JP2000264743A - Easily sinterable basic irregular refractory material and kiln using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an irregular refractory material which can be sintered at <1300 deg.C and develops its strength. SOLUTION: This basic irregular refractory material contains 50 to 98 wt.% of MgO component and the balance of two or more kinds of other components selected from Al2O3, B2O3, CaO, FeO, MgO, MnO, P2O5 and SiO2, and an inevitable impurity component. A part or the whole of the magnesia intergranular region produces a liquid phase at 500 to 1400 deg.C. Further, the irregular refractory material contains zirconia, zircon, carbon, carbide, boride, nitride or metals. Other components consists of, by weight ratio, SiO2:CaO=35:55 to 80:20, Al2O3: CaO=60:30 to 30:60, SiO2:Al2O3=85:15 to 50:50, FeO:SiO2=100:0 to 35:55. MnO: SiO2=80:20 to 50:50, P2O5:CaO=100:0 to 50:50, P2O5:Al2O3=80:20 to 70:30 and P2O5:SiO2=100:0 to 5:95, and are included in total by 2 to 30 wt.%. Or, the material contains B2O3 and SiO2 in total by 2 to 30 wt.% in a weight ratio, of B2O3:SiO2=100:0 to 5:95, and contains 70 to 98 wt.% of MgO. The obtd. basic irregular refractory material is used for the kiln.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an amorphous refractory used in a kiln for metal refining and the like.

[0002]

2. Description of the Related Art Stamp materials, ramming materials, and mortars, which are irregular refractories, are widely used in various places. Stamping materials and ramming materials are widely used not only as wear linings for kilns but also as fillers for expansion allowances due to filling gaps and their shrinkability. The work is performed by a dry method without adding moisture or by a wet method to which a binder such as water of about several weight% is added. Mortar is mainly used for filling joints of fixed refractories such as bricks, but is also used for filling gaps and as a filler for expansion like the stamp material. The work is carried out dry or wet without adding moisture.

On the other hand, irregular-shaped refractories such as plastic refractories, patching materials, trowel coating materials, and cast materials are sometimes used as fillers.

[0004]

When an amorphous refractory is used as a filler for filling gaps or expanding allowances, if any gas flows into the gaps or expansion allowance, the amorphous refractories are carried away by the gas flow. It is lost or moved by the tilting of the kiln, etc., and disappears, leaving gaps and expansion allowance hollow, loosening the refractory lining and causing bricks to fall off.
In addition, gas may be blown out from the joints of the wear bricks through the cavities, resulting in holes. Further, when a carbon-containing refractory is used for the wear lining, if the amorphous refractory disappears and a cavity is formed, the carbon-containing refractory may be oxidized from the back side. Such a phenomenon is often seen when the gap between the wear brick and the permanent brick in a vacuum tank such as an RH facility is filled with an amorphous refractory, and is particularly remarkable when the work is performed in a dry manner. The main component of these amorphous refractories in this case is magnesia (pericles)
It is.

[0005] The direct cause of the disappearance of the amorphous refractory is gas flow and tilting. However, there is also a problem that the strength of the amorphous refractory is not sufficient and the particles are apt to fall apart. Taking the case of the filler between the wear brick and the perm brick of the vacuum tank of the RH equipment as an example, every time the brick is constructed in one step, 10 to 2 is required.
In many cases, the filling work is performed in a gap of 0 mm. Fillers are required to have fluidity, so dry or small amounts (5% by weight or less) of a binder are added for stamping materials and ramming materials, and mortar is used as it is or several% by weight.
Is often added in a dry manner by adding clay, or water is added at about 10 to 30% by weight and poured. In the case of a casting material, water is added by adding 3 to 20% by weight of water.

[0006] The temperature near the boundary between the wear brick and the permanent brick depends on the remaining size of the wear brick.
0 to 1400 ° C. Magnesia is difficult to sinter and does not easily sinter in this temperature range. Further, since the strength of the binder also decreases in this temperature range, these irregular refractories disappear due to gas flow or tilting. An object of the present invention is to provide an amorphous refractory which sinters at 1400 ° C. or lower and has a high strength.

[0007]

[MEANS FOR SOLVING THE PROBLEMS]
As a result of further research and development, the present invention was obtained. Ie book
The gist of the invention is as follows (1) to (5).
It is. (1) 50 to 98% by weight of MgO component, the remainder being other
Al as a component of_TwoO _Three, B_TwoO_Three, CaO, FeO,
MgO, MnO, P_TwoO_FiveAnd SiO_TwoTwo or more
And refractory made of inevitable impurities.
Some or all of the gnesian grain boundaries are at 500-1400 ° C
Easily sinterable, basic amorphous, resistant to liquid phase
Fire.

(2) Other components are SiO 2 in a weight ratio._Two: Ca
O is 45:55 to 80:20, Al _TwoO_Three: CaO is 6
0: 40-40: 60, SiO_Two: Al_TwoO_ThreeIs 85:
15-50: 50, FeO: SiO_TwoIs 100: 0-4
5:55, MnO: SiO_TwoIs 80:20 to 50: 5
0, P_TwoO_Five: CaO is 100: 0 to 50:50, P_Two
O_Five: Al_TwoO_ThreeIs 80: 20-70: 30 and P_TwoO
_Five: SiO_TwoIs one or more of 100: 0 to 5:95
And that the total amount is 2 to 30% by weight
The easily sinterable basic amorphous refractory according to (1), which is characterized in that:

(3) Other components are B ₂ O ₃ : Si in weight ratio.
O ₂ is 100: 0-5: 95, the total amount thereof 2-30
The easily sinterable basic amorphous refractory according to (1), containing 70 to 98% by weight of MgO by weight. (4) Further, one or more of zirconia, zircon, carbon, carbide, boride, nitride and metal are used in total of 0 to 0.
The sinterable amorphous refractory according to any one of (1) to (3), which contains 40% by weight.

(5) A kiln using the easily sinterable basic amorphous refractory according to any one of (1) to (4). In this specification, those represented by element symbols such as MgO, SiO ₂ and CaO represent chemical component names. Also magnesia, silica,
Those written in katakana such as calcia indicate substance names.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The amorphous refractory of the present invention mainly comprises magnesia. The operation when filling the space between the wear brick and the permanent brick in the vacuum chamber will be described below. The amorphous refractory of the present invention generates a liquid phase at a relatively low temperature of 500 to 1400 ° C., and when used as a filler, sintering proceeds and the strength is developed. For this reason, the refractory lining is kept healthy without being lost by the gas flow or tilting, and the carbon-containing refractory is not oxidized from the back side.

The amorphous refractory of the present invention contains at least 50% by weight of an MgO component. Magnesia makes up most of the MgO component. There is no problem with the magnesia to be used, either an electrofused product or a sintered product. In the case of a sintered product, either a natural product or a synthetic product can be used. However, from the viewpoint of corrosion resistance and strength, the purity of magnesia is desirably 85% by weight or more.

The feature of the easily sinterable amorphous refractory of the present invention is 5
A liquid phase is formed at a temperature of from 00 to 1400 ° C., and liquid phase sintering is caused. This is because the starting material undergoes reconciliation melting or non-refractory melting at 1400 ° C. or lower, that is, a liquid phase is formed when coexisting with another substance, or a substance having a melting point of 1400 ° C. or lower is contained. The sinterable amorphous refractory of the present invention contains 50 to 98% by weight of MgO and is mainly composed of magnesia. The magnesia forms the skeleton of the refractory, and the resulting liquid phase serves as an adhesive. It is important to control the ratio of the skeleton and the adhesive in order to keep the refractory healthy so that it does not deform or fall apart. In order to make the amount of the skeleton proper, the MgO component needs to be 50 to 98% by weight. Further, the liquid phase as the adhesive is generated in a portion such as a magnesia grain boundary. In this way, Mg
If the refractory is made such that a liquid phase is generated at a temperature of 1400 ° C. or less in a portion where the O component is small, particularly in a portion where the MgO component is 30% by weight or less, a liquid phase is generated at a magnesia grain boundary, and the skeleton and the adhesive are arranged well. can do. Since the liquid phase is generated at a high temperature and changes to a solid phase when the temperature decreases, when the refractory of the present invention is examined at room temperature, the role of the adhesive is played by the solid phase generated from the liquid phase. It is. Therefore, strictly speaking, the liquid phase or the solid phase formed therefrom plays the role of the adhesive.

If the temperature at which the liquid phase is generated is extremely low, problems may occur, such as agglomeration due to frictional heat during mixing or kneading, or abnormal sintering at high temperatures, causing shrinkage of the work piece. There is. For this reason, the temperature at which the liquid phase occurs should be 500 ° C. or higher and 1400 ° C. or lower. The liquid phase generation temperature can be examined with a microscope that allows observation while heating the sample with a heating device.

When the refractory of the present invention is examined after cooling, a substance which forms a liquid phase at 1400 ° C. or lower or a substance having a melting point of 1400 ° C. or lower when coexisting with other substances may be detected. It may change to a substance with a high melting point. The operation in a typical system of the present invention will be described. In MgO-SiO ₂ -CaO-based, SiO ₂ in the composition of the refractory weight ratio: CaO 45: 55-8
At 0:20, the total amount of SiO ₂ and CaO is 2 to 30% by weight, preferably 10 to 30% by weight, and more preferably 1 to 30% by weight.
The content is 5 to 30% by weight, and the MgO content is 50 to 98% by weight. Is subtracted from the composition of the MgO component in 25-5 _{wt%, CaO · MgO · 2SiO 2} ( _{diopside), 2CaO · MgO · 2SiO 2} ( Akamanaito)
Becomes an aggregate containing a substance having a low melting point, such as 1400 ° C.
A liquid phase is generated below, and liquid phase sintering occurs. Refractory is MgO
Although the components are used in a state where the components are not reduced, the SiO ₂ component and the CaO component sometimes form a liquid phase with the MgO component, which promotes sintering. As a result, the refractory microstructure
A structure in which magnesia as a skeleton is joined to the resulting liquid phase. The total amount of SiO ₂ and CaO is set to 2 to 30% by weight and the content of MgO is set to 50 to 98% by weight because the liquid phase is too small to be sintered or a large amount of liquid phase is generated and the refractory itself is formed. In order to prevent the excessive softening. To satisfy the refractory composition described above, various combinations of raw materials can be considered. Magnesia is as described above. As the SiO ₂ source, for example, silica stone, frit, silica flour and the like can be used, and as the CaO source, for example, quick lime, slaked lime, calcium carbonate, dolomite and the like can be used. Further, as the compound of SiO ₂ and CaO, Portland cement, CaO.SiO ₂ (wollastonite), blast furnace slag, and the like can be selected. In the case of this refractory, when heat-treated at 1400 ° C. for 3 hours,
The SiO ₂ source and the CaO source react and disappear, and magnesia and CaO.MgO.SiO ₂ (Monticelite) and 2M
gO.SiO ₂ (forsterite) or 3CaO
・ It changes to MgO.2SiO ₂ (Merbinite),
An unreacted portion may remain.

In the case of the MgO--Al ₂ O ₃ --CaO system, the weight ratio of Al ₂ O ₃ : CaO is 60: 40-4.
At 0:60, the total amount of Al ₂ O ₃ and CaO is 2 to 30% by weight, preferably 10 to 30% by weight, and MgO is 50 to 50% by weight.
98% by weight. When the MgO component is reduced to 10% by weight or less from this composition, an aggregate containing 12CaO.7Al ₂ O ₃ is formed, and a eutectic is formed at 1400 ° C. or less to produce a liquid phase.
The refractory is used without reducing the MgO component, but the Al ₂ O ₃ component and the CaO component sometimes generate a liquid phase with the MgO component, which promotes sintering. As a result, the microstructure of the refractory is a structure in which magnesia as a skeleton is joined to the generated liquid phase. The reason that the total amount of Al ₂ O ₃ and CaO is set to 2 to 30% by weight and the MgO content is set to 50 to 98% by weight is that the liquid phase is too small to be sintered or a large amount of liquid phase is generated. This is to prevent the refractory itself from being extremely softened. To satisfy the refractory composition described above, various combinations of raw materials can be considered. The magnesia is as described above. For example, synthetic alumina, bauxite and the like can be used as the Al ₂ O ₃ source, and quick lime, slaked lime, calcium carbonate, dolomite and the like can be used as the CaO source. As the compound of Al ₂ O ₃ and CaO, for example, alumina cement can be used.
12CaO.7 which is commercially available as an auxiliary material for steelmaking
Al ₂ O ₃ -CaO-based substances including Al ₂ O ₃ can also be used. In the case of this refractory, when heat-treated at 1400 ° C. for 3 hours, 12CaO · 7Al ₂ O ₃ remains together with magnesia.

MgO-SiO_Two-Al_TwoO_ThreeIn the case of a system
About the weight ratio of SiO_Two: Al _TwoO_ThreeIs 85:15
~ 50: 50, SiO_TwoAnd Al_TwoO_ThreeThe total amount of
30% by weight, desirably 10 to 30% by weight of MgO
50 to 98% by weight. From this composition, MgO
When reduced to 10% by weight, 2MgO.2Al_TwoO_Three・ 5S
iO_Two(Cordierite), and it becomes 14
A liquid phase is formed below 00 ° C. Refractories reduce MgO content
It is used without any_TwoComponents and Al_Two
O_ThreeIn some parts, a liquid phase occurs with the MgO component, which is
To promote. As a result, the microstructure of the refractory
A magnesia forms a structure in which the resulting liquid phases are joined.
Note that SiO_TwoAnd Al_TwoO_ThreeAnd the total amount of 2 to 30% by weight
The reason why the MgO content is set to 50 to 98% by weight is that the liquid phase
Is too small to sinter, or too much liquid phase
This is to prevent the refractory itself from being extremely softened. the above
In order to satisfy the refractory composition of the various combinations of raw materials
Can be considered. Magnesia, SiO_TwoSource, Al_TwoO_Threesource
Is as described above. In addition, SiO_TwoAnd Al_Two
O_Three3Al which is a compound of_TwoO_Three・ 2SiO_Two(Murai
G), MgO and SiO_TwoAnd Al_TwoO_Three2 which is a compound of
MgO · 2Al_TwoO_Three・ 5SiO_Two(Cody Eli
G) can also be used. In the case of this refractory, 14
After heat treatment at 00 ° C. for 3 hours, SiO 2_TwoSource and Al_TwoO_Three
The source reacts and disappears, and magnesia and 2MgO.SiO_Two
(Forsterite) and MgO / Al_TwoO_Three(Spine
), But an unreacted portion may remain.

The main system has been described above.
MgO-FeO-SiO_TwoSystem, MgO-MnO-SiO
_TwoSystem, MgO-B_TwoO_Three-SiO_TwoSystem, MgO-P_TwoO
_Five-CaO-based, MgO-P_TwoO_Five-Al_TwoO_ThreeSystem, Mg
OP_TwoO_Five-SiO_TwoThe same is true for the system. Note that
Mills generated in the steel rolling process, etc., as the FeO source
Kale, MnO-SiO_TwoSources include manganese ore
Can be used. B_TwoO _ThreeBoric acid or borosilicate glass as source
Etc. are available. Also P_TwoO_FiveSources are phosphate ore, phosphorus
Acid-based glass, phosphorus pentoxide, and the like can be used.

The easily sinterable amorphous refractory of the present invention further comprises one or more of zirconia, zircon, carbon, carbide, boride, nitride, and metal in a total amount of 0-4.
0% by weight. If the content exceeds 40% by weight, the balance between the amounts of magnesia and the liquid phase will be lost, and the durability of the refractory will be impaired. The amorphous refractory of the present invention can be used as a stamp material, a ramming material, and a mortar, either dry or with a binder added. Further, it can be used as a trowel coating material or a patching material by increasing the amount of a binder to impart plasticity, or as a pouring material by adding water, a sol, a resin and a solvent thereof. The construction method may be a commonly used method.

[0020]

[Example 1] Sintered magnesia having a purity of 95% by weight was sized to a particle size of 0.3 mm or less, and the particle size was adjusted to 0.1 m.
10% by weight of silica stone (purity 96% by weight) pulverized to less than 100 m and Portland cement (SiO ₂ = 23% by weight, CaO
= 64% by weight) to obtain a mortar of MgO = 76% by weight, SiO ₂ = 12% by weight and CaO = 6% by weight.

This was applied to a gap of 15 mm between the permanent brick and the wear brick on the side wall of the lower tank at 300 tRH. Perm brick is made of magcro, wear brick is made of MgO
-C quality. As for the construction method, first, after the perm brick was constructed, the mortar was inserted into the gap between the back brick and the perm brick with an iron bar and dry-constructed each time the wear brick was built one step.

The completed lower furnace was used as usual after drying and heating, and after using 510 ch, the condition of the refractory lining and mortar was examined. The remaining size of the wear brick was 90 to 70 mm, and there was no noticeable loosening or abnormality. In addition, the mortar was sintered and no disappeared portion was observed, and the mortar was sound. The back of the MgO-C brick was almost oxidized. The strength of this mortar measured by preparing a sample by the method described in Example 5 was 3 MPa.

At 1350 ° C., a liquid phase was formed at the magnesia grain boundary, and at 1400 ° C., the generation rate of the liquid phase at the magnesia grain boundary was 50%. The effect that occurred in the mortar described in Example 1 was due to the above-mentioned MgO—SiO ₂ —
It is thought to be based on the action of the CaO system. [Example 2] Sintered magnesia having a purity of 95% by weight
mm or less, and alumina cement (Al ₂ O ₃ = 4)
2% by weight, CaO = 37% by weight), 30% by weight, MgO = 67% by weight, Al ₂ O ₃ = 13% by weight, C
A dry stamp material of aO = 11% by weight was used.

This was installed in a gap of 15 mm between the permanent brick and the wear brick on the side wall of the lower tank of 300 tRH. Perm brick is made of magcro, wear brick is made of MgO
-C quality. After the perm brick was constructed, the stamp material was inserted into the gap between the back brick and the perm brick with an iron bar and dry-constructed every time the wear brick was built.

The lower tank after the completion of the furnace construction was used as usual after drying and heating, and after using 535 channels, the conditions of the refractory lining and the stamp material were examined. The remaining size of the wear brick was 100 to 70 mm, and there was no noticeable loosening or abnormality.
The stamp material was sintered and no disappeared part was observed, and the stamp material was sound. The back of the MgO-C brick was almost oxidized. The strength of this stamp material measured and prepared by the method described in Example 5 was 5MPa.
a. However, the amount of added water was 3% by weight.

At 1350 ° C., a liquid phase was formed at the magnesia grain boundary, and at 1400 ° C., the generation rate of the liquid phase at the magnesia grain boundary was 100%. The effect that occurred in the stamp material described in Example 2 was due to the above-described MgO—Al ₂
O ₃ is considered to be based on the action of the -CaO system. Example 3 Sintered magnesia having a purity of 95% by weight was prepared with a particle size of 1
mm, and 23% by weight of cordierite (SiO ₂ = 48% by weight, Al ₂ O ₃ = 33% by weight, MgO = 8% by weight) having a particle size of 0.5 mm or less are mixed.
= 75% by weight, Al ₂ O ₃ = 8% by weight, SiO ₂ = 11
A weight% of the casting material was used.

This was installed in a gap of 15 mm between the permanent brick and the wear brick on the lower tank side wall of 300 tRH. Perm brick is made of magcro, wear brick is made of MgO
-C quality. The construction method was as follows. After the perm brick was constructed, 25% by weight of water was added and kneaded into the gap between the back brick and the perm brick every time the wear brick was built one step.

The completed lower furnace was used as usual after drying and heating, and after using 542 channels, the condition of the refractory lining and the pouring material was examined. The remaining size of the wear brick was 90 to 60 mm, and there was no noticeable loosening or abnormality. The cast material was sintered, and no disappeared part was observed, and it was sound. The back of the MgO-C brick was almost oxidized. The strength of the casting material measured and prepared by the method described in Example 5 was 5MPa.
a.

At 1350 ° C., a liquid phase was formed at the magnesia grain boundary, and the generation rate of the liquid phase at the magnesia grain boundary at 1400 ° C. was 40%. Note that the action that occurred in the casting material described in Example 3 was the same as that of the aforementioned MgO--SiO
_It is thought to be based on the action of the _2- Al ₂ O ₃ system. Example 4 Sintered magnesia having a purity of 95% by weight was sized to a particle size of 0.5 mm or less, and clay (SiO ₂ = 55) was added thereto.
% By weight, Al ₂ O ₃ = 28% by weight) 20% by weight and calcium carbonate having a particle size of 0.1 mm or less (purity: 95% by weight) 7
Wt. And water are mixed and kneaded, and MgO = 69 wt.
iO ₂ = 11% by weight, Al ₂ O ₃ = 6% by weight, CaO =
It was 4% by weight of a plastic refractory.

This was applied to a gap of 15 mm between the permanent brick and the wear brick on the side wall of the lower tank at 300 tRH. Perm brick is made of magcro, wear brick is made of MgO
-C quality. The construction method, first, after perm brick construction, plastic refractories are slightly thicker than 15 mm,
Wear bricks were constructed at a height of one step, and the wear bricks were pressed against each other and compressed to 15 mm.

After completion of the furnace construction, the lower tank was used as usual after drying and heating, and after using 523 channels, the condition of the refractory lining and the plastic refractory was examined. The remaining size of the wear brick was 90 to 60 mm, and there was no noticeable loosening or abnormality. Further, the plastic refractory sintered and no disappeared part was observed, and was sound. The back of the MgO-C brick was almost oxidized. Example 5
The strength of this plastic refractory, which was prepared and measured by the method described in the above section, was 5 MPa. In the preparation of the sample, the plastic refractory was pressed into a mold and molded without adding any additional water.

At 1350 ° C., a liquid phase was formed at the magnesia grain boundary, and the generation rate of the liquid phase at the magnesia grain boundary at 1400 ° C. was 70%. The effect that occurred in the plastic refractory described in Example 4 was due to the aforementioned MgO-
SiO ₂ —Al ₂ O ₃ or MgO—SiO ₂ —C
aO system or considered based on the effect of MgO-Al ₂ O ₃ -CaO based.

[Example 5] A mortar shown in Table 2 was prepared and evaluated by combining the raw materials shown in Table 1. The particle diameters of all the raw materials were 0.3 mm or less. 25% by weight of water to which polyvinyl alcohol is added is added and kneaded, and 40 × 40 ×
Pour into a 40 mm mold, cure as it is at room temperature for 24 hours, remove from mold and dry at 110 ° C. for 24 hours.
Heat-treated at 3 ° C. for 3 hours. Thereafter, the compressive strength was measured at room temperature.

The strength of the product of the present invention was at least three times that of the comparative product, and the effect of the present invention was confirmed. In addition, the temperature at which a liquid phase is formed at the magnesia grain boundary in A to F and 1400
Table 2 also shows the generation rate of the liquid phase at the magnesia grain boundary at ℃. In Comparative Example A, no liquid phase was formed at 1500 ° C.

[0035]

[Table 1]

[0036]

[Table 2]

[0037]

According to the present invention, the refractory lining of the kiln can be structurally stabilized, oxidation can be suppressed, the operation of the kiln can be stabilized, and the life can be prolonged. Eventually, the cost of manufacturing steel and the like can be reduced.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F27D 1/00 F27D 1/00 K F Term (Reference) 4G033 AA01 AA02 AA03 AA04 AA06 AA07 AA12 AA14 AA16 AA18 AB08 BA01 BA05 BA06 4K002 AA01 AA02 BC03 4K013 CE01 CE09 CF12 CF18 CF19 4K051 AA00 AA02 AA05 BB03 BB08 BD05 BE03 BF03 GA01 LB04

Claims (5)

[Claims] Claims 1. An MgO component containing 50 to 98% by weight,
The rest is Al ₂ O ₃ , B ₂ O ₃ , CaO,
An amorphous refractory comprising two or more of FeO, MgO, MnO, P ₂ O ₅ and SiO ₂ and an unavoidable impurity component, wherein a part or all of a magnesia grain boundary is 500 to 14
An easily sinterable basic amorphous refractory which forms a liquid phase at 00 ° C. 2. Other components in weight ratio of SiO ₂ : CaO of 45:55 to 80:20 and Al ₂ O ₃ : CaO of 60:
40 to 40:60, 85:15 for SiO ₂ : Al ₂ O ₃
~50: 50, FeO: SiO ₂ is 100: 0 to 45:
55, MnO: SiO ₂ is 80:20 to 50:50, P
₂ O ₅ : CaO is 100: 0 to 50:50, P ₂ O ₅ :
Al ₂ O ₃ is 80:20 to 70:30 and P ₂ O ₅ : S
_2. The easily sinterable basic amorphous refractory according to claim 1, wherein iO2 is composed of one or more of 100: 0 to 5:95, and the total amount is 2 to 30% by weight. . 3. The composition according to claim ₂ , wherein the other components are B ₂ O ₃ : SiO ₂ by weight.
2. The easily sinterable basic amorphous refractory according to claim 1, wherein the content is 100: 0 to 5:95, the total amount is 2 to 30% by weight, and 70 to 98% by weight of MgO is contained. 4. The method according to claim 1, further comprising a total of 0 to 40% by weight of one or more of zirconia, zircon, carbon, carbide, boride, nitride and metal.
The easily sinterable amorphous refractory according to any one of the above. 5. A kiln using the easily sinterable basic amorphous refractory according to any one of claims 1 to 4.