KR100356372B1 - Method of producing fuel for corez furnace - Google Patents

Abstract

The present invention relates to a method for producing a fuel for Korex melting furnace, which is a powder coke having a particle size of 10 mm or less and waste plastics are mixed at 5: 95 to 85: 15% by weight, and the mixture is molded to form 10 to 60 The process of manufacturing the molded object which has a particle size of mm is included.

This manufacturing method can be usefully produced fuel of the Corex furnace using powder coke and waste plastic that has been conventionally disposed.

Description

Method for producing fuel for Korex melting furnace {METHOD OF PRODUCING FUEL FOR COREZ FURNACE}

[Industrial use]

The present invention relates to a method for producing fuel for corex furnaces, and more particularly, to provide a method for producing fuel for corex furnaces using powdered coke and waste plastic, which has been conventionally disposed of.

[Prior art]

The corex facility used in the steelmaking field is composed of a reduction furnace for reducing iron ore and a melting furnace for melting the reduced iron supplied from the reduction furnace. In such a furnace, a heat source for melting the supplied reduced iron, that is, coal as fuel And coke is used. The corex melting furnace drops and feeds raw materials such as reduced iron and fuel into the upper portion of the corex melting furnace, and dissolves the reduced iron by the reaction heat generated by the combustion reaction of the oxygen gas and the fuel introduced through the tuyere located below. It is a device for manufacturing.

In this way, since the fuel is dropped into the upper portion of the corex melting furnace, when the powdered coke is used as a fuel, the powdered coal or the coke may be discharged out of the corex melting furnace before being used as fuel due to the air flow of the generated generated gas. Therefore, powdery, especially coke having a particle size of 10 mm or less is not used as fuel, and only coarse coal and coke are used as fuel.

For this reason, powdered coke obtained in large quantities in the steelmaking process is being disposed of without being used as fuel in a Corex furnace.

In addition, waste plastics generated in industrial or living worlds are recycled by selecting pure materials that are useful in the recycling industry, but mixed waste plastics containing a lot of impurities are landfilled to cause environmental problems.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a method for producing a corex melting furnace fuel using powder coke.

In order to achieve the above object, the present invention is to mix powder coke with a particle size of 10mm or less and waste plastic in 5: 95 to 85: 15% by weight; It provides a method for producing a fuel for Korex melting furnace comprising the step of molding the mixture to produce a molded article having a particle size of 10 to 60mm.

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

Conventionally, when powder coke is used as fuel in a Corex melting furnace, it can be discharged out of the melting furnace before being used as fuel due to the rising air flow of the gas generated in the melting furnace in the charging process, so that it cannot be used as a Corex melting furnace. Thus, powder coke has not been utilized and has been disposed of as industrial waste.

The present invention relates to a method of making bulk coke that cannot be used in such a way so that it can be used as fuel in a Corex furnace.

In order to prepare the powder coke in a mass, powder coke and waste plastic are first mixed. Powder coke can be used in all powder coke having a particle size of 10 mm or less, which is not generally used in steelmaking process, no special pretreatment step is required.

The waste plastic may serve as a binder for binding the powder coke as well as the waste plastic itself as a fuel and a reducing material of the Corex melting furnace. The waste plastics can be used in both film and solid form, and mixed waste plastics may be used instead of a single substance. In particular, it can be used without pretreatment even if soil, other oily or inorganic foreign substances are mixed to some extent. The particle size of the waste plastic is not particularly limited, but the physically suitable particle size during mixing and heating is about 50 mm or less, more preferably 20 mm or less.

The mixing ratio of the powder coke and waste plastic used in the present invention varies depending on the properties of the desired molded body and the type of raw material, but usually 5 to 85 wt% of the powder coke and 15 to 95 wt% of the waste plastic are mixed on a weight basis. Here, the amount of waste plastic used should be at least 15% by weight or more, and if it is less than 15% by weight, the role of the binder provided by the waste plastic is insufficient, which makes it difficult to form powder coke, and the amount of waste plastic used is 95% by weight. If it exceeds, the amount of powder coke occupies is so small that the purpose of using waste powder coke is weakened, which is not preferable.

The obtained powder coke and waste plastic mixture (hereinafter referred to as "mixture") are molded to prepare a molded article having a particle size of 10 to 60 mm, preferably 30 to 50 mm.

The molding method may use a hot extrusion method or a hot roller press method. To explain these two methods in detail, first, the heat extrusion method is introduced into a single screw or double screw extruder with a heating device, and then heated to a temperature, that is, the temperature at which the waste plastic softens or melts, It is a method of extracting with the attached nozzle and shaping to an appropriate particle size. At this time, the appropriate heating temperature is adjusted to 100 ~ 250 ℃ according to the composition of the waste plastic components and mixture, the particle size is adjusted to 10 to 60mm, more effectively 30 to 50mm by using the extrusion nozzle. The extrudate discharged from the extruder nozzle can be cut to a desired length, that is, 10 to 60 mm, more effectively 30 to 50 mm to produce a molded body.

The heated roller press method is a method of heating by using the same screw as in the above-mentioned heat extrusion method, then discharging it without passing through an extrusion nozzle and supplying it to a roller press to form it. The heat extrusion method differs from the method of directly supplying to a roller press and molding by applying an appropriate pressure. According to this method, the molding speed can be made faster. The particle size in the roller press can be adjusted according to the size of the mixture pocket formed on the roll surface. In the present invention, a briquette shape of 10 to 60 mm, more effectively 30 to 50 mm, is suitable.

In the molding method, the step of heating the mixture may be carried out using a rotary kiln. In other words, the mixture is supplied to a rotary kiln furnace and heated to 100 to 250 ° C., and then the mixture is supplied to an extruder or a roller press to be molded according to the above method. This method has the advantage of reducing the power load generated during the heating of the mixture in the extruder, it is an effective molding method especially when the particle size of the waste plastic is large.

The molded product of the powder coke and waste plastic mixture prepared by the above method does not have a problem of being introduced into the corex furnace as an alternative fuel by using the existing fuel charging equipment, and since it uses the unused powder coke and the waste plastic as an effective fuel, the fuel cost In terms of savings, it provides a very effective economic means. In particular, since the fuel provided by the present invention is utilized in a reducing atmosphere to a high temperature corex, it is generally possible to recycle very environmentally friendly waste plastics without any dioxin or other contaminants generated when burning waste plastics. Will be provided.

Hereinafter, preferred examples and comparative examples of the present invention are described.

(Example 1-6 and Control Example 1)

In the process of producing the bulk coke in the steel mill, the coke produced by the coke was collected to have a maximum particle size of 10mm or less. Waste plastics were mixed waste plastics having a calorific value of about 8000 kcal / kg as a mixture of various waste plastics.

The mixed waste plastic was crushed to a size of about 50 mm in a crusher, and then the collected powder coke was mixed. At this time, the mixing ratio of waste plastic and powder coke is shown in Table 1 below.

The mixture was introduced into a single screw extruder equipped with a heating device, heated to 200 ° C., and then a molded product was manufactured by a heat extrusion method in which a heated product was discharged through an extruder nozzle. At this time, the particle size was adjusted to 30 to 50 mm.

(Example 7-12 and Control Example 2)

The molding method was carried out in the same manner as in Example 1 except that the heating roller press method was used instead of the hot compression molding method. In the heating roller press method, the mixture was introduced into a single screw extruder equipped with a heating device, heated to 130 ° C., and fed into a roller press to be molded.

The moldability of the moldings prepared by the methods of Examples 1-12 and Comparative Examples 1-2 were measured, and the results are shown in Tables 1 and 2, respectively.

Mixing ratio [wt%] [powder coke: waste plastic] Formability Heat Compression Molding Example 1 5: 95 ◎ Example 2 20: 80 ◎ Example 3 50: 50 ◎ Example 4 70: 30 Ο Example 5 80: 20 Ο Example 6 85: 15 △ Comparative Example 1 90: 10 ×

Mixing ratio [wt%] [powder coke: waste plastic] Formability Heated roller press molding Example 7 5: 95 ◎ Example 8 20: 80 ◎ Example 9 50: 50 ◎ Example 10 70: 30 Ο Example 11 80: 20 Ο Example 12 85: 15 Ο Comparative Example 2 90: 10 △

(Double-circle): Very excellent moldability, O: Excellent moldability, (triangle | delta): Moldability normal, ×: Poor moldability

As shown in Table 1 and Table 2, the molded products of Examples 1 to 12 in which the amount of waste plastic used is 15 to 95% by weight are excellent in heat compression molding and hot roller press molding, while the amount of waste plastic used is 15%. For smaller control examples 1 and 2 it can be seen that the moldability is poor in hot compression molding and hot roller press molding.

In addition, in order to find out whether the molded article prepared according to the embodiment of the present invention is useful as a fuel in the Corex melting furnace, by measuring the calorific value of the coke and bulk coal currently used as fuel and the calorific value of the molded bodies of Examples 2, 3 and 5 The results are shown in Table 3 below.

Kinds Calorific Value [kcal / ㎏] Example 2 7800 Example 3 7550 Example 5 7280 Block coke 7100 Block coal 7500

As shown in Table 3, the molded article produced by the method of Examples 2, 3 and 5 shows a calorific value similar to or greater than that of the bulk coke and the bulk coal conventionally used as the fuel of the Corex melting furnace, It can be seen that it can be useful.

The production method of the present invention can be usefully produced fuel of the Corex furnace using powder coke and waste plastic that has been conventionally disposed.

Claims (4)

Powder coke having a particle size of 10 mm or less and waste plastic are mixed at 5:95 to 85:15 wt%; Molding the mixture to prepare a molded body having a particle size of 10 to 60 mm A method for producing fuel for a Korex melting furnace comprising a step. The method of claim 1, wherein the forming process uses a hot extrusion or hot roller press molding process. The manufacturing method according to claim 2, wherein in the hot extrusion molding or hot roller press molding process, the heating process is performed using a rotary kiln furnace. The manufacturing method according to claim 1, wherein the molded body has a particle size of 30 to 50 mm.