JP3606707B2 - Ash melting furnace - Google Patents

Description

すなわち、これら各試験片における構成材料としては、その平均粒径が５０μｍのものを使用し、混合は水を用いたボールミルで行い、バインダーとしてポリビニールアルコール（ＰＶＡ）を３重量部加えるとともに、混合時間は２４時間とし、その後、乾燥器により１２０℃にて２４時間乾燥した。こうして得られた粉末材料を、３００ｋｇ／ｃｍ^２の圧力にてプレス成形した後、大気中にて１６００℃で２時間焼結させることにより、７０×７０×６５ｍｍの角柱状試験片を得た。
【００１５】
次に、この試験片の中央部にφ３０×３５ｍｍの孔を形成し、この孔に、下記の［表２］に示すスラグを充填し、大気中にて、１４００℃でもって
２時間加熱保持した。
【００１６】
【表２】

そして、保持後、中央部を切断して、浸食された部分の面積を測定した。なお、評価は、比較を容易にするために、Ａｌ_２Ｏ_３の１００％材における値を１とし、各試験片を相対評価したもので、従来から用いられている組成であるＡｌ_２Ｏ_３−Ｃｒ_２Ｏ_３材料の値と同等または優れていれば「○」、劣っていれば「×」の評価を与えた。
【００１７】
したがって、試験片２，３，４，６および７（本発明品）に示すように、ＺｒＯ_２が１０〜４０％の範囲内が良好であることが分かる。但し、試験片１（比較品）に示すように、Ａｌ_２Ｏ_３−ＺｒＯ_２との割合が５０：５０の場合には、冷却中にクラックが発生した。
【００１８】
このように、コスト低減化のために、Ａｌ_２Ｏ_３の一部を、ＳｉＯ_２で置き換えても、試験片２，３，４，６および７に示すように、塩基度が０．５〜１．０の範囲内でかつＳｉＯ_２の添加割合が５〜１０％の範囲内なら問題はないが、試験片５（比較品）に示すように、塩基度が０．５であっても、ＳｉＯ_２の添加割合が１５％になると、溶損比および浸透比が大きくなってしまい、不適である。なお、試験片８（比較品）に示すように、ＺｒＯ_２が１０％で、ＳｉＯ_２が５％の場合でも、焼却灰の塩基度が１．５と、１．０を超えた場合には、溶損比および浸透比が大きくなり、不適であることが分かる。
【００１９】
なお、上記試験片３と同じ組成を用いて、４００×４００×２００ｍｍのブロックを製作し、塩基度が０．５の焼却灰を溶融する灰溶融炉に組み込み、２００時間の連続運転後に、このブロックと、既に組み込まれている従来のもの、すなわちＣｒ_２Ｏ_３を２０％含有したＡｌ_２Ｏ_３からなる耐火物とを比較した結果、従来の耐火物は１０ｍｍ溶損したのに対して、本発明に係るブロックの溶損は９ｍｍであった。すなわち、本発明に係る耐火物の方が、耐久性において優れていることが確認された。
【００２０】
次に、本発明の第２の実施の形態における灰溶融炉に用いられる耐火物について説明する。
この第２の実施の形態に係る耐火物の構成は、ＺｒＯ_２を１０〜４０％で残部がＡｌ_２Ｏ_３からなる耐火物において、このＡｌ_２Ｏ_３の一部を、５〜１０％の範囲でＭｇＯに置き換えたものである。
【００２１】
この耐火物は、第１の実施の形態と同様に、ごみ焼却灰を溶融処理するための灰溶融炉の炉本体の内壁部の材料として使用され、またこのときの灰溶融炉内に供給される焼却灰は、その塩基度が１．０〜２．０の範囲内のものとされる。
【００２２】
このような耐火物の構成によると、Ｃｒ_２Ｏ_３の替わりに、ＺｒＯ_２およびＭｇＯを使用して耐食性を有せしめたので、耐火物の廃棄処理が容易であるとともに、使用するＺｒＯ_２の量が４０％以下となり、製造コストが安価になる。
【００２３】
そして、上記構成の耐火物を灰溶融炉の内壁部として使用する場合には、被溶融物である焼却灰の塩基度が１．０〜２．０の範囲内で効果が生じる。ここで、Ａｌ_２Ｏ_３、ＺｒＯ_２およびＭｇＯの割合を、種々変化させて耐火物の試験片を製作するとともに、第１の実施の形態と同様の試験を行った結果を、下記の［表３］に基づき説明する。
【００２４】
【表３】

勿論、［表３］における試験片の形状および試験方法は、第1の実施の形態と同じものが採用されている。
【００２５】
［表３］から分かるように、試験片１２〜１６（本発明品）に示すように、ＺｒＯ_２が１０〜４０％およびＭｇＯが５％〜１０％の範囲内であれば、溶損比および浸透比が小さく、評価は「○」であった。
【００２６】
すなわち、コスト低減化のために、Ａｌ_２Ｏ_３の一部を、ＭｇＯで置き換えても、試験片１２〜１６に示すように、塩基度が１．０〜２．０の範囲内でかつＭｇＯの添加割合が５〜１０％の範囲内なら問題はない。しかし、試験片１１（比較品）に示すように、焼却灰の塩基度が０．５と、１．０未満である場合には、溶損比および浸透比が大きくなり、不適であることが分かる。
【００２７】
【発明の効果】
以上のように、本発明の各灰溶融炉の構成によると、耐火壁の構成成分であるＡｌ _２ Ｏ _３ の一部を、５〜１０重量％の範囲でＳｉＯ _２ に、または５〜１０重量％の範囲でＭｇＯに置き換えたので、Ｃｒ_２Ｏ_３を使用しないため、環境面に対して問題がなく、またＡｌ_２Ｏ_３とＺｒＯ_２とだけで構成する場合に比べて、安価な耐火物が得られ、しかもこれらの耐火物を灰溶融炉に使用する際に、溶融する焼却灰の塩基度を所定の範囲に、すなわちＳｉＯ_２を添加する場合には０．５〜１．０の範囲に、またＭｇＯを添加する場合には１．０〜２．０の範囲にすることにより、耐火物としての効果が良好に発揮される。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an ash melting furnace.
[0002]
[Prior art]
Usually, a corrosion-resistant refractory is used as a constituent material of a furnace wall of a melting furnace for melting incineration ash such as garbage.
[0003]
Conventionally, as this refractory, a material based on Al ₂ O ₃ and added with about 5 to 20 wt% of Cr ₂ O ₃ is used, or 40 wt% of ZrO ₂ is added to Al ₂ O _3. Materials added beyond that were used.
[0004]
[Problems to be solved by the invention]
However, according to the former material described above, Cr ₂ O ₃ has a disadvantage that it causes problems in the environmental aspect, particularly in processing as a waste material, and ZrO ₂ is effective as a substitute for Cr ₂ O _3. However, there was a problem of becoming expensive.
[0005]
Accordingly, an object of the present invention is to provide an ash melting furnace that uses a refractory that is easy to process and inexpensive.
[0006]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the ash melting furnace of the present invention comprises ZrO _{2 in an amount} of 10 to 40% by weight, the balance being Al ₂ O ₃ , and a part of the Al ₂ O ₃ in an amount of 5 to 10% by weight. An incinerator ash melting furnace with an inner wall formed of a refractory material that is replaced with SiO ₂ in the above range, and the basicity of the incinerated ash is used within a range of 0.5 to 1.0 It is.
[0007]
In another ash melting furnace of the present invention, ZrO ₂ is 10 to 40% by weight and the balance is Al ₂ O ₃ , and a part of the Al ₂ O ₃ is MgO in the range of 5 to 10% by weight. The incineration ash melting furnace has an inner wall portion formed of a refractory material that is replaced with refractory, and is used within a basicity range of 1.0 to 2.0.
[0008]
According to the configuration of each ash melting furnace, a part of Al ₂ O ₃ which is a component of the fire wall is changed to SiO ₂ in the range of 5 to 10% by weight , or MgO in the range of 5 to 10% by weight. so replaced, because it does not use the _Cr 2 _{O 3,} there is no problem with respect to environmental and compared with the case of constructing only _Al 2 _{O 3} and ZrO _2, inexpensive refractories can be obtained. Moreover these When using the refractory material in the ash melting furnace, the basicity of the incinerated ash to be melted is within a predetermined range, that is, within the range of 0.5 to 1.0 when SiO ₂ is added, and MgO is added. When it does, the effect as a refractory is exhibited favorably by making it the range of 1.0-2.0.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
The following describes ash melting furnace that put to the embodiment of the present invention.
First, the refractory used for the ash melting furnace in the first embodiment of the present invention will be described.
[0010]
Arrangement of refractory according to the first embodiment, the ZrO ₂ 10 to 40 wt% in the refractory material balance of _Al 2 _{O 3} (hereinafter, simply indicated by%), the _Al 2 _{O 3} A part is replaced with SiO ₂ in a range of 5 to 10%.
[0011]
Then, the refractory is used as a constituent material of the inner wall of the furnace body of ash melting furnace for melting processing waste incineration ash and incineration ash supplied to the ash melting furnace of this time, the base The degree is in the range of 0.5 to 1.0.
[0012]
According to such a refractory structure, instead of Cr ₂ O ₃ , ZrO ₂ and SiO ₂ are used to provide corrosion resistance, so that it is easy to dispose of the refractory and the ZrO ₂ used The amount is 40% or less, and the manufacturing cost is low.
[0013]
And when using the refractory of the said structure as an inner wall part of an ash melting furnace, an effect arises in the range whose basicity of the incinerated ash which is a to-be-melted material is 0.5-1.0. Here, refractory specimens were manufactured based on JIS R2214 with various ratios of Al ₂ O ₃ , ZrO _2, and SiO _{2 being} changed, and the results of predetermined tests were explained based on [Table 1]. To do.
[0014]
[Table 1]

That is, as a constituent material in each of these test pieces, those having an average particle diameter of 50 μm are used, mixing is performed by a ball mill using water, and 3 parts by weight of polyvinyl alcohol (PVA) is added as a binder and mixed. The time was set to 24 hours, and then dried at 120 ° C. for 24 hours using a dryer. The powder material thus obtained was press-molded at a pressure of 300 kg / cm ² and then sintered in the atmosphere at 1600 ° C. for 2 hours to obtain a 70 × 70 × 65 mm prismatic test piece.
[0015]
Next, a hole of 0 30 × 35 mm in central part in this test specimen, in the hole, filling the slag shown in Table 2 below, in the atmosphere, heated for 2 hours retained with at 1400 ° C. did.
[0016]
[Table 2]

And after holding | maintenance, the center part was cut | disconnected and the area of the eroded part was measured. In order to facilitate the comparison, the value of 100% Al ₂ O _{3 in} a 100% material was set to 1, and each test piece was relatively evaluated. Al ₂ O ₃ , which has been conventionally used, is used. A rating of “◯” was given if it was equal to or better than the value of the —Cr ₂ O ₃ material, and “x” was given if it was inferior.
[0017]
Therefore, as shown in test pieces 2, 3, 4, 6 and 7 (product of the present invention), it can be seen that the ZrO ₂ content in the range of 10 to 40% is good. However, as shown in test piece 1 (comparative product), cracks occurred during cooling when the ratio of Al ₂ O ₃ —ZrO ₂ was 50:50.
[0018]
Thus, even if a part of Al ₂ O ₃ is replaced with SiO ₂ for cost reduction, as shown in test pieces 2, 3, 4, 6 and 7, the basicity is 0.5 to There is no problem if the addition ratio of SiO ₂ is in the range of 1.0 to 10%, but as shown in test piece 5 (comparative product), even if the basicity is 0.5, When the addition ratio of SiO ₂ is 15%, the melting loss ratio and the penetration ratio are increased, which is not suitable. In addition, as shown in the test piece 8 (comparative product), even when ZrO ₂ is 10% and SiO ₂ is 5%, the basicity of the incineration ash exceeds 1.5 and 1.0. It can be seen that the melting loss ratio and the permeation ratio are large, which is inappropriate.
[0019]
In addition, a 400 × 400 × 200 mm block was manufactured using the same composition as the test piece 3 and incorporated into an ash melting furnace for melting incineration ash having a basicity of 0.5, and after 200 hours of continuous operation, As a result of comparing the block with a conventional one already incorporated, that is, a refractory made of Al ₂ O ₃ containing 20% of Cr ₂ O ₃ , the conventional refractory was melted by 10 mm, The melting loss of the block according to the present invention was 9 mm. That is, it was confirmed that the refractory according to the present invention is superior in durability.
[0020]
Next, the refractory used for the ash melting furnace in the 2nd Embodiment of this invention is demonstrated.
Arrangement of refractory according to the second embodiment, the refractory material balance of ZrO ₂ 10-40 percent of _Al 2 _{O 3,} a portion of the _Al 2 _{O 3,} of 5-10% The range is replaced with MgO.
[0021]
The refractory, as in the first embodiment, is used as the material of the inner wall of the furnace body of ash melting furnace for melting processing waste incineration ash, also be supplied to the ash melting furnace of this time The incineration ash has a basicity in the range of 1.0 to 2.0.
[0022]
According to such a refractory structure, since ZrO ₂ and MgO are used instead of Cr ₂ O ₃ to provide corrosion resistance, it is easy to dispose of the refractory and the amount of ZrO _{2 to be} used. Is 40% or less, and the manufacturing cost is low.
[0023]
And when using the refractory of the said structure as an inner wall part of an ash melting furnace, an effect arises in the range whose basicity of the incinerated ash which is a to-be-melted material is 1.0-2.0. Here, while producing the test piece of a refractory by changing the ratio of Al ₂ O ₃ , ZrO ₂ and MgO variously, the results of the same test as in the first embodiment are shown in the following [Table 3].
[0024]
[Table 3]

Of course, the shape and test method of the test piece in [Table 3] are the same as those in the first embodiment.
[0025]
As can be seen from Table 3, as shown in the test piece 12 to 16 (present invention), if it is within range ZrO ₂ is 10 to 40% and MgO 5% to 10%, melting ratio and The penetration ratio was small and the evaluation was “◯”.
[0026]
That is, even if a part of Al ₂ O ₃ is replaced with MgO for cost reduction, the basicity is within the range of 1.0 to 2.0 and MgO as shown in test pieces 12 to 16. If the addition ratio is in the range of 5 to 10%, there is no problem. However, as shown in the test piece 11 (comparative product), when the basicity of the incinerated ash is 0.5 and less than 1.0, the melting loss ratio and the penetration ratio are increased, which may be inappropriate. I understand.
[0027]
【The invention's effect】
As described above , according to the configuration of each ash melting furnace of the present invention, a part of Al ₂ O ₃ which is a constituent component of the fire wall is made SiO ₂ in the range of 5 to 10% by weight , or 5 to 10% by weight. % MgO, because Cr ₂ O ₃ is not used, there is no environmental problem, and the refractory is less expensive than the case where only Al ₂ O ₃ and ZrO ₂ are used. When these refractories are used in an ash melting furnace, the basicity of the incinerated ash to be melted is within a predetermined range, that is, in the range of 0.5 to 1.0 when SiO ₂ is added. Moreover, when adding MgO, the effect as a refractory is exhibited well by making it the range of 1.0-2.0.

Claims (2)

The inner wall is formed of a refractory material in which ZrO ₂ is 10 to 40% by weight and the balance is Al ₂ O ₃ and a part of the Al ₂ O ₃ is replaced with SiO ₂ in the range of 5 to 10% by weight. A furnace for melting incinerated ash,
An ash melting furnace characterized in that the basicity of incinerated ash is used within a range of 0.5 to 1.0. The inner wall portion is formed of a refractory material in which ZrO ₂ is 10 to 40% by weight and the balance is Al ₂ O ₃ and a part of the Al ₂ O ₃ is replaced with MgO in the range of 5 to 10% by weight. An incinerator ash melting furnace,
An ash melting furnace, wherein the basicity of incinerated ash is used within a range of 1.0 to 2.0.