JPH11228242A - Ramming material for induction furnace - Google Patents

Ramming material for induction furnace

Info

Publication number
JPH11228242A
JPH11228242A JP10048682A JP4868298A JPH11228242A JP H11228242 A JPH11228242 A JP H11228242A JP 10048682 A JP10048682 A JP 10048682A JP 4868298 A JP4868298 A JP 4868298A JP H11228242 A JPH11228242 A JP H11228242A
Authority
JP
Japan
Prior art keywords
powder
induction furnace
ramming material
weight
less
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
JP10048682A
Other languages
Japanese (ja)
Inventor
Noboru Nakamura
登 中村
Makoto Ebina
誠 蝦名
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Coorstek KK
Original Assignee
Toshiba Ceramics Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Toshiba Ceramics Co Ltd filed Critical Toshiba Ceramics Co Ltd
Priority to JP10048682A priority Critical patent/JPH11228242A/en
Publication of JPH11228242A publication Critical patent/JPH11228242A/en
Granted legal-status Critical Current

Links

Abstract

PROBLEM TO BE SOLVED: To provide a ramming material used for an induction furnace as a material for lining the inner surface of the induction furnace, having excellent corrosion resistance and thermal shock resistance and not causing the advance of a crack to the coil side of a non-operated surface, even when the crack is generated on an operation surface due to the flow friction of a molten metal and thermal shock, because the ramming material forms a compact sintered layer on the operation surface in a proper thickness and leaves a powder layer without being hardened up to the coil side of the non-operated surface, and thereby capable of avoiding the generation of troubles such as the leak of the molten metal. SOLUTION: This ramming material for introduction furnaces comprises 1-7 wt.% of a powdery material having a particle diameter of >=0.5 mm, 30-80 wt.% of molten silica having a SiO2 purity of >=98% and a granule diameter of <=5 mm and the remainder of natural silica having a SiO2 purity of >=98% and a granule diameter of <=5 mm. The powdery particles having the particle diameter of <=0.5 mm are obtained by grinding a sintered product or a molten and solidified product having a porosity of <=2% and comprising 67-77 wt.% of SiO2 component, 18-28 wt.% of Al2 O3 component and totally 2-7 wt.% of at least one kind of component selected from TiO2 , Fe2 O3 , CaO, MgO, Na2 O and K2 O.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【0001】[0001]

【発明の属する技術分野】本発明は、鋳鉄等を溶解する
ための誘導炉の内張り材として用いるラミング材に関
し、より詳細には、誘導炉の内張り材として、稼働面に
は緻密な焼結層を適正な厚さで形成し、然も非稼働面コ
イル側までは硬化されず粉体層が残存するため、耐食
性、耐熱衝撃性に優れると共に、例え、溶湯の流動摩擦
や熱衝撃により稼働面に亀裂が発生した場合でも該亀裂
が非稼働面のコイル側まで進行せず、湯漏れ等のトラブ
ルの発生を回避出来る誘導炉用ラミング材に関する。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ramming material used as a lining material of an induction furnace for melting cast iron and the like, and more particularly, as a lining material of an induction furnace, a dense sintering layer on a working surface. Is formed with an appropriate thickness, and the non-operating surface is not cured up to the coil side, and the powder layer remains, so it has excellent corrosion resistance and thermal shock resistance, as well as the operating surface due to the flow friction and thermal shock of the molten metal. The present invention relates to a ramming material for an induction furnace that can prevent the occurrence of troubles such as hot metal leaks even when a crack is generated in the non-operating surface, even if the crack is generated.

【0002】[0002]

【従来の技術】鋳鉄等の溶解を行う誘導炉の内張り材に
は、従来から焼結バインダ−として硼酸を添加した天然
シリカ質ラミング材や焼結バインダ−として硼酸を添加
した天然シリカ質と溶融シリカ質の混合系ラミング材、
或いは、焼結バインダ−を添加しない高純度溶融シリカ
質ラミング材等が一般的に使用されてきた。誘導炉の築
炉過程に於いて、炉の内張りは、通常、例えば図2に示
すように、誘導コイル1のコイル保護用耐火物2の内面
側に、断熱シート3をセットし、ラミング材4を先ず炉
床部に装入し、エアーランマーで充填施工し、仕上げの
後、築炉シリンダー5を炉床上の中央にセットし、築炉
シリンダー5と断熱シート3の間にラミング材4を更に
装入してエアーランマーで充填施工することによりによ
り行う。
2. Description of the Related Art Conventionally, a lining material of an induction furnace for melting cast iron or the like includes a natural siliceous ramming material containing boric acid as a sintering binder and a natural siliceous material containing boric acid as a sintering binder. Silica-based ramming material,
Alternatively, a high-purity fused siliceous ramming material to which no sintering binder is added has been generally used. In the process of constructing the induction furnace, the lining of the furnace is usually set, for example, by setting a heat insulating sheet 3 on the inner surface side of the coil protection refractory 2 of the induction coil 1 as shown in FIG. Is first charged into the hearth, filled with an air rammer, and after finishing, the furnace-building cylinder 5 is set at the center on the furnace-bed, and the ramming material 4 is further placed between the furnace-building cylinder 5 and the heat insulating sheet 3. It is performed by charging and filling with an air rammer.

【0003】誘導炉の稼働は、この容器状に形成された
内張り材の内部に溶融すべき金属を投入しコイルに通電
することにより誘導加熱して、該金属を溶融し溶湯とす
る。この内張り材は、溶湯の流動摩擦による物理的損
耗、エロージョン等の化学作用が重畳された損耗、或い
は熱衝撃による損傷等に対し耐性を持たせる必要がある
ところから、鋳鉄等の溶湯と接するその稼動面側は、誘
導炉の稼働時に於いて、焼結層のような緻密で硬い層を
形成することが好ましく、一方内張り材のコイル側、即
ち非稼働面側は、例え、該稼動面側に亀裂等の損傷が発
生した場合でも、それが伝播して背面側(非稼動面のコ
イル側)にまで到達しないよう稼動面側層に比べてより
柔かく脆くない粉体層が残存することが好ましい。しか
しながら、上記、従来のラミング材の内、硼酸が添加さ
れたラミング材は、硼酸の添加によりその稼働面側の表
面近傍には緻密な焼結層が形成される反面、添加された
硼酸の影響により、ラミング材のコイル側(背面側)ま
で硬化し、稼働面に発生した亀裂が非稼働面のコイル側
まで達し、このため該稼働面の亀裂から侵入した金属溶
湯は非稼働面のコイル側まで浸透し、極端な場合には、
湯漏れ等のトラブルに至る場合もあった。
In the operation of the induction furnace, a metal to be melted is put into the inside of the lining material formed in the shape of a container, and the coil is energized for induction heating to melt the metal to form a molten metal. This lining material needs to be resistant to physical wear due to the flow friction of the molten metal, wear superimposed with chemical action such as erosion, or damage due to thermal shock, etc. It is preferable that the working surface side forms a dense and hard layer such as a sintered layer during the operation of the induction furnace, while the coil side of the lining material, that is, the non-working surface side is, for example, the working surface side. Even if damages such as cracks occur, a powder layer that is softer and less brittle than the working side layer may remain so that it does not propagate and reach the rear side (the coil side of the non-working side). preferable. However, among the above-mentioned conventional ramming materials, the ramming material to which boric acid is added forms a dense sintered layer near the surface on the working surface side by the addition of boric acid. As a result, the ramming material hardens to the coil side (back side), and the cracks generated on the working surface reach the coil side on the non-working surface. And in extreme cases,
In some cases, problems such as hot water leaks occurred.

【0004】一方、焼結バインダー無添加の高純度溶融
シリカ質ラミング材は、熱膨張率が小さいため亀裂の発
生は少なく、又、焼結バインダーが添加されないことか
ら非稼動面のコイル側には十分な粉体層が存在し、湯漏
れトラブルが少ない反面、稼動面に緻密な焼結層が生成
しにくく、このため溶湯成分との反応による化学的浸食
や、溶湯の電磁誘導攪拌作用による物理的損耗を受けや
すく、摩耗耐性に難があり、十分な耐用性を有するもの
は得られていない。
On the other hand, a high-purity fused siliceous ramming material to which no sintering binder is added has a low coefficient of thermal expansion, so that cracks are less likely to occur. Although there is a sufficient powder layer and there are few troubles of molten metal leakage, it is difficult to form a dense sintered layer on the operating surface, so chemical erosion due to reaction with the molten metal component and physical melting due to electromagnetic induction stirring action of the molten metal Those which are susceptible to mechanical wear, have poor abrasion resistance, and do not have sufficient durability.

【0005】[0005]

【発明が解決しようとする課題】従って、本発明は、上
記した技術的課題を解決するためになされたものであ
り、稼働面には緻密な焼結層が適正な厚さで存在し、そ
の背面側、即ち非稼動面コイル側には硬化されない粉体
層が残存し、両層がバランス良く存在するため、耐食
性、耐熱衝撃性に優れ、耐久使用性の極めて良好な誘導
炉用ラミング材提供することを目的とするものである。
SUMMARY OF THE INVENTION Accordingly, the present invention has been made to solve the above-mentioned technical problem, and a dense sintered layer having an appropriate thickness exists on an operating surface. A ramming material for induction furnaces with excellent corrosion resistance, thermal shock resistance, and extremely good durability is provided because a powder layer that is not cured remains on the back side, that is, on the non-operating surface coil side, and both layers are present in a well-balanced manner. It is intended to do so.

【0006】[0006]

【課題を解決するための手段】本発明によれば、SiO
2 成分67乃至77重量%、Al23 成分18乃至2
8重量%及びTiO2 ,Fe23 CaO,MgO,N
2 O及びK2 Oから選ばれた少なくとも1種の成分を
合計量で2乃至7重量%含有し、気孔率が2%以下の焼
結体又は溶融固化体を粉砕して成る粒径0.5mm以下
の粉体1乃至7重量%と、SiO2 純度98%以上、粒
径5mm以下の溶融シリカ30乃至80重量%と、残部
が、SiO2 純度98%以上、粒径5mm以下の天然シ
リカからなる誘導炉用ラミング材が提供される。
According to the present invention, SiO 2 is used.
2-component 67 to 77 wt%, Al 2 O 3 component 18 to 2
8% by weight and TiO 2 , Fe 2 O 3 CaO, MgO, N
a 2 O and K 2 O at least one component in a total amount of 2 to 7% by weight, and a particle size of 0 to 2% by crushing a sintered body or a molten and solidified body having a porosity of 2% or less. following a powder 1 to 7 wt% .5mm, SiO 2 purity of 98% or more, less and fused silica 30 to 80 wt% particle diameter 5mm, balance, SiO 2 purity of 98% or more, a particle diameter 5mm or less natural A ramming material for an induction furnace comprising silica is provided.

【0007】本発明の誘導炉用ラミング材は、溶融シリ
カ、天然シリカの2種類のシリカ基材粉体に焼結助剤と
して機能する特定組成の粉体を少量、且つ特定配合範囲
で組合せ配合して成る点が顕著な特徴である。即ち、特
定量比のシリカとアルミナに少量のTiO2 、Fe2
3 、CaO、MgO、Na2 O及びK2 Oから選ばれた
少なくとも1種の金属酸化物を組合せ配合した混合物の
焼結体乃至溶融固化体を粉砕して得られた粉体から成る
本発明のこの特定焼結助剤は、誘導炉稼動時に、内張り
材としてのラミング材中に於いて、稼働面には緻密な焼
結層を適正な厚さで形成させ、一方、その背面側、即ち
非稼動面コイル側には硬化されない粉体層を残存させる
作用を奏する。
The ramming material for an induction furnace according to the present invention is obtained by combining two kinds of silica base powders of fused silica and natural silica with a small amount of a powder having a specific composition functioning as a sintering aid in a specific mixing range. This is a remarkable feature. That is, a small amount of TiO 2 , Fe 2 O
3. The present invention comprising a powder obtained by pulverizing a sintered body or a melt-solidified body of a mixture in which at least one metal oxide selected from CaO, MgO, Na 2 O and K 2 O is combined and blended. This specific sintering aid, during operation of the induction furnace, in the ramming material as a lining material, to form a dense sintered layer with an appropriate thickness on the working surface, while the back side, that is, The effect is that an uncured powder layer remains on the non-operation surface coil side.

【0008】この本発明の特定焼結助剤の奏する特有の
作用効果が如何なるメカニズムにより達成されるかにつ
いては、必ずしも明確に解明されたわけではないが、コ
イルの高周波電流又は低周波電流により誘起された鋳鉄
等金属の発熱による溶融状態温度領域下で、該ラミング
材組織中に存在するこの特定焼結助剤が、その組織粒子
の粒界相に集まり組織粒同志の融着作用を促進すること
によりラミング材の該溶融金属と接する稼動側面に緻密
な焼結層を形成させる一方、該稼動面より低温となる背
面側では、この様な焼結助剤による融着促進作用が起ら
ず、粉体層のまま残留するためと推測される。
[0008] Although the mechanism by which the specific action and effect of the specific sintering aid of the present invention is achieved has not been clearly elucidated, it is not always clear, but it is induced by the high frequency current or low frequency current of the coil. The specific sintering aid present in the structure of the ramming material under the temperature range of the molten state caused by the heat of the cast metal such as cast iron gathers in the grain boundary phase of the structure particles to promote the fusion action of the structure particles. While the dense sintering layer is formed on the working side of the ramming material in contact with the molten metal, on the back side where the temperature is lower than the working side, the fusion promoting action by such a sintering aid does not occur, It is assumed that the powder layer remains as it is.

【0009】後記の実施例からも明らかなように、本発
明のラミング材を内張りして築炉した誘導炉は、焼結層
と粉体層が夫々適正な厚みでバランス良く形成され、こ
のため、従来のラミング材を内張りした誘導炉に比べて
亀裂や損耗の発生が抑制されると共に、例え、溶湯の流
動摩擦や熱衝撃により稼働面に亀裂が発生した場合でも
該亀裂が非稼働面のコイル側まで進行せず、湯漏れ等の
トラブルの発生を回避でき、然も、耐熱性、耐食性、耐
熱衝撃性に極めて優れた誘導炉内張り材となる。
As will be apparent from the examples described later, in the induction furnace constructed by lining the ramming material of the present invention, the sintered layer and the powder layer are each formed with an appropriate thickness in a well-balanced manner. In addition, the occurrence of cracks and wear is suppressed as compared with a conventional induction furnace lined with a ramming material, and even when a crack occurs on the working surface due to the flow friction or thermal shock of the molten metal, the crack is formed on the non-working surface. Since it does not proceed to the coil side, it is possible to avoid the occurrence of troubles such as hot water leakage, and of course, it becomes an induction furnace lining material that is extremely excellent in heat resistance, corrosion resistance and thermal shock resistance.

【0010】[0010]

【発明の実施の形態】本発明の誘導炉用ラミング材は、
上記した通り、2種類のシリカ基材粉体と焼結助剤とし
て用いる特定焼結体又は溶融固化体の粉砕物粉体との特
定配合比の混合物から成る。本発明のラミング材に用い
るこの焼結助剤としての粉体は、SiO2 成分が67乃
至77重量%、好ましくは、68乃至76重量%、Al
23 成分が18乃至28重量%、好ましくは、19乃
至27重量%、及び、TiO2 ,Fe23,CaO,
MgO,Na2 O及びK2 Oから選ばれた少なくとも1
種の金属酸化物成分を合量で2乃至7重量%、好ましく
は、3乃至6重量%、夫々含有した気孔率2%以下の焼
結体又は溶融固化体を原料材として用い、この焼結体又
は溶融固化体を粉砕して粒径0.5mm以下とした粉体
である。この粉体は、焼結助剤として、誘導炉稼動時
に、内張り材としてのラミング材中に於いて、稼働面に
は緻密な焼結層を適正な厚さで形成させ、一方、その背
面側、即ち非稼動面側には硬化されない粉体層を残存さ
せるという重要な作用をする。
BEST MODE FOR CARRYING OUT THE INVENTION The ramming material for an induction furnace according to the present invention comprises:
As described above, the mixture is composed of a mixture of two kinds of silica base powder and a powder of a specific sintered body or a ground powder of a melt-solidified substance used as a sintering aid at a specific mixing ratio. The powder as the sintering aid used in the ramming material of the present invention contains 67 to 77% by weight, preferably 68 to 76% by weight of SiO 2 component,
2 O 3 component is 18 to 28 wt%, preferably 19 to 27 wt%, and, TiO 2, Fe 2 O 3, CaO,
At least one selected from MgO, Na 2 O and K 2 O
A sintered body having a porosity of 2% or less or a melt-solidified body containing 2 to 7% by weight, preferably 3 to 6% by weight in total of various kinds of metal oxide components is used as a raw material. It is a powder having a particle size of 0.5 mm or less by pulverizing a body or a melt-solidified body. This powder is used as a sintering aid to form a dense sintered layer on the working surface in an appropriate thickness in the ramming material as a lining material during operation of the induction furnace, while the back side That is, it has an important function of leaving a powder layer that is not cured on the non-operating surface side.

【0011】本発明の焼結助剤粉体に於いて、焼結体又
は溶融固化体に含有される金属酸化物成分は、TiO
2 ,Fe23 ,CaO,MgO,Na2 O、K2 Oの
内から選ばれた少なくとも1種であるが、これ等の内で
もFe23 又はMgO、及びK2 Oとの組合せ成分か
ら成るものが焼結性の点からより好ましい。本発明で規
定した上記組成の範囲外の焼結体乃至溶融固化体、又は
その気孔率が2%以上のものを用いた場合には、上記緻
密な焼結層と残存粉体層とが夫々適正な厚さでバランス
良く存在する誘導炉内張り材を形成させることはできな
い。
In the sintering aid powder of the present invention, the metal oxide component contained in the sintered body or the molten and solidified body is TiO.
2, Fe 2 O 3, CaO , MgO, Na 2 O, is at least one selected from among K 2 O, the combination also Fe 2 O 3 or MgO, and K and 2 O among which such Those composed of components are more preferable from the viewpoint of sinterability. When a sintered body or a melt-solidified body having a composition outside the above range specified by the present invention, or a body having a porosity of 2% or more, the dense sintered layer and the residual powder layer are respectively provided. It is not possible to form a well-balanced induction furnace lining with an appropriate thickness.

【0012】また、本発明の該焼結助剤としての粉体
は、その粒径が0.5mm以下であることも重要で、
0.5mmを越える粒径の粉体では、少量の添加量で稼
動面側に適正な焼結層を形成させる作用効果を充分有効
に達成させることができない。上記粉体粒径は、0.4
mm以下であることがより好ましい。本発明では、この
焼結助剤粉末をラミング材全量に対し1乃至7重量%、
好ましくは2乃至6重量%配合する。配合量が1重量%
未満の場合には、誘導炉内張り材の非稼動面側には十分
な粉体層が残存するが、稼動面側に緻密で適正な厚さの
焼結層を形成することができない。一方、配合量が7重
量%を越えると、稼動面側には十分な焼結層が生成され
るが、耐熱性が大きく低下し、又耐食性も低下する。
It is also important that the powder as the sintering aid of the present invention has a particle size of 0.5 mm or less.
With a powder having a particle size exceeding 0.5 mm, the effect of forming an appropriate sintered layer on the operating surface side with a small amount of addition cannot be achieved sufficiently and effectively. The powder particle size is 0.4
mm is more preferable. In the present invention, the sintering aid powder is used in an amount of 1 to 7% by weight based on the total amount of the ramming material.
Preferably, 2 to 6% by weight is blended. 1% by weight
If it is less than 1, a sufficient powder layer remains on the non-operating surface side of the induction furnace lining material, but a dense sintered layer having an appropriate thickness cannot be formed on the operating surface side. On the other hand, if the amount exceeds 7% by weight, a sufficient sintered layer is formed on the working surface side, but the heat resistance is greatly reduced and the corrosion resistance is also reduced.

【0013】本発明の焼結助剤粉末を調製するには、例
えば、高純度シリカ粉末、アルミナ粉末、及びTiO
2 ,Fe23 ,CaO,MgO,Na2 O、K2 O等
の金属酸化物粉末の内1種乃至数種を混合し、この混合
粉に水を加え、練り土状に混練し、抜き出し成形あるい
はプレス成形法で緻密化して成形し、乾燥後の成形体を
炉内で、大気ガス雰囲気下に1350乃至1450℃の
温度で焼結するか、1700乃至1800℃で溶融固化
し、得られた焼結体乃至溶融固化体を粉砕して、篩別す
る等により粒径0.5mm以下の粉末に調製する。
To prepare the sintering aid powder of the present invention, for example, high-purity silica powder, alumina powder, and TiO
2 , one or more of metal oxide powders such as Fe 2 O 3 , CaO, MgO, Na 2 O, and K 2 O are mixed, water is added to the mixed powder, and the mixture is kneaded into a kneaded soil. The molded body after densification is formed by extrusion molding or press molding, and the dried molded body is sintered in a furnace at a temperature of 1350 to 1450 ° C. in an atmosphere gas atmosphere at a temperature of 1350 to 1450 ° C. or melted and solidified at a temperature of 1700 to 1800 ° C. The obtained sintered body or melt-solidified body is crushed and sieved to prepare a powder having a particle size of 0.5 mm or less.

【0014】次に、本発明に於いて、該ラミング材を構
成するシリカ基材としての溶融シリカ粉体としては、S
iO2 純度98%以上、好ましくは、98.5%以上
で、粒径が5mm以下、好ましくは、4.5mm以下の
溶融シリカ破砕物粉体が用いられる。溶融シリカは、熱
膨張率が小さく、この純度98重量%以上、粒径5mm
以下の溶融シリカ粉体を配合することにより、本発明の
ラミング材に優れた耐熱衝撃性を付与し、亀裂の発生を
抑制すると共に、仮に稼動面に亀裂が発生した場合でも
その亀裂の拡大、進行を抑止する作用を奏する。溶融シ
リカ粉体のSiO2 純度が98%以下のものは、耐熱性
が劣ったり、溶融金属汚染の可能性があったり、緻密な
焼結層が形成し難い等のため好ましくなく、粒径が5m
m以上のものは振動充填成形時に粒度の偏析を起し易く
誘導炉内張り材として均質で十分な強度有する成形体に
成型することが困難であり、好ましくない。
Next, in the present invention, the fused silica powder as a silica base material constituting the ramming material is S powder.
Fused silica powder having an iO 2 purity of 98% or more, preferably 98.5% or more and a particle size of 5 mm or less, preferably 4.5 mm or less is used. Fused silica has a small coefficient of thermal expansion, a purity of 98% by weight or more, and a particle size of 5 mm.
By blending the following fused silica powder, imparts excellent thermal shock resistance to the ramming material of the present invention, suppresses the occurrence of cracks, and even if cracks occur on the operating surface, the expansion of the cracks, It has the effect of inhibiting progress. Fused silica powder having a SiO 2 purity of 98% or less is not preferred because of poor heat resistance, possibility of molten metal contamination, and difficulty in forming a dense sintered layer. 5m
Those with m or more are apt to cause segregation of particle size at the time of vibration filling molding, and it is difficult to mold a molded article having a uniform and sufficient strength as an induction furnace lining material, which is not preferable.

【0015】本発明のラミング材に於いては、溶融シリ
カ粉体を、30乃至80重量%、好ましくは、35乃至
75重量%の範囲で配合する。溶融シリカ粉体の配合量
が30重量%未満では、ラミング材の耐熱衝撃性の向上
が殆ど見られず、80重量%を越えると残存膨張性が低
下するため、冷却時に於ける亀裂発生の抑制効果が低減
される。
In the ramming material of the present invention, the fused silica powder is blended in an amount of 30 to 80% by weight, preferably 35 to 75% by weight. When the amount of the fused silica powder is less than 30% by weight, the thermal shock resistance of the ramming material is hardly improved, and when it exceeds 80% by weight, the residual swelling property is reduced. The effect is reduced.

【0016】また、上記溶融シリカ基材粉体と組合せで
用いられる天然シリカ粉体としては日本国内や世界各地
で産出される天然珪石の破砕物乃至粉末を用いることが
でき、本発明に於いては、これ等の天然シリカの内で
も、SiO2 純度98%以上、好ましくは、98.5%
以上で、粒径が5mm以下、好ましくは、4.5mm以
下のものを用いる。上記天然シリカは、耐食性に優れて
いるという特性を有し、本発明のラミング材に優れた耐
食性を付与する。天然シリカ粉体のSiO2 純度が98
%以下のものは、耐熱性が劣ったり、溶融金属汚染の可
能性があったり、緻密な焼結層が形成し難い等のため好
ましくなく、粒径が5mm以上のものは振動充填成形時
に粒度の偏析を起し易く、誘導炉内張り材として均質で
十分な強度有する成形体に成型することが困難であり、
好ましくない。
The natural silica powder used in combination with the above-mentioned fused silica base powder may be a crushed or powdered natural silica stone produced in Japan or around the world. Among these natural silicas, the purity of SiO 2 is 98% or more, preferably 98.5%
As described above, those having a particle size of 5 mm or less, preferably 4.5 mm or less are used. The natural silica has a characteristic of being excellent in corrosion resistance and imparts excellent corrosion resistance to the ramming material of the present invention. Natural silica powder with SiO 2 purity of 98
% Or less is not preferred because heat resistance is inferior, there is a possibility of molten metal contamination, and it is difficult to form a dense sintered layer. It is difficult to mold into a molded body with uniform and sufficient strength as an induction furnace lining material,
Not preferred.

【0017】本発明に於いて、上記の天然シリカ粉体の
配合量は、ラミング材全量に対し、前記溶融シリカの配
合量、前記焼結助剤の配合量の残部である。天然シリカ
の添加量が15重量%未満では、ラミング材の耐食性が
劣るだけでなく適正な残存膨張性が得られない。また、
添加量が70重量%を越えると、耐食性は向上するが、
熱膨張率が大きくなり、耐熱衝撃性の低下を来す。天然
シリカ粉体の添加量は、25乃至65重量%の範囲が特
に好ましい。
In the present invention, the amount of the natural silica powder is the balance of the amount of the fused silica and the amount of the sintering aid relative to the total amount of the ramming material. If the added amount of the natural silica is less than 15% by weight, not only the corrosion resistance of the ramming material is deteriorated, but also a proper residual expansion property cannot be obtained. Also,
If the amount exceeds 70% by weight, the corrosion resistance is improved,
The coefficient of thermal expansion increases and the thermal shock resistance decreases. The addition amount of the natural silica powder is particularly preferably in the range of 25 to 65% by weight.

【0018】本発明のラミング材を内張り材として誘導
炉を築炉するには、従来法と同様の方法を用いて良く、
例えば、300kg高周波誘導炉の築炉の場合、本発明
のラミング材配合物を図1(b)に示したように、コイ
ルの内側にあるコイル保護用耐火物の内面に断熱シート
をセットした後、ラミング材配合物を炉床部に所定量装
入し、エアーランマーで充填施工する。次いで、炉床施
工面を平滑に仕上げた後、築炉シリンダーを炉床中央に
セットし、築炉シリンダーと断熱シートの間の炉壁部に
所定量のラミング材を装入しエアーランマーで充填施工
する。炉壁部は、上記操作を繰り返しながら上部に延長
し炉上部迄充填施工して築炉を完了する。この様にして
築炉された炉の内張り材容器内に銑鉄等の原料を投入
し、コイルに通電して原料金属を溶融する。
To build an induction furnace using the ramming material of the present invention as a lining material, a method similar to the conventional method may be used.
For example, in the case of a 300 kg high frequency induction furnace, after setting the ramming material composition of the present invention on the inner surface of the refractory for coil protection inside the coil as shown in FIG. Then, a predetermined amount of the ramming compound is charged into the hearth, and filled with an air rammer. Next, after finishing the hearth construction surface smoothly, set the furnace cylinder at the center of the hearth, insert a predetermined amount of ramming material into the furnace wall between the furnace cylinder and the insulation sheet, and fill it with an air rammer Execute. The furnace wall is extended to the upper part while repeating the above operation, and the furnace is completed by filling up to the furnace upper part. A raw material such as pig iron is charged into a lining material container of the furnace thus constructed, and a coil is energized to melt the raw material metal.

【0019】[0019]

【実施例】「実施例1乃至6」溶融シリカ粉末(SiO
2 純度98.5%、粒径5mm以下)と天然珪石粉末
(SiO2 純度98.5%、粒径5mm以下)及び焼結
助剤(成分組成:SiO2 72重量%、Al23 23
重量%、Fe23 1.0重量%、K2 O3.5重量
%、他0.5重量%、気孔率:1.8%の焼結体の粒径
0.4mm以下の粉末)とを夫々表1に示された量配合
した誘導炉ラミング材用供試材を用意した(実施例1乃
至6)。これ等の供試材を図1に示す300kg高周波
誘導炉に下記の方法で張り合わせた。張り合わせ方法
は、コイル保護用耐火物2の内面に、断熱シート3をセ
ットした後、実施例1の供試材を炉床部に所定量装入
し、エアーランマーで充填し施工した。施工完了後、炉
床施工面を平滑に仕上げ、築炉シリンダー5を炉床の中
央にセットし、図1及び図2に示すように築炉シリンダ
ー5と断熱シート3の間に仕切り板6を3等分間隔でセ
ットして、3種類の供試材(実施例1乃至3と実施例4
乃至6について夫々別個に作成)を各々仕切られた炉壁
部に所定量装入した。供試材を装入後、各供試材の表面
を平らに揃え、仕切り板6を炉上部に引き抜き、エアー
ランマーで充填施工した(1回当たりの施工高さ60乃
至70mm)。施工後、打ち継ぎ面でのラミネーション
防止のため、施工面の目荒らしを行い、再度仕切り板6
をセットし、以降同様な方法で炉上部まで充填施工し
た。築炉完了後、銑鉄を用いて熔解試験を行った。即ち
銑鉄200kgを、1600乃至1620℃で5時間保
持し、その後出湯し冷却する試験を2回繰り返した。こ
の溶解試験終了後の内張り材の状態を評価した結果を表
1に示す。
EXAMPLES Examples 1 to 6 Fused silica powder (SiO 2)
2 purity 98.5%, particle size 5mm or less) and natural silica rock powder (SiO 2 purity 98.5%, particle size 5mm or less) and a sintering aid (chemical composition: SiO 2 72 wt.%, Al 2 O 3 23
Wt%, Fe 2 O 3 1.0 wt%, K 2 O3.5 wt%, other 0.5% by weight, a porosity of 1.8% particle size 0.4mm or less powder sintered body) and Were prepared in the amounts as shown in Table 1 to prepare test materials for induction furnace ramming materials (Examples 1 to 6). These test materials were bonded to the 300 kg high frequency induction furnace shown in FIG. 1 by the following method. The laminating method was as follows. After setting the heat insulating sheet 3 on the inner surface of the refractory 2 for protecting the coil, a predetermined amount of the test material of Example 1 was charged into the hearth, and filled with an air rammer. After the completion of the construction, the hearth construction surface is finished smoothly, the furnace hearth cylinder 5 is set at the center of the hearth, and the partition plate 6 is placed between the furnace hearth cylinder 5 and the heat insulating sheet 3 as shown in FIGS. By setting at equal intervals, three types of test materials (Examples 1 to 3 and Example 4
To 6 were separately prepared) were charged in a predetermined amount into the furnace wall section. After charging the test materials, the surfaces of the test materials were made flat, the partition plate 6 was pulled out to the upper part of the furnace, and filled with an air rammer (construction height per operation: 60 to 70 mm). After construction, roughening of the construction surface is performed to prevent lamination on the joint surface, and the partition plate 6
Was set, and the furnace was filled up to the upper part in the same manner. After the furnace was completed, a melting test was performed using pig iron. That is, a test in which 200 kg of pig iron was held at 1600 to 1620 ° C. for 5 hours, and thereafter, tapping and cooling was repeated twice. Table 1 shows the results of evaluating the state of the lining material after the completion of the dissolution test.

【0020】「比較例1乃至3」焼結助剤を使用せず
(比較例1)乃至焼結助剤として有水硼酸を用いた(比
較例2,3)以外は実施例と同じ溶融シリカ、天然珪石
を用い、それらを表2に示した量配合したラミング材用
供試材(比較例1乃至3)を用意し、実施例と同様にし
て誘導炉に張り合わせ、築炉完成後同様に溶解試験して
溶解試験終了後の内張り材の状態を評価した。結果を表
2に示す。
Comparative Examples 1 to 3 The same fused silica as in the Examples except that no sintering aid was used (Comparative Example 1) or hydrated boric acid was used as the sintering aid (Comparative Examples 2 and 3) A sample material for ramming material (Comparative Examples 1 to 3) was prepared by using natural silica stone and blending them in the amounts shown in Table 2, and bonded to an induction furnace in the same manner as in the Example, and similarly after completion of the furnace construction. After the dissolution test, the state of the lining material after the dissolution test was evaluated. Table 2 shows the results.

【0021】表1及び表2に示した結果から、耐食性、
溶湯に対する耐浸潤性に関しては、実施例、比較例とも
ほぼ同等の性能を示すが、実施例1乃至6は、何れも良
好な焼結層を形成するのに対し、焼結助剤を配合しない
比較例1では焼結性が悪く充分な焼結層が形成されない
ことが判る。また、実施例では何れも非稼動面コイル側
には、充分な粉体層が残存するのに対し、焼結助剤とし
て有水硼酸を配合した比較例2,3の内張り材では粉体
層の残存が充分でなく、非稼動面コイル側にも硬化が生
じていることが判る。
From the results shown in Tables 1 and 2, the corrosion resistance,
Regarding the infiltration resistance to the molten metal, the examples and comparative examples show almost the same performance. However, in Examples 1 to 6, all formed a good sintered layer, but did not contain a sintering aid. In Comparative Example 1, it was found that the sinterability was poor and a sufficient sintered layer was not formed. In each of the examples, a sufficient powder layer remained on the non-operating surface coil side, whereas the powder layers were not used in the lining materials of Comparative Examples 2 and 3 in which hydrous boric acid was blended as a sintering aid. It can be seen that the residual was not sufficient, and that the non-operating surface coil side was also hardened.

【0022】[0022]

【表1】 [Table 1]

【0023】尚、表1の焼結層、粉体層の評価について
は、以下の基準で評価した。即ち、焼結層の厚みが10mm
〜20mmの場合は優(○)、焼結層の厚みが9mm 以下及び
21mm以上の場合は劣(×)、粉体層の厚みが25mm以上の
場合は優(○)、粉体層の厚みが24mm以下の場合は劣
(×)とした。
The sintering layer and powder layer in Table 1 were evaluated according to the following criteria. That is, the thickness of the sintered layer is 10 mm
Excellent (○) when the thickness is up to 20mm, the thickness of the sintered layer is 9mm or less and
When the thickness was 21 mm or more, it was poor (x), when the thickness of the powder layer was 25 mm or more, it was excellent (o), and when the thickness of the powder layer was 24 mm or less, it was poor (x).

【0024】[0024]

【表2】 [Table 2]

【0025】尚、表2の焼結層、粉体層の評価について
は、表1の場合と同様、以下の基準で評価した。即ち、
焼結層の厚みが10mm〜20mmの場合は優(○)、焼結層の
厚みが9mm 以下及び21mm以上の場合は劣(×)、粉体層
の厚みが25mm以上の場合は優(○)、粉体層の厚みが24
mm以下の場合は劣(×)とした。
Incidentally, the evaluation of the sintered layer and the powder layer in Table 2 was carried out according to the following criteria as in the case of Table 1. That is,
Excellent (○) when the thickness of the sintered layer is 10 mm to 20 mm, poor (×) when the thickness of the sintered layer is 9 mm or less and 21 mm or more, and excellent (○) when the thickness of the powder layer is 25 mm or more. ), Powder layer thickness is 24
When it was less than mm, it was evaluated as poor (x).

【0026】[0026]

【発明の効果】本発明の誘導炉用ラミング材は上記した
構成により、誘導炉壁に内張りした場合、耐食性、耐熱
衝撃性に優れ、稼動面に緻密な焼結層が適正な厚さで形
成され、然もその非稼動面コイル側は硬化することなく
粉体層が残存する。このために、仮に稼動面に生じた微
細な亀裂から溶湯が進入した場合でも溶湯の進入はこの
硬化していない粉体層で阻止され非稼動面にまでは及ば
ず、操炉時の安全性が一層確実に担保される。また、こ
の硬化していない粉体層が存在することによって、焼結
バインダーとして硼酸を用いた従来品に比較して炉の解
体が容易で、解体に要する労力を大幅に低減できる。更
に、コイル側に粉体層が残存することにより、炉壁の断
熱効果も向上し、熱消費量の低減も達成できる。
The ramming material for an induction furnace according to the present invention has excellent corrosion resistance and thermal shock resistance when it is lined with the induction furnace wall, and a dense sintered layer is formed on an operating surface with an appropriate thickness. As a result, the powder layer remains without being cured on the non-operation surface coil side. For this reason, even if the molten metal enters through a fine crack generated on the working surface, the intrusion of the molten metal is prevented by this unhardened powder layer and does not reach the non-working surface, and the safety during furnace operation Is more reliably secured. In addition, the presence of the unhardened powder layer makes it easier to disassemble the furnace as compared with the conventional product using boric acid as a sintering binder, and can greatly reduce the labor required for disassembly. Further, since the powder layer remains on the coil side, the heat insulating effect of the furnace wall is improved, and the heat consumption can be reduced.

【図面の簡単な説明】[Brief description of the drawings]

【図1】図1は、誘導炉の築炉に於いてラミング材を内
張りする過程を説明するための概略図(平面図)であ
る。
FIG. 1 is a schematic diagram (plan view) for explaining a process of lining a ramming material in an induction furnace.

【図2】図2は、図1の一部断面図である。FIG. 2 is a partial sectional view of FIG. 1;

【符号の説明】[Explanation of symbols]

1 誘導コイル 2 コイル保護用耐火物 3 断熱シート 4 内張り材 5 築炉シリンダー 6 仕切板 REFERENCE SIGNS LIST 1 induction coil 2 refractory for coil protection 3 heat insulating sheet 4 lining material 5 furnace cylinder 6 partition plate

Claims (3)

【特許請求の範囲】[Claims] 【請求項1】 SiO2 成分67乃至77重量%、Al
23 成分18乃至28重量%及びTiO2 ,Fe2
3 ,CaO,MgO,Na2 O及びK2 Oから選ばれた
少なくとも1種の成分を合計量で2乃至7重量%含有
し、気孔率が2%以下の焼結体又は溶融固化体を粉砕し
て成る粒径0.5mm以下の粉体1乃至7重量%と、S
iO2 純度98%以上、粒径5mm以下の溶融シリカ3
0乃至80重量%と、残部がSiO2 純度98%以上、
粒径5mm以下の天然シリカからなることを特徴とする
誘導炉用ラミング材。
1. An SiO 2 component of 67 to 77% by weight, Al
18-28% by weight of 2 O 3 component and TiO 2 , Fe 2 O
3 , pulverizing a sintered or molten solid containing at least one component selected from CaO, MgO, Na 2 O and K 2 O in a total amount of 2 to 7% by weight and having a porosity of 2% or less. 1 to 7% by weight of a powder having a particle size of 0.5 mm or less,
fused silica 3 with iO 2 purity of 98% or more and particle size of 5 mm or less
0 to 80% by weight, with the balance being 98% or more of SiO 2 purity,
A ramming material for an induction furnace, comprising a natural silica having a particle size of 5 mm or less.
【請求項2】 前記焼結体又は溶融固化体の粉砕粉体の
粒径が0.4mm以下であることを特徴とする請求項1
に記載された誘導炉用ラミング材。
2. The particle size of the pulverized powder of the sintered body or the melt-solidified body is 0.4 mm or less.
A ramming material for an induction furnace described in (1).
【請求項3】 前記焼結体又は溶融固化体の粉体2乃至
6重量%、前記溶融シリカ35乃至75重量%及び前記
天然シリカ19乃至63重量%からなることを特徴とす
る請求項1または請求項2に記載された誘導炉用ラミン
グ材。
3. The method according to claim 1, comprising 2 to 6% by weight of the powder of the sintered body or the fused solid, 35 to 75% by weight of the fused silica and 19 to 63% by weight of the natural silica. A ramming material for an induction furnace according to claim 2.
JP10048682A 1998-02-13 1998-02-13 Ramming material for induction furnace Granted JPH11228242A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP10048682A JPH11228242A (en) 1998-02-13 1998-02-13 Ramming material for induction furnace

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP10048682A JPH11228242A (en) 1998-02-13 1998-02-13 Ramming material for induction furnace

Publications (1)

Publication Number Publication Date
JPH11228242A true JPH11228242A (en) 1999-08-24

Family

ID=12810100

Family Applications (1)

Application Number Title Priority Date Filing Date
JP10048682A Granted JPH11228242A (en) 1998-02-13 1998-02-13 Ramming material for induction furnace

Country Status (1)

Country Link
JP (1) JPH11228242A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2013173657A (en) * 2012-02-27 2013-09-05 Agc Ceramics Co Ltd Dry ramming material and method for manufacturing refractory material using the same
CN103851916A (en) * 2014-02-13 2014-06-11 成都市双流恒生锻造有限公司 Method for manufacturing heat-storage forging heating furnace by utilizing quartzitic sandstone
CN107602086A (en) * 2017-09-28 2018-01-19 辽宁中镁控股股份有限公司 A kind of magnesium calcareous ramming mass produced with waste refractory materials and its manufacture method
KR101989253B1 (en) * 2017-12-27 2019-06-13 현대제철 주식회사 Melting refractory composition for blast furnace

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2013173657A (en) * 2012-02-27 2013-09-05 Agc Ceramics Co Ltd Dry ramming material and method for manufacturing refractory material using the same
CN103851916A (en) * 2014-02-13 2014-06-11 成都市双流恒生锻造有限公司 Method for manufacturing heat-storage forging heating furnace by utilizing quartzitic sandstone
CN103851916B (en) * 2014-02-13 2016-04-27 成都市双流恒生锻造有限公司 White afrodite manufactures the method for heat accumulating type forge furnace
CN107602086A (en) * 2017-09-28 2018-01-19 辽宁中镁控股股份有限公司 A kind of magnesium calcareous ramming mass produced with waste refractory materials and its manufacture method
CN107602086B (en) * 2017-09-28 2020-06-09 辽宁中镁控股股份有限公司 Magnesium-calcium ramming mass produced by using waste refractory materials and manufacturing method thereof
KR101989253B1 (en) * 2017-12-27 2019-06-13 현대제철 주식회사 Melting refractory composition for blast furnace

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