KR20120073976A - Refractory compositions of high strength plug for tap hole of converter using by waste mg-cr brick - Google Patents

Abstract

PURPOSE: A refractory composition of high intensity plug for converter tap hole using waste magnesite-chrome refractories are provided to reduce discarding cost and to increase source utility rate. CONSTITUTION: A refractory composition of high intensity plug for converter tap hole using waste magnesite-chrome refractories comprises raw materials and binding materials. The raw materials comprise main raw materials and scale powder which is supplementary raw material. The main raw material comprises waste magnesite-chrome refractories, magnesia powder, and alumina powder. The binding material combines the main raw material and supplementary raw material. The raw material comprises 60-70 weight% of the waste magnesite-chrome refractories, 7-10 weight% of magnesia powder, 3-5 weight% of alumina powder, and 20-25 weight% of scale powder. 5-8 parts by weight of the binding material is included based on 100.0 parts by weight of the raw material. 1-3 parts by weight of the powdered phenol resin and 4-5 parts by weight of the liquid phenol resin are included.

Description

REFRACTORY COMPOSITIONS OF HIGH STRENGTH PLUG FOR TAP HOLE OF CONVERTER USING BY WASTE Mg-Cr BRICK}

The present invention relates to a refractory composition capable of producing a plug by recycling a pulverized product with waste smoke generated after use as an internal refractories such as an RH facility to a refractory, and more specifically, magnesia powder, alumina, etc. The present invention relates to a fire resistant composition capable of producing a high strength converter outlet plug comprising a powder, scale powder and a binder.

In the steel mill has a variety of refractory material such as MgO-C-based kite, MgO-based kite, MgO-Cr ₂ O ₃ is used as a kite-based refractory material, such as built-in converter, ladle, RH equipment.

These refractories are replaced with new fire retardants after a certain period of use, at which time a large amount of spent smoke occurs. Most of the waste refractories thus generated are disposed of in landfills. The landfill of waste refractories may be accompanied by environmental pollution problems, and landfill is also a limitation.

Therefore, if the waste smoke from the steel mill can be reused, it is preferable in terms of reducing the refractory cost and recycling of resources. In addition, it is more preferable if the waste lead can be regenerated into a refractory which is an original use, since the refractory price is high.

Until now, as in Japanese Patent Application Laid-Open No. Hei 8-319152, a part of the waste smoke was crushed and added to the aggregate of refractory brick, and it was not applied to the converter outlet slag spill control plug.

The present invention has been made in order to solve the above problems, recycled refractory raw materials and magnesia powder, alumina powder, iron (Fe) made by crushing the refractory bricks remaining after repairing used after the internal repair such as RH facilities It is an object of the present invention to supply a refractory composition of a high strength plug for controlling converter outlet slag outflow using powder as a raw material and phenol resin as a binder.

Embodiments of the present invention for achieving the above object is a raw material comprising waste magnesium lead and pulverized product, magnesia powder, alumina powder; and scale powder that is a subsidiary material; and a binder for combining the main and subsidiary materials ; Provides a refractory composition of the high-strength plug for the converter tap using a closed refractory containing macro.

The raw material of the embodiment according to the present invention includes 60 to 70% by weight of waste magnesia lead and crushed powder, 7 to 10% by weight of magnesia powder, 3 to 5% by weight of alumina powder, 20 to 25% by weight of scale powder, It may include 5 to 8 parts by weight based on 100 parts by weight of the raw material.

The binder of the embodiment according to the present invention may be composed of a powdered phenol resin and a liquid phenol resin, the powdered phenol resin may be 1 to 3 parts by weight, and the liquid phenol resin may be 4 to 5 parts by weight.

Powdered phenol resin of the embodiment according to the invention is characterized in that the novolak, the liquid phenol resin is a resol.

In the embodiment according to the present invention, the waste magnesia lead and pulverized product is 1 to 5 mm, magnesia powder is 0.074 mm or less, alumina powder is 0.045 mm or less, and scale powder is 0.074 mm or less.

As described above, the present invention usefully recycles the refractory bricks produced in large quantities after use in RH facilities, VTS ladles of STS plants, lime kilns, and rotary kilns for cement manufacturing, to dispose or dispose of them. In addition to reducing the required cost and increasing the utilization of resources, it is also possible to provide a refractory composition for manufacturing high-impact plugs for slag control of converter outlets by recycling the waste magro. . In addition, it is possible to reduce the cost of disposal by reducing waste while efficiently using finite resources.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention.

Such an embodiment may be embodied in various different forms by one of ordinary skill in the art as an example, the scope of the present invention is not limited to the embodiments described below.

Example according to the present invention is 60-70% by weight of waste magnesia lead and ground powder, 7-10% by weight of magnesia powder, 3-5% by weight of alumina powder, and Fe scale powder 20 as an auxiliary material to adjust the volume specific gravity. It includes ~ 25% by weight, the binder for combining the main raw material and the sub-material is added 5 to 8 parts by weight based on 100 parts by weight of the raw material, the binder is phenol resin 1 to 3 weight of powdered phenol resin (novolak) It relates to a fire resistant composition containing 4 to 5 parts by weight of a liquid phenol resin (resol).

The present invention as described above is to use the recycled fire-resistant aggregates of the refractory aggregates by grinding the lead with waste magnet generated in the RH facility. The slag or present impurities are attached to the moving parts of the waste macrowax generated in the RH facility or are slightly deteriorated by thermal action, but are sufficient to serve as a fire-resistant aggregate. The slag components, i.e., SiO ₂ , Fe ₂ O ₃ , CaO, etc., increase, but there is no significant difference from the original smoke before use. Therefore, it is possible to recycle lead for refractory aggregates of refractory materials by pulverizing the lead with waste magnets.

Therefore, in the embodiment according to the present invention, a part of the magnesia clinker used for the raw material of the plug used for controlling the converter outlet slag is replaced with a pulverized product of the waste magnesia so as to supply the magnesyl plug.

Hereinafter, the waste magnesia lead and pulverized product, magnesia powder, and alumina powder will be referred to as main raw materials, and the Fe scale powder will be referred to as secondary raw materials. Hereinafter, the reason for the numerical limitation of the main raw material, the sub raw material and the binder will be described.

Although the amount of the waste micro lead and the pulverized product of the embodiment according to the present invention is 60 to 70% by weight of the raw material, it is better to use a large amount of the ground micro lead with the waste micrograph as long as it does not reduce the workability and corrosion resistance of the plug refractory material. If it exceeds 70% by weight, the bond strength after firing is weakened, and when used at less than 60% by weight, the specific gravity is lowered and the fire resistance is lowered.

The magnesia powder has a particle size of 0.074 mm or less, and if the content is less than 7% by weight, the load softening temperature is weak, so that the bonding strength is weak when used in molten steel, and if the content is more than 10% by weight, the thermal shock is not preferable.

The alumina powder uses fine powder having a particle size of 0.045 mm or less, and improves plastic strength by reacting with magnesia during use to generate spinel (MgAl ₂ O ₄ ). If the content of the alumina powder is less than 3% by weight, the strength-promoting effect is insignificant. If the content is more than 5% by weight, the formation of excessive spinel decreases cracking and volume specific gravity, which is not preferable.

The Fe scale powder (iron powder) is to allow the specific gravity of the refractory for the dart (plug) to take the midpoint between the specific gravity of the molten steel and the specific gravity of the slag, when the content is less than 20% by weight, the specific gravity becomes smaller, the plug for controlling the slag Since the flotation above the slag existing in the upper part of the molten steel makes it impossible to control the slag outflow, if the content is more than 25% by weight, the corrosion resistance is lowered, which is not preferable.

In addition, the phenol resin used as a binder is used to impart strength at room temperature and hot strength. The phenol resin is mixed with liquid phenol resin and powdered phenol resin to add 5 to 8 parts by weight based on 100 parts by weight of the raw material. It is preferable. When the amount of the phenol resin is used in an amount less than 5 parts by weight, the moldability is poor, the bonding strength is not sufficient, and when the amount of the phenol resin is more than 8 parts by weight, the moldability such as cracking between layers becomes worse due to excessive filling, and the specific gravity is low, which is not preferable.

At this time, the powdered phenol resin is used novolak, the liquid phenol resin is used resol, the powdered phenol resin is added 1 to 3 parts by weight, the liquid phenol resin is added to 4 to 5 parts by weight. If less than 1 part by weight of powdered phenol resin is added, the bonding strength is weak. If it exceeds 3 parts by weight, the moldability is poor at the time of mixing. At this time, the particle size of the powdered phenol resin is used to less than 0.074mm, in order to increase the reactivity with the liquid phenol resin.

Hereinafter, an embodiment according to the present invention will be described.

[Example]

The physical and mechanical properties of the specimens prepared by mixing-kneading for 10 minutes on the plugs as shown in Table 1, molding 20x20x80mm specimens at a molding pressure of 400kg / ㎠, drying at 110 ° C for 24 hours, and reducing firing at 1500 ° C for 5 minutes. The properties were evaluated. In addition, a cylindrical specimen having a diameter of 50 mm and a height of 50 mm was prepared, and the load softening temperature was measured.

Examples 1 to 4 are refractories for converter outlet slag outflow control plugs having excellent strength characteristics according to embodiments of the present invention. Comparative Example 1 of the comparative examples is the addition of excessively pulverized crushed with the waste Mag, and the addition of less alumina powder is weak bond strength after firing. This is because the formation of spinel is weak during the heat treatment in hot. Also, as the amount of waste smoke and pulverized product increases, the amount of mixing of slag adhering to the surface of waste smoke increases.

In Comparative Example 2, the alumina powder is excessively added to the refractory composition, and the Fe-scale powder is out of the embodiment according to the present invention, so the volume specific gravity is low, which causes a problem as a plug. Comparative Example 3 and Comparative Example 4 is not preferable because the addition amount of the binder is out of the range of the embodiment according to the present invention, the cracking and strength is weak during molding, or the volume specific gravity is lowered.

In Comparative Example 5, a small amount of pulverized lead with waste magnes was added, and a large amount of magnesia powder was added.

                                          (weight%) division Example Comparative example One 2 3 4 One 2 3 4 5 Composition composition Waste Mug Brick Bricks
(1-5mm) 65 65 70 65 73 65 65 65 55 magnesia
Powder (-0.074mm) 7 10 7 7 5 10 10 10 15 Alumina Powder
(-0.045mm) 3 5 3 3 2 10 5 5 5 Fe scale powder
(-0.074mm) 25 20 20 25 20 15 20 20 25 Phenolic Resin +3 +3 +1 +3 +3 +3 +1 +3 +3 Phenolic Resin +3 +3 +4 +5 +3 +3 +2 +7 +3 characteristic Molding state O O O O O O O X X Volume specific gravity 3.3 3.2 3.1 3.3 3.1 2.8 3.2 2.9 2.8 110 ℃ x24hr dry bending strength (kg / ㎠) 220 215 220 240 205 210 60 120 80 Plastic strength (kg / ㎠)
(1500 ℃ x 5min) 80 90 80 85 40 80 50 80 40 Load softening temperature (T)
(℃) 1550 1560 1550 1550 1450 1540 1500 1550 1480

Claims (6)

Main raw material including waste magnesia lead and ground powder, magnesia powder, alumina powder; and
Raw materials comprising; scale powder that is an auxiliary material;
Bonding material for combining the main raw material and the sub raw material;
Refractory composition of the high-strength plug for the converter tap using the closed macro refractory containing a. The method of claim 1,
The raw material includes 60 to 70% by weight of waste magnesium lead and pulverized product, 7 to 10% by weight of magnesia powder, 3 to 5% by weight of alumina powder, and 20 to 25% by weight of scale powder, and the binder is 100 parts by weight of the raw material. Refractory composition of the high-strength plug for converter tap using the closed macro refractory containing 5 to 8 parts by weight. The method according to claim 1 or 2,
The binder is a refractory composition of a high-strength plug for converter taps using waste magnesia refractory consisting of powdered phenol resin and liquid phenol resin. The method of claim 3,
The powdered phenol resin is 1 to 3 parts by weight, the liquid phenol resin is 4 to 5 parts by weight of refractory composition of the high-strength plug for converter taps using waste macro refractories. The method of claim 4, wherein
The powdered phenolic resin is a novolak, the liquid phenolic resin is a refractory composition of the high-strength plug for converter taps using the waste macro refractory, characterized in that the resol. The method of claim 5,
The fired composition of the high-strength plug for the converter outlet using waste magnesia refractory, characterized in that the waste micro lead and pulverized product is 1 to 5 mm, magnesia powder is 0.074 mm or less, alumina powder is 0.045 mm or less, and scale powder is 0.074 mm or less. .