KR100328085B1 - Preparation method of calcia clinker with good hydration resistance - Google Patents

Preparation method of calcia clinker with good hydration resistance Download PDF

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KR100328085B1
KR100328085B1 KR1019970071687A KR19970071687A KR100328085B1 KR 100328085 B1 KR100328085 B1 KR 100328085B1 KR 1019970071687 A KR1019970071687 A KR 1019970071687A KR 19970071687 A KR19970071687 A KR 19970071687A KR 100328085 B1 KR100328085 B1 KR 100328085B1
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calcia
clinker
resistance
cao
present
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KR1019970071687A
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Korean (ko)
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KR19990052232A (en
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이철규
최주태
문희경
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이구택
포항종합제철 주식회사
신현준
재단법인 포항산업과학연구원
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    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/64—Burning or sintering processes
    • C04B35/65—Reaction sintering of free metal- or free silicon-containing compositions
    • C04B35/651—Thermite type sintering, e.g. combustion sintering
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
    • C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
    • C04B2235/3205—Alkaline earth oxides or oxide forming salts thereof, e.g. beryllium oxide
    • C04B2235/3208—Calcium oxide or oxide-forming salts thereof, e.g. lime
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
    • C04B2235/40—Metallic constituents or additives not added as binding phase
    • C04B2235/402—Aluminium
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/65—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes
    • C04B2235/658—Atmosphere during thermal treatment

Abstract

PURPOSE: A method for preparing a calcia(CaO) clinker is provided, to improve the hydration resistance of a calcia clinker without deterioration of the erosion resistance and the heat resistance. CONSTITUTION: The method comprises the steps of adding 0.2-1.0 vol% of metal aluminum powder to calcia and molding the mixture into a certain shape; firing the molded one at a temperature of 1,200-1,400 deg.C; and thermite reacting the primarily fired one. The calcia is prepared by calcining calcite powder. Preferably the primary firing process is carried out for 3-5 hours under the inert condition; and the thermite reaction is carried out by an arc discharging in a graphite furnace.

Description

내수화성이 우수한 칼시아 클링커의 제조방법Method for producing calcia clinker with excellent water resistance

본 발명은 제철, 제강설비의 내화재로 사용되는 부정형 내화물의 제조방법에 관한 것으로서, 보다 상세하게는 내수화성이 우수한 부정형 칼시아(calcia) 클링커의 제조방법에 관한 것이다.The present invention relates to a method for producing an amorphous refractory material used as a refractory material for steel and steelmaking facilities, and more particularly, to a method for producing an amorphous calcia clinker having excellent water resistance.

통상 칼시아(CaO)는 철강재의 정련용 플럭스(flux) 등 여러 용도로 사용되고 있다. 그러나, 칼시아는 그 자체만으로도 약 2000℃ 의 고온에서 소결되는 고온재료로서, 정련용 플럭스 이외에도 각종 내화재로 사용될 수 있음에도 불구하고 대기중의 수분과 수화반응(hyration reaction)이 용이하여 그 용도가 특정분야로 제한되는 단점이 있다.Generally, calcia (CaO) is used for various purposes, such as flux for refining steel. However, Calcia is a high-temperature material sintered at a high temperature of about 2000 ° C by itself, and although it can be used as various refractory materials in addition to refining fluxes, it is easy to hydration reactions with moisture in the air and thus its use is specific. There are disadvantages that are limited to the field.

이러한 칼시아의 단점을 보완하여 칼시아를 각종 내화재 등 다양한 용도로 사용하기 위해 칼시아의 수화반응을 억제하는 기술이 다수 제안되어 왔다. 예를들면, 일본 특허공고 昭55-35354호, 昭 61-21182호 및 昭 59-27731호 등에는 칼시아에 산화철, 산화규소, 산화티탄, 산화알루미늄, 산화마그네슘 등의 다양한 산화물을 혼합하여 이 혼합물을 고온에서 열처리함으로써 그 소성체의 표면에 저융점 물질이 감싸도록 하여 수화반응을 억제하는 기술이 개시되어 있다. 그러나, 상기 방법들과 같이, 칼시아에 저융점 물질이 다량 함유되면 칼시아의 입자크기가 작아지며, 이에 따라 융점이 낮아져 내수화성은 개선되나 칼시아의 내침식성 등의 고유 장점을 잃게 되는 단점이 있다.In order to compensate for the disadvantages of Kalcia, a number of techniques for suppressing hydration of Kalcia have been proposed for using Kalcia for various uses such as various fireproof materials. For example, Japanese Patent Publications No. 55-35354, No. 61-21182, and No. 59-27731 are incorporated into calcia by mixing various oxides such as iron oxide, silicon oxide, titanium oxide, aluminum oxide, and magnesium oxide. The technique which suppresses a hydration reaction by making a low melting point material wrap on the surface of the baking body by heat-processing a mixture at high temperature is disclosed. However, as in the above methods, when a large amount of low melting point material is contained in Kalcia, the particle size of Kalcia is reduced, thereby lowering the melting point, thereby improving water resistance, but losing the inherent advantages such as Kalcia's corrosion resistance. There is this.

따라서, 본 발명은 칼시아와 금속 알루미늄과의 테르밋(thermit) 반응을 이용하므로써 내침식성, 내열성 등의 칼시아 고유의 성질을 유지하면서도 내수화성이 우수한 칼시아 클링커의 제조방법을 제공함에 그 목적이 있다.Accordingly, an object of the present invention is to provide a method for preparing calcia clinker having excellent water resistance while maintaining calcia intrinsic properties such as erosion resistance and heat resistance by using a thermal reaction between calcia and metal aluminum. have.

도1은 본 발명의 실험에 사용된 1차소성 가열장치의 개략 구조도1 is a schematic structural diagram of a primary firing apparatus used in an experiment of the present invention

도2는 본 발명의 실험에 사용된 테르밋 반응장치의 개략 구조도Figure 2 is a schematic structural diagram of the thermite reaction apparatus used in the experiment of the present invention

상기 목적 달성을 위한 본 발명은 칼시아(CaO)에 금속알루미늄 분말을 0.2~1.0vol%의 범위로 첨가하여 일정 형태로 성형한 후 상기 성형물을 1200~1400℃ 의 범위에서 열처리하여 1차소성한 다음, 1차소성물을 테르밋반응시키는 내수화성이 우수한 부정형 칼시아 클링커의 제조방법에 관한 것이다.The present invention for achieving the above object is added to the metal aluminum powder in the calcia (CaO) in the range of 0.2 ~ 1.0 vol% to form a predetermined shape and then heat-treated the molded product in the range of 1200 ~ 1400 ℃ primary firing Next, the present invention relates to a method for producing an amorphous calcia clinker having excellent water resistance to thermite reaction of a primary calcined product.

이하, 본발명의 제조방법에 대하여 상세히 설명한다.Hereinafter, the manufacturing method of the present invention will be described in detail.

본 발명은 미세한 금속알루미늄 분말을 칼시아(CaO)에 일정량 첨가하여 성형한 후, 이 성형물을 1차소성하여 용융알루미늄에 의한 칼시아의 입자를 재배열시킨 다음, 용해, 석출이 일어나는 과정에서 테르밋반응을 일으켜 칼시아 계면에 액상의 칼슘알루미네이트를 형성시켜 칼시아의 치밀화를 도모함에 그 특징이 있다.The present invention is formed by adding a predetermined amount of fine metal aluminum powder to calcia (CaO), and then molding the molded product first to rearrange the particles of calcia by molten aluminum, and then dissolve and precipitate in the process of melting and precipitation. It is characterized by the formation of a liquid calcium aluminate at the interface of calcia and densification of calcia.

먼저, 상기 금속알루미늄 분말의 첨가량은 0.2~1.0vol%의 범위로 설정함이 바람직하다. 상기 금속알루미늄 분말은 칼시아를 환원시키면서 칼슘아루미네이트를 형성하여 칼시아의 수화를 방지하는 작용을 하는데, 그 첨가량이 0.2vol%미만일 때는 수화방지억제 효과가 미흡하다. 또한, 금속알루미늄의 첨가량이 1.0vol%이상인 경우 과잉의 알루미늄에 의해 오히려 내침식성 등 칼시아의 고유 특성을 저하시켜 바람직하지 않다.First, the addition amount of the metal aluminum powder is preferably set in the range of 0.2 ~ 1.0vol%. The metal aluminum powder forms calcium aluminate while reducing calcia to prevent hydration of calcia, and when the addition amount is less than 0.2 vol%, the hydration inhibitory effect is insufficient. In addition, when the addition amount of metal aluminum is 1.0 vol% or more, it is not preferable because excess aluminum lowers the intrinsic properties of calcia such as erosion resistance.

이렇게 적정량의 금속알루미늄이 첨가된 혼합물은 일정 형태로 성형한 후 상기 성형물을 1200~1400℃ 의 범위에서 열처리하여 1차소성한다. 이러한 소성과정에서 상기 성형물은 용융알루미늄에 의해 칼시아의 입자가 재배열된다. 이때, 소성온도가 1200℃ 이하에서는 칼시아의 치밀화가 일어나기 곤란하기 때문에 1200℃이상에서 소성을 행해야 한다. 그러나, 소성온도가 너무 높으면 열원단위가 증가되므로 1400℃이하에서 실시함이 바람직하다. 그리고, 소성은 Ar 등의 불활성분위기에서 약 3~5 시간 동안 실시함이 적절하다.The mixture in which the appropriate amount of metal aluminum is added is molded into a predetermined form, and the molded product is firstly baked by heat treatment in the range of 1200 to 1400 ° C. In the firing process, the molded article is rearranged by particles of calcia by molten aluminum. At this time, since the densification of calcia does not occur easily at the baking temperature of 1200 degrees C or less, you need to bake at 1200 degreeC or more. However, if the firing temperature is too high, it is preferable to carry out at 1400 ° C. or less since the heat source unit increases. And, firing is appropriately carried out in an inert atmosphere such as Ar for about 3 to 5 hours.

상기 1차소성물을 테르밋반응시키면 이때의 발열량에 의해 칼시아 계면에 액상의 칼슘알루미네이트를 형성되며 냉각후에는 칼시아의 치밀화를 도모할 수 있다.Thermite reaction of the primary calcined product forms liquid calcium aluminate at the interface of calcia by the calorific value at this time, and after cooling, densification of calcia can be achieved.

이와같이, 제조된 칼시아는 탄화규소계 클링커에 비해 용탕내의 개재물 혼입억제에 우수한 특성이 있기 때문에 특히 내수화성이 우수하여 침식저항과 내열성이 요구되는 내화재의 클링커로서 매우 적합하다.Thus, the calcia produced is particularly suitable as a clinker of a refractory material that is excellent in hydration resistance and requires erosion resistance and heat resistance, because it has superior characteristics in suppressing inclusions in the molten metal as compared to silicon carbide-based clinker.

이하, 실시예를 통하여 본발명을 상세히 설명한다.Hereinafter, the present invention will be described in detail through examples.

[실시예1]Example 1

평균입도가 20㎛이고 순도 99%인 시약급의 칼사이트(calcite; CaCO3) 분말을 전기로를 이용하여 1000℃에서 2시간 동안 하소시켜 칼시아(CaO)를 얻었다. 상기 칼시아에 평균입도 20㎛이고 순도가 99.1%인 금속알루미늄 분말을 0.5vol% 로 첨가시켜 혼련한 다음, 이 혼합물을 이용하여 18.7MPa의 압력으로 성형하였다.Calsite (calcite; CaCO 3 ) powder of reagent grade having an average particle size of 20 μm and a purity of 99% was calcined at 1000 ° C. for 2 hours using an electric furnace to obtain calcia (CaO). The aluminum aluminum powder having an average particle size of 20 µm and a purity of 99.1% was added to Kalcia and kneaded at 0.5 vol%, and then the mixture was molded at a pressure of 18.7 MPa.

성형된 시편은 다시 도1과 같은 열처리장치(10)에서 1400℃ 까지 가열하여 1차소성하였다. 즉, 양측이 씰링재(3)로 밀봉된 알루미나관(2)내에 시편(1)을 적치하고, Ar탱크(7)와 산소탱크(8)로부터 Ar 및 산소를 흘리면서 열처리하였다. 본 발명의 모사 열처리장치(10)의 미설명부호 `4'는 열전대, `5'는 유량계, `6'은 건조기를 나타낸다.The molded specimen was first baked by heating up to 1400 ° C. in the heat treatment apparatus 10 as shown in FIG. 1. That is, the specimen 1 was placed in the alumina tube 2 sealed at both sides by the sealing material 3, and heat-treated while Ar and oxygen were flowing from the Ar tank 7 and the oxygen tank 8. Unexplained reference numeral 4 of the simulated heat treatment apparatus 10 of the present invention denotes a thermocouple, 5 denotes a flow meter, and 6 denotes a dryer.

이렇게 1차소성한 시편은 테르밋반응을 조장하였다. 상기 테르밋반응은 도2와 같은 반응장치(20)를 이용하였다. 즉, 시편(1)을 흑연도가니(22)내에 장입한 다음, 가열체(21)로 가열하면서 흑연도가니(2)에 탄소봉(23)을 연결하고, 아크방전을 시켜 Al 분말과 CaO 분말간에 테르밋반응을 조장하였다.This primary fired specimen promoted thermite reaction. The thermite reaction was performed using a reaction apparatus 20 as shown in FIG. That is, the specimen 1 is charged into the graphite crucible 22, and then the carbon rod 23 is connected to the graphite crucible 2 while heating with the heating body 21, and arc discharge is performed to form thermite between the Al powder and the CaO powder. The reaction was encouraged.

상기와 같이 제조된 본 발명의 칼시아 클링커는 테르밋 반응온도가 1200℃에 이를 때까지는 상대밀도가 감소하였으나 온도가 상승하면서 소결이 촉진되어 알루미늄을 0.5% 첨가한 시편의 경우 1550℃에서 이론밀도의 94%를 나타내었으며, 이 소결체는 대기중에서 수화반응을 일으키지 않고 64일간 지탱되었다.The calcia clinker of the present invention prepared as described above has a relative density decreased until the thermite reaction temperature reaches 1200 ℃, but sintering is promoted as the temperature increases, so that the specimen with 0.5% of aluminum has a theoretical density of 1550 ℃. It was 94%, and the sintered body was supported for 64 days without causing hydration in the atmosphere.

[실시예2]Example 2

실시예1과 같이 제조된 칼시아(CaO)를 이용하여 박판주조기의 사이드댐(side dam)용 내화물을 제조하였다. 이렇게 제조된 본 발명의 칼시아 클링커를 함유한 내화물(발명재)과 종래의 알루미나-탄화규소계 내화물(종래재A), 그리고 정형내화물(종래재B)의 특성을 비교하고, 그 결과를 표1에 나타내었다.Refractories for side dams of thin plate casting machines were prepared using calcia (CaO) prepared as in Example 1. The characteristics of the refractory (invention) containing the calcia clinker of the present invention thus prepared, and the conventional alumina-silicon carbide-based refractory (traditional material A), and the standard refractories (traditional material B) are compared, and the results are shown in the table. 1 is shown.

실시예Example 발명재Invention 종래재AConventional material A 종래재BConventional material B Al2O3SiCSiO2ZrO2MgOCaO탄소Al 2 O 3 SiCSiO 2 ZrO 2 MgOCaO Carbon 54---0.435454 --- 0.4354 7214----87214 ---- 8 77-28--777-28--7 결합재(%)첨가수분량(%)Binder (%) Addition Water Content (%) 2626 2626 --- 부피비중겉보기 기공율압축강도(kg/cm2)꺽임강도(kg/cm2)열전도율선팽창율(1500℃)침식저항탕면청정도Volume Specific Gravity Porosity Compressive Strength (kg / cm 2 ) Bending Strength (kg / cm 2 ) Thermal Conductivity Linear Expansion Rate (1500 ℃) Erosion Resistance 2.916.0720983.81.3양호양호2.916.0720983.81.3 Good 2.716.3696904.01.2양호보통2.716.3696904.01.2 Good 3.113.514001906.51.5불량불량3.113.51400 1906.51.5 Defective

표1에 나타난 바와 같이, 본 발명재는 부정형 내화물인 종래재(A)와 거의 동등이상의 특성을 유지하고 있다. 또한, 본 발명의 칼시아 함유 내화물은 종래재(A)에 비하여 탕면청정도가 매우 우수함을 알 수 있다. 보통 규산화물 함유 내화재가 CaO함유 내화재에 비하여 용탕내로 산화되는 정도가 심하는 점에서 본 발명의 내화물은 고청정강 제조에 매우 유리함을 알 수 있다.As shown in Table 1, the present invention retains almost the same characteristics as those of the conventional material (A), which is an amorphous refractory material. In addition, it can be seen that the calcia-containing refractory material of the present invention is very excellent in the freshness of the noodles when compared to the conventional material (A). It is understood that the refractory material of the present invention is very advantageous for the production of high clean steel in that the degree of oxidation of the silica-containing refractory material into the molten metal is more severe than that of the CaO-containing refractory material.

또한, 본 발명의 내화물은 종래재(B)와 같은 일반 정형 내화물에 비해서도 탕면청정도뿐만아니라 침식저항 측면에서도 우수한 특성을 보이고 있다.In addition, the refractory material of the present invention exhibits excellent properties in terms of rust resistance as well as erosion resistance as compared with general standard refractory materials such as the conventional material (B).

상술한 바와같이, 본 발명에 의하면 칼시아와 금속 알루미늄과의 테르밋(thermit) 반응을 이용하므로써 내침식성, 내열성 등의 칼시아 고유의 성질을 유지하면서도 내수화성이 우수한 칼시아 클링커가 제공되며, 이러한 칼시아 클링커는 내침식이 요구되는 고청정강 제조용 내화물로서 매우 유용한 효과가 있다.As described above, the present invention provides a calcia clinker having excellent water resistance while maintaining calcia intrinsic properties such as erosion resistance and heat resistance by using a thermal reaction between calcia and metal aluminum. Calcia clinker has a very useful effect as a refractory for producing high clean steels requiring corrosion resistance.

Claims (4)

칼시아(CaO)에 금속알루미늄 분말을 0.2~1.0vol%의 범위로 첨가하여 일정 형태로 성형한 후 상기 성형물을 1200~1400℃ 의 범위에서 열처리하여 1차소성한 다음, 1차소성물을 테르밋반응시킴을 특징으로 하는 내수화성이 우수한 부정형 칼시아 클링커의 제조방법The metal aluminum powder is added to calcia (CaO) in the range of 0.2 to 1.0 vol%, and then molded into a predetermined form. Process for producing amorphous calcia clinker with excellent water resistance, characterized in that the reaction 제1항에 있어서, 상기 칼시아는 칼사이트(calcite) 분말을 하소시킨 것임을 특징으로 하는 제조방법The method of claim 1, wherein the calcia is calcined (calcite) powder characterized in that the manufacturing method 제1항에 있어서, 상기 1차소성은 불활성분위기에서 3~5시간 동안 행함을 특징으로 하는 제조방법The method according to claim 1, wherein the primary firing is performed for 3 to 5 hours in an inert atmosphere. 제2항에 있어서, 상기 테르밋반응은 1차소성물을 흑연도가니내에서 아크방전에 의해 행함을 특징으로 하는 제조방법The method of claim 2, wherein the thermite reaction is characterized in that the primary firing is carried out by arc discharge in a graphite crucible.
KR1019970071687A 1997-12-22 1997-12-22 Preparation method of calcia clinker with good hydration resistance KR100328085B1 (en)

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