JP2801948B2 - Filter media for molten metal - Google Patents
Filter media for molten metalInfo
- Publication number
- JP2801948B2 JP2801948B2 JP2083253A JP8325390A JP2801948B2 JP 2801948 B2 JP2801948 B2 JP 2801948B2 JP 2083253 A JP2083253 A JP 2083253A JP 8325390 A JP8325390 A JP 8325390A JP 2801948 B2 JP2801948 B2 JP 2801948B2
- Authority
- JP
- Japan
- Prior art keywords
- weight
- binder
- filter medium
- particle size
- molten metal
- 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.)
- Expired - Lifetime
Links
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Landscapes
- Ceramic Products (AREA)
- Compositions Of Oxide Ceramics (AREA)
- Manufacture And Refinement Of Metals (AREA)
- Filtering Materials (AREA)
Description
【発明の詳細な説明】 ［産業上の利用分野］ 本発明は金属溶湯、特にアルミニウム溶湯中に含まれ
る不純物（介在物）を濾過するに適した金属溶湯用濾材
に関する。Description: TECHNICAL FIELD The present invention relates to a metal melt filter medium suitable for filtering impurities (inclusions) contained in a molten metal, particularly an aluminum molten metal.
［従来の技術］ 金属の薄板や箔は金属溶湯をインゴットに鋳造し、こ
れを圧延することにより製造される。ところが、金属溶
湯に含まれる金属酸化物や耐火物の微小破片等の固形不
純物がそのままインゴット中に混入すると、これを圧延
して薄板や箔等を製造する過程でピンホール、表面欠陥
が発生することがある。これを防ぐには、溶湯中から固
形不純物を除去する必要があり、そのために、従来、ガ
ラスクロス、アルミナボール或はセラミックフォーム等
を溶湯濾過用のフィルターとして使用していた。[Prior Art] A metal thin plate or foil is produced by casting a molten metal into an ingot and rolling it. However, when solid impurities such as metal oxides contained in the molten metal and minute pieces of refractory are directly mixed into the ingot, pinholes and surface defects are generated in the process of rolling and manufacturing thin plates and foils. Sometimes. To prevent this, it is necessary to remove solid impurities from the molten metal. For this purpose, glass cloth, alumina balls, ceramic foam, or the like has conventionally been used as a filter for filtering the molten metal.
ところが、ガラスクロスは安価であるが早期に目詰ま
りし易く、またアルミナボールは一旦捕獲した不純物が
流出し易いため濾過精度に劣り、更にセラミックフォー
ムは気孔径が大きいため微細な不純物を充分に濾過でき
ないという欠点がある。However, glass cloth is inexpensive, but is easily clogged at an early stage, and alumina balls are poor in filtration accuracy because impurities once trapped easily flow out.Furthermore, ceramic foams have a large pore size and thus sufficiently filter fine impurities. There is a drawback that you can not.
そこで、例えば特公昭52−22327号公報、特開昭64−2
1019号公報等に示されるように、炭化珪素やアルミナ等
の骨材粒子を無機質結合材により結合させて骨材粒子間
に無数の微細連続気孔を形成した構成のチューブ状の濾
材が使用されつつある。この濾材によれば、上記した他
のフィルターに比較して濾過性能が優れており、目詰ま
りを長期間にわたり防止でき、また捕獲した不純物の流
出がなく、しかも気孔径を適切になし得て精密な濾過が
可能になるという利点がある。Therefore, for example, Japanese Patent Publication No. 52-22327, Japanese Patent Application Laid-Open
As shown in Japanese Patent No. 1019, a tubular filter medium having a structure in which aggregate particles such as silicon carbide and alumina are bonded by an inorganic binder to form countless fine continuous pores between the aggregate particles is being used. is there. According to this filter medium, the filtration performance is excellent as compared with the above-mentioned other filters, clogging can be prevented for a long time, there is no outflow of trapped impurities, and the pore diameter can be appropriately formed, and the precision can be improved. There is an advantage that a proper filtration can be performed.
［発明が解決しようとする課題］ しかしながら、特公昭52−22327号公報では、用いら
れる結合材中のSiO2が10〜50重量％、B2O3が５〜20重量
％であるためホウケイ酸ガラスが生成する。このように
結合材中のSiO2が多いため、アルミニウム溶湯に還元さ
れ、耐蝕性およびSi流出の問題がある。[Problems to be Solved] However, in JP-B-52-22327, SiO 2 10 to 50% by weight of the binder in the used, borosilicate since a B 2 O 3 is 5-20 wt% Glass forms. As described above, since the amount of SiO 2 in the binder is large, it is reduced to molten aluminum, and there is a problem of corrosion resistance and outflow of Si.
一方、上記のように骨材粒子を無機質結合材で結合さ
せる場合、無機質結合材がアルミニウムボレイト（9Al2
O3・2B2O3）のごとき針状結晶を生成すると、この結晶
は例えばアルミニウム溶湯に対して濡れ性が悪く、反応
し難い（耐食性に優れた）物質であるため、好ましい。
上記した特開昭64−21019号公報ではB2O315〜80％、Al2
O32〜60％、CaO5〜30％およびMgO5〜20％の組成を有す
る結合材を用いているが、このような組成の結合材にお
いても、生原料を用いた場合には、如何に均一に混合を
行なっても組成のバラツキがみられ、焼成体の強度およ
び結合材組成のバラツキが認められ、均一な溶融状態を
得ることができず、アルミニウムボレイト（9Al2O3・2B
2O3）の生成量が少ない、また、冷却速度を−30〜−70
℃/hrで行なっても、溶融状態が不均一であるため、ア
ルミニウムボレイト（9Al2O3・2B2O3）の生成量が少な
く、焼成体内でのバラツキも認められる。On the other hand, when the aggregate particles are bonded with the inorganic binder as described above, the inorganic binder is made of aluminum borate (9Al 2
When O 3 · 2B 2 O 3) to produce such a needle-like crystals, since the crystals for example poor wettability to molten aluminum, is excellent) material in the reaction difficult (corrosion resistance, preferably.
In JP 64-21019 discloses that the B 2 O 3 15~80%, Al 2
A binder having a composition of 2 to 60% O3, 5 to 30% CaO and 5 to 20% MgO is used. However, even if the mixture is mixed, the composition varies, the strength of the fired body and the composition of the binder are varied, a uniform molten state cannot be obtained, and aluminum borate (9Al 2 O 3 .2B
2 O 3 ) is small and the cooling rate is -30 to -70.
Even at a temperature of ° C./hr, the molten state is non-uniform, so that the amount of aluminum borate (9Al 2 O 3 .2B 2 O 3 ) generated is small, and variations in the fired body are observed.
このように、アルミニウムボレイト（9Al2O3・2B
2O3）の生成量が少ない場合には、特にアルミニウム溶
湯に対する耐食性に問題が生じ、最悪の場合には濾材が
崩壊するという危険性がある。Thus, aluminum borate (9Al 2 O 3 · 2B
When the amount of 2 O 3 ) produced is small, there is a problem particularly in the corrosion resistance to the molten aluminum, and in the worst case, there is a risk that the filter medium will collapse.
［課題を解決するための手段］ そこで、本発明者は上記した問題を解決するため種々
検討を行なったところ、無機質結合材として特定組成で
かつ特定粒度のフリットを用いることにより、アルミニ
ウムボレイトの生成量を多くすることができ、濾材の長
寿命化が図れることを見出し、本発明を完成したもので
ある。[Means for Solving the Problems] The present inventor has made various studies to solve the above-mentioned problems. As a result, by using a frit having a specific composition and a specific particle size as an inorganic binder, the aluminum borate can be used. The inventors have found that the amount of generation can be increased and the life of the filter medium can be extended, and the present invention has been completed.
即ち、本発明によれば、セラミック骨材粒子を無機質
結合材により結合させた多孔質の濾材であって、該結合
材がB2O315〜80重量％、Al2O32〜60重量％、CaO0〜30重
量％およびMgO5〜50重量％の組成を有するフリットであ
り、該フリットの50％粒子径が10〜35μｍであることを
特徴とする金属溶湯用濾材、が提供される。That is, according to the present invention, the ceramic aggregate particles a filter medium of a porous conjugated by inorganic binding material, the binding material is B 2 O 3 15 to 80 wt%, Al 2 O 3 2~60 weight %, CaO of 0 to 30% by weight and MgO of 5 to 50% by weight. A frit having a 50% particle size of 10 to 35 μm is provided.
［作用］ 本発明においては、結合材としてホウ酸系組成物から
なり、その粒径が所定以下であるフリットを用いること
に特徴を有するものである。[Function] The present invention is characterized in that a frit composed of a boric acid composition and having a particle size of a predetermined size or less is used as a binder.
このようなフリットを結合材として用いることによ
り、より多くのアルミニウムボレイト（9Al2O3・2B
2O3）が生成され、濾材の長寿命化を達成することがで
きる。By using such a frit as a binder, more aluminum borate (9Al 2 O 3 .2B
2 O 3 ) is generated, and a longer life of the filter medium can be achieved.
本発明で用いる骨材としては、金属溶湯と反応せず、
適切な粒度のものを容易に入手できることが必要である
が、アルミナ質、炭化珪素質、窒化珪素質、ジルコニア
質の如きセラミック骨材粒子がそれらの条件を満足す
る。又、用いるセラミック骨材粒子の平均粒子径は通常
約0.3〜3.0mm程度のものが用いられる。The aggregate used in the present invention does not react with the molten metal,
It is necessary that particles of appropriate particle size be readily available, but ceramic aggregate particles such as alumina, silicon carbide, silicon nitride, and zirconia satisfy these conditions. The average particle diameter of the ceramic aggregate particles used is usually about 0.3 to 3.0 mm.
また、骨材粒子としては下記で定義される形状指数が
100〜130の範囲のものを用いることが好ましい。In addition, as an aggregate particle, the shape index defined below is
It is preferable to use one having a range of 100 to 130.
即ち、第１図に示す骨材の投影図において、その最大
直径をＭ、該最大直径Ｍに直交する径をＢ、投影面積を
Ａ、円周長さをＰとしたとき、形状指数（SF）は次の式
で表される。That is, in the projection view of the aggregate shown in FIG. 1, when the maximum diameter is M, the diameter orthogonal to the maximum diameter M is B, the projection area is A, and the circumferential length is P, the shape index (SF ) Is represented by the following equation.
SF＝（SF1＋SF2＋SF3）/3 ここで、 SF1＝（π/4）×（M2/A）×100 SF2＝（1/4π）×（P2/A）×100 SF3＝（M/B）×100 である。SF = (SF 1 + SF 2 + SF 3 ) / 3 where SF 1 = (π / 4) × (M 2 / A) × 100 SF 2 = (1 / 4π) × (P 2 / A) × 100 SF 3 = (M / B) x 100.
因みに、真球の形状指数は100となる。 Incidentally, the shape index of a true sphere is 100.
このような形状指数の範囲の骨材粒子を用いた場合、
均一な気孔径を有する多孔質体が得られるため、濾材の
不純物の捕集精度が向上し、好ましい。When using aggregate particles in such a shape index range,
Since a porous body having a uniform pore size can be obtained, the accuracy of collecting impurities in the filter medium is improved, which is preferable.
無機質結合材としては、上記したように、まずその組
成が、B2O315〜80重量％、Al2O32〜60重量％、CaO0〜30
重量％、およびMgO5〜50重量％の範囲を有するフリット
であることが必要である。アルミニウムボレイト（9Al2
O3・2B2O3）の生成のためには上記のような組成が必要
であり、しかもフリットであるため均一溶融性を十分に
確保することができる。As described above, the inorganic binder first has a composition of B 2 O 3 15 to 80% by weight, Al 2 O 3 2 to 60% by weight, CaO 0 to 30% by weight.
It must be a frit having a weight percent, and a range of 5-50% by weight of MgO. Aluminum borate (9Al 2
For the generation of O 3 · 2B 2 O 3 ), the above composition is necessary, and since it is a frit, uniform melting property can be sufficiently ensured.
さらに、フリットは、その50％粒子径が10〜35μｍで
ある。50％粒子径が35μｍを超えると粒度分布にバラツ
キが出来、得られる多孔質濾材の強度が劣ることとな
り、好ましくない。Further, the frit has a 50% particle size of 10 to 35 μm. When the 50% particle size exceeds 35 μm, the particle size distribution varies, and the strength of the obtained porous filter medium is deteriorated, which is not preferable.
又、上記した特定組成、粒度の無機質結合材のセラミ
ック骨材粒子に対する配合割合は、骨材粒子100重量部
に対し、無機質結合材が４〜20重量部が好ましい。The mixing ratio of the inorganic binder having the above specific composition and particle size to the ceramic aggregate particles is preferably 4 to 20 parts by weight of the inorganic binder with respect to 100 parts by weight of the aggregate particles.
このような特定組成、粒度の無機質結合材を骨材粒子
に結合させる場合、1200〜1400℃まで加熱して無機質結
合材を溶融させ、その後800℃までを１時間当り30〜70
℃の冷却速度にて徐冷するような条件にて焼成・徐冷す
ると、アルミニウムボレイト（9Al2O3・2B2O3）の結晶
化が適切に行なわれ、好ましい。When bonding the inorganic binder having such a specific composition and particle size to the aggregate particles, the inorganic binder is heated by melting to 1200 to 1400 ° C., and then heated to 800 ° C. for 30 to 70 hours per hour.
Firing and slow cooling under the condition of slow cooling at a cooling rate of ° C. is preferable because crystallization of aluminum borate (9Al 2 O 3 .2B 2 O 3 ) is appropriately performed.
なお濾材の形状はチューブ状に限られず板状であって
もよい。又、濾材の厚さは通常15〜35mm程度であればよ
い。The shape of the filter medium is not limited to the tube shape, but may be a plate shape. In addition, the thickness of the filter medium may be usually about 15 to 35 mm.
次に、本発明に係る濾材の製造方法の例を説明する。 Next, an example of a method for producing a filter medium according to the present invention will be described.
例えば、アルミナ、炭化珪素、窒化珪素などのセラミ
ック骨材粒子100重量部に対し、B2O315〜80重量％、Al2
O32〜60重量％、CaO0〜30重量％およびMgO5〜50重量％
の組成を有し、その50％粒子径が10〜35μｍのフリット
からなる無機質結合材を４〜20重量部添加し、カルボキ
シメチルセルロース（CMC）、リグニンスルホン酸カル
シウム、デキストリン等の有機バインダーと適当量の水
分を加え、混練を行なった後所定形状の成形体に成形す
る。次いで、得られた成形体を乾燥後、通常1100℃以上
の温度にて焼成を行なうことにより、本発明の濾材を得
ることができる。For example, with respect to 100 parts by weight of ceramic aggregate particles such as alumina, silicon carbide and silicon nitride, 15 to 80% by weight of B 2 O 3 and Al 2
O 3 2 to 60 wt%, CaO0～30 wt% and MgO5~50 wt%
Of 4 to 20 parts by weight of an inorganic binder composed of a frit having a 50% particle size of 10 to 35 μm, and an appropriate amount of an organic binder such as carboxymethyl cellulose (CMC), calcium lignin sulfonate, dextrin, etc. Is added, and the mixture is kneaded, and then molded into a molded body having a predetermined shape. Next, the obtained molded body is dried and then calcined usually at a temperature of 1100 ° C. or more, whereby the filter medium of the present invention can be obtained.
［実施例］ 以下、本発明を実施例に基づきさらに詳細に説明する
が、本発明はこれらの実施例に限られるものではない。EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.
（実施例１） 粒度が14〜28メッシュの焼結アルミナを骨材粒子と
し、無機質結合材の組成、形態、粒度を変化させ、骨材
100重量部に対し、各種重量の結合材を有機バインダ
ー、水とともに添加して混練を行なった。(Example 1) Sintered alumina having a particle size of 14 to 28 mesh was used as aggregate particles, and the composition, shape, and particle size of the inorganic binder were changed.
To 100 parts by weight, various weights of a binder were added together with an organic binder and water, and kneading was performed.
次に得られた混合物を用い、外径100mmφ、内径60mm
φ、長さ900mmのパイプ形状品を成形し、105℃で乾燥後
結合材が十分に溶融する1300℃まで昇温し、３時間保持
した後800℃まで１時間当り50℃の冷却速度で徐冷する
ことにより、焼成された濾材を作製した。Next, using the obtained mixture, outer diameter 100 mmφ, inner diameter 60 mm
Form a pipe with a diameter of 900mm, dry at 105 ° C, raise the temperature to 1300 ° C, where the binder is sufficiently melted, hold for 3 hours, then slowly cool to 800 ° C at a cooling rate of 50 ° C per hour. By cooling, a fired filter medium was produced.
得られた濾材について、粉末Ｘ線回折法によりアルミ
ニウムボレイト（9Al2O3・2B2O3）の結晶化℃（＝16.5
゜の9Al2O3・2B2O3のピーク高/43.4゜のα−Al2O3のピ
ーク高）を求めた。また、室温における３点曲げによる
抗折強度も測定した。With respect to the obtained filter medium, crystallization of aluminum borate (9Al 2 O 3 .2B 2 O 3 ) was conducted by powder X-ray diffraction method.
° 9Al 2 O 3 · 2B 2 peak of O 3 high /43.4 DEG alpha-Al 2 O 3 peak height) were determined. Also, the bending strength by three-point bending at room temperature was measured.
結果を表１に示す。 Table 1 shows the results.
なお、表１において、No.6、８〜12は本発明の範囲外
の場合を示している。In Table 1, Nos. 6, 8 to 12 indicate cases outside the scope of the present invention.
表１から明らかな通り、結合材としてホウ酸系組成物
からなり、その粒径が所定以下であるフリットを用いる
と、それ以外の場合（No.6、８〜12）に比し、濾材の曲
げ強度、あるいはアルミニウムボレイトの結晶化度が低
くなることがわかる。As is clear from Table 1, when a frit composed of a boric acid-based composition and having a particle size equal to or less than a predetermined value is used as a binder, the filter material has a smaller particle size than other cases (No. 6, 8 to 12). It can be seen that the bending strength or the crystallinity of aluminum borate is reduced.
（実施例２） 実施例１で作製された濾材のうち、No.1、９、13、17
を選び、それら濾材のホウ素（Ｂ）除去率を求め、表２
に示した。 (Example 2) Among the filter media prepared in Example 1, No. 1, 9, 13, 17
Was selected and the boron (B) removal rate of the filter media was determined.
It was shown to.
［発明の効果］ 以上説明した通り、本発明の濾材によれば、結合材と
してホウ酸系組成物でありその粒径が所定以下であるフ
リットを用いたので、曲げ強度が大になるとともに、結
合材によりアルミニウムボレイトの針状結晶がより多く
生成されるため、金属溶湯からの不純物捕集性能が向上
するという利点を有するものである。 [Effects of the Invention] As described above, according to the filter medium of the present invention, a boric acid-based composition and a frit having a particle size equal to or less than a predetermined value are used as the binder, so that the bending strength is increased, The binder has the advantage that more needle-like crystals of aluminum borate are generated, thereby improving the performance of collecting impurities from the molten metal.
第１図は骨材の形状指数を算出する際に用いる骨材の投
影説明図である。FIG. 1 is an explanatory drawing of the projection of the aggregate used when calculating the shape index of the aggregate.
───────────────────────────────────────────────────── フロントページの続き (58)調査した分野(Int.Cl.6，ＤＢ名) C22B 9/02 B01D 39/20──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. 6 , DB name) C22B 9/02 B01D 39/20
Claims (1)
結合させた多孔質の濾材であって、 該結合材がB2O315〜80重量％、Al2O32〜60重量％、CaO0
〜30重量％およびMgO5〜50重量％の組成を有するフリッ
トであり、該フリットの50％粒子径が10〜35μｍである
ことを特徴とする金属溶湯用濾材。1. A porous filter medium in which ceramic aggregate particles are bound by an inorganic binder, wherein the binder is 15 to 80% by weight of B 2 O 3 , 2 to 60% by weight of Al 2 O 3 ,
A frit having a composition of about 30% by weight and 5-50% by weight of MgO, wherein the frit has a 50% particle size of 10-35 μm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2083253A JP2801948B2 (en) | 1990-03-30 | 1990-03-30 | Filter media for molten metal |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2083253A JP2801948B2 (en) | 1990-03-30 | 1990-03-30 | Filter media for molten metal |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH03285027A JPH03285027A (en) | 1991-12-16 |
| JP2801948B2 true JP2801948B2 (en) | 1998-09-21 |
Family
ID=13797174
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2083253A Expired - Lifetime JP2801948B2 (en) | 1990-03-30 | 1990-03-30 | Filter media for molten metal |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2801948B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH06256069A (en) * | 1993-02-26 | 1994-09-13 | Kikusui Kagaku Kogyo Kk | Ceramic porous material and its production |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2523707B2 (en) * | 1987-11-11 | 1996-08-14 | 日本碍子株式会社 | Method for manufacturing filter material for molten metal |
-
1990
- 1990-03-30 JP JP2083253A patent/JP2801948B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH03285027A (en) | 1991-12-16 |
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