KR20160116857A - Polymer scrap for steel manufacturing and manufacturing method of the same - Google Patents

Abstract

The present invention relates to a polymer scrap for manufacturing steel and a manufacturing method thereof. According to an embodiment of the present invention, provided are a polymer scrap for manufacturing steel and a manufacturing method thereof, wherein the polymer scrap comprises a polymer, a recarburizing agent, and fine luppe and ferrum, which are materials for dissolution and reduction of scrap metal, and are derived from waste. Moreover, provided is the polymer scrap which can reduce a production cost and a steel manufacturing unit production, and improve quality of steel.

Description

TECHNICAL FIELD [0001] The present invention relates to a polymer scrap for a steelmaking raw material,

The present invention relates to a polymer scrap for steelmaking raw material and a manufacturing method thereof, and more particularly, to a scrap for polymeric steelmaking raw material which is produced by recycling a polymer derived from industrial and general wastes to reduce the unit cost of the steelmaking industry. And a manufacturing method thereof.

As steelmakers 'utilization rates continue to decline due to continuous price reductions of iron ore and coal worldwide, low-cost steel imports from China and the increase in the prices of subsidiary materials and energy required for the steelmaking process, domestic steelmakers' The need for process development is intensifying.

On the other hand, the steelmaking industry consumes a large amount of raw materials and energy, and after steelmaking, a large amount of by-products and wastes are generated along with steel, and such by-products and wastes contain a large amount of highly utilizable materials including iron have. As a part of the efforts mentioned above, steelmaking waste is recovered and recycled into the steelmaking process and other industries. However, the reduction of the unit cost of the steelmaking process using such a technology is still insufficient.

In this regard, Korean Patent Laid-Open Publication No. 10-2014-001635 discloses a reduced slag ball preparation material produced to recycle steelmaking reduced slag, which is a waste generated in the secondary refining process of steelworks, And a method for manufacturing the reduced slag ball forming material.

However, according to the conventional technology, there is a difficulty in the process when the waste is recycled and utilized for the operation, and the effect of recycling the waste is weak, and a new technique related thereto is needed.

The technical problem to be solved by the present invention is to reduce the amount of the carbon dioxide used in the prior art in the steelmaking process, and to reduce the cost by recycling the polymer derived from industrial and general wastes.

Also, maximizing the recycling of various industrial and general wastes, the technical task is to reduce the unit cost of the steelmaking process, increase the efficiency and alleviate environmental problems.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not intended to limit the invention to the precise form disclosed. There will be.

According to an aspect of the present invention, there is provided a scrap for a steelmaking raw material, comprising 10 to 15% by weight of a polymer and 3 to 20% by weight of a germanium and 60 to 70% And a method for producing the same. In this case, the polymer scrap includes grit and fermented products, and the ratio of the fermented product to the fermented product is 1: 3 to 1:25.

The process for producing polymer scrap according to an embodiment of the present invention includes the steps of crushing a polymer (S100), mixing the crushed polymer with a carbonizing agent to produce a mixture (S200), and molding the mixture to form a compacted scrap (S300).

Further, the solidifying agent can be introduced into the step of mixing the carbonaceous material (S200), and the step (S300) of processing the compressed scrap described above can include a heating and pressurizing step.

The polymer used in the above-mentioned polymer scrap is a polymer generated from waste including waste tire, waste wire cable and waste plastic. Specific examples of the polymer include low-density polyethylene (LDPE), high-density polyethylene (HDPE), polypropylene (PS), polyethylene terephthalate (PET), polyester, polyurethane, polyamide, polycarbonate (PC) and isoprene rubber, polychloroprene rubber, styrene-butadiene rubber (SBR), acrylonitrile-butadiene rubber (ABR), or a copolymer thereof.

In addition, it is characterized in that it contains at least one substance in cokes and pulverized coal, anthracite coal, bituminous coal, graphite and bituminous coal.

According to one embodiment of the present invention, it is possible to reduce the amount of coke used as a sub-raw material in the conventional operation and to recycle the polymer derived from the waste, thereby reducing the unit cost of the raw material during the operation, It is possible to maximize environmental problems.

In addition, the polymer contributes to slag forming, the core of steelmaking, to reduce energy costs, increase the efficiency of electric furnaces, and increase steelmaking productivity.

In addition, the polymer can act as a binder, making it possible to increase the amount of soluble carbon in the melt to make steel of the desired strength.

It should be understood that the effects of the present invention are not limited to the above effects and include all effects that can be deduced from the detailed description of the present invention or the configuration of the invention described in the claims.

FIG. 1 is a flowchart showing a manufacturing process of a polymer scrap for steelmaking raw material according to an embodiment of the present invention.
FIG. 2 is a process diagram showing a manufacturing step of a polymer scrap for steelmaking raw material according to an embodiment of the present invention
Figure 3 is a photograph of a polymer scrap produced according to one embodiment of the present invention
Figure 4 is a cross-sectional view of an apparatus for testing polymer scrap produced in accordance with an embodiment of the present invention.
Fig. 5 is a flow chart showing an electric furnace operation process
FIG. 6A is a graph showing the carbonaceous gas component analysis results of the comparative example
FIG. 6B is a graph showing the carbonization gas component analysis result of Example 1
FIG. 6C is a graph showing the carbonization gas component analysis result of Example 2
7A is a graph showing slag volume ratios with respect to time in Comparative Example and Example 1
7B is a graph showing slag volume ratios with respect to time in Comparative Examples and Example 2

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and similar parts are denoted by like reference characters throughout the specification.

Throughout the specification, when a part is referred to as being "connected" (connected, connected, coupled) with another part, it is not only the case where it is "directly connected" "Is included. Also, when an element is referred to as "comprising ", it means that it can include other elements, not excluding other elements unless specifically stated otherwise.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, the terms "comprises" or "having" and the like refer to the presence of stated features, integers, steps, operations, elements, components, or combinations thereof, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

Embodiments of the polymer scrap for steelmaking raw material utilizing the waste and the manufacturing method thereof will be described with reference to the accompanying drawings and experimental examples.

In one embodiment, the polymer scrap is a material for dissolution and reduction of iron which is the main material of the steelmaking process. It contains 10 to 15 wt% of polymer and 3 to 20 wt% of germanium and 60 to 70 wt% of fine irregular iron and cast iron .

Further, in the polymer scrap, the ratio of the grit to the molten iron of the fine powder is 1: 3 to 1:25. Although it contains about 60 to 95% of iron that is useful, it contains scrap iron that avoids its use as a raw material in steel scrap. If it is included in polymer scrap, it contributes to waste recycling and improves the recovery rate of steel .

Coke, pulverized coal and anthracite are included as the gasoline. When the content is less than 3% by weight, the reducing ability is lowered. If the content is more than 20% by weight, the cost of the subordinate material is raised, which is suitable for use as polymer scrap I can not.

The polymer is obtained by recycling waste including waste tires, waste wire cables and waste plastics. Specific components are low density polyethylene (HDPE), polypropylene (PP), polyvinyl chloride (PVC) (PS), polyethylene terephthalate (PET), polyester, polyurethane, polyamide, polycarbonate (PC) and isoprene rubber, polychloroprene rubber, styrene-butadiene rubber (SBR), acrylonitrile- May be one or more polymers or copolymers thereof in rubber (ABR).

In addition, if the ratio of the polymer contained in the polymer scrap is less than 10 wt%, the effect of reducing the costs of the subsidiary material is insufficient, which is not suitable for use as a polymer scrap. If the polymer scrap contains more than 15 wt%, the energy efficiency is reduced and excessive by- And it may be difficult to use it as raw material for steelmaking.

The gasifier is used to reduce iron and to adjust the carbon content in the molten steel. It contributes to slag forming and reduces the transfer of heat energy to unnecessary parts during operation, thereby improving the efficiency of electric furnace, reducing energy cost, protecting refractories, It is possible to exhibit the effect of promoting the effect.

In addition, the polymer obtained by recycling the waste can perform a similar action to the above-mentioned carbonizing agent and can contribute to cost reduction by decreasing the content of the carbonizing agent in the production of polymer scrap for steelmaking raw material.

The reaction formula related to the reduction reaction of iron by the gas phase agent can be expressed as follows.

Fe (l) + C (s) - > Fe (l) + CO (g)

FeO (l) + CO (g) - > Fe (l) + CO ₂ (g)

C (s) + CO ₂ (g) → 2CO (g)

On the other hand, the polymer decomposes into hydrocarbons during operation and can be expressed as follows.

Polymer → CnHm (g)

CnHm (g) → nC (s ) + m / 2H 2 (g)

_{CnHm (g) + nCO 2 (} g) → 2nCO (g) + m / 2H 2 (g)

N and m are natural numbers.

The hydrogen, carbon, and carbon monoxide gases generated in the above reaction are involved in the reduction of iron, and the reaction formula for this is as follows.

FeO (l) + H ₂ (g) - > Fe (l) + H ₂ O

Fe (l) + C (s) - > Fe (l) + CO (g)

FeO (l) + CO (g)? Fe (l) + CO ₂ (g)

In addition, direct reduction of iron oxide (FeO) present in the slag may occur due to hydrocarbons generated in the polymer scrap, which is a mixture of the carbonizer and the polymer.

In one embodiment, the hydrocarbon generated in the polymer scrap may be a methane (CH _4), reduction of the iron for this can be expressed by the following equation.

CH ₄ (g) + 4FeO (l) → 4Fe (l) + CO 2 (g) + H 2 O (g)

CH ₄ (g) → C (s) + 2H 2 (g)

_{FeO (l) → H 2 (} g) → Fe (l) + H 2 O (g)

Referring to the above-mentioned reaction formula, not only methane can directly reduce iron oxide but also iron oxide may be reduced by its decomposition gas.

FIG. 1 and FIG. 2 are a flow chart and a process diagram showing a manufacturing process of a polymer scrap according to an embodiment.

Referring to this, in one embodiment, a method of manufacturing a polymer scrap includes a step (S100) of breaking a polymer (S100), a step (S200) of mixing a crushed polymer with a carbonating agent to form a mixture (S200) (S300). It is also possible to further incorporate a solidifying agent, which can make the composition uniform and the forming of the compressed scrap useful in the step (S200) of preparing the mixture by incorporating the carbonating agent, (S300) may include a heating and pressurizing process. A photograph of the polymer scrap produced by the above-described embodiment is shown in Fig.

In addition, a scrap test apparatus 400 was used to analyze the performance of the manufactured polymer scrap, and FIG. 4 shows a scrap test apparatus. The scrap tester 400 includes a crucible 420 on which the sample 410 is placed and a horizontal path 450 to which the crucible 420 is fixed and a thermocouple 430 for generating high temperature heat, A gas inlet 440 and a gas outlet 460.

Next, an electric furnace operation using polymer scrap will be described.

First, electric arc furnace (EFA) operation is a steelmaking process that uses arc-shaped currents between electrodes to obtain thermal energy and uses scrap metal scrap as the main material.

Fig. 5 shows the electric furnace operation process. The process of electric furnace operation using polymer scrap will be explained with reference to this.

The electric furnace 100 includes an electrode 110 for generating thermal energy for dissolving scrap metal, a scrap charging part 150 and a fuel gas injecting part 120 as a main material, a first charging part 130 as a subsidiary material, An injection part 140 and a flux charging part 160. [

At this time, the polymer scrap may be charged through the scrap charging unit 150 or the first charging unit 130, which is the charging unit for the secondary raw material, and utilized as a raw material for electric furnace operation.

Crushed lime, dolomite, and limestone may be used as the solvents for the electric furnace operation. They act on desulfurization and dephosphorization reactions and contribute to slag forming, thereby preventing oxidation of molten steel and protecting refractories.

Oxidizing impurities are generated by the oxygen supplied during the stirring of the molten steel dissolved in the electric furnace, which reacts with the solvent to form the oxidizing slag and is discharged separately from the molten steel.

The molten steel is introduced into a ladle 200. The ladle 200 includes an electrode 210 for generating heat energy and an alloy charging part 220 and a second charging device 230 ).

Fe-Si, Fe-Mn, Si-Mn, etc. may be used as the alloy iron during the operation of the ladle 200, and they may be used for the purpose of preventing oxidation of molten steel by performing deoxidation. In the ladle 200, oxygen is excessively mixed and the components of the molten steel are adjusted in the above process. At this time, the reducing slag is generated, and is discharged separately from the molten steel similarly to the oxidation slag.

The ladle 200 containing the refined molten steel moves to the upper portion of the continuous casting apparatus 300 and the molten steel in the ladle 200 is introduced into the tundish 310. The tundish 310 performs a function of injecting molten steel into the mold 320 at a predetermined amount and speed. The mold 320 casts the molten steel into a desired shape, cools the molten steel by the cooling water, 330 can be manufactured.

Hereinafter, the present invention will be described in detail with reference to experimental examples using a polymer scrap according to an embodiment of the present invention.

<Examples>

Polymer scraps containing the ingredients shown in Table 1 were prepared through heating and pressing processes.

division Furtherance Example 1 Coke + Polyethylene Terephthalate (PET) Example 2 Coke + Polyurethane (PU) Example 3 Coke + Low Density Polyethylene (LDPE) Example 4 Coke + Low Density Polyethylene (LDPE)

Comparative Example

A heavy coke containing 100 wt% of coke was used as a comparative example.

Hereinafter, the present invention will be described with reference to experimental examples using the above examples and comparative examples.

Experimental Example 1

Composition analysis was carried out using the comparative example and the example 1 and the example 2 shown in table 1. The analytical results are shown in Table 2, where an important factor is the weight of the fixed carbon. Referring to Table 2, it can be confirmed that the fixed carbon weights of Comparative Examples and Examples 1 and 2 are similar. This means that the coke content can be reduced and low cost recycled polymers can be used instead.

Composition [wt%] Comparative Example Example 1 Example 2 Fixed carbon 79.80 70.70 72.09 Volatile matter 3.00 10.30 8.80 Ash 17.02 19.00 18.30 sulfur 0.29 0.27 0.27 moisture 1.00 1.49 1.53

Experimental Example 2

Gas components produced by carbonizing the comparative example and the example 1 and the example 2 shown in Table 1 were analyzed. At this time, blank data was extracted to exclude gas components already existing in the measurement environment, and gas components generated when the carbonization time was 1 minute and 15 minutes were detected.

The carbonization gas component analysis results of Comparative Example and Examples 1 and 2 are shown in Figs. 6A, 6B and 6C, respectively.

Referring to these results, it was confirmed that H ₂ , H ₂ O, and CO gases were generated during combustion in both Comparative Examples and Examples. As described above, these gases can participate in the reduction reaction of iron in the steelmaking process. In other words, it can be confirmed that the polymer scrap containing recycled polymer can be used as raw material for steelmaking to reduce the cost by reducing the content of coke as an additive material in the steelmaking process.

Experimental Example 3

The slag foaming properties were analyzed using Comparative Examples and Examples 1 and 2 shown in Table 1. FIG. 7A is a graph showing the slag volume ratio versus time for the comparative example and the first embodiment, and FIG. 7B is a comparison result of the slag volume ratio for the comparative example and the second embodiment.

Referring to this, it can be seen that the slag volume ratio of Example 1 and Example 2 is large over almost the entire time, which means that the slag foaming property is great.

Slag foaming is an unnecessary part of the operation, which reduces the transfer of heat energy, thereby improving the efficiency of the furnace, reducing the energy cost, protecting the refractory and improving the recovery rate of the iron source. When the polymer scrap is used for the operation, It can be seen that the slag forming operation can be maximized.

Experimental Example 4

25% by weight of coke, 25% by weight of LDPE and 50% by weight of fine irregularities and fermented steel, and was produced through heating and pressurization at 150 to 300 占 폚 in Example 3.

The resultant was heated at 1550 ° C for 5 minutes using a scrap tester 400. As a result, the grit and cast iron contained in Example 3 were dissolved and reduced by 90% for 5 minutes, and the iron oxide contained in the grit and cast iron was 100% But only 7% of the coke was consumed. This means that the iron is reduced by the polymer, and it can be confirmed that the polymer scrap can exhibit excellent reducing ability when used in the operation.

Experimental Example 5

The comparative example and the example 4 shown in Table 1 were used for electric furnace operation to analyze the content of molten carbon in molten steel. Example 4 contained 70% by weight of coke and 30% by weight of LDPE, and the operation was carried out with different amounts of loading. Table 3 shows the loading amounts and the soluble carbon contents of the comparative example and the example 4.

Heat Loading scrap form Charge amount [kg] Soluble carbon [%] One Comparative Example 1,100 0.093 2 Comparative Example 1,100 0.068 3 Example 4 840 0.155 4 Example 4 820 0.163 5 Comparative Example 1,100 0.075 6 Comparative Example 1,100 0.093 7 Example 4 1,040 0.215 8 Example 4 600 0.11 9 Comparative Example 1,100 0.095 10 Comparative Example 1,100 0.078

Referring to Table 3, it can be confirmed that the loading amount of the comparative example is the same as 1,100 kg, and contains 0.075% to 0.095% of soluble carbon and 0.048% of average soluble carbon.

In addition, in Example 4, when the loading amount was varied from 600 kg to 1,040 kg, it was confirmed that the soluble carbon content was 0.11% to 0.215% and the average was 0.161%. Sol - char carbon is an important factor controlling the strength of steel, and it can show the effect of increasing the amount of soluble carbon in molten steel when polymer scrap is used in operation.

In addition, in the electric furnace operation using the comparative example and the example 4, the electric power consumption of 10 kW / T is decreased, the effective power is increased by 0.4 MW, the heat transfer rate is increased by 1.5 ° C./min, Respectively.

As a result, it can be seen that the use of the low-priced polymer selected from the waste in the steelmaking process has the advantage of cost reduction and production of high-quality steel compared to the conventional coke-based operation, and efficient process is possible.

It will be understood by those skilled in the art that the foregoing description of the present invention is for illustrative purposes only and that those of ordinary skill in the art can readily understand that various changes and modifications may be made without departing from the spirit or essential characteristics of the present invention. will be. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. For example, each component described as a single entity may be distributed and implemented, and components described as being distributed may also be implemented in a combined form.

The scope of the present invention is defined by the appended claims, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included within the scope of the present invention.

100: Electric furnace
110: electrode
120: fuel gas injection unit
130: First granular material charging part
140:
150: Scrap loading part
160: solvent injection part
200: Ladle
210: electrode
220: Alloy iron loading
230: Second granular material charging part
300: continuous casting device
310: Turn Dish
320: Mold
330: Cutting section
400: Scrap test device
410: sample
420: Crucible
430: Thermocouple
440: gas inlet
450: horizontally
460: gas outlet
S100: Polymer crushing step
S200: Mixture preparation step
S300: Compressed scrap processing step

Claims (9)

A polymer scrap for steelmaking raw material,
As a material for the dissolution and reduction of scrap iron,
10 to 15% by weight of polymer;
From 3 to 20% by weight of carbon; And
By weight of fine powder and 60 to 70% by weight of fermented iron.
The method according to claim 1,
The polymer scrap includes fine irregularities and fermentation,
Wherein the ratio of the molten steel to the molten steel is 1: 3 to 1:25.
The method according to claim 1,
Wherein the polymer is a polymer derived from waste containing waste tire, waste wire cable and waste plastic.
The method according to claim 1,
The composition of the polymer may be selected from the group consisting of low density polyethylene (LDPE), high density polyethylene (HDPE), polypropylene (PP), polyvinyl chloride (PVC), polystyrene (PS), polyethylene terephthalate (PET), polyester, , A polycarbonate (PC) and at least one polymer selected from among isoprene rubber, polychloroprene rubber, styrene-butadiene rubber (SBR) and acrylonitrile-butadiene rubber (ABR) Polymer scrap.
The method according to claim 1,
Wherein the carbonizer comprises at least one material selected from the group consisting of coke and pulverized coal, anthracite coal, bituminous coal, graphite and bituminous coal.
In the production of polymer scrap,
Disrupting the polymer;
Mixing the crushed polymer with a carbonylating agent to prepare a mixture; And
Shaping the mixture to process a compressed scrap; To
The method of manufacturing a polymer scrap for a steelmaking raw material according to claim 1,
The method according to claim 6,
Wherein the polymer scrap includes a polymer, a gelling agent, a grit of fine powder, and fermented iron.
The method according to claim 6,
In the step of preparing the mixture by incorporating the above-mentioned carbon dioxide agent,
And adding a solidifying agent to mix the carbonizer and the polymer.
The method according to claim 6,
Wherein the step of processing the compressed scrap includes a heating and pressurizing step.

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