KR101532338B1 - method for producing of molten iron - Google Patents

Abstract

The present invention relates to a method for producing molten iron from slag generated during a copper smelting process, comprising the steps of: providing a molten metal containing copper smelting slag in a vessel; injecting an additive to maintain the temperature of the molten metal; And adding a reducing agent to the molten material so as to reduce the molten material, thereby reducing the iron oxide in the copper smelting slag to recover the iron source.
Therefore, the use of copper smelting slag can reduce the amount of iron ore consumed to manufacture the molten iron, and the molten copper can be mass-produced at a low price due to the relatively low cost copper smelting slag.
In addition, 80% or more of the iron oxide content in the copper smelting slag can be recovered as molten iron, thereby achieving a high profitability material efficiency and saving costs for disposing or filling the copper smelting slag.

Description

The present invention relates to a method for producing molten iron,

The present invention relates to a method for manufacturing a molten iron, and more particularly, to a molten iron manufacturing method capable of easily recovering a molten iron contained in a copper smelting slag generated in copper smelting as a molten iron.

Generally, the molten iron discharged from the blast furnace is produced as molten steel through a steelmaking process such as a pre-treatment process, a transforming process, and a secondary refining process, and the molten steel is continuously cast to form a slab, a bloom, Blanks and the like.

Chartered iron from the blast furnace is produced by a sintering process in which sintering sintered iron ore and coke are charged into the blast furnace and heated. In other words, chartered iron from the blast furnace uses iron ore as a source of iron, and the cost of iron ore is rising in the domestic and overseas steelmaking markets, and iron ore supply is not smoothly supplied. There have been many plans for this.

In recent years, a method for manufacturing molten iron using a low-grade iron source compared to iron ore has been actively applied among measures for securing iron sources.

However, such a low-grade iron source is mixed with a high-grade iron ore to produce a molten iron, which causes a problem that a small amount of molten iron is produced.

In addition, since a high-grade iron ore is required to be mixed in proportion to the amount of the low-grade iron source material, a method of easily manufacturing the iron wire using the low-grade iron source material is not established.

KR 1319027 B

The present invention provides a method of manufacturing a molten iron which can reduce the cost of manufacturing a molten iron utilizing a low-cost iron source compared to iron ore.

The present invention provides a method of manufacturing a molten iron capable of easily recovering iron resources present in the copper smelting slag to a molten iron through a reduction reaction.

A method for manufacturing a molten iron according to an embodiment of the present invention comprises the steps of: preparing a melt containing copper smelting slag in a vessel; injecting an additive to maintain the temperature of the melt; and adding a reducing agent to the molten melt And reducing the melt.

The step of preparing the melt containing the copper smelting slag may include dissolving the copper smelting slag after the copper smelting slag is put into the vessel alone or mixing and dissolving at least one of scrap and molten iron in the copper smelting slag.

The additive may be added to the copper smelting slag in an amount of 0.1 to 0.4.

The reducing agent is a carbon-containing material, and may include coal and waste tire.

The reducing agent may be added in an amount of 0.01 or more of the amount of the copper smelting slag.

If the reducing agent is a waste tire, the waste tire may be put in an amount of 0.05 or more of the amount of the copper smelting slag.

It is possible to continuously perform the process of stirring the molten material from the step of feeding the sub-raw material or reducing the molten material.

The stirring may be performed using at least one of gas stirring and mechanical stirring.

The melting temperature of the melt may be 1350 DEG C or higher.

In the step of reducing the melt, the reduction time of the melt may be performed for 5 minutes or more immediately after the addition of the reducing agent.

After the step of reducing the melt, a step of separating the molten metal recovered from the melt and leaving the molten metal in another container may be carried out.

According to the method of manufacturing a molten iron according to the embodiment of the present invention, the iron source in the copper smelting slag can be easily recovered as a molten iron. That is, the iron source in the melt can be easily recovered by the reduction reaction by adding an appropriate amount of the additive and the reducing agent to the amount of the copper smelting slag to the melt containing the slag generated in the process of smelting the copper.

Therefore, the iron source of the copper smelting slag can be replaced with the iron resource produced by using iron ore. At this time, since the production amount of slag is abundant, it is possible to reduce the consumption of iron ore and the cost of raw materials, which are conventionally used for making iron ores by using iron ore, so that the iron ores can be mass-produced at low prices.

In addition, more than 80% of the iron source content in the copper smelting slag can be recovered as molten iron, thereby achieving a high profitability material efficiency and saving the cost for disposing or filling the copper smelting slag.

1 is a flowchart showing a method of manufacturing a molten iron according to an embodiment of the present invention.
2 is a diagram illustrating an example of constituting a melt according to an embodiment of the present invention.
FIG. 3 is a view showing a high frequency induction furnace, which can be schematically explained through experimentation with the reduction ratio of FIG. 1; FIG.
4 is a graph showing the reduction ratio of the copper smelting slag according to the content of additives in the copper smelting slag.
5 is a graph showing the reduction ratio of the copper smelting slag according to the content of the reducing agent.
6 is a graph showing the reduction ratio of the copper smelting slag with respect to the reduction reaction time.
7 is a graph showing the reduction ratio of the copper smelting slag with or without stirring.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. It will be apparent to those skilled in the art that the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, It is provided to let you know. Wherein like reference numerals refer to like elements throughout.

A method for manufacturing a molten iron according to an embodiment of the present invention is a method for manufacturing a molten iron using slag generated in the copper smelting process. The molten metal containing the copper smelting slag is received in a container and the iron source of the copper smelting slag is recovered I can suggest how to do it. At this time, the vessel may be a ladle in which the copper smelting slag is received. Hereinafter, with reference to FIG. 1 to FIG. 7, a description will be given of the method of manufacturing a molten iron according to an embodiment of the present invention and the reduction ratio according to the processing range of the copper smelting slag, respectively.

Slag ( Slag )

Slag is a by-product of producing steel products from natural resources such as iron ore, coal and limestone. The slag used in the embodiment of the present invention is a by-product copper slag produced in the copper smelting process, and copper smelting slag generates about 1.4 kg when producing 1 kg of pure copper, About one million tons are generated. Moreover, copper smelting slag is expected to continue to increase due to the continuous expansion of copper production due to the increase in copper consumption, and it is required to increase the disposal cost and secure landfill.

On the other hand, the copper smelting slag is composed of the components shown in Table 1 below. The theoretical values of the constituents of the copper smelting slag are T.Fe: 38 to 42, Cu: 0.75 to 0.8, S: 0.65, Ni: 0.01 to 0.02, Pb: 0.2 to 0.5, Zn: 1.0 to 1.5, CaO: 2 to 4.5, SiO ₂ : 30 to 34, Al ₂ O ₃ : 4.5, MgO: 1.5. However, the analytical values of the components of the copper smelting slag used in the recovery process of the molten iron from the copper smelting slag according to the embodiment of the present invention using the reduction test apparatus 1 are T.Fe: 39.17, Cu: 0.83, S: 0.61, C: 0.0055, Ni: 0.04, Pb: 0.22, Zn: 0.92, CaO: 2.53, SiO 2: 32.64, Al 2 O 3: 4.11, MgO: 0.95, P 2 O 5: 0.12 , And TiO ₂ : 0.37.

Analytical value Theoretical value



ingredient
(wt%) T.Fe 39.17 38 to 42 Cu 0.83 0.75 to 0.8 S 0.61 0.65 C 0.0055 - Ni 0.04 0.01 to 0.02 Pb 0.22 0.2 to 0.5 Zn 0.92 1.0 to 1.5 CaO 2.53 2 to 4.5 SiO ₂ 32.64 30 to 34 Al ₂ O ₃ 4.11 4.5 MgO 0.95 1.5 P ₂ O ₅ 0.12 - TiO ₂ 0.37 -

It is a result of the method of manufacturing the molten iron according to the embodiment of the present invention that T.Fe among the components constituting the copper smelting slag is recovered and separated into molten iron. Hereinafter, the method of manufacturing the molten iron will be described in order.

1 is a flowchart showing a method of manufacturing a molten iron according to an embodiment of the present invention. 2 is a diagram illustrating an example of constituting a melt according to an embodiment of the present invention. FIG. 3 is a view showing a high frequency induction furnace, which can be schematically explained through experimentation with the reduction ratio of FIG. 1; FIG. 4 is a graph showing the reduction ratio of the copper smelting slag according to the content of additives in the copper smelting slag. 5 is a graph showing the reduction ratio of the copper smelting slag according to the content of the reducing agent. 6 is a graph showing the reduction ratio of the copper smelting slag with respect to the reduction reaction time. 7 is a graph showing the reduction ratio of the copper smelting slag with or without stirring.

Referring to FIG. 1, a method of manufacturing a molten iron according to an embodiment of the present invention includes the steps of: providing a ladle containing melts containing copper-smelting slag; injecting an additive for maintaining the temperature of the melt; And reducing the molten material.

First, the flash smelting process for smelting copper is mainly a smelting process for dissolving the copper concentrate to separate the intermediate matte and the slag, removing Fe and S from the matte, And a refining and casting process that casts into the form of an anode that can be electrolyzed by removing residual sulfur and trace impurities during roasting. At this time, the mat and the slag generated in the furnace are separated due to the difference in specific gravity, and the slag is discharged periodically. The thus separated mats are discharged into the matte flood ladle and then transported and supplied to the converter, and the copper smelting slag is discharged to the slag disposal vessel and transferred to the slag treatment station.

For example, the copper smelting slag may be provided in the form of a cooled lump in an excavated state, or it may be pulverized to a predetermined particle size to have a powder form. In this case, in the present invention, since a melt containing the copper-smelting slag is to be prepared in the process of producing the molten iron, it is possible to prepare the steel in a state of being crushed to a predetermined size after cooling in order to reduce the consumption of heat source for melting the copper- .

After the copper smelting slag is prepared in a predetermined form, a ladle containing the copper smelting slag is prepared in the ladle (S100). At this time, in order to prepare the melt containing the copper smelting slag, it is preferable that the copper smelting slag is contained in the ladle alone and then the copper smelting slag is melted or at least one of scrap and molten iron is mixed with the copper smelting slag, . That is, as shown in Fig. 2, the melt containing the copper smelting slag is obtained by A) only copper smelting slag is contained in the ladle and then melted, B) melted by mixing the copper smelting slag and the molten iron, Melting the mixture of the smelting slag and the scrap, and D) melting the slag, the scrap and the molten iron to melt the mixture. At this time, if molten metal is prepared by mixing at least one of scrap and molten iron in addition to copper smelting slag, T.Fe contained in scrap and molten iron can also be recovered, so that the amount of molten iron produced can be increased.

The scrap and molten iron that may be contained in the melt will be briefly described below.

scrap( Scrap )

Scrap is generally a steel source necessary for manufacturing steel in an electric furnace, for example, scrap iron. Unlike iron ores (or sintered ores), various components are included depending on the intended use. For this reason, various types of ingredients are contained in the charcoal which uses scrap as an iron source. At this time, when the scrap is mixed with the copper smelting slag to prepare the molten metal, the component of the scrap that causes the quality degradation of the steel can be removed through the refining process after the molten iron is manufactured.

ship chartering

Charcoal is generally produced in furnaces and contains iron sources for the production of steel. At this time, the iron wire can be manufactured by receiving iron ore and coke in a furnace and applying heat to melt the iron ore and coke. In the present invention, the molten iron that may be contained in the melt containing the copper smelting slag may be iron ore as a raw material as described above, or may be a molten iron produced by incorporating the above-mentioned scrap into a part of iron ore. In the present invention, the constituent elements constituting the molten iron are not limited, and it may be a molten material containing the iron source so that the molten iron can be recovered after being mixed with the copper smelting slag.

As such, the mixture containing copper smelting slag and containing at least one of scrap and molten iron can be melted while being heated to a predetermined temperature or higher. At this time, the melting temperature of the mixture can be heated to 1350 ° C or higher. The melting point of the copper smelting slag is about 1200 ° C or more because the melting point of Fe contained in the copper smelting slag is higher than 1200 ° C, The melt containing the slag may be melted to provide a melt. Here, the melt may further be heated to a temperature range of 1400 to 1600 degrees. When the melt exhibits a temperature as described above, it is possible to easily dissolve the materials to be added later to the melt.

After the melt containing the copper smelting slag is prepared, a process of adding the additive to the melt is performed (S200). CaO (burnt lime) can be added, for example, and the quicklime introduced into the melt can be put in order to maintain the melting temperature of the melt. The quicklime reacts with SiO2 in the melt to form CaO-SiO2. In this case, the melting point of the pure quicklime is as high as 2750 ° C, so it is not easy to liquefy (liquefy). However, when CaO-SiO 2 is formed, the melting point falls to 1450 ° C. In addition, when iron oxide (FeO) is supplied as a component of the copper smelting slag, CaO-SiO2-FeO is formed to lower the melting point to 1300 ° C and the quicklime is easily formed into a liquid phase and incorporated into the melt

On the other hand, the additive added into the melt may include 0.1 to 0.4 of the amount of the copper smelting slag used in the melt. At this time, when the additive material is out of the above range and is input to the melt, the reduction rate of the molten iron from the melt is not more than 80%, and the reduction is not easy. Therefore, the input amount of quicklime may be 0.1 to 0.4. Since the data supporting the reduction rate according to the input amount of quicklime is presented through the experiment, after the sequential description of the method of manufacturing the molten iron is completed, the reduction ratio according to the amount of the sub- Let's take a look.

After the additive is charged into the melt, a reducing agent is introduced into the melt (S300). The reducing agent is added to recover the molten iron from the melt, i.e., to reduce T. Fe in the melt. In this case, a material containing carbon may be used as the reducing agent, for example, coal (coke) and waste tire may be included, and the particle size of the reducing agent put into the melt is not limited, but the smaller the particle size, . The reducing agent is reduced by the reaction represented by the following general formula (1). When FeO in the melt reacts with carbon C in the reducing agent, stabilized Fe can be recovered.

On the other hand, the reducing agent to be introduced into the melt may be supplied with 0.01 or more of the amount of copper smelting slag used in the melt. At this time, when the reducing agent is a waste tire, the waste tire may be supplied with 0.05 or more of the amount of the copper smelting slag. Here, since the content of carbon in the waste tire is generally smaller than that of coal, it is preferable that the waste tire further contains a predetermined amount of the coal. In the case where the amount of the reducing agent and the reducing agent to be charged are such that the amount of the waste tires to be charged is lower than the above range and the temperature of the melt is 1400 at a temperature of 1400 to 1600 ° C. which is a normal temperature of the melt, Is not more than 80%, the amount of the reducing agent can be increased to the above range. In this case, the data that can support the reduction rate of the melt according to the amount of the reducing agent, like the above-mentioned subsidiary material, is shown in FIG. 5, and will be described below.

When the quicklime and the reducing agent are inputted (S200, S300) in this order, the process of stirring the melt (S400) is performed to increase the reaction rate of the reducing agent and increase the reduction rate. At least one of gas stirring and mechanical stirring may be used to stir the melt. That is, the melt agitation using a gas is carried out by a plug and / or a lance for introducing a gas into the bottom and / or top of the ladle containing the melt, as known in the art, and the reaction with the melt by the plug and / It is possible to perform gas stirring by blowing an inert gas such as Ar. On the other hand, the mechanical stirring can be performed through the impeller. The impeller is connected to a blade (blade) having a predetermined length and a predetermined shape on the outer side of the rotating shaft with respect to the rotating shaft. Therefore, the impeller can be agitated by rotating the rotating shaft of the impeller while the blade of the impeller is immersed in the melt.

On the other hand, the stirring of the melt may be carried out in the course of injecting the above-mentioned subsidiary material or may be carried out in the course of injecting the reducing agent. That is, the stirring operation can increase the reaction rate of the melt and the additive and the reducing agent when an additional element is added to the melt.

When the reducing agent is dissolved in the molten material through the stirring operation after the molten material is introduced into the molten material, iron oxide (FeO) in the molten material is reduced by a reducing agent (S500) and the molten iron is recovered (S600). At this time, the reduction time of the melt in the process of reducing the melt may be performed for 5 minutes or more immediately after the introduction of the reducing agent into the melt. At this time, when the reduction time of the melt proceeds within 5 minutes, the melt is not reduced. Therefore, the melt should react with the reducing agent for at least 5 minutes. At this time, data that can support the reduction rate of the melt according to the reaction time, like the above-mentioned additives and the reducing agent, are shown in FIG. 6 and will be described below.

As described above, the iron of the copper smelting slag is reduced by adding the auxiliary material and the reducing agent to the melt containing the copper smelting slag, and the molten iron recovered is separated from the slag and can be withdrawn and withdrawn to the container containing the melted material (S600). At this time, as a method of separating the molten iron from the molten slag and the remaining slag, the molten iron can be selected using the magnetic force sensing means. That is, the molten iron which is magnetized can be recovered through the magnetic force sensing means, and the slag is not affected by the magnetic force sensing means, and can be discharged without being withdrawn together with the molten iron.

Hereinafter, a reduction test apparatus 1 capable of empirically representing the above-described method of manufacturing a molten iron will be described. A graph showing a reduction rate depending on the amounts of the sub materials and the reducing agent described above will be described.

Referring to FIG. 3, the reduction test apparatus 1 briefly shows a laboratory test apparatus for producing molten iron by reducing T. Fe from a copper smelting slag with a reducing agent, and has a crucible 30 A housing 10 defining an inner space and a lid 15 covering an opened upper surface of the housing 10 and an auxiliary block 13 for placing a crucible 30 on the interior of the housing 10 May be provided. At this time, a crucible (30) carbon crucible is used and a melt containing the copper smelting slag can be accommodated therein. At this time, on the outer side of the housing 10, a heating means 70 is arranged to surround the housing 10 to heat the melt in the crucible 30. As the heating means 70, means capable of heating the melt at high frequency can be used.

In this case, 200 g of copper-smelting slag, a predetermined mixture of CaO and a reducing agent are received in the carbon crucible 30, and then the crucible 30 is mounted in the 1 kg class high frequency induction furnace. At this time, the target temperature of the melt is set to 1400 to 1600 占 폚. Then, when the melt reaches the target temperature, the carbon rod 50 disposed on the crucible is lowered and immersed in the melt, and the carbon rod 50 is rotated to stir the melt. At this time, the stirring speed may be set to 60 rpm.

First, the reduction ratio according to the amount of CaO added to the melt under the above experimental conditions will be described with reference to Table 2 and FIG.

Reduction rate (%) Remarks 1400 ° C 1600 ° C
CaO input
(g)
0 57.3 84 · Copper smelting slag input: 200g

25 80.5 100 50 95 100 75 63 99.2

Here, the reduction rate was experimentally divided into cases where the temperature of the melt was 1400 ° C. and 1600 ° C., respectively. When the amount of CaO was 50 g, the reduction rate of the melt was the highest at each temperature. When the amount of CaO is increased beyond 50 g, the reduction rate gradually decreases. However, when 75 g is added, the reduction rate of the melt decreases to 63% at 1400 ° C. In this case, when the temperature of the melt is 1400 ° C., the sensitivity to the CaO input is more sensitive than the melt of 1600 ° C., so that the reduction rate is drastically lowered. Therefore, when the amount of CaO added is considered, the input amount of quicklime can be put in the range of 0.1 to 0.4 with respect to the amount of copper smelting slag.

Hereinafter, the reduction ratio according to the amount of the reducing agent charged into the melt through Table 3 and FIG. 5 will be described.

Reduction rate (%) Remarks 1400 ° C 1600 ° C Reducing agent input
(g) 0 to 2 77 ~ 77 ↑ 83 ~ 83 ↑ · Copper smelting slag input: 200g
· CaO input amount: 50 g
Stirring: 50 rpm 2 or more 82 ~ 82 ↑ 93 ~ 93 ↑ 10 95 100

Here, the amount of the quicklime charged into the melt prior to the addition of the reducing agent was 50 g of CaO, which was the amount of the highest reduction ratio in the melt state of 1400 ° and 1600 °, based on the above-mentioned experimental values. Here, in order to obtain a reduction rate of 80% or more at each temperature, it is understood that the amount of the reducing agent should be 2 g or more. It is preferable that the amount of the reducing agent is 0.01 or more with respect to the amount of the copper smelting slag. At this time, when the pure carbon material such as general coal or coke is used as the reducing agent, 0.01 is added to the amount of copper smelting slag, and in the case of waste tire, the amount of waste carbon is 25% It may be added in an amount of 0.05 or more based on the amount used.

In addition, the tendency of reduction rate according to the reaction time of the melt and the reducing agent is shown in Table 4 and FIG. 6.

Reduction rate (%) Remarks 1400 ° C 1600 ° C

Reaction time
(minute) 0 to 4 - -
· Copper smelting slag input: 200g
· CaO input amount: 50 g
· Reducing agent input: 2g or more
Stirring: 50 rpm 5 85.8 99.2 10 84.8 97.3 30 86.5 98.8 45 93 100 60 95 100

Here, the reduction rate (%) of the melt having the temperatures of 1400 ° C. and 1600 ° C. according to the reaction time is as follows. When the elapsed time after the addition of the reducing agent is over 5 minutes, the reduction ratio of each temperature is more than 80% It can be confirmed that the value for the reduction rate can not be obtained in the case of less than 5 minutes, that is, 0 to 4 minutes after the addition of the reducing agent. In order to obtain a reduction rate of 80% or more through a stable reaction, it is necessary to react for at least 5 minutes after the reducing agent is added to the molten material to reduce the reduction rate of the molten material to 80% or more , So that the reduction time of the melt is preferably 5 minutes or more.

Finally, the graph of FIG. 7 shows the results of the addition of the additives and the reducing agent to the melt and the reduction of the non-stirring light oil. Referring to this, it can be confirmed that when the melt is stirred, the reduction rate is increased at each temperature by performing the reduction process of the melt. That is, when the stirring is not performed, the reduction ratios of 69% and 83% are shown in the melts of 1400 ° and 1600 °, respectively. When the stirring is performed, the melts of 1400 ° and 1600 °, respectively, show the reduction ratios of 77% and 91% . Therefore, in order to increase the reduction ratio, stirring is indispensably required, and no choice is made for gas stirring and mechanical stirring in the experimental data. However, stirring may be performed simultaneously with gas stirring and mechanical stirring.

As described above, according to the embodiment of the present invention, iron oxide present in the copper smelting slag is reduced and recovered as molten iron, so that the amount of iron ore consumed to manufacture molten iron in the past can be reduced. In addition, by recycling the slag generated during copper smelting, the amount of molten iron produced can be increased by using a large amount of slag, and the waste treatment cost consumed for treating the slag can be reduced, .

Although the present invention has been described with reference to the accompanying drawings and the preferred embodiments described above, the present invention is not limited thereto but is limited by the following claims. Accordingly, those skilled in the art will appreciate that various modifications and changes may be made thereto without departing from the spirit of the following claims.

M: Melt 1: Reduction test apparatus
30: Crucible 50: Carbon rod
70: Heating means

Claims (11)

A method for producing a molten iron,
Providing a vessel with a melt containing copper smelting slag;
Adding an additive for maintaining the temperature of the melt to a range of 0.1 to 0.4 based on the amount of the copper smelting slag; And
Adding a reducing agent to the molten material to which the additive is added in an amount of 0.01 or more based on the amount of the copper smelting slag to recover and reduce at least 80% of the iron source content in the molten iron to a molten iron. The method according to claim 1,
Wherein the step of preparing the melt containing the copper smelting slag comprises:
The copper smelting slag is solely injected into the vessel and then melted,
And mixing and dissolving at least one of scrap and molten iron in the copper smelting slag. delete The method according to claim 1 or 2,
The reducing agent is a carbon-containing material,
A method of manufacturing molten iron including coal and waste tire. delete The method of claim 4,
Wherein when the reducing agent is a waste tire, the waste tire is charged in an amount of 0.05 or more of the amount of the copper smelting slag. The method according to claim 1 or 2,
Wherein the molten metal is continuously stirred from the step of introducing the subsidiary material or reducing the molten material to the molten metal. The method of claim 7,
Wherein the stirring is performed using at least one of gas stirring and mechanical stirring. The method of claim 2,
Wherein the melt temperature of the melt is 1350 DEG C or higher. The method according to claim 1 or 2,
The reduction time of the melt in the step of reducing the melt,
Wherein the reducing agent is carried out for at least 5 minutes immediately after the introduction of the reducing agent. The method according to claim 1 or 2, wherein
After the step of reducing the melt,
Separating the molten iron recovered from the melt and leaving the molten iron to another vessel.

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