KR20170006005A - Method of manufacturing Carbon Paste and Method of manufacturing Ferro Alloy using Carbon Paste for Self-baking Electrode - Google Patents

Abstract

The present invention relates to a method for manufacturing carbon paste inputted for forming a self-baking continuous electrode as an electrode used in an electric furnace, the carbon paste for a self-baking electrode manufactured by the same, and a method for manufacturing ferroalloy using the carbon paste for a self-baking electrode. The method for manufacturing carbon paste for a self-baking electrode according to the present invention includes a step of preparing a mixture of raw materials of paste, a mixing step of mixing each raw material of the mixture by stirring and kneading while binding each raw material of the mixture with a binder, and a forming step of obtaining the carbon paste by forming the stirred and kneaded paste into a regular shape. According to the present invention, a crack of an electrode rod is prevented and segregation is reduced by simply solving the non-uniformity of shrinkage amounts due to various causes and improving the physical intensity of the electrode rod, and thereby productivity of the ferroalloy is increased. In addition, the present invention provides advantages of high strength and reduced weight of ferroalloy and effectiveness in environment protection.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method for manufacturing a carbon paste for self-extinguishing electrodes and a method for manufacturing ferroalloy using carbon paste,

The present invention relates to a carbonaceous paste for a self-extinguishing electrode and a method for producing an iron alloy using the carbon paste, and more particularly, to a carbonaceous paste for carbon self- A carbon paste for self-extinguishing electrodes manufactured according to this manufacturing method, and a method for producing an alloy iron using the carbon paste for self-extinguishing electrodes.

Generally, ferroalloy is essential for producing steel through blast furnace or electric furnace. Alloy iron is a kind of pig iron containing a large amount of elements other than carbon. It is mainly used as a deoxidizing agent, a deoxidizing agent and a denitrating agent in the production and steel making of alloy steel or alloy cast iron, and most of them are manufactured by electric furnace and crucible.

An electric furnace used for the production of alloyed iron is a furnace using electricity as a heat source, and is easy to operate and has high temperature. Electrodes used in the electric furnace are divided into a fired electrode or a solid electrode and a self-sustaining continuous electrode which are fired by shape. It is necessary to newly connect the solid electrode according to consumption.

Self-firing Continuous electrode is filled with raw material of paste made by kneading carbon material and binder in cylindrical case and naturally self-fired by resistance heat by conduction and energization of furnace, so electrode In the meantime, some graphitized and high quality electrodes are formed. There is a Smeederberg type electrode in which the case is completely made of iron plate and a Miege type and Toyama type electrode in which the case is made by combining the case with the segment of the sintered electrode and the center is filled with the raw material and is followed sequentially.

The Sonderborg electrode is the most commonly used self-sustaining electrode. The Söderberg electrode is a self-assembled electrode based on a carbon-based material in the form of powder, such as calcined or electro-calcined anthracite, mixed together by a pitch or tar bond material Lt; / RTI > Once prepared, the paste is inserted into the vessel with moderate resistance during deformation of the electrode material occurring in the furnace, and after charging the furnace with mineral charge, the vessel is lowered near the charge surface and then supplied with electricity in the form of an electric arc Due to the high temperature generated by the heat derived from the electric arc furnace, which is generally between 1000 ° C and 2000 ° C, the electric charge is dissolved and the electrode paste is cured inside the container.

As an electrode paste for a self-plastic continuous electrode, an electrode paste for an electrode made of graphite free of a hydrocarbon-based binder and a method for producing the same is disclosed in Korean Patent Publication No. 2012-0092715.

However, in the conventional self-sustaining continuous electrode, the physical strength of the electrode rod is lowered due to the decrease of the bonding force of the bonding agent, such as the pitch or the cortar, and frequent cutting is caused, and the paste (high temperature liquid) There is a problem that cracks occur in the electrode rod due to uneven shrinkage amount. Uneven shrinkage is caused by uneven fusion and solidification of the outside and inside of the electrode due to the dissociation, the generation of pores due to moisture and volatile matter at the time of solidification of the liquid / solid interface and the temperature difference between the electrode and the ore where the electrode is inserted into the furnace, And a decrease in strength when the electrode is lowered to cause a falling of the theater.

Disclosure of the Invention The present invention has been made to solve the problems of the conventional self-sustained continuous electrode, and it is an object of the present invention to prevent the electrode from cracking and to reduce the splaying by simply increasing the physical strength of the electrode rod and solving the shrinkage- The present invention provides a method for producing a carbonaceous paste for a self-extinguishing electrode which is high in strength and high in weight and light in weight, and is useful for protecting the environment, and a method for producing an alloyed iron using carbon paste.

The method for producing a carbonaceous paste for self-extinguishing electrodes according to the present invention comprises the steps of preparing a mixture of paste raw materials, mixing the raw materials of the mixture with a binder while stirring and kneading the mixture, mixing the kneaded paste with a certain form And a forming step of obtaining a carbon paste by molding.

The composition of the mixture is 85 to 90 wt% of fixed carbon, 8 to 12 wt% of ash, 1 to 13 wt% of volatile matter, and 1 to 10 wt% of carbon fiber. The binder may be any inorganic or organic binder. The composition ratio of the mixture and the binder is 70 to 90 wt% of the mixture and 10 to 30 wt% of the binder.

The forming step of the forming step may be a cylinder type or a briquette type.

The method for manufacturing ferroalloy using carbon paste for self-extinguishing electrode according to the present invention comprises the steps of filling the case with a carbon paste to a predetermined level, charging the electric furnace with the mineral charge, lowering the case to the vicinity of the charge surface, Thereby dissolving the mineral charges and curing the carbon paste inside the case, and adding the carbon paste to the case to an initial level of the carbon paste.

According to the method for producing a carbonaceous paste for a self-extinguishing electrode and the method for producing an alloyed iron using carbon paste according to the present invention, it is possible to prevent the electrode from cracking by simply increasing the physical strength of the electrode rod and easily resolving the shrinkage- , The productivity of ferroalloys is increased, the strength is high, the weight is reduced, and the effect is useful for protecting the environment.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a process diagram showing a method for producing a carbonaceous paste for a self-extinguishing electrode according to an embodiment of the present invention; FIG.
Figs. 2 (a) and 2 (b) are photographs showing the carbon paste molded in the molding step of Fig. 1. Fig.
3 is a process diagram showing a method for producing an alloy iron using carbon paste for self-extinguishing electrodes according to an embodiment of the present invention.
Fig. 4 is a view showing an autogenous electrode in an electric furnace in the method for producing the ferroalloy of Fig. 3;
Fig. 5 is an explanatory diagram showing the formation state of the self-assembling electrode of Fig. 4;

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Note that, in the drawings, the same components are denoted by the same reference symbols as possible. Further, the detailed description of known functions and configurations that may obscure the gist of the present invention will be omitted. For the same reason, some of the components in the drawings are exaggerated, omitted, or schematically illustrated.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a process diagram showing a method for producing a carbonaceous paste for a self-extinguishing electrode according to an embodiment of the present invention; FIG. As shown in the figure, the method for producing a carbonaceous paste for a self-extinguishing electrode includes a step (S10) of preparing a mixture, a mixing step (S20), and a molding step (S30).

Step S10 of preparing the mixture is a step of preparing a mixture of paste raw materials. The composition of the mixture is 85 to 90 wt% of fixed carbon, 8 to 12 wt% of ash, 1 to 13 wt% of volatile matter, and 1 to 10 wt% of carbon fiber . Fixed carbon, ash, and volatile matter are the main components of coal and can be easily obtained through a drying process that removes moisture from the coal.

Carbon fiber refers to a fiber composed of at least 92% of carbon, and is a heat-treated fiber having a diameter of 5 to 15 탆 composed of only carbon by thermal decomposition of an organic material at a temperature of about 800 to 1500 캜 , And an electrical resistivity of 10 ^-1 to 10 ^-2 Ω · cm. The carbon fibers are classified into PAN, Pitch and Rayon based carbon fibers according to the manufacturing method and starting materials. Particularly, the pan carbon fiber is known as a high-performance filler having high tensile strength and shear strength and is most widely used. PAN-based carbon fibers are also used in this embodiment, and the length of the carbon fibers is preferably 5 to 40 mm.

PAN-based carbon fibers are prepared by chlorination and stabilization of PAN (polyacrylonitrile) -based fibers, followed by carbonization or graphitization treatment in an inert atmosphere. The most important process in the production of PAN-based carbon fibers is the chlorination process. In this process, the PAN molecules become ladder-type polymers whose main component is the pyrimidine ring, which is easy to control the carbonization reaction. Chlorinated fibers are only roughened to this process. Since the ordinary PAN fibers used for clothing and the like are difficult to form a desirable ladder-type molecular structure in themselves, they are modified and used by means of copolymerization or the like. This improves fiber performance and productivity. PAN fibers are usually produced by wet or dry spinning. The solvent and coagulating solution vary according to the preparation method, but there is little difference in characteristics. The properties (in particular, the strength and the modulus of elasticity) can be varied within a considerable range in the subsequent carbonization process or graphitization process.

The mixing step (S20) is a step of mixing the raw materials of the mixture with a binder while mixing and kneading. The binder may be an inorganic binder such as pitch or tar, or an organic binder such as a carbohydrate. The composition ratio of the mixture and the binder is 70 to 90 wt% of the mixture and 10 to 30 wt% of the binder.

The shaping step S30 is a step of shaping the agitated paste into a certain shape in the mixing step S20 to obtain a carbon paste. The molding step S30 is formed into a Briquite type as shown in FIG. 2A or a cylinder as shown in FIG. 2B. The bristle type is obtained by drying the agglomerated paste and crushing it in the form of particles. The particle size is preferably 40 to 70 mm. The particle size represents the maximum length of the length (length), length (width) and height based on the hexagonal particle. The cylinder type was prepared by putting agitated kneaded paste in a cylinder. The size of the molded cylindrical carbon paste is preferably 400 to 600 mm in diameter and height.

FIG. 3 is a process diagram showing a method for producing alloyed iron using carbon paste for self-extinguishing electrodes according to an embodiment of the present invention, and FIG. 4 is a view showing a self-etched electrode in an electric furnace in the method for producing alloyed iron in FIG. As shown in the figure, a method of manufacturing alloy iron using a carbonaceous paste for a self-extinguishing electrode includes a step (S110) of filling a carbon paste into a case, a step (S120) of charging an electric furnace with a mineral charge, S130), and adding a carbon paste (S140).

The step of filling the carbon paste into the case (S110) is a step of filling the carbon paste (cp) formed in the case 110 to a predetermined level and covering the case with the case cover 112 as shown in Fig. Fig. 4 shows a state in which a cylindrical carbon paste is filled. The case 110 is inserted into the mantle 120 and is movable up and down. A holder 130 for holding the case 110 is installed under the mantle 120.

The step of charging the electric furnace with the mineral charge (S120) is a step of charging the furnace into the electric furnace (see FIG. 5) with the mineral-based charge as the raw material of the ferroalloy.

In step S130 of curing the carbon paste, the case 110 is lowered to the vicinity of the charge surface to supply electricity to dissolve the mineral charges and cure the carbon paste in the case 110. [ As shown in FIG. 5, the upper solid carbon paste gradually becomes higher in temperature as it is lowered, and firing is started at a temperature of about 500 ° C. in the furnace, resulting in a hardened baked electrode. At the end of the baked electrode, the mineral charge is dissolved at a temperature of about 1400 ° C. The solid carbon paste turns into a soft paste at a temperature of 60 to 80 ° C in the upper part, and the temperature rises while descending.

The step of adding the carbon paste (S140) is a step of adding a carbon paste into the case 110 as the baked electrode is consumed after the reduction of the ferroalloy material in the furnace. Accordingly, the manufacturing process of the alloy iron is continued.

The manufacturing process of the alloy iron using the carbon paste is similar to the manufacturing process of the alloy iron using the Sederberg electrode, and thus a detailed description thereof will be omitted.

It should be noted that the embodiments of the present invention disclosed in the present specification and drawings are only illustrative of the present invention in order to facilitate the understanding of the present invention and are not intended to limit the scope of the present invention. It will be apparent to those skilled in the art that other modifications based on the technical idea of the present invention are possible in addition to the embodiments disclosed herein.

110: Case 112: Case cover
120: mantle 130: holder
cp: carbon paste

Claims (5)

Preparing a mixture of paste raw materials;
A mixing step of mixing the raw materials of the mixture with a binder while stirring and kneading the mixture;
A molding step of molding the agitated kneaded paste into a predetermined shape to obtain a carbon paste;
Wherein the carbonaceous paste is a carbonaceous paste. The method according to claim 1,
Wherein the composition of the mixture is 85 to 90 wt% of fixed carbon, 8 to 12 wt% of ash, 1 to 13 wt% of volatile matter, and 1 to 10 wt% of carbon fiber. The method according to claim 1,
Wherein the forming step of the forming step is a cylindrical or a bristle type. A carbon paste for self-extinguishing electrodes produced by the production method according to any one of claims 1 to 3. A method for producing ferroalloy using carbon paste for self-extinguishing electrode according to claim 4,
Filling the case with the carbon paste to a predetermined level;
Charging the electric furnace with a mineral charge;
Lowering the case to the vicinity of the charge surface to supply electricity to dissolve the mineral charges, and curing the carbon paste in the case;
Adding carbon paste to the casing to an initial level of the carbon paste;
Wherein the carbonaceous paste for self-extinguishing electrodes is a carbonaceous material.

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