothermic, and expands to become 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. 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 desulfurization dust may be slag dust or KR slag dust as a desulfurization by-product generated in a steelmaking and steelmaking process. This desulfurization dust uses limestone as a desulfurization material in order to prevent the release of sulfuric acid gas to the atmosphere during iron making and steelmaking of steelworks. The decarbonated CaO particulate matter at high temperature and the sulfur component are combined with each other so that a large amount of SO ₃ component and CaO Component.

Therefore, when the red mud having a high water content and the incineration residue containing a large amount of calcium oxide and the desulfurized dust are mixed, the water reacts with the red mud as the calcium hydroxide is produced by the above reaction. 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.

After reducing the water content of the mixture through such a process, when the mixture is put into a rotary dryer, the drying efficiency is increased, and the fuel cost of about 30,000 won per 1 ton of red mud can be sufficiently dried, thus ensuring economical process operation.

The specific surface area of the incineration residue and the desulfurization dust is preferably 2,000 to 6,000 cm ² / g. If the specific surface area of the incineration residue and the desulfurization dust is less than 2,000 cm ² / g, the effect of reducing water content is deteriorated when mixed with red mud because of insufficient particulate matter. If the specific surface area exceeds 6,000 cm ² / g, The apparent density decreases during transportation, which is scattered during weighing and transportation, and facility operation is degraded.

Further, in the present invention, a mixture obtained by mixing the red mud, the incineration residue, and the desulfurized dust is put into a rotary dryer and directly heated to dry the mixture. The mixture can be put into a direct heating rotary dryer to recover completely dried red mud dry powder with a moisture content of 2% by weight or less.

In addition, it is preferable that a strength-inducing agent is incorporated so as to exhibit the strength of the fire-proofing using the red mud dry powder. The strength agent may further include at least one of Portland cement, blast furnace slag cement, fly ash cement, or portland cement mixed with slag fine powder and fly ash, wherein the strength modifier includes the red mud dry powder More preferably 5 to 100 parts by weight, relative to 100 parts by weight. The cement is usually purchased and used in the market.

The strength agent is preferably incorporated in an amount of 5 to 100 parts by weight based on 100 parts by weight of the red mud dry powder. If it is mixed with less than 5 parts by weight, it can not develop a predetermined strength. Therefore, there is a risk of re-slurrying when the fire-retardant composition is mixed with soil to form a solidified body and then contacted with rain water, ground water and surface water. If excess amount is added, excessive amount of hydrate is generated and the strength is greatly increased. However, it is too hard to exceed the soil dynamical standard value, so that there is a fear that the property of fire is not satisfied.

The pozzolanic activator may further include 10 to 50 parts by weight of the pozzolanic active agent per 100 parts by weight of the red mud dry powder, .

If the amount is less than 10 parts by weight, the pozzolanic activity is insufficient and it is difficult to maintain the long-term strength. When the amount is more than 50 parts by weight, the amount of cement in the mixture becomes relatively insufficient.

The pozzolanic activator is preferably a coal ash or a blast furnace slag powder having a calcium oxide (CaO) content of less than 10% by weight.

Hereinafter, a method for manufacturing a dirt fire using the red mud according to the present invention will be described.

Method of producing heulgo fire compositions utilizing the red mud of the present invention 1) with respect to 100 parts by weight of red mud sludge, a calcium oxide (CaO) content is at least 20% by weight oxide, the ferric oxide (Fe ₂ O ₃₎ content Mixing 10 to 200 parts by weight of incineration residue and desulfurization dust of 5% by weight or more; 2) completely drying the red mud mixture by injecting the mixture into a rotary dryer; 3) mixing 5 to 100 parts by weight of the cement and 10 to 50 parts by weight of the pozzolan active agent with respect to 100 parts by weight of the red mud dry powder.

When the incineration residues and desulphurization dust in the step 1 is less than 10 parts by weight of mixed because the water content reduced enough to be held too much fuel cost during drying through the rotary dryer, when incorporated into 200 parts by weight of ferric oxide (Fe ₂ O ₃₎ If the content is more than 5% by weight, the red color of red mud is reduced too much, and the color required for the fire in the soil can not be satisfied.

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

First, 50 parts by weight of a high calcium coal ash having a calcium oxide content of 38% by weight and an iron oxide ferrite content of 8% by weight was mixed with 100 parts by weight of red mud with a water content of 53% by weight and a calcium oxide content of 43% 50 parts by weight of iron sulfate desulfurizing powder (CH) in weight% was uniformly mixed to prepare a completely dried red mud dry powder using a test chamber drying furnace. To 100 parts by weight of the dried red mud powder, 50 parts by weight of blast furnace slag cement and 50 parts by weight of CaO And 25 parts by weight of coal ash having a content of 2% by weight were uniformly mixed to prepare a mortar fire.

Next, 20 parts by weight of dirt fire and 20 parts by weight of water, which are the same amount as that of fire-fighting fire, were added to 100 parts by weight of natural earth (loess), and the mixture was sufficiently mixed with a forced mixer. And cured at 20 for 7 days.

Comparative Example

In Comparative Example, 20 parts by weight of portland cement commercially available and 20 parts by weight of water equivalent to cement were added to 100 parts by weight of natural soil (loess), and the mixture was thoroughly mixed with a forced mixer. And cured at 20 for 28 days.

Performance test method and result of solidified soil

As shown in Table 1 below, the compressive strength was measured by KS F 2343 and the KS F 2322 method was used for the permeability test.

Experiment Way Remarks Compressive strength KS F 2343 Uniaxial compressive strength method Permeability coefficient KS F 2322 Variable Strain Test

The test results for the examples and comparative examples according to Table 1 are as shown in Table 2.

division Example Comparative Example Compressive strength (kgf / cm ² )
3 days 13.5 12.8 7 days a year 26.4 19.7 28 days old 36.3 25.7 Permeability Coefficient (cm / sec) 28 days old 5.58 × 10 ^-7 5.37 × 10 ^-7

(One) Uniaxial compressive strength  change

As shown in Table 2, the uniaxial compressive strength of the soil solidification using the soil fire produced by the present invention was measured as 36.3 kgf / cm ² on the 28th day of age, and the unconfined compressive strength which it was born excellently appear more 25.7kgf / cm ^2, was packing the soil and fire, slope stabilization and fire, soft soil improvement material, liner, backfill material such strength that can take advantage of a variety of materials for soil.

This is due to the reduction of moisture and the development of strength by the absorption exothermic reaction when mixed with fire and fire, so that the consolidation of the particles can be achieved by consolidation of the particles and the calcium silicate reaction is induced by the CaO and SiO ₂ components, The solidification reaction occurs and the strength is increased.

(2) Permeability characteristics

As can be seen from the measurements of the permeability coefficient of Table 2, the permeability coefficient of the day 28 was measured. Therefore, it is considered that the dirt fire composition using the red mud manufactured by the present invention is superior to the solidification method using the existing cement as the fire fire, and the fire extinguishing composition for the wastewater layer construction of the landfill, It is considered to be worthy of being used for fire-fighting purposes, fire-fighting for DCM construction methods, etc.

Claims (5)

1) An incineration residue 5 to 20% by weight of calcium oxide (CaO) and a ferric oxide (Fe ₂ O ₃ ) content of 5% by weight or more, based on 100 parts by weight of red mud with a water content of 30% And 5 to 200 parts by weight of a desulfurization dust having a calcium oxide (CaO) content of 20% by weight or more and a ferric oxide (Fe ₂ O ₃ ) content of 5% by weight or more to form a redmud mixture;
2) drying the redmud mixture to produce redmud dry powder; And
3) mixing 5-100 parts by weight of the strength development and 10-50 parts by weight of the pozzolan activator with 100 parts by weight of the red mud dry powder,
The incineration residue is 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, and incinerator residue generated in incinerator burning petro coke,
The desulfurization dust is discharged from a steel making and steelmaking process of a steel mill,
Wherein the strength agent comprises at least one of a portland cement, a blast furnace slag cement, a fly ash cement, and a ternary cement,
The ternary cement is obtained by mixing slag fine powder and fly ash into the portland cement,
Wherein the pozzolanic activator is a coal ash or a blast furnace slag powder having a calcium oxide (CaO) content of less than 10% by weight. delete delete delete delete