KR20110083311A - Magnesia - olivine monolithic refractory and method for preparing the same - Google Patents

Abstract

PURPOSE: Magnesia-olivine-based monolithic refractory and a method for preparing the same are provided to reduce high-temperature-linear-change of the refractory by mixing natural olivine clinker and a binder with a magnesia clinker. CONSTITUTION: Magnesia-olivine-based monolithic refractory includes 5-280 parts by weight of an olivine clinker, 1.0-3 parts by weight of slaked lime, 0.1-3 parts by weight of deflocculant, 0.1-3 parts by weight of paper powder, and 0.1-3 parts by weight of poly-based fiber, based on 100.0 of a magnesia clinker. The magnesia clinker is dead burned magnesia, caustic-calcined magnesia, fused magnesia, seawater magnesia. The olivine clinker is fosterite, fayalite, or the composite of the fosterite and the fayalite.

Description

Magnesia-Olivine Monolithic Refractory and Method for Preparing the Same}

The present invention relates to a magnesia-olivinic amorphous refractory material, and more particularly, a magnesia-olivine-based amorphous refractory material prepared by mixing magnesia clinker, olivine clinker, slaked lime, peptizing agent, equity and poly-based fibers, and a method of manufacturing the same. It is about.

Generally, T / D (Tundish) used in the continuous casting method as a casting facility for steelmaking and steelmaking receives molten steel from ladle, stabilizes molten steel, and sends it to a mold to facilitate molten steel control and temperature management. It is used to secure the cleanliness of the molten steel as a step of constantly pouring the prepared molten steel from the ladle (Ladle) to the casting mold (Casting Mold).

The tundish is an iron shell forming an appearance, a permanent refractory finished on the inner surface of the iron shell, and when the permanent refractory is directly exposed to molten steel, a temperature decrease of the molten steel due to heat loss and the removal of the present after attachment. It is made of T / D Lining material which is in contact with molten iron and molten steel while forming the inner wall surface of T / D, which is installed on the surface of permanent refractory for the purpose of preventing the damage due to mechanical shock.

Conventional T / D Lining construction material is MgO (Dead Burned Magnesia) -based material, which has a high hot expandability, permanent field and fusion phenomenon, and greatly degrades workability or deteriorates the quality of molten steel when dismantling coating materials after operation. There is a problem.

Accordingly, Korean Patent No. 830829 is characterized in that the additive is composed of a binder, a flocculant, a plasticizer and an anti-expansion agent to 100% by weight of the clinker configured to have a ratio of calcite and aluminum nitride in a molar ratio of 9: 1 to 6: 4. In the present invention, Korean Patent No. 805730 discloses clinker composed of kneading dolomite and calcite with one or both of magnesia and magnesite such that magnesium oxide and calcium oxide have a molar ratio of 9: 1 to 1: 9. were presented to 100 parts by weight of the basic coating refractory composition by adding a binder, a flocculating agent, a plasticizer and pokyeol agent in this invention to the price is less expensive that the coating material by the CO ₂ generated in the refractory composition of the industrial use is easy, and the pre-heating It has the effect of being capable of specific gravity, and there is almost no reaction fusion with the interior material for tundish. But dismantling is excellent, there was a lack of corrosion and surface wettability.

Accordingly, the present inventors have made diligent efforts to solve the above problems. As a result, the amorphous refractories prepared by mixing natural olivine clinker and a binder with magnesia clinker have improved physical properties, infiltration resistance and sintering resistance, and have high temperature line change, and thus dismantling. It was confirmed that this improvement was completed the present invention.

An object of the present invention is to provide a magnesia-olivine-based amorphous refractory having excellent corrosion resistance, sintering property and dismantling property, and a method for producing the same.

In order to achieve the above object, the present invention, with respect to 100 parts by weight of magnesia clinker, 5 to 280 parts by weight of olivine clinker, 0.1 to 3 parts by weight of lime, 0.1 to 3 parts by weight of peptizing agent, 0.1 to 3 parts by weight and 0.1 to 3 parts by weight of the poly-based fiber to provide an amorphous refractory excellent in corrosion resistance, disintegration and sinterability.

The present invention also comprises the steps of (a) mixing 5 to 280 parts by weight of olivine clinker based on 100 parts by weight of magnesia clinker; (b) adding and mixing 0.1 to 3 parts by weight of calcined lime, 0.1 to 3 parts by weight of peptizing agent, 0.1 to 3 parts by weight, and 0.1 to 3 parts by weight of poly-based fibers; And (c) kneading the mixture to prepare a magnesia-olivine-based amorphous refractory material.

The magnesia-olivinic amorphous refractory according to the present invention is prepared by mixing a natural olivine clinker and a binder with a magnesia clinker, thereby improving physical properties, infiltration resistance and sintering properties, and having low temperature change, thereby having excellent disassembly.

Figure 1 shows a process for producing an amorphous refractory using the olivine clinker according to the present invention.
Figure 2 shows the XRD graph of magnesia-olivine-based clinker amorphous refractory.
3 is a photograph showing the projection and adhesion properties by applying the amorphous refractory material prepared in Comparative Example (previous product) and Example 2 to T / D.
Figure 4 is a photograph showing the evaluation of the corrosion resistance of the amorphous refractory prepared in Comparative Examples (previous products), Examples 1 and 2.
Figure 5 is a photograph showing the disassembly after construction by applying the amorphous refractory prepared in Comparative Example (previous product), Example 2 to T / D.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In general, the nomenclature used herein and the experimental methods described below are well known and commonly used in the art.

In one aspect, the present invention, with respect to 100 parts by weight of magnesia clinker, 5 to 280 parts by weight of olivine clinker, 0.1 to 3 parts by weight of slaked lime, 0.1 to 3 parts by weight of peptizing agent, 0.1 to 3 parts by weight and 0.1 to 3 parts by weight of poly-based fiber It relates to a magnesia-olivine-based amorphous refractory comprising from 3 parts by weight.

In the present invention, a clinker is also referred to as a lump in which a part of a component is melted and the whole is made of a sintered mass. Generally, the raw material of cement is baked in small mass by rotary klin.

The magnesia-olivine clinker mixture of the present invention contains a large amount of silica components compared to the conventional magnesia clinker, and adds 5 to 280 parts by weight of the olivine clinker based on 100 parts by weight of the magnesia clinker, which was previously used for amorphous refractory materials. One mixture.

In the present invention, magnesia (Magneisa) clinker is a white powder made by burning metal magnesium, magnesium carbonate, magnesium nitrate and the like as an oxide of magnesium in the air, slightly dissolved in water to show alkalinity. The chemical formula is MgO and is also called magnesium oxide or goto. Melting point is 2,800 ℃ Crystal system is cubic system (NaCl type), specific gravity 3.65, specific heat is 0.24cal / g · ℃ Thermal conductivity is 0.097cal / cm · sec · ℃ (25 ℃) and coefficient of thermal expansion 10.8 * 10 ^-6 / (500 It has a high melting point at) ℃, excellent base resistance and electrical insulation at high temperatures, high thermal flatness coefficient and thermal conductivity, and high light transmittance and low cost. The manufacturing method is a process of calcination, washing with water, drying and calcining magnesium hydroxide by acting lime oil (石 물) on sea water, and then calcining. The magnesia thus produced is called seawater magnesia. Calcined magnesia (or calcined magnesia, caustic-calcined magnesia), or calcined magnesia, which is calcined at a low temperature of 700 to 1000 ° C depending on the temperature of calcining. It can also be distinguished. Light magnesia is highly active and alkaline in water, so it is mainly used in medicine, adsorbents, papermaking, fertilizers, cement, etc. On the other hand, magnesia is used for high-temperature optics, lighting materials, basic fire retardants, raw materials of bricks, crucible materials, etc., because the magnesia has a specific gravity greater than 3.5 and is almost inactive. Fused magnesia, melted at a high temperature above 2,750 ° C, is mainly used for electrical insulators and refractory materials. In the present invention, the magnesia clinker may be preferably soso magnesia and the content of MgO may be about 90%.

In the present invention, the olivine (olivine) clinker is a coarse mineral belonging to the tetragonal system, and the chemical formula is (Mg, Fe) ₂ SiO ₄ and forms a columnar crystal, but the crystal is not clear. It is also called Chrysolite and is known as Peridot when it is gem-quality. In the present invention, the olivine clinker is a posterior (Forsterite, magnesium discontinued, goto olivine, Mg ₂ SiO ₄ ) and Payalite (Fayalite, iron discontinued, Fe ₂ SiO ₄ ) and the ratio of magnesium and iron As mixed composites (ie solid solutions with varying ratios of Mg and Fe), the olivine component is usually expressed in the molar ratio of iron and magnesium. Fosterite has an exceptionally high melting point of up to 1900 ° C, but the melting point of Faylite is around 1200 ° C. Olive or yellowish brown, grayish red, transparent or translucent, streaky white, hardness 6.5-7, density 3.2g / (posterite) ~ 4.4g / (pallite). Most have been used as a source of magnesia (MgO) in the steelmaking process, or as a soluble phosphate fertilizer as an industrial raw material. In the present invention, the olivine clinker may be 100% pure natural mineral and may be used by grinding to a particle size of 1 mm or less.

When the olivine clinker is calcined or melted before use, not only the cost increases, but the shrinkage rate of the produced refractory material may be greatly increased as the temperature increases.

Specifically, after applying the amorphous refractory material prepared according to the present invention to the tundish temperature is raised to 1000 ℃ and 1500 ℃ and the shrinkage rate when 3 hours has been shown in Table 1. When the olivine clinker is used by calcining or melting, the shrinkage rate is large, and thus the adhesiveness is too strong in the process of applying and repairing the product after use, so that many residues remain during disassembly, so it may not be easy to use.

Temperature ( ℃ )
 % Shrinkage when calcined or molten olivine Shrinkage when using natural olivine (%) 1000
-0.1 0.16 1500
-0.8 -0.4

In the case of using natural olivine without additional processing as in the present invention, since the shrinkage rate is low, it will be excellent in dismantling when applied to the product.

In the present invention, "refractory material" is a material that withstands high temperature, and it is a general term of non-metal inorganic material which can maintain its strength sufficiently without softening at high temperature of at least 1,000 ° C or more and can withstand chemical action. Refractoriness measurement method by (KS) refers to the fire resistance of more than SK26 (melting cone falling temperature: 1,580 ℃).

"Amorphous refractory" refers to a refractory in the form of a powder or slurry rather than having a uniform shape like a refractory brick. It is a powder or soft soil composed of particles of refractory aggregate particles, binders and additives adjusted in particle size, and is constructed in an arbitrary shape at a construction site. Being refractory. In use, the powdery thing is mixed with a liquid such as water and molded.

In the present invention, with respect to 100 parts by weight of magnesia clinker, the olivine clinker may include 5 to 280 parts by weight, and when mixed at a ratio outside the parts by weight, problems such as lowering of fire resistance or deterioration of dismantling may occur. .

In particular, 40-50 parts by weight of the olivine clinker may be mixed with respect to 100 parts by weight of the magnesia-olivine-based amorphous refractory material of the present invention, and when the olivine is more than 50 parts by weight, the low melting point compound in the matrix may be over-formed to lower the fire resistance. This may lead to deterioration of corrosion resistance, and if the olivine is less than 40 parts by weight, deterioration in dissolution occurs due to cost problems and the remaining linear change rate problem.

In addition, magnesia clinker is contained 40 to 60 parts by weight based on 100 parts by weight of the magnesia-olivinic amorphous refractory material of the present invention, when the magnesia clinker is contained less than 40 parts by weight, there is a corrosion resistance problem, if the price exceeds 60 parts by weight Problems and degradation of disassembly occur.

In addition, 0.5 to 12 parts by weight of a binder is included with respect to the magnesia clinker and the olivine clinker, and the binder has the functions of improving adhesion, projectability and strength, preventing heat spreading, and preparing a uniform mixture. , Silica, equity, poly-based fibers and peptizing agent, and may further include one or more components selected from the group consisting of ultra fine silica, soda silicate and bubble generator.

In the present invention, the calcined lime has a function of improving the strength of the amorphous refractory according to the present invention, may be included 0.1 to 3 parts by weight based on 100 parts by weight of magnesia clinker. When added in excess of the weight part, the strength may be improved, but cracks may occur due to rapid hardening, and when less, the strength is lowered.

In the present invention, the peptizing agent has a function to allow uniform mixing of the amorphous refractory according to the present invention, 0.3 parts by weight may be included. When added in excess of the said weight part, a drooping phenomenon arises, and when it adds less, projection property falls. Materials used as peptizing agents include naphthalene sulfonase, melamine sulfonate and sodium lignosulfonate.

In the present invention, the stake has a function of preventing the explosion of the amorphous refractory according to the present invention, 0.1 to 3 parts by weight based on 100 parts by weight of magnesia clinker. If it is added in excess of the weight, the projection property is lowered and the corrosion resistance may be lowered due to the decrease in specific gravity. If the amount is added in a small amount, the explosion may occur and the flow rate may increase due to the increase in specific gravity. In the case of firing olivine, if the stake is added during the manufacture of the refractory, the corrosion resistance is remarkably degraded, so that the stake cannot be applied as a component of the binder. The addition of a stake may indicate the ability to prevent bursting without compromising corrosion resistance.

In the present invention, the poly-based fiber has a function of improving the strength of the amorphous refractory according to the present invention, may be included 0.1 to 3 parts by weight based on 100 parts by weight of magnesia clinker. If it is added in excess of the weight, the projection property is lowered and a cost problem occurs, and if it is added less, explosion may occur. As the poly-based fibers, polyvinyl alcohol fibers, polyvinyl chloride fibers, polypropylene fibers and the like can be used.

In the present invention, the ultra fine silica exhibits the effect of reducing projection property, adhesion, and added moisture of the amorphous refractory according to the present invention, and may include 1 to 10 parts by weight based on 100 parts by weight of magnesia clinker. If it is out of the above range, the projection property, the adhesiveness is lowered and the amount of added moisture excessively flows down occurs.

In the present invention, the soda silicate has a function of improving the strength of the amorphous refractory according to the present invention, may be included 0.1 to 3 parts by weight based on 100 parts by weight of magnesia clinker. In case of adding more than the weight, the strength may increase, but a cost problem arises, and when less added, the strength decreases.

In the present invention, the bubble generator has a function of improving the adhesion and the projectability of the amorphous refractory according to the present invention, may be included 0.01 to 3 parts by weight based on 100 parts by weight of magnesia clinker. When it exceeds 3 parts by weight, the specific gravity decreases due to the formation of a large amount of pores, so that the corrosion resistance may be lowered, and when added below 0.01, the adhesion may be lowered due to the increase in specific gravity.

Magnesia-Olivin-based amorphous refractory according to the present invention is manufactured as a T / D coating material and an electric furnace spray material which is periodically repaired for the operation stability of the T / D (Tundish) in the equipment for refining steelmaking and the protection of the furnace body. It is possible to apply the magnesia clinker and the olivine clinker to exhibit the characteristics of magnesia, which are excellent in infiltration resistance, dismantling property and sinterability. In addition, the low magnesia content provides a low-cost, yet refractory amorphous refractory with reinforced properties exhibiting properties corresponding to Dead Burned Magnesia.

The present invention, in another aspect (a) mixing 5 to 280 parts by weight of olivine clinker with respect to 100 parts by weight of magnesia clinker; (b) adding and mixing 0.1 to 3 parts by weight of calcined lime, 0.1 to 3 parts by weight of peptizing agent, 0.1 to 3 parts by weight and 0.1 to 3 parts by weight of poly-based fibers; And (c) kneading the mixture of step (b) to produce a magnesia-olivine-based amorphous refractory.

In particular, the present invention relates to a method for producing an amorphous refractory material without mixing or sintering a binder including magnesia clinker, olivine clinker and ultra-fine silica, and the process is simplified to facilitate manufacturing and to reduce costs. It works.

In the present invention, in step (a), 5 to 280 parts by weight of olivine clinker is mixed with respect to 100 parts by weight of magnesia, but the mixing may be performed using a high speed mixer or the like.

In the present invention, the step (b), in the group consisting of ultrafine silica, soda silicate and bubble generator can be added to and mixed with the magnesia-olivine mixture as a binder lime, peptizing agent, equity and poly-based fibers One or more selected ingredients may be further added and mixed.

In the present invention, in the step (c) can be prepared by kneading the mixture of step (b) magnesia-olivine-based amorphous refractory, in the mixing and kneading process, preferably the high speed mixer mixer can be used In addition, a tammixer, a monson mixer, a pedal mixer, etc. can be used.

Here, the mixing time or the reaction temperature is not particularly limited, but may be performed for 2 to 6 minutes at room temperature, for example.

Hereinafter, the present invention will be described in more detail by way of examples. These examples are intended to illustrate the present invention in more detail, and it will be apparent to those skilled in the art that the scope of the present invention is not limited to these examples.

Example: magnesia -  Preparation of Olivine-Based Amorphous Refractory

Through the process shown in Figure 1, after putting a certain amount of magnesia and natural olivine in the mixing ratio shown in Table 2 and mixed for 2 minutes at room temperature with a High Speed Mixer, ultrafine silica, calcined lime, sodium silicate, bubbles as a binder to the mixture Generator, peptizer, stake and poly-based fibers were added and kneaded for 6 minutes at room temperature using a High Speed Mixer. Magnesia was purchased from Samhwa Huaping Co., Ltd. China , and the amount of silica improved the corrosion resistance by controlling the amount so as not to reduce the projectability. The production conditions required for the other manufacturing process were the same as the conventionally known general amorphous refractory manufacturing method. The prepared amorphous refractory was molded by mixing 100 parts by weight of the clinker mixture and 20.8 parts by weight of water with respect to the combined weight of the binder, and magnesia-olivine clinker-based amorphous refractory was confirmed by an X-ray diffractometer. )

division Comparative example Example 1 Example 2 Compounding ratio (%) DBM 90% 95 57 47 Natural olivine - 40 50 bookbinder 7.05 5.05 5.05 Added moisture (%) 20.8 20.8 20.8

Experimental Example 1: Physical Properties and Projection Test

The physical properties and the projectability evaluations of the comparative examples (previous products) prepared in the composition of Table 2, the amorphous refractory materials prepared in Examples 1 and 2 were carried out as follows.

Projection time measurements were made using a test projector (mortar gun-paint injector) and tested using a kneaded mixture with 20.8% water. The degree of deflection was visually observed and the projection height was based on 70 mm. Projectivity was calculated by the following equation.

Calculation 1:

 The physical properties of the specimens were 160 * 40 * 40, fired at 1500 ° C. for 3 hours, and the residual line change, strength, and specific gravity were measured after natural cooling.

The results are shown in Table 3 below.

division Comparative example Example 1 Example 2 Projection time (sec) 52.2 48.6 52.5 Deflection degree (measurement: upper, middle, lower) Prize medium Prize Projection Comparison - 6.8 -0.57 Physical Characteristics Remaining linear change (%) -3.69 -1.32 -1.36 Strength (Mpa) 11.9 18.3 15.8 importance 1.87 1.84 1.86

As a result of evaluation of physical properties, as the specific gravity of magnesia-olivine clinker itself according to the present invention is lowered, the amorphous refractory specific gravity was lowered compared to the conventional amorphous refractory, the strength was significantly improved, and the projection property was equivalent. Figure 3 is a photograph of the evaluation of the projection and adhesion, it can be seen that the same level of projection and visibility of the prior art.

Experimental Example 2: Corrosion Resistance Test

A rotary erosion machine was used to test the corrosion resistance of the comparative examples (previous products) and the amorphous refractory materials prepared in Examples 1 and 2. Average temperature (Average Temperature) during the test is 1650 ℃, and the slag used is slag with 150ton electricity. Table 4 shows the representative components of Slag used. The results of the evaluation are shown in Table 5, and the photographs of the results are shown in FIG. 4, and the magnesia-olivine-based amorphous refractory materials prepared in Examples 1 and 2 were compared with the comparative examples (primary products). Could.

SiO ₂ CaO Fe ₂ O ₃ MgO Al ₂ O ₃ KnO Cr ₂ O ₃ 22.39 20.74 13.43 9.38 19.90 10.30 2.57

Slag Representative: C / S 0.92

division Comparative Example (Primary Product) Example 1 Example 2 Corrosion resistance index 1.00 1.02 1.05

In addition, Figure 5 shows a photograph dismantled after the construction of the comparative example (the conventional product) and the product of Example 2, it can be confirmed that the embodiment product of the present invention is superior to the conventional product disassembly.

Experimental Example 3: Constructability Test

In the preparation of the amorphous refractory material in the above embodiment, in order to confirm the effects of the peptizing agent, equity, poly-based fiber and calcined lime added together, the amorphous refractory material prepared using only magnesia and olivine clinker (Comparative Example 2) And comparative experiments with amorphous refractory materials (Comparative Example 3) prepared with the exception of peptizing agents, equity, poly-based fibers and slaked lime in the mixture of Example 1.

Example 1 Comparative Example 2 Comparative Example 3 Construction share Specific gravity can be adjusted below 1.8 Difficulty adjusting the weight Difficulty adjusting the weight Construction and repair ease Not easy Not easy Adhesion Easy to adjust construction thickness Dripping Dripping Water content (%) 20 27 29 Curing time 4-5 hours More than 80 hours More than 72 hours

As shown in Table 6, the amorphous refractory material of Example 1 according to the present invention was prepared by adding a peptizing agent, a stake, a poly-based fiber, and slaked lime, thereby exhibiting remarkable effects in terms of uniformity, thermal protection, and strength improvement of the refractory material. Therefore, in terms of function, the construction process is easy, and the amount of added moisture is reduced, thereby shortening the curing period.

Having described the specific part of the present invention in detail, to those skilled in the art, such a specific description is only a preferred embodiment, which is clearly not limited by the scope of the present invention something to do. Thus, the substantial scope of the present invention will be defined by the appended claims and their additives.

No sign used

Claims (8)

100 parts by weight of magnesia clinker, including 5 to 280 parts by weight of olivine clinker, 0.1 to 3 parts by weight of lime, 0.1 to 3 parts by weight of peptizing agent, 0.1 to 3 parts by weight and 0.1 to 3 parts by weight of poly-based fibers. Magnesia-olivine-based amorphous refractory characterized by.
Magnesia according to claim 1, further comprising one or more components selected from the group consisting of 1 to 10 parts by weight of ultra fine silica, 0.1 to 3 parts by weight of soda silicate, and 0.01 to 3 parts by weight of the foaming agent. Olivine-based amorphous refractory.
The magnesia-olivine-based amorphous refractory according to claim 1, wherein the magnesia clinker is magnesia, light magnesia, molten magnesia or seawater magnesia.
The method of claim 1, wherein the olivine clinker is forsterite (Forsterite, Mg ₂ SiO ₄ ), Faylite (Fayalite, Fe ₂ SiO ₄ ), or magnesia-Oler characterized in that the composite of the fosterite Binary amorphous form refractory.
Process for the preparation of magnesia-olivinic amorphous refractory according to claim 1, comprising the following steps:
(a) mixing 5 to 280 parts by weight of olivine clinker based on 100 parts by weight of magnesia clinker;
(b) mixing 0.1 to 3 parts by weight of calcined lime, 0.1 to 3 parts by weight of peptizing agent, 0.1 to 3 parts by weight, and 0.1 to 3 parts by weight of poly-based fibers; And
(c) kneading the mixture of step (b) to produce a magnesia-olivinic amorphous refractory.
6. The method of claim 5, wherein in step (b), at least one component selected from the group consisting of 1 to 10 parts by weight of ultra fine silica, 0.1 to 3 parts by weight of soda silicate, and 0.01 to 3 parts by weight of the foaming agent may be added and mixed. A method for producing a magnesia-olivine-based amorphous refractory, which can be used.
The method according to claim 5, wherein the magnesia clinker is magnesia, light magnesia, molten magnesia or seawater magnesia.
The method according to claim 5, wherein the olivine clinker is forsterite (Forsterite, Mg ₂ SiO ₄ ), Faylite (Fayalite, Fe ₂ SiO ₄ ), or magnesia-Oler characterized in that the composite of the fosterite and phallite Method for producing a poor type amorphous refractory.

Images