WO2020013400A1

WO2020013400A1 - Method for treating sintering flue gas desulfulization byproduct

Info

Publication number: WO2020013400A1
Application number: PCT/KR2018/015328
Authority: WO
Inventors: 서성모; 박현서; 한웅희; 이세원
Original assignee: 주식회사 포스코
Priority date: 2018-07-11
Filing date: 2018-12-05
Publication date: 2020-01-16
Also published as: KR102013311B1

Abstract

Introduced is a method for treating a sintering flue gas desulfurization byproduct, the method comprising the steps of: mixing a byproduct including sodium carbonate and sodium sulfate with calcium carbonate and carbon to prepare a mixture; melting the mixture; mixing the melted mixture with water to prepare a mixed solution; separating, from the mixed solution, a precipitate including calcium sulfide and calcium sulfate; concentrating and drying the mixed solution from which the precipitate has been separated, to recover a product including sodium carbonate and sodium bicarbonate.

Description

2020/013400 1 »（： 1 ^ 1 {2018/015328

【Specification】

[Name of invention]

Sintered flue gas desulfurization by-product treatment method

Technical Field

The present invention relates to a method for treating sintered flue gas desulfurization by-products. More specifically, the present invention relates to a method for treating sintered flue gas desulfurization by-products which can reduce landfill costs by recycling or reusing sintered flue gas desulfurization by-products classified as general waste.

[Technique to become background of invention]

During the sintering process of steelworks, heavy tank (犯狀 0 ₃ ) is used as a desulfurization agent to remove the arising from the flue gas line. After desulfurization, all the dust generated is classified as general waste and landfilled.

The estimated amount of desulfurized dust generated is about 70,000 tons per year, and the cost burden is high due to the continuous increase in landfill costs due to lack of landfill. Therefore, if it is possible to switch back to soda ash or mid-bath through the development of regeneration technology through dry or wet method, it can be recycled in sintering process or used in steel making process, which can reduce landfill cost and improve cost competitiveness through new profit creation.

Generally, soda ash and sodium bicarbonate are regenerated by wet treatment using the Solvay method, but in the present invention, the molten ash is melted at a high temperature in parallel with the dry and wet treatment, and then eluted in an aqueous solution. I would like to switch the use of.

[Content of invention]

【Problem to solve】

The present invention provides a sintering exhaust gas desulfurization by-product processing method capable of recycling the ^"sinter flue gas desulfurization by-products classified as wastes or reduce landfill costs through use conversion.

[Measures of problem]

Sintered flue gas desulfurization by-product treatment method according to an embodiment of the present invention is calcium carbonate and carbon in the by-product containing sodium carbonate and sodium sulfate 2020/013400 1 »（： 1 ^ 1 {2018/015328

Mixing to prepare a mixture; Melting the mixture; Mixing the molten mixture with water to prepare a mixed solution; Separating the precipitate containing calcium sulfide and calcium sulfate from the mixed solution; And concentrating and drying the mixed solution from which the precipitate is separated to recover the obtained product including sodium carbonate and sodium hydrogen carbonate. . After separating the precipitate, reacting the mixed solution from which the precipitate is separated with the composition containing barium; Separating the solid compound including barium sulfate from the mixed solution reacted with the composition; And injecting carbon dioxide into the mixed solution from which the compound is separated.

In the step of preparing the mixture, the byproduct may include 10 to 40% by weight sodium carbonate, 50 to 85% by weight sodium sulfate and 1 to 10% by weight sodium chloride.

In the step of preparing the mixture, the weight ratio (byproduct: calcium carbonate: carbon) of the by-product, the calcium carbonate and the carbon may be 1: 1: 1 to 1: 1.4: 2.

In the melting of the mixture, the mixture may be melted at 900 to 1100 for 1 to 3 hours.

In the step of preparing the mixed solution, the molten mixture may be mixed with water of 20 to 501 :.

In the step of preparing the mixed solution, the weight ratio (melted mixture: water) of the molten mixture and the water may be 1: 2 to 1: 10.

In the step of reacting the mixed solution with a composition containing barium, the composition comprises a barium compound and water, the weight ratio of the barium compound and the water (barium compound: water) is 1: 3 to 1: 10 days Can be.

In the step of reacting the mixed solution with the composition containing barium, the content of the barium in the composition may be 30% by weight or more.

In the step of reacting the mixed solution with a composition containing barium, as the composition, a ferro manganese Tallinn slag eluate generated in the production of high manganese steel with a manganese content of 10% by weight or more may be used. 2020/013400 1 »（： 1 ^ 1 {2018/015328

In the step of blowing carbon dioxide into the mixed solution, the blown carbon dioxide is reacted with the barium remaining in the mixed solution, the molar ratio of the remaining barium and the blown carbon dioxide (residual barium: blown carbon dioxide) is 1 : 1 can be sub-phase.

In the step of preparing the mixture, the by-product may be produced by introducing a heavy tank (조 0 ₃ ) for the removal of the present in the sintered flue gas.

【Effects of the Invention】

According to the method for treating sintered flue gas desulfurization by-products according to an embodiment of the present invention, as well as reducing the landfill cost of sintered flue gas desulfurization by-products that are entirely landfilled, it is possible to expect to generate profits and improve corporate image by converting wastes into valuable resources. have.

【Brief Description of Drawings】

1 is a view showing a sintered flue gas desulfurization by-product treatment method according to an embodiment of the present invention.

2 is a graph showing a change in sulfur component according to an embodiment of the present invention.

3 is a photograph showing the obtained product according to an embodiment of the present invention.

[Specific contents for carrying out invention]

Terms such as first, second and third are used to describe various parts, components, regions, layers and / or sections, but are not limited to these. These terms are only used to distinguish one part, component, region, layer or section from another part, component, region, layer or section. Accordingly, the first portion, component, region, layer or section described below may be referred to as the second portion, component, region, layer or section without departing from the scope of the invention.

The terminology used herein is for reference only to specific embodiments and is not intended to limit the invention. As used herein, the singular forms “a,” “an,” and “the” include plural forms as well, unless the phrases clearly mean the opposite. As used in this specification, the meaning of “comprising” embodies a particular characteristic, region, integer, step, operation, element and / or component, and the presence of another characteristic, region, integer, step, operation, element and / or component. Excluding additions 2020/013400 1 »（： 1 ^ 1 {2018/015328

no.

When a portion is referred to as being "on" or "on" another portion, it may be directly on or on the other portion or may be accompanied by another portion in between. In contrast, when a part is mentioned as "directly above" another part, no other part is intervened.

Although not defined otherwise, all terms including technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. Commonly defined terms used are additionally interpreted as having a meaning consistent with the related technical literature and the presently disclosed contents, and are not interpreted as ideal or very formal meaning unless defined.

In addition, unless otherwise indicated,% means weight% and X is 0.0001 weight%.

Hereinafter, embodiments of the present invention will be described in detail so as to be easily implemented by those skilled in the art. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

Sintered flue gas desulfurization by-product treatment method

In the method for treating sintered flue gas desulfurization by-product according to an embodiment of the present invention, as shown in FIG. 1, preparing a mixture by mixing calcium carbonate and carbon in a by-product including sodium carbonate and sodium sulfate, melting the mixture, and molten mixture Preparing a mixed solution by mixing with water, separating the precipitate containing calcium sulfide and calcium sulfate from the mixed solution, and concentrating and drying the mixed solution from which the precipitate was separated, thereby obtaining a sodium carbonate and sodium hydrogencarbonate. Recovering the same.

After separating the precipitate, reacting the mixed solution from which the precipitate is separated with the composition containing barium, separating the solid compound containing barium sulfate from the mixed solution reacted with the composition, and separating the compound. The method may further include injecting carbon dioxide into the solution.

First, in the step of preparing a ^mixture, sodium carbonate and sodium sulfate 2020/013400 1 »（： 1 ^ 1 {2018/015328

Calcium carbonate and carbon are mixed with the byproducts included. By-products may be by-products from the sinter flue gas desulfurization process. Specifically, by-products can be produced through the following reactions.

Present in the sinter flue gas

For removal, heavy fish (： 0 ₃ ) can be added. The sodium bicarbonate may be thermally decomposed by the sintered flue gas having a temperature of about 140 to 1501: and converted into sodium bicarbonate sodium bicarbonate as in the following scheme.

[Reaction Scheme 1] 2 ｛(¾ 此₂期₃ + ¾ 0 As described above, thermal decomposition of the fish produces porous sodium carbonate with improved adsorption performance, and as shown in the following scheme, conversion to sodium sulfate by reaction with urea Can be.

[Scheme 2] 此₂ ¥ ₃ + ₂ + 1 / 2¾ 必 0 ₄ + 期₂

By-products generated in the sintered flue gas desulfurization process generated through the above reactions may specifically include 10 to 40 wt% sodium carbonate, 50 to 85 wt% sodium sulfate, and 1 to 10 wt% sodium chloride based on the total by-product weight. .

However, if the sodium bicarbonate does not react entirely according to the input amount, unreacted sodium carbonate may be present. As a result, sodium carbonate is present in the by-product, and chlorine in the exhaust gas may be mixed as an impurity, so that sodium chloride may be included in the by-product.

Calcium carbonate and carbon are added to these by-products to prepare a mixture. In this case, the weight ratio of the by-product, calcium carbonate, and carbon may be 1: 1: 2 to 1: 1.4: 2. If the weight ratio of calcium carbonate is too small, the reaction may be insufficient and the reaction may not be performed properly. On the other hand, when the weight ratio of calcium carbonate is too large, the amount of addition may be excessive, so that all of the calcium carbonate is not melted and the reaction efficiency may be reduced.

Next, in the step of melting the mixture, the mixture is melted at a specific temperature so that the conversion of sulfur components in the mixture is achieved.

Specifically, at 900 to 11001 :, the mixture may be melted for 1 to 3 hours. If the temperature is too low, a large amount of unmelted material remains 2020/013400 1 »（： 1 ^ 1 {2018/015328

The reaction may not work properly. On the other hand, if the temperature is too high, a large amount of underfired 030 components remain, which may reduce the reaction efficiency.

If the melt time is too short, the reaction may not be completed completely, if the melt time is too long, the fluidity is difficult to separate from the crucible or refractory can be lowered the real rate.

Next, in the step of preparing a mixed solution, the molten mixture is mixed with water to ionize the sodium component and the carbonic acid component onto the mixed solution which is an aqueous solution, and calcium sulfide, calcium sulfate, calcium oxide and calcium carbonate having low solubility in water. The back is present in the solid phase, so the sulfur component is first removed through solid-liquid separation. This can also be confirmed through FIG.

In this case, the temperature of the water may be 20 to 501: the molten mixture and the weight ratio of the water may be 1: 2 to 1: 10.

If the amount of water is too small, not all of the elution can be precipitated sodium components, and if the amount of water is too large, the amount of sodium ions eluted too low may be economical.

Next, in the step of reacting the mixed solution with the barium-containing composition, the sulfur component and the barium in the mixed solution may meet and precipitate the barium sulfate. Thereafter, the sulfur component may be secondarily removed through solid-liquid separation. This can also be confirmed through FIG.

In the composition containing barium, the ferromanganthalin slag eluate generated in the production of high manganese steel having a manganese content of 10% by weight or more may be used.

Specifically, the content of barium in the composition may be 30% by weight or more based on the total weight of the composition. The composition may include a barium compound and water, and the weight ratio of the barium compound and water may be 1: 3 to 1:10.

Next, in the step of injecting carbon dioxide into the mixed solution, the barium component remaining in the mixed solution may be removed by blowing carbon dioxide. The reaction of barium and carbon dioxide may result in precipitation of barium carbonate. In this case, the molar ratio of the barium remaining in the mixed solution and the carbon dioxide blown may be 1: 1: 1 or more. If the carbon dioxide is too small, sufficient reaction with the remaining barium cannot occur. 2020/013400 1 »（： 1 ^ 1 {2018/015328

Next, in the step of recovering the obtained product, the mixed solution is concentrated and dried. Through this, as shown in FIG. 3, a yield containing sodium carbonate and sodium bicarbonate can be obtained.

By recycling such yields, not only will landfill costs be reduced, but new profits can also be created to improve cost competitiveness.

Hereinafter, specific examples of the present invention will be described. However, the following examples are only specific examples of the present invention, and the present invention is not limited to the following examples.

Example

EXAMPLE 1 A mixture was prepared by mixing the by-product generated in the sintered flue gas desulfurization process with calcium carbonate and carbon. By-products included sodium carbonate, sodium sulfate and sodium chloride, and the by-products consisted of 25 weight percent sodium carbonate, 70 weight percent sodium sulfate and 5 weight sodium chloride and other impurities relative to the total weight of the by-product. The sulfur concentration of the initial by-product [到 was about 14.70%. By-products, calcium carbonate and carbon were mixed so that the weight ratio was 1: 1.2: 2.

The mixture was melted at about 10001: for 2 hours. Thereafter, the molten mixture was mixed with water of about 351: to prepare a mixed solution, and the mixture was mixed so that the weight ratio of water was 1: 6.

Thereafter, the mixed solution was solid-liquid separated to remove sulfur from the mixed solution by removing precipitates including solid calcium sulfide, calcium sulfate, calcium oxide, and calcium carbonate. Through this, when the obtained solution is concentrated and dried as it is to remove the precipitate is recovered as a powder, as can be seen in Table 1 and Figure 2, sulfur concentration [到 dropped to about 2.66%, about 81% It can be seen that the sulfur component has been removed.

[Example Example] As in Example 1, the process was carried out, but after the sulfur component was first removed by removing the precipitate from the mixed solution, the mixed solution from which the precipitate was removed was not concentrated and dried, but contained barium. The prepared composition was reacted. The components of the barium-containing composition are shown in Table 1 below.

The composition containing barium is the ferromanganese produced in the production of high manganese steel 2020/013400 1 »（： 1 ^ 1 {2018/015328

The Tallinn slag eluate contained a barium compound and water, and the weight ratio of the barium compound and water was 1: 6.

Next, the mixed solution reacted with the composition was subjected to solid-liquid separation to separate solid barium sulfate. Carbon dioxide was blown into the solution in which the solid phase and the barium sulfate were separated, and reacted with barium remaining in the solution. The molar ratio of the remaining barium and the charged carbon dioxide was blown to be 1: 1.2.

Then, when the solution is concentrated, dried and recovered in a powdered state, as can be seen in Table 1 and FIG. 2 below, sulfur concentration [引 dropped to about 0.62%, it can be seen that about 95% sulfur component was removed.

Most of the sulfur in the byproducts could be removed.

[Table 1]

The present invention is not limited to the above embodiments and / or embodiments, but may be manufactured in various forms, and a person of ordinary skill in the art to which the present invention pertains may change the technical spirit or essential features of the present invention. It will be appreciated that it can be practiced in other specific forms without doing so. Therefore, it is to be understood that the embodiments and / or embodiments described above are illustrative in all respects and not restrictive.

Claims

2020/013400 1 »（： 1 ^ 1 {2018/015328 【claims】

[Claim 1]

Preparing a mixture by mixing calcium carbonate and carbon with by-products including sodium carbonate and sodium sulfate;

Melting the mixture;

Mixing the molten mixture with water to prepare a mixed solution;

Separating the precipitate containing butyric calcium sulfide and calcium sulfate with the mixed solution; And

Concentrating and drying the mixed solution from which the precipitate is separated to recover the obtained product containing sodium carbonate and sodium hydrogen carbonate; Sintered flue gas desulfurization by-product treatment method comprising a.

[Claim 2]

The method of claim 1,

After the step of separating the precipitate,

Reacting the mixed solution from which the precipitate is separated with a composition containing barium;

Separating the solid compound including barium sulfate from the mixed solution reacted with the composition; And

Injecting carbon dioxide into the mixed solution separated from the compound; Sintered flue gas desulfurization by-product processing method further comprising.

[Claim 3]

The method of claim 1,

In the step of preparing the mixture,

The by-product is,

A process for treating sintered flue gas desulfurization by-products comprising 10 to 40% by weight sodium carbonate, 50 to 85% by weight sodium sulfate and 1 to 10% by weight sodium chloride. [Claim 4]

The method of claim 1,

In the step of preparing the mixture,

Of the byproduct, the calcium carbonate, and the carbon 2020/013400 1 »（： 1 ^ 1 {2018/015328

The weight ratio (byproduct: calcium carbonate: carbon) is 1: 1: 2 to 1: 1.

4: 2 sinter flue gas desulfurization by-product treatment method.

[Claim 5]

The method of claim 1,

In the step of melting the mixture,

Sintered flue gas desulfurization by-product method for melting the mixture for 1 to 3 hours at 900 to 1100.

[Claim 6]

The method of claim 1,

In the step of preparing the mixed solution,

A sintered flue gas desulfurization by-product method for mixing the molten mixture with water of 20 to 501 :.

[Claim 7]

The method of claim 1,

In the step of preparing the mixed solution,

The molten mixture and the weight ratio of the water (molten mixture: water) is 1: 2 to 1:10, the sintered flue gas desulfurization by-product method.

[Claim 8]

The method of claim 2,

In the step of reacting the mixed solution with a composition containing barium, the composition,

Containing barium compounds and water,

The barium compound and the weight ratio (barium compound: water) of the water is 1: 3 to 1:10 sintered flue gas desulfurization by-product method.

[Claim 9]

The method of claim 2,

In the step of reacting the mixed solution with a composition containing barium, the content of the barium in the composition is 30% by weight or more method for treating sintered flue gas desulfurization by-product.

[Claim 10] 2020/013400 1 »（： 1 ^ 1 {2018/015328

The method of claim 2,

In the step of reacting the mixed solution with a composition containing barium, as a composition, a method for treating sintered flue gas desulfurization by-product using ferro-manganese delineated slag eluate generated during the production of high manganese steel with a manganese content of 10% by weight or more.

[Claim 11]

The method of claim 2,

In the step of blowing carbon dioxide into the mixed solution,

Reacting the blown carbon dioxide with barium remaining in the mixed solution,

And the molar ratio of the remaining barium and the blown carbon dioxide (residual barium: blown carbon dioxide) is 1: 1. 1 or more.

[Claim 12]

The method of claim 1,

In the step of preparing the mixture,

The by-products are produced by introducing a sodium bicarbonate (此敗 0 ₃ ) to remove the present in the sintered flue gas desulfurization by-products.