KR102541715B1 - Method of manufacturing recarburizing agent and recarburizing agent manufactured by the method - Google Patents

Abstract

The present invention relates to a method for manufacturing a recarburizing agent and a recarburizing agent using the method, and more particularly, a step of collecting waste carbon scraps, and a step of primarily crushing the collected waste carbon scraps to a size of 10 to 50 mm And, characterized in that it comprises the step of secondary crushing the primary crushed scrap to a size of 1 ~ 10mm, and the step of sorting the secondary crushed scrap with a particle size separator. According to the present invention, there are advantages of high calorific value, excellent recovery rate, and no environmental pollution. In addition, waste carbon scrap is used, and the manufacturing process is simple, so the manufacturing cost is also low.

Description

Manufacturing method of recarburizing agent and recarburizing agent by the method

The present invention relates to a method for producing a recarburizing agent and a recarburizing agent by the method, and more particularly, by producing a recarburizing agent only by crushing and sorting waste carbon scrap, the production cost is low and it does not cause environmental pollution. It also relates to a method for producing a recarburizer having a high calorific value and recovery rate, and a recarburizer by the method.

In the field of steelmaking using an electric furnace for obtaining iron from iron oxide, many studies are being conducted to secure high-purity iron, increase yield, and improve productivity.

In order to solve this problem, impurities are separated in an electric furnace and iron oxide is reduced by preparing slag and foaming using the slag.

The slag contains a recarburizing agent. The recarburiser is a material that is mainly introduced for the purpose of adjusting the carbon content during the process of manufacturing molten steel by dissolving metal materials during the steelmaking process. In addition to the function of controlling the carbon content, these recarburizers increase the temperature of the molten steel by increasing the thermal conductivity of the entire molten steel, and also perform the function of ensuring an even temperature distribution throughout the molten steel, and are added for the purpose of reducing or deoxidizing iron oxide Sometimes it becomes.

As a recarburizer used for slag forming in an electric furnace, conventional electrodes, pitch coke, petroleum coke, natural graphite, waste tires and waste plastics have been used. These coals help form slag by generating additional heat and steam (H ₂ O) through CO gas ejection through FeO reduction in slag and combustion with active oxygen as the carbon bond structure is thermally decomposed at high temperature.

Among them, artificial graphite is made of petroleum coke and pitch coke, and has a high purity of 99.2% fixed carbon, but requires heat treatment steps such as hardening and sulfur and nitrogen removal, and is expensive and uneconomical. There is a disadvantage that a lot of dust is generated during use due to the high content, so that the surroundings of the furnace are not clean.

Pitch coke is produced by dry distillation of a mixture of Green Petroleum voke and coal ash, and has the disadvantage of low carbon recovery due to its low specific gravity.

Petroleum coke is used as a recarburizer after firing due to its high moisture and volatile content, but due to its high nitrogen content, considerable attention is required to prevent nitrogen defects.

In addition, natural graphite has a low recovery rate due to its low carbon content and high ash content, and there is a risk of explosion of the molten metal due to its high moisture content.

Also, in some cases, high-molecular carbon such as thermoplastic resins derived from waste plastics is used. However, these recarburizers have the disadvantage of adversely affecting the health of workers as well as environmental pollution because they emit volatile organic compounds (VOCs) contained in waste tires or waste plastics during the treatment process before being put into molten steel. there is.

In addition, these conventional recarburizers require a separate high-temperature calcination or high-temperature carbonization process to remove moisture, impurities, etc., which increases manufacturing costs, and since powder materials are molded and used, a lot of dust is generated during use. There were downsides.

Therefore, there is a demand for a recarburizing agent that uses waste resources, has a low manufacturing cost, does not cause environmental pollution, and has excellent quality.

KR 10-2210486 B1 KR 10-2372369 B1

Therefore, an object of the present invention is to provide a method for producing a high-quality recarburizer having a simple manufacturing process, low cost, no environmental pollution, excellent recovery rate, and high calorific value, and a recarburizer by the method there is

The method for producing a recarburizer and the recarburiser according to the method for achieving the above object include collecting waste carbon scraps, and first crushing the collected waste carbon scraps to a size of 10 to 50 mm It is characterized in that it comprises the step of secondly crushing the primary crushed scrap to a size of 1 to 10 mm, and the step of sorting the secondary crushed scrap with a particle size separator.

The waste carbon scrap is characterized in that at least one of a waste carbon refrigerant, a waste carbon stopper, a waste carbon electrode, a waste carbon brush, and a waste carbon lump.

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The waste carbon scrap is characterized in that the fixed carbon content is 98.5 to 100% by weight.

And the recarburiser according to the present invention is characterized in that it is prepared by the above method.

According to the present invention, there are advantages of high calorific value, excellent recovery rate, and no environmental pollution. In addition, waste carbon scrap is used, and the manufacturing process is simple, so the manufacturing cost is also low.

1 is a view showing a manufacturing process of a recarburizing agent according to the present invention.
Figure 2 is a photograph of carbon scrap according to the present invention.
Figure 3 is a photograph of the recarburiser prepared by the present invention
4 and 5 are schematic views of a sorter according to the present invention.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

The greatest feature of the present invention is that only waste carbon scrap, which is a discarded waste resource, is used as a raw material, and a high-quality recarburizing agent is easily manufactured by simply crushing and sorting it.

More specifically, the method for manufacturing a recarburizer according to the present invention, as shown in FIG. 1, includes the steps of collecting waste carbon scraps, first crushing the collected waste carbon scraps to a size of 10 to 50 mm, and It is characterized in that it includes the step of secondarily crushing the primary crushed scrap to a size of 1 to 10 mm, and the step of sorting the secondary crushed scrap with a particle size separator.

Hereinafter, this will be described in detail step by step with reference to FIG. 1 .

Steps to collect waste carbon scrap

First, discarded waste carbon scrap is collected.

In the present invention, the waste carbon scrap may be at least one of waste carbon refrigerants, waste carbon stoppers, waste carbon electrodes, and waste carbon brushes. In addition, it is natural that various waste carbon scraps discarded at other industrial sites can be used.

The above waste carbon refrigerant, waste carbon stopper, waste carbon electrode rod, waste carbon brush, etc. are continuously generated and discarded as by-products of processes in various industrial sites, and the fixed carbon content relative to the total weight is 98.5% by weight or more, that is, 98.5 to 98.5%. At 100%, it has sufficient carbon content as a recarburizing agent. At this time, the remainder consists of ash and volatile matter.

In addition, since these waste carbon scraps are not in powder form, there is no need to mix and mold them with a separate binder, so there is little dust generation, and the dissolution rate and recovery rate are also excellent, and the water content is low, so that separate It does not require pretreatment, so it has the advantage of significantly reducing manufacturing costs. That is, while having the efficiency of the electrode seolgae carbonizer grade, the price is low, there is an advantage that there is no generation of dust.

2 is a photograph of waste carbon scrap used in the present invention.

Primary crushing of the collected waste carbon scrap to a size of 10 to 50 mm

Next, the collected waste carbon scrap is primarily crushed to a size of 10 to 50 mm. At this time, the primary crushing may use a jaw crusher or the like, but is not necessarily limited thereto.

Since the primary crushing does not require a specific particle size and is a pretreatment for secondary crushing, the size does not necessarily need to be 10 to 50 mm, but it is most preferable to crush about 10 to 50 mm in consideration of crushing efficiency. do.

Secondary crushing of the primary crushed scrap to a size of 1 to 10 mm

And the primary crushing scrap is secondary crushing to a size of 1 ~ 10mm. At this time, it is preferable to use a hammer crusher for the secondary crushing, but this is not necessarily limited.

In the present invention, the reason why the scrap is crushed to a size of 1 to 10 mm is that the particle size is most preferably 1 to 10 mm in consideration of the dissolution rate, recovery rate, and pollution problem of the recarburiser. That is, if the particle size is too large, the dissolution rate is slow, resulting in poor coal gas efficiency, and if the particle size is too small, problems such as a drop in recovery rate may occur.

Sorting the secondary crushed scrap with a particle size separator

Next, the secondary crushed scrap is sorted by a particle size separator.

At this time, the particles are selected in sizes of 2 to 10 mm, 1 mm or less, and 11 mm or more, but 2 to 10 mm in size and 1 mm or less in size can be used as recarburizers. It is re-introduced to the secondary crushing step and crushed again.

Here, in the particle size separator, it is preferable to arrange the sorting machine as shown in FIG. 4 to increase the manufacturing efficiency, and the shape of the sorting machine is not limited.

In addition, by arranging the sorting machine as shown in FIG. 5, scrap of 2 to 10 mm size can be re-sorted into 2 to 5 mm and 6 to 10 mm, so that the 2 to 5 mm size of recarburiser has better dissolution rate, recovery rate, etc. because it does

In addition, it is natural that the sorting machine can be replaced or added as necessary to sort into particles of various sizes within 1 to 10 mm.

Figure 3 is a photograph of a recarburiser prepared by the present invention, the left side is a recarburiser having a size of 1 to 10 mm, and the right side is a recarburiser having a size of 1 mm or less.

On the other hand, the recarburizing agent according to the present invention, in the screening step, is selected into a size of 2 to 5 mm, a size of 6 to 10 mm, a size of 1 mm or less, and a size of 11 mm or more, 50% by weight of the size of 2 to 5 mm, 6 to 10 mm It is preferable to mix with 40% by weight of the size and 10% by weight of the size of 1mm.

This is because the recarburiser having such a mixing ratio has the best thermal efficiency and recovery rate.

As described above, the present invention has the advantage that it is possible to manufacture a recarburizing agent with excellent quality only through the process of pulverizing and sorting waste carbon scrap without a separate difficult process, and has excellent economic efficiency.

In addition, the recarburiser prepared by the above method has the advantage of high calorific value, excellent recovery rate, and no generation of VOCs.

Hereinafter, the present invention will be described in more detail through specific examples.

(Example 1)

Waste electrodes (98.9% fixed carbon) were collected, firstly pulverized to a size of 10 to 50 mm with a jaw crusher, and secondly pulverized to a size of 1 to 10 mm with a hammer crusher. Then, it was sorted by a particle size sorter, classified into 2 to 10 mm, 1 mm or less, and 11 mm or more, and 11 mm or more was re-crushed through a process of re-grinding with a hammer crusher. 1 to 10 mm was used as the recarburiser.

(Example 2)

Waste carbon stopper (98.7% fixed carbon) was collected, and it was firstly pulverized to a size of 10 to 50 mm with a jaw crusher, and then secondarily pulverized to a size of 1 to 10 mm with a hammer crusher. Then, it was sorted by a particle size sorter, classified into 2 to 10 mm, 1 mm or less, and 11 mm or more, and 11 mm or more was re-crushed through a process of re-grinding with a hammer crusher. 1 to 10 mm was used as the recarburiser.

(Example 3)

It was carried out in the same way as in Example 1, but one of 1 mm or less was used as a recarburiser.

(Example 4)

It was carried out in the same manner as in Example 1, but re-screened to a size of 2 to 5 mm, and used as a recarburiser.

(Example 5)

Carried out in the same manner as in Example 1, but selecting 2 to 5 mm size, 6 to 10 mm size, 1 mm or less size, and 11 mm or more size, 2 to 5 mm size 50% by weight, 6 to 10 mm size 40% by weight, and The size of 1 mm was mixed at 10% by weight.

(Comparative Example 1)

Anthracite and polyethylene resin were mixed in a weight ratio of 1:1, and then molded to have a particle diameter of 5 mm.

(Test Example 1)

Thermal efficiency, presence or absence of boiling phenomenon, and recovery rate of Examples 1, 2, 3, 4, and 5 were measured.

The thermal efficiency was measured based on KS E 3707, and the presence or absence of the boiling phenomenon was measured by actually charging the carbonaceous agent into the electric furnace and measuring the amount of bubbles formed on the slag surface of the electric furnace after 25 to 35 minutes of reaction time. , the presence or absence of a boiling phenomenon was confirmed. Depending on the intensity of bubble generation, it was expressed as strong or medium. The recovery rate is measured by measuring the weight of iron oxide input when the first electric furnace is charged, calculating the amount of theoretical pure iron (Fe) contained in the iron oxide, and measuring the weight of pure iron recovered after the process is completed. was calculated.

Test Example 1 Results division Thermal efficiency (kcal) Whether or not there is a boiling phenomenon Recovery rate (%) Example 1 9585 approximately 93.42 Example 2 9621 approximately 93.55 Example 3 9152 approximately 92.21 Example 4 9695 approximately 94.12 Example 5 9718 approximately 94.64 Comparative Example 1 8010 river 91.11

As shown in Table 1, it was confirmed that the recarburizers of Examples 1 to 5 according to the present invention had a high recovery rate of pure iron while having high thermal efficiency.

In the above, the present invention has been described in detail using preferred embodiments, but the scope of the present invention is not limited to specific embodiments, and should be interpreted according to the appended claims. In addition, those skilled in the art should understand that many modifications and variations are possible without departing from the scope of the present invention.

Claims (7)

Collecting waste carbon scrap;
Primary crushing the collected waste carbon scraps to a size of 10 to 50 mm;
Secondarily crushing the primary crushed scrap to a size of 1 to 10 mm;
Including the step of sorting the secondary crushed scrap with a particle size separator,
In the selection step,
2 to 5 mm in size, 6 to 10 mm in size, 1 mm or less in size, and 11 mm or more in size, 50% by weight in 2 to 5 mm size, 40% by weight in 6 to 10 mm size, and 10% by weight in 1 mm size. ,
The sorted 2 to 10 mm size and 1 mm or less size are respectively transported to a hopper and packed, and if the secondary crushed scrap is 11 mm or larger in size, it is reintroduced to the secondary crushing step.
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The waste carbon scrap is a method for producing a recarburizer, characterized in that the fixed carbon content is 98.5 to 100% by weight.
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