JP3985082B2 - Refractories and how to use refractories - Google Patents
Refractories and how to use refractories Download PDFInfo
- Publication number
- JP3985082B2 JP3985082B2 JP23673798A JP23673798A JP3985082B2 JP 3985082 B2 JP3985082 B2 JP 3985082B2 JP 23673798 A JP23673798 A JP 23673798A JP 23673798 A JP23673798 A JP 23673798A JP 3985082 B2 JP3985082 B2 JP 3985082B2
- Authority
- JP
- Japan
- Prior art keywords
- powder
- refractory
- zro
- melting
- mgo
- 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 - Fee Related
Links
Images
Landscapes
- Gasification And Melting Of Waste (AREA)
- Compositions Of Oxide Ceramics (AREA)
- Furnace Housings, Linings, Walls, And Ceilings (AREA)
Description
【０００１】
【発明の属する技術分野】
この発明は、たとえば焼却灰、産業廃棄物等を溶融して減容化する溶融炉の炉材等として用いられる耐火物およびその用途に関する。
【０００２】
【従来の技術】
従来、上記溶融炉の炉材としては、Ｃｒ2 Ｏ3 １０重量％を含み、残部Ａｌ2 Ｏ3 からなる耐火物が用いられていた。Ｃｒ2 Ｏ3 は、この耐火物の耐食性を向上させるために含有させられている。
【０００３】
【発明が解決しようとする課題】
しかしながら、従来の耐火物はＣｒ2 Ｏ3 を含んでいるので、この耐火物からなる炉材を用いた溶融炉で焼却灰、産業廃棄物等を溶融するさいに、毒性を有する６価のクロムが発生する可能性があり、しかも６価のクロムが発生するため耐火物の廃棄処理についても苦慮しているのが現状である。
【０００４】
この発明の目的は、上記問題を解決し、Ｃｒ2 Ｏ3 を含有せず、しかも従来の耐火物と同等の耐食性を有する耐火物を提供することにある。
【０００５】
【課題を解決するための手段と発明の効果】
この発明による耐火物は、ＭｇＯ粉末５〜２０重量％およびＺｒＯ ２ 粉末５〜２０重量％を含み、残部ＭｇＡｌ ２ Ｏ ４ 粉末である混合粉末を焼結してなるものである。
【０００６】
上記耐火物を作製する混合粉末の組成は、図１において、点Ａ（ＭｇＯ５重量％、ＺｒＯ２５重量％、ＭｇＡｌ２Ｏ４９０重量％）、Ｂ（ＭｇＯ２０重量％、ＺｒＯ２５重量％、ＭｇＡｌ２Ｏ４７５重量％）、Ｃ（ＭｇＯ２０重量％、ＺｒＯ２２０重量％、ＭｇＡｌ２Ｏ４６０重量％）、Ｄ（ＭｇＯ５重量％、ＺｒＯ２２０重量％、ＭｇＡｌ２Ｏ４７５重量％）で囲まれる範囲内である。但し、この発明の耐火物を作製する混合粉末には、不可避不純物が含まれていてもよい。
【０００７】
この発明の耐火物において、ＭｇＯおよびＺｒＯ２は、溶損を小さくして耐食性を向上させる効果を有するが、混合粉末中におけるＭｇＯ粉末およびＺｒＯ２ 粉末の含有量がそれぞれ５重量％未満であるとこの効果は得られず、ＭｇＯ粉末の含有量が上限値を越えると強度が著しく低下する。また、ＺｒＯ２ 粉末の含有量が２０重量％を越えてもかえって溶損が大きくなって耐食性が低下する。したがって、混合粉末中のＭｇＯ粉末およびＺｒＯ２ 粉末の含有量はそれぞれ５〜２０重量％の範囲内で選ぶべきである。また、ＭｇＡｌ２Ｏ４は、耐溶損性および耐浸透性に優れたベース材料である。
【０００８】
この発明の耐火物は、焼却灰や産業廃棄物の溶融炉の炉材として使用した場合にも毒性を呈することなく、しかも毒性を呈しないので廃棄処理を容易に行うことができる。さらに、従来の耐火物と同等の耐食性を有する。
この発明の耐火物において、混合粉末中のＺｒＯ２ 粉末のうちの少なくとも一部をＺｒＳｉＯ４ 粉末で置換することができる。この場合も、作用効果は変わることがない。
【０００９】
この発明による耐火物の使用方法は、上記耐火物を、塩基度が０．５〜２．０の範囲である被溶融物を溶融する溶融炉の炉材に使用するものである。
【００１０】
一般の産業廃棄物、焼却灰等の塩基度は上記範囲内であり、これらの溶融処理に十分対応することができる。しかも、上記範囲内の塩基度の被溶融物に対して、耐火物は十分な耐食性を有する。
【００１１】
【発明の実施の形態】
以下、この発明の具体的実施例を比較例とともに示す。
【００１２】
実施例１〜６および比較例３〜４
平均粒径５０μｍのＭｇＡｌ2 Ｏ4 粉末と、平均粒径５０μｍのＭｇＯ粉末と、平均粒径５０μｍのＺｒＯ2 粉末またはＺｒＳｉＯ4 粉末とを表１に示す割合で混合し、この混合粉末に、バインダーとしてポリビニルアルコール粉末を混合粉末１００重量部に対して３重量部の割合で添加した。ついで、バインダー添加混合粉末を、水を用いてボールミルで２４時間攪拌混合した後乾燥器にて１２０℃で２４時間乾燥させた。ついで、この乾燥粉末を３００ｋｇ／ｃｍ2 の圧力でプレス成形し、さらに大気中において１５００℃×２時間の焼結を行い、縦２００ｍｍ、横１００ｍｍ、高さ５０ｍｍの試料を得た。
【００１３】
比較例１〜２および５〜６
平均粒径５０μｍのＡｌ2 Ｏ3 粉末と、平均粒径５０μｍのＣｒ2 Ｏ3 粉末とを表１に示す割合で混合して得られた混合粉末を用いた他は、上記実施例１と同様にして、試料を得た。
【００１４】
評価試験１
各試料の圧縮強度を測定するとともに、溶損速度を測定した。
【００１５】
圧縮強度はJIS Ｒ２２０６により測定した。
【００１６】
溶損速度は、回転浸食法により測定した。すなわち、各試料を回転ドラム中にセットし、プロパンガスバーナで１５００℃に加熱した後、表２に示す浸食剤を投入し、浸食剤を３０分毎に交換しつつ８時間経過した後の試料中央部の減肉量を求め、この減肉量から溶損速度を算出した。なお。浸食剤は焼却灰と同じ組成を有するものである。
【００１７】
これらの結果も表１に示す。
【００１８】
【表１】
なお、表１の評価の欄において、○は比較例と同等の特性を有することを表し、×は比較例よりも劣る特性を有することを表す。
【００２０】
【表２】
表１に示す結果から、この発明の組成範囲の耐火物によれば、塩基度０．５〜２．０の浸食剤に対して、従来のＣｒ2 Ｏ3 １０重量％を含み、残部Ａｌ2 Ｏ3 からなる耐火物と同等、もしくはそれ以上の耐食性を有することが分かる。
【００２２】
また、ＭｇＯおよびＺｒＯ２を含まないものは溶損が大きく、混合粉末中のＭｇＯ粉末の含有量が２０重量％を越えると溶損は小さいものの強度が著しく低下し、混合粉末中のＺｒＯ２ 粉末の含有量が２０重量％を越えると溶損が大きくなる。したがって、いずれの場合も焼却灰等の溶融炉に用いるには適していないことが分かる。
【００２３】
評価試験２
実施例２と同じ組成の耐火物から４００ｍｍ×４００ｍｍ×２００ｍｍのブロックを作製し、これを塩基度０．５である産業廃棄物の溶融炉に組み込み、２００時間の連続運転を行った。運転終了後上記ブロックを溶融炉から取出し、溶融炉に組み込まれている従来のＣｒ2 Ｏ3 １０重量％を含み、残部Ａｌ2 Ｏ3 からなる耐火物と比較した。その結果、従来の耐火物は１３ｍｍ溶損したのに対し、上記ブロックの溶損は１２ｍｍであり、従来の耐火物に比べて耐食性に優れていることが判明した。
【図面の簡単な説明】
【図１】ＭｇＯ、ＺｒＯ2 およびＭｇＡｌ2 Ｏ4 の３成分系の組成図である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a refractory material used as a furnace material or the like of a melting furnace for melting incinerated ash, industrial waste, etc. to reduce the volume, and its use.
[0002]
[Prior art]
Conventionally, as a furnace material of the melting furnace, a refractory material containing 10% by weight of Cr 2 O 3 and the balance being Al 2 O 3 has been used. Cr 2 O 3 is contained in order to improve the corrosion resistance of the refractory.
[0003]
[Problems to be solved by the invention]
However, since conventional refractories contain Cr 2 O 3 , toxic hexavalent chromium is used when melting incineration ash, industrial waste, etc. in a melting furnace using a furnace material made of this refractory. In addition, since hexavalent chromium is generated, it is difficult to dispose of refractories.
[0004]
An object of the present invention is to provide a refractory that solves the above problems and does not contain Cr 2 O 3 and has corrosion resistance equivalent to that of a conventional refractory.
[0005]
[Means for Solving the Problems and Effects of the Invention]
The refractory according to the present invention is obtained by sintering a mixed powder that includes 5 to 20 wt% of MgO powder and 5 to 20 wt% of ZrO 2 powder and the balance being MgAl 2 O 4 powder .
[0006]
The composition of the mixed powder for producing the refractory is shown in FIG. 1 as point A (MgO 5 wt%, ZrO 2 5 wt%, MgAl 2 O 4 90 wt%), B (MgO 20 wt%, ZrO 2 5 wt%, MgAl 2 O 4 75 wt%), C (MgO 20 wt%, ZrO 2 20 wt%, MgAl 2 O 4 60 wt%), D (MgO 5 wt%, ZrO 2 20 wt%, MgAl 2 O 4 75 wt%) It is within the range surrounded by. However, the mixed powder for producing the refractory according to the present invention may contain inevitable impurities.
[0007]
In the refractory of the present invention, MgO and ZrO 2 have the effect of reducing corrosion loss and improving the corrosion resistance, but the content of MgO powder and ZrO 2 powder in the mixed powder is less than 5% by weight, respectively. This effect cannot be obtained, and when the content of MgO powder exceeds the upper limit, the strength is remarkably lowered. Moreover, even if the content of the ZrO 2 powder exceeds 20% by weight, the melting loss is increased and the corrosion resistance is lowered. Therefore, the contents of MgO powder and ZrO 2 powder in the mixed powder should be selected within the range of 5 to 20% by weight, respectively. MgAl 2 O 4 is a base material excellent in resistance to melting and penetration.
[0008]
The refractory material of the present invention does not exhibit toxicity even when used as a furnace material for incinerator ash or industrial waste melting furnace, and since it does not exhibit toxicity, it can be easily disposed of. Furthermore, it has corrosion resistance equivalent to that of conventional refractories .
In the refractory of the present invention, at least a part of the ZrO 2 powder in the mixed powder can be replaced with the ZrSiO 4 powder . Also in this case, the operational effect does not change.
[0009]
Using refractory according to the invention, the refractory, basicity is to use the furnace material of the melting furnace for melting an object to be melt in the range of 0.5 to 2.0.
[0010]
The basicity of general industrial waste, incinerated ash, etc. is within the above range, and can sufficiently cope with these melting treatments. Moreover, the refractory has sufficient corrosion resistance with respect to the material having the basicity within the above range.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, specific examples of the present invention will be described together with comparative examples.
[0012]
Examples 1-6 and Comparative Examples 3-4
An MgAl 2 O 4 powder having an average particle size of 50 μm, an MgO powder having an average particle size of 50 μm, and a ZrO 2 powder or ZrSiO 4 powder having an average particle size of 50 μm are mixed in the ratio shown in Table 1, and a binder is added to the mixed powder. The polyvinyl alcohol powder was added at a ratio of 3 parts by weight to 100 parts by weight of the mixed powder. Subsequently, the binder-added mixed powder was stirred and mixed with water in a ball mill for 24 hours, and then dried at 120 ° C. for 24 hours with a dryer. Subsequently, this dry powder was press-molded at a pressure of 300 kg / cm 2 and further sintered in the atmosphere at 1500 ° C. for 2 hours to obtain a sample having a length of 200 mm, a width of 100 mm, and a height of 50 mm.
[0013]
Comparative Examples 1-2 and 5-6
And Al 2 O 3 powder having an average particle size of 50 [mu] m, in addition to a Cr 2 O 3 powder having an average particle size of 50 [mu] m using a mixed powder obtained by mixing in the proportions shown in Table 1, similarly to the Example 1 A sample was obtained.
[0014]
Evaluation test 1
While measuring the compressive strength of each sample, the melting rate was measured.
[0015]
The compressive strength was measured according to JIS R2206.
[0016]
The erosion rate was measured by the rotary erosion method. That is, each sample was set in a rotating drum, heated to 1500 ° C. with a propane gas burner, then the erodant shown in Table 2 was added, and the sample center after 8 hours while changing the erodant every 30 minutes The thickness reduction of the part was calculated | required, and the melting rate was computed from this thickness reduction. Note that. The erodant has the same composition as the incinerated ash.
[0017]
These results are also shown in Table 1.
[0018]
[Table 1]
In addition, in the column of evaluation of Table 1, ◯ represents having the same characteristics as the comparative example, and × represents having characteristics inferior to the comparative example.
[0020]
[Table 2]
From the results shown in Table 1, according to the refractory having the composition range of the present invention, the erodant having a basicity of 0.5 to 2.0 contains 10% by weight of conventional Cr 2 O 3 and the balance Al 2. It can be seen that it has a corrosion resistance equivalent to or higher than that of refractory made of O 3 .
[0022]
Further, containing no MgO and ZrO 2 are melting is large, the strength of those content of MgO powder in the mixed powder is less corrosion exceeds 20% by weight is significantly reduced, ZrO 2 powder in the mixed powder When the content of exceeds 20% by weight, the melting loss increases. Therefore, it turns out that it is not suitable for using in melting furnaces, such as incineration ash, in any case.
[0023]
A 400 mm × 400 mm × 200 mm block was prepared from a refractory having the same composition as in Example 2, and this was incorporated into an industrial waste melting furnace having a basicity of 0.5, and was continuously operated for 200 hours. After completion of the operation, the block was taken out from the melting furnace and compared with a conventional refractory containing 10% by weight of Cr 2 O 3 incorporated in the melting furnace and the balance being Al 2 O 3 . As a result, the conventional refractory was melted by 13 mm, whereas the above-mentioned block had a melt damage of 12 mm, which was found to be superior in corrosion resistance compared to the conventional refractory.
[Brief description of the drawings]
FIG. 1 is a composition diagram of a ternary system of MgO, ZrO 2 and MgAl 2 O 4 .
Claims (3)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23673798A JP3985082B2 (en) | 1998-08-24 | 1998-08-24 | Refractories and how to use refractories |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23673798A JP3985082B2 (en) | 1998-08-24 | 1998-08-24 | Refractories and how to use refractories |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2000072536A JP2000072536A (en) | 2000-03-07 |
| JP3985082B2 true JP3985082B2 (en) | 2007-10-03 |
Family
ID=17005047
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP23673798A Expired - Fee Related JP3985082B2 (en) | 1998-08-24 | 1998-08-24 | Refractories and how to use refractories |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3985082B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6261983B1 (en) * | 2000-01-12 | 2001-07-17 | Baker Refractories | Magnesia spinel refractory brick |
-
1998
- 1998-08-24 JP JP23673798A patent/JP3985082B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JP2000072536A (en) | 2000-03-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA2093615C (en) | Electric arc furnace dust as a raw material for brick | |
| WO2018007364A1 (en) | Multi-coated electrode for welding stainless steel | |
| JP3985082B2 (en) | Refractories and how to use refractories | |
| JP3780398B2 (en) | How to use refractories | |
| JP4328053B2 (en) | Magnesia-spinel brick | |
| JP3610523B2 (en) | Fused slag refractory material composition and molten slag refractory material | |
| JP6615276B1 (en) | Chromia brick | |
| US4999325A (en) | Rebonded fused brick | |
| JP3606707B2 (en) | Ash melting furnace | |
| JP3361581B2 (en) | Taphole filler | |
| EP0521679B1 (en) | Burned refractories with low water soluble chromium(VI)oxide content | |
| JP3327536B2 (en) | Irregular refractories for waste melting furnace pouring and waste melting furnace using the same | |
| JP2518559B2 (en) | Refractory materials and their preparation method | |
| JPH11199317A (en) | Refractory for furnace wall and melting furnace using this refractory | |
| JP4677915B2 (en) | Refractory and melting furnace made of this refractory | |
| JP3088096B2 (en) | High corrosion resistant alumina-chromium refractory | |
| JP3088095B2 (en) | Alumina-chromium refractory | |
| JP3875054B2 (en) | Refractory composition for ash melting furnace | |
| CN112759374B (en) | Anti-coking agent for hazardous waste incineration line and preparation method thereof | |
| JPH07223872A (en) | Alumina spinel casting material | |
| JP3375758B2 (en) | Furnace for melting waste | |
| JPH11130548A (en) | Basic amorphous refractories | |
| JP3617012B2 (en) | Waste melting furnace | |
| JP2002020161A (en) | Binder material for high corrosion-resistant refractory | |
| JP3475256B2 (en) | Basic refractories |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20041012 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20050628 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20050829 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20070529 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20070625 |
|
| R150 | Certificate of patent or registration of utility model |
Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100720 Year of fee payment: 3 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110720 Year of fee payment: 4 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120720 Year of fee payment: 5 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130720 Year of fee payment: 6 |
|
| LAPS | Cancellation because of no payment of annual fees |