KR100355140B1 - A method of producing and using MgO-C based refractory bricks with a coated back side for prevention of oxidation - Google Patents

Abstract

PURPOSE: Provided are a method for producing a coating MgO-C based brick which prevents the contact of tough graphite of the brick and oxygen of air, and thus prevents the backside oxidation of the brick, even if air is flowed into backside of the brick, and use of the brick. CONSTITUTION: The method for producing a fluorinated brick containing graphite phosphate, comprising the steps of adding 2-8 wt% of metal oxidation inhibitor and 2-5 wt% of binder to 80-95 wt% of MgO and 5-20 wt% of graphite phosphate, and then sequentially crushing, classifying, storing, weighing, kneading, molding the mixture, and then drying the molded product at 400 deg.C, and finally examining the dried product, is characterized by further comprising the step of heating a glass consisting of 60-75 wt% of SiO2, 15 wt% or less of Na2O, 10 wt% or less of B2O3, 10 wt% or less of ZnO, 7 wt% or less of CaO, and 7 wt% or less of Al2O3 to 900-1300 deg.C and fusing the glass, and then immersing the backside of the fluorinated brick into the fused glass to coat the backside with the glass.

Description

A method of producing and using MgO-C based refractory bricks with a coated back side for prevention of oxidation}

The present invention relates to a manufacturing method and a method of using a coating lead for prevention of back oxidation, in detail, the coating to prevent the back oxidation by coating the back of the lead with glass to prevent the contact of carbon and oxygen contained in the lead The present invention relates to a method for producing MgO-C based wort and a method of using the prepared coated MgO-C based wort.

In general, the steelmaking and smelting process undergoes a high-temperature refining process, and thus a refractory having a high corrosion resistance at high temperatures is essentially used in a ladle, which is a container for molten metal. As shown in FIG. 1, the refractory is constructed in the ladle, and is constructed from the inner side of the ladle required for the refining operation to the permanent field kite 20, the semi-permanent kite 30, and the built-up kite 100. The built-in wire 100 is actually divided into a slag line lead, a wall lead, and a floor lead according to the use position as being in contact with a high temperature molten metal. Particularly, the slag portion 200 in which the slag is concentrated is used as a lead having a property of excellent corrosion resistance in molten steel and slag, and a representative lead is a fluorine-based MgO-C-based lead having MgO and impression graphite as the main raw material ( It is also called `` mag carbon yeonwa ''). The mag carbon lead satisfies both excellent corrosion resistance and spalling resistance against molten steel and slag simultaneously.

However, the impression graphite constituting the mag carbon brim has a problem of deteriorating physical properties of the mag carbon brim by making the vaporization of [C] react with oxygen in the air, thereby making the brittle brittle. In particular, the hot molten metal heats the air so that the oxygen in the air oxidizes the drawn graphite as in the following reaction formula, thereby rapidly lowering the physical properties of the lead.

C + 1 / 2O ₂ = C

CO + 1 / 2O ₂ = CO ₂

CO ₂ + C = 2CO

C + O ₂ = CO ₂

In addition, as in Scheme 5, the oxides of Fe, Mn, and Cr contained in the slag react with the impression graphite to promote vaporization of the impression graphite, thereby making the duct weak.

C + [Fe, Cr, Mn] O ₂ = [Fe, Cr, Mn] + CO

In addition, the reaction takes place more actively at the back surface 130 than at the surface of the pontoon, as shown in FIG. The reason is that a part of slag is attached to the surface of the surface of the lead to form a coating layer to block the contact with oxygen, while air is introduced into the gap between the mortar and the lead at the back of the edge, This is responsible for creating an atmosphere that can easily occur in the reaction. In addition, the back oxidation also progresses in proportion to the increase in the number of times of use of the ladle, and the ladle becomes vulnerable. In such a state, refining work may cause melt impact or lagging of the ladle to avoid slag, or melt leakage due to erosion of the melt. there was.

In order to solve this problem, conventionally, a metal powder such as Al, Si, which reacts with oxygen before [C], is added to the lead to suppress oxidation of [C] by inhibiting the above reaction. The method of preventing the oxidation of [C] by making it react was used. However, this method has some effects but does not completely inhibit the reaction.

Therefore, the present invention, even if the air flows into the rear portion of the lead to solve the above-mentioned problem MgO- to prevent the back oxidation of the lead by preventing the contact between the tough graphite and the oxygen in the air constituting the lead It provides a method of manufacturing and using a C-based lead.

1 is a cast ladle refractory construction cross-sectional view.

Figure 2 (a) is a cross-sectional view showing the rear oxidation process of the conventional [C] containing fluorine lead.

(B) is a cross-sectional view showing a back oxidation process with a back oxidation coating lead according to the present invention.

Figure 3 (a) is a plan view of the back anti-oxidation coating lead according to the invention.

(B) is a cross-sectional view of the backside anti-oxidation coating lead according to the invention.

Figure 4 (a) is a perspective view of a kite used in the embodiment.

(B) is a schematic diagram showing the test method.

* Description of the symbols for the main parts of the drawings *

10 ... backing anti-oxidation coating and 11-1 ... longitudinal coating layer

11-2 ... thickness coating layer 12 ... molten contact surface

20 ... Permanent Field Yeonwa 30 ... Associate Director General Yeonwa

40 ... mortar 50 ... as an experiment

51 ... insulation

The present invention is by weight, 80% to 95% MgO and 5% to 20% graphite is added by adding 2 to 8% metal antioxidant and 2 to 5% binder, pulverization, classification, storage, basis weight, kneading, In the manufacturing method of the impression graphite-containing fluorine lead produced by molding, drying at 400 ° C. or lower, and in the weight% between the drying step and the inspection step, SiO ₂ 60% or more and 75% or less, Na ₂ The glass having 15% or less of O, 10% or less of B ₂ O _3, 10% or less of ZnO, 7% or less of CaO and 7% or less of Al ₂ O ₃ is heated to a temperature of 900 ° C to 1300 ° C for melting, and then the molten glass The present invention relates to a method for producing a backside anti-oxidation coating MgO-C-based lead consisting of depositing and coating the back of the impression graphite-containing fluorine lead.

In addition, the present invention is when using the prepared MgO-C-based lead prepared by the above method, the coated portion is in contact with each other by using a method for use with the backing anti-oxidation coating MgO-C based to build without using mortar It is composed.

Hereinafter, the present invention will be described in detail.

As the carbon carbon lead, suitable for the present invention, MgO is added in an amount of 80% to 95% and 5% to 20% of graphite, which is added as 2% to 8% gold oxidant antioxidant and 2% to 5% binder. Such a mag carbon lead is usually manufactured through a pulverization, classification, storage, basis weight, kneading, molding, drying, and inspection process. It is preferable to use what is produced by drying the carbon carbon lead after drying for 6 hours to 400 ° C or less after molding.

The manufacturing method of the coating MgO-C type | system | group lead according to this invention consists of a process of depositing and coating the said graphite graphite containing fluorine lead in the longitudinal direction between the said drying process and the test process. At this time, as a glass component suitable for this invention, if it is a substance which forms a liquid phase in 700 to 1300 degreeC, Preferably it is 900 to 1300 degreeC, it can be used. As such a glass component, for example, by weight%, SiO ₂ 60% or more and 75% or less, Na ₂ O 15% or less, B ₂ O ₃ 10% or less, ZnO 10% or less, CaO 7% or less and Al ₂ O ₃ 7 And glass formed by% or less.

When coating the MgO-C-based lead in the present invention, it is preferable to coat with molten glass within 1/5 of the length of the ear. This is to prevent the contact of the coated glass with the molten metal when the furnace is constructed using the coated MgO-C-based lead. When the glass is in contact with the molten metal, the corrosion resistance of the glass is weaker than that of the mortar or MgO-C-based lead, so the intrusion of the molten metal is easily generated. In particular, when coating the Mag carbon yeonwa, as shown in Figure 3, it is preferable that the longitudinal coating layer (11-1) of the yeonwa 3mm or less, the thickness coating layer 11-2 is 1.5mm or less. . When the lead and the thickness direction coating layer 11-2 is more than 1.5mm, since the typical mortar coating thickness is about 2 to 3mm, it is difficult to form a horizontal when the lead is constructed. In addition, when the thickness of the lead and the longitudinal coating layer (11-1) exceeds 3mm, a portion of the glass may be melted down during use or reacted with mortar.

On the other hand, when built using the anti-oxidation coating MgO-C-based lead prepared by the above manufacturing method, as shown in Figure 2 (b), the coated parts are in contact with each other using a mortar (40) The inflow of air from the back surface 13 to the molten contact surface 12 can be prevented.

In the case of using the MgO-C based anti-corrosive coating 10 for anti-oxidation of the present invention, even if air is introduced from the outside, the contact between the soft-fiber 10 and the air is blocked by the soft-surface glass loading layer 11, Part of the upper and lower ends are in contact with the glass layer 11 to prevent the introduction of air to fundamentally prevent the conditions of the back oxidation. Therefore, the oxidation of [C] does not occur, and the coated glass starts melting at around 900 ° C. to increase the adhesive force between the lead 10 and the lead 10 to prevent dropping of the lead 10.

In order to verify the above-mentioned action, the following implementation was carried out.

EXAMPLE

As shown in FIG. 4 (a), the present invention relates to a conventional [C] -containing fluorinated MgO-C wire 100 made of 230 mm in length, 150 mm in width, and 80 mm in height, and a wire of the same material and size as the wire 100. In accordance with the coating treatment to prepare the anti-oxidation coating MgO-C Yeonwa (10). At this time, the glass component used when coating the coating MgO-C edge of the present invention, in weight percent, SiO ₂ 66.9%, Na ₂ O 10.4%, B ₂ O ₃ 7.5%, ZnO 4.8%, CaO 6.2% and Al ₂ O ₃ was 4.2%.

As shown in FIG. 4 (b), the 170 mm was inserted into the experimental furnace 50 heated to 1600 ° C., followed by one hour, and then cooled five times in the air for 5 minutes. At this time, the experiment furnace 50 prevented the outflow of heat by using the heat insulating material (51). Then, as shown in Fig. 4 (a), 50 mm was cut from the rear surface, and the strength and weight of the wire were compared to prepare a table as follows.

Table 1 is a weight comparison table, shows the weight of the conventional lead when the weight of the coated lead according to the present invention is 100. As shown in Table 1, it can be seen that compared with the coating lead according to the present invention, the weight of the conventional lead is reduced by 3 to 5%. This is [3] oxidized and vaporized by 3 to 5% by weight with conventional smoke.

Table 2 is a strength comparison table, which shows the strength of the conventional lead when the back strength with the coated lead according to the present invention is 100. As shown in Table 2, compared with the coated lead according to the present invention, it can be seen that the conventional lead is reduced by about 20% or more. This is because in the conventional smoke, the density of the smoke is inhibited by the oxidation of [C].

Therefore, it can be seen that the oxidation resistance of [C] is prevented from the coated lead for back oxidation prevention according to the present invention to maintain good strength.

As described above, according to the present invention, even when air flows into the rear portion of the MgO-C-based lead, it is possible to prevent back oxidation of the lead by preventing contact between the drawn graphite constituting the lead and oxygen in the air. It extends life and prevents leakage of molten metal, which contributes to safety work and productivity.

Claims (4)

By weight, 80% to 95% MgO and 5% to 20% increase graphite, 2 to 8% metal antioxidant and 2 to 5% binder are added. Grinding, classification, storage, basis weight, kneading, molding, 400 ℃ In the manufacturing method of the graphite phosphate-containing fluorine lead produced through the following drying and inspection process, Between the drying process and the inspection process, in weight percent, SiO ₂ 60% or more and 75% or less, Na ₂ O 15% or less, B ₂ O ₃ 10% or less, ZnO 10% or less, CaO 7% or less and Al ₂ O _After the glass composition of ₃ 7% or less is heated to a temperature of 900 ℃ ~ 1300 ℃ and melted, the molten glass is deposited by coating the back of the impression graphite-containing fluorine lead, MgO- Method for producing C-based lead. The method of claim 1, The method of manufacturing a coating MgO-C-based lead for back oxidation, characterized in that to deposit so that less than 1/5 of the total length is coated toward the rear surface of the lead. The method of claim 1, The thickness of the coating layer of the yeonwak is 1.5mm or less in the yeonwa thickness direction, the method of producing a coating MgO-C-based yeonwae for preventing oxidation, characterized in that the immersion so as to be 3mm or less in the yeonwa longitudinal direction. Method of using a coating MgO-C based anti-oxidation coating for anti-oxidation, characterized in that when the coated MgO-C based yeonwa prepared in accordance with claim 1, the parts in contact with each other is constructed without construction using mortar. .

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