JP6453824B2 - Inorganic fiber molded body - Google Patents

Description

  The present invention relates to an inorganic fibrous molded body.

  Asbestos has been used as a heat insulating material and the like because it is lightweight, easy to handle, and excellent in heat resistance. However, asbestos is banned because it is inhaled by the human body and causes diseases in the lungs. Instead, heat-resistant ceramic fibers (RCF) are used. The heat-resistant ceramic fiber is usually an inorganic fiber containing 40 to 60% by weight of silica and 30 to 60% by weight of alumina, and is considered to have higher heat resistance than asbestos and lower health problems than asbestos. Carcinogenicity is suspected. Accordingly, various alkaline earth silicate (AES) wool has been developed as a biosoluble inorganic fiber that does not cause a problem even when inhaled by the human body, or hardly occurs. Generally, alkaline earth silicate wool is an inorganic fiber containing silica and magnesia and / or calcia, and usually contains 18 to 50 wt% of magnesia and calcia, and 50 to 82 wt% of silica.

  Conventional inorganic fibers, like asbestos, are secondary-processed into regular and irregular shapes, together with various binders and additives, and are used as joint materials and fireproof tiles in furnaces such as heat treatment equipment, industrial kilns, and incinerators. It is used as a heat insulating brick, iron skin, heat insulating material and the like. When used, it is often exposed to high temperatures and is required to have heat resistance.

  In addition, alumina is often used as a member in the furnace, and there is a problem that the fibers contained in the secondary processed product react with the alumina and the secondary processed product or member adheres or melts. .

  AES wool is generally inferior to RCF in heat resistance and alumina resistance. Inorganic fibers having biosolubility and heat resistance and alumina reactivity comparable to RCF have been studied and developed (for example, Patent Documents 1 to 3). These AES wools have a high silica content of 70% by weight or more, have higher heat resistance than conventional AES wools, and some have a heat-resistant temperature as high as 1300 ° C., similar to RCF.

JP 2005-515307 A JP-T-2005-514318 JP 2016-37427 A

Insulating boards using inorganic fibers are often affixed to the wall surface in the furnace, and in that case, only one side inside the furnace is strongly heated, causing a problem of cracking.
The subject of this invention is providing the inorganic fiber molded object which is hard to break by single-sided heating including AES wool whose silica content is 70 weight% or more with high heat resistance.

  As a result of diligent research, the present inventors have found that when a molded body made of AES wool containing a high content of silica is heated to 1100 ° C., cristobalite crystals of silica are formed, which causes cracking. Furthermore, in order to suppress the formation ratio of the cristobalite crystals in the molded body, it was found that cracking could be suppressed by mixing AES wool having a low silica content, and the present invention was completed.

According to the present invention, the following inorganic fibrous molded body is provided.
1. One or more metal oxides selected from calcia and magnesia, silica, a first inorganic fiber containing 18-30 wt% of the metal oxide and 70-82 wt% of the silica;
One or more metal oxides selected from calcia and magnesia, and containing silica, 18 to 50% by weight of the metal oxide, and a second inorganic fiber containing 50 to 70% by weight of the silica. Inorganic fibrous molded body.
2. 2. The inorganic fibrous molded body according to 1, wherein a weight ratio of the first inorganic fiber to the second inorganic fiber is 1st inorganic fiber: 2nd inorganic fiber = 5 to 95: 95-5.
3. The first inorganic fiber includes 90% by weight or more of the metal oxide and silica,
3. The inorganic fiber molded body according to 1 or 2, wherein the second inorganic fiber includes 90% by weight or more of the metal oxide and silica.
4). The inorganic fiber molded body according to any one of 1 to 3, wherein the first inorganic fiber includes the following components in the following content.
SiO ₂ : 70% by weight to 82% by weight
One or more selected from MgO and CaO: 18% by weight to 30% by weight
One or more selected from Al ₂ O ₃ , TiO ₂ and ZrO ₂ : 0 wt% to 6 wt%
5. The inorganic fiber molded body according to any one of 1 to 4, wherein the first inorganic fiber includes the following components in the following content.
SiO _2: 72 wt% to 82 wt%
MgO: 8 to 22% by weight
CaO: 4 to 14% by weight
Al ₂ O _3: 0 wt% to 3 wt%
5. Mainly composed of three components of SiO ₂ , MgO and CaO The inorganic fiber molded body according to any one of 1 to 5, wherein the second inorganic fiber includes the following components in the following content.
SiO _2: 57 wt% to 70 wt% less than MgO and one or more selected from CaO: 30 wt% to 43 wt%
One or more selected from Al ₂ O ₃ , TiO ₂ and ZrO ₂ : 0 wt% to 3 wt%
7). The inorganic fiber molded body according to any one of 1 to 6, wherein the second inorganic fiber includes the following components in the following content.
SiO ₂ 58 wt% or more and less than 70 wt% CaO 25 to 38 wt%
MgO 2 to 10% by weight
Al ₂ O ₃ 0% by weight to 3% by weight
8). Any one of 1 to 7 wherein the content of surplus silica is 50 mol% or less when it is assumed that Si, Ca, Mg and Al have produced crystals of diopside, wollastonite, enstatite and mullite to the maximum extent. An inorganic fibrous molded body according to any one of the above.
9. The inorganic fibrous molded article according to any one of 1 to 8, wherein the silica content is 75% by weight or less.
10. The inorganic fiber molded body according to any one of 1 to 9, which does not crack when one surface is heated at 10.100 ° C. for 24 hours.
11. The inorganic fiber molded body according to any one of 1 to 10, which does not crack when one surface is heated at 1200 ° C. for 24 hours.

  ADVANTAGE OF THE INVENTION According to this invention, the inorganic fiber molded object which contains the AES wool whose silica content is 70 weight% or more, and cannot be easily broken by single-sided heating can be provided.

It is a schematic sectional drawing of the single-sided heating evaluation furnace used in the experiment example. It is an XRD chart of the inner side, the center, and the outer side part of the board heated in 1100 degreeC measured in Experimental example 1 (2). It is the XRD chart after 1100 degreeC whole surface heating of the board which consists of HS1 and LS2 from which the mixing ratio measured in Experimental example 3 differs. It is a graph which shows the shrinkage | contraction rate by heating of the board which consists of HS1 and LS2 from which the mixing ratio measured in Experimental example 3 differs.

  The inorganic fibrous molded body of the present invention is a mixture of AES wool containing silica at a high content of 70% by weight or more and AES wool containing silica at a low content of less than 70% by weight. Specifically, the inorganic fibrous molded body of the present invention includes one or more metal oxides selected from calcia and magnesia, and silica, 18 to 30% by weight of metal oxide, and 70 to 82% by weight of silica. A first inorganic fiber containing 1%, one or more metal oxides selected from calcia and magnesia, and silica, 18 to 50% by weight of metal oxide, and 50% to less than 70% by weight of silica. 2 inorganic fibers. The first and second inorganic fibers can contain other oxides in addition to silica, calcia, and magnesia.

The first inorganic fiber preferably contains the following components in the following content.
SiO ₂ : 70% by weight to 82% by weight
One or more selected from MgO and CaO: 18% by weight to 30% by weight
One or more selected from Al ₂ O ₃ , TiO ₂ and ZrO ₂ : 0 wt% to 6 wt%

The content of SiO _{2 in} the first inorganic fiber is preferably 70% by weight to 82% by weight, more preferably 72% by weight to 81% by weight, still more preferably 73% by weight to 80% by weight, particularly preferably 75% by weight. ~ 80% by weight.
The content of one or more metal oxides selected from MgO and CaO in the first inorganic fiber is preferably 18% by weight to 29% by weight, more preferably 19% by weight to 28% by weight, and even more preferably 20% by weight. -27% by weight.
The content of one or more metal oxides selected from Al ₂ O ₃ , TiO ₂ and ZrO _{2 in} the first inorganic fiber is preferably 0% by weight to 4% by weight, for example 0% by weight to 3% by weight. Or it can be 1 to 2 weight%.

The 1st inorganic fiber can contain the following ingredients with the following contents.
SiO ₂ 70 wt% to 82 wt%
CaO 0.5 wt% to 9 wt%
MgO 10 wt% to 29.5 wt%
Al ₂ O ₃ 0% by weight to 3% by weight

Moreover, the 1st inorganic fiber can contain the following components with the following content.
SiO ₂ 70 wt% to 82 wt%
CaO 15 wt% to 30 wt%
MgO 0% to 3% by weight
Al ₂ O ₃ 0% by weight to 5% by weight

Moreover, the 1st inorganic fiber can contain the following components with the following content. This fiber is excellent in heat resistance, alumina reaction resistance and biosolubility.
SiO _2: 72 wt% to 82 wt%
MgO: 8 to 22% by weight
CaO: 4 to 14% by weight
Al ₂ O _3: 0 wt% to 3 wt%
The main component is three components of SiO ₂ , MgO and CaO.
The main component is the three components with the highest content (% by weight) among all the components contained in the inorganic fiber (the component with the highest content, the component with the second highest content, and the content with the third It means that three of the higher components are SiO ₂ , MgO and CaO.

Moreover, the 1st inorganic fiber can contain the following components with the following content. This fiber is excellent in heat resistance, alumina reaction resistance and biosolubility.
SiO _2: 73.6 wt% to 82 wt%
MgO: 9.0 to 21.3% by weight
CaO: 5.1 wt% to 12.4 wt%
Al ₂ O _3: 0 wt% to less than 2.3 wt.% Fe ₂ O _3: 0 wt% to 0.50 wt%
The main component is three components of SiO ₂ , MgO and CaO.

  The first inorganic fiber contains one or more selected from MgO and CaO and silica, preferably 90% by weight or more, for example, 95% by weight, 97% by weight, 98% by weight or 99% by weight or more. be able to.

The content of SiO _{2 in} the second inorganic fiber is preferably 55% to 69% by weight, more preferably 57% to 67% by weight, still more preferably 58% to 65% by weight, particularly preferably 59% by weight. ~ 64% by weight.
The content of one or more metal oxides selected from MgO and CaO in the second inorganic fiber is preferably 20% to 45% by weight, more preferably 25% to 43% by weight, for example 30% by weight. ˜43 wt%, 31 wt% ˜43 wt%, 32 wt% ˜42 wt%, or 33 wt% ˜40 wt%.
The content of one or more metal oxides selected from Al ₂ O ₃ , TiO ₂ and ZrO _{2 in} the second inorganic fiber is preferably 0% to 6% by weight, for example 0% to 4% by weight. Or it can be 0.1 to 2 weight%.

The second inorganic fiber preferably contains the following components in the following content.
SiO _2: 57 wt% to 70 wt% less than MgO and one or more selected from CaO: 30 wt% to 43 wt%
One or more selected from Al ₂ O ₃ , TiO ₂ and ZrO ₂ : 0 wt% to 3 wt%

The second inorganic fiber more preferably contains the following components in the following content.
SiO ₂ : 58% by weight to 65% by weight
One or more selected from MgO and CaO: 33 wt% to 42 wt%
One or more selected from Al ₂ O ₃ , TiO ₂ and ZrO ₂ : 0 wt% to 2 wt%

The 2nd inorganic fiber can contain the following ingredients with the following contents.
SiO ₂ 58 wt% or more and less than 70 wt% CaO 25 to 38 wt%
MgO 2 to 10% by weight
Al ₂ O ₃ 0% by weight to 3% by weight

  The second inorganic fiber contains one or more selected from MgO and CaO and silica, preferably 90% by weight or more, for example, 95% by weight, 97% by weight, 98% by weight, or 99% by weight or more. be able to.

  The first and second inorganic fibers are each selected from Sc, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Y, or a mixture thereof. The oxide may or may not be included. The amount of these oxides may be 3.0% by weight or less, 2.0% by weight or less, 1.0% by weight or less, or 0.5% by weight or less, respectively.

The first and second inorganic fibers may or may not contain each of alkali metal oxides (Na ₂ O, Li ₂ O, K ₂ O, etc.), each of which is 3% by weight or less in total. 2% by weight or less, 1% by weight or less, 0.5% by weight or less, 0.4% by weight or less, 0.3% by weight or less, 0.2% by weight or less, or 0.10% by weight or less. it can.

The first and second inorganic _{fibers, ZnO, B 2 O 3,} P 2 O 5, SrO, Fe 2 O 3, BaO, may or may not contain each of the _Cr 2 _{O 3,} respectively, 3. It can be 0 wt% or less, 2.0 wt% or less, 1.0 wt% or less, 0.5 wt% or less, less than 0.1 wt%, or 0.05 wt% or less.

  Moreover, you may combine the quantity of said each component arbitrarily, respectively.

  The blend ratio (weight ratio) of the first inorganic fiber and the second inorganic fiber may be 5 to 95:95 to 5, preferably 10 to 90:90 to the first inorganic fiber: second inorganic fiber. 10, more preferably 20-80: 80-20, still more preferably 20-60: 80-40, particularly preferably 25-55: 75-45, most preferably 30-50: 70-50. As the first inorganic fiber and the second inorganic fiber, inorganic fibers each having a predetermined composition can be used alone or in combination.

The first and second inorganic fibers can be produced by a known method such as a melting method or a sol-gel method.
The average fiber diameter of the first and second inorganic fibers is usually 0.1 to 50 μm, for example, 0.5 to 20 μm or 1 to 10 μm.

Since the first and second inorganic fibers have the above composition, they are dissolved in physiological saline having a pH of 7.4.
The dissolution rate constant is a measurement method described in the examples, preferably 100 ng / cm ² · h or more, 300 ng / cm ² · h or more, 500 ng / cm ² · h or more, 800 ng / cm ² · h or more, or 1000 ng / cm ² · h or more.

  The molded body can contain an organic binder, an inorganic binder, an inorganic powder, a fixing agent, an aggregating agent, a chelating agent and the like in addition to inorganic fibers. As long as these do not impair the effects of the present invention, those usually used can be used. Examples of the organic binder include starch, acrylic resin, polyacrylamide, pulp, and acrylic emulsion, and examples of the inorganic binder include colloidal silica such as anionic colloidal silica and cationic colloidal silica, alumina sol, bentonite, and clay mineral. Examples of the inorganic powder include ceramic powder such as silica, alumina, titania, zirconia, silicon nitride, and silicon carbide, and carbon powder such as carbon black. Preferably, the molded body can comprise 50% by weight or more, more preferably 75% by weight or more, and still more preferably 80% by weight or more of the first and second inorganic fibers.

  The inorganic fibrous molded body of the present invention is preferably free from cracking when one side is heated at 1100 ° C. or 1200 ° C. for 24 hours by the method described in the examples.

  The inorganic fibrous molded body of the present invention preferably has high alumina resistance. When measured by the method described in the examples, it is preferable that the alumina pellets do not adhere by heating at 1200 ° C. for 8 hours. Moreover, it is preferable that the part which contacts an alumina pellet by 1300 degreeC heating for 8 hours does not fuse | melt.

  The heat shrinkage ratio is preferably 3.5% or less, more preferably 3.3% or less, and most preferably 3.0% or less in heating at 1300 ° C. for 8 hours when measured by the method described in Examples. .

  When the inorganic fibrous molded body is heated at a high temperature, a crystal of a single oxide of Si, or a crystal of a composite oxide of Si and Ca, Mg and / or Al is formed. Remaining unreacted when Si, Ca, Mg, Al, components such as inorganic fibers and other binders contained in the board, produced diopside, wollastonite, enstatite and mullite crystals to the maximum This silica is used as excess silica. Excess silica can be an indicator of the amount of cristobalite that can be produced. The excess silica in the inorganic fibrous molded body is preferably 50 mol% or less, more preferably 45 mol% or less, still more preferably 40 mol% or less, and particularly preferably 35 mol% or less.

  The amount of silica contained in the inorganic fibrous molded body is determined by the amount of silica contained in the inorganic fibers and the amount of silica contained in other components, but the amount of excess silica tends to decrease as the amount of silica decreases. Accordingly, the amount of silica contained in the inorganic fibrous molded body is preferably 75% by weight or less, more preferably 70% by weight or less.

  Although the shape of an inorganic fibrous molded object is not limited, For example, a block, a board, a mold, an indeterminate form etc. are mentioned.

Hereinafter, although a specific Example is shown, this invention is not limited to this Example.
Table 1 shows the fiber composition used in the experiment.

Since AES fibers contain MgO and CaO, they are more biosoluble than RCF fibers.
The biosolubility of HS1 and RCF1 was measured by the following method.
The inorganic fiber was placed on a membrane filter, and physiological saline having a pH of 7.4 was dropped on the fiber with a micropump, and the filtrate that passed through the fiber and the filter was stored in a container. The collected filtrate was taken out after 24 hours, and the eluted components were quantified with an ICP emission spectrometer, and the solubility was calculated. The measurement elements of HS1 are the three elements, Si, Mg, and Ca, which are the main elements, and the measurement elements of RCF1 are the two elements, Si and Al, which are the main elements. The average fiber diameter was measured and converted to a dissolution rate constant (unit: ng / cm ² · h) which is the amount of elution per unit surface area / unit time.
For the average fiber diameter, 400 or more fibers were observed and photographed with an electron microscope, and then the diameter of the photographed fiber was measured to obtain an average value of all the measured fibers.
HS1 is about 1400ng / cm ² · h, RCF1 was about 20ng / cm ² · h.

Experimental example 1 (comparative example)
(1) Generation of cracks Using HS1 having the composition described in Table 1, 5.5 parts by weight of colloidal silica, 5 parts by weight of starch, 1 part by weight of chelating agent, and 1 part by weight of flocculant with respect to 100 parts by weight of HS1 Was blended in an amount of 0.5 parts by weight to produce an HS1 board having a length of 860 mm, a width of 450 mm, and a thickness of 50 mm. The presence or absence of a crack when the HS1 board was heated on one side was examined by the following method.

An RCF1 board was produced in the same manner as described above except that RCF1 having the composition shown in Table 1 was used.
A four-layered single-sided heating evaluation furnace was produced. FIG. 1 is a schematic sectional view of a single-sided heating evaluation furnace. In this figure, the single-sided heating evaluation furnace 1 is composed of a board having four layers of walls, an HS1 board (sample to be measured) is used as the inner layer 11, the layers 12 and 13 are RCF1 boards, and the outer layer 14 is a cage. An acid calcium board was used. The panel heater 20 was heated to 800, 900, 1000, 1100, and 1200 ° C. for 24 hours, respectively. The results are shown in Table 2. The HS1 board cracked when heated at 1100 ° C. and cooled.

(2) XRD measurement The XRD measurement was carried out under the following conditions for the furnace inner side, center part, and interface side of the HS1 board after heating at 1100 ° C. in (1). The result is shown in FIG. As shown in this figure, it was found that cristobalite (SiO ₂ ) crystals were generated inside the furnace.
In addition, XRD measurement was performed on the HS1 board heated at 800, 900, 1000, 1100, 1200, and 1300 ° C. for 8 hours. The results are shown in Table 2. As shown in Table 2, it can be seen that a large amount of cristobalite is generated at 1100 ° C. or higher.
XRD measurement conditions:
Measuring device: Ultimate III made by Rigaku
Measurement conditions: X-ray: CuKα ray, voltage: 40 KV, current: 30 mA,
Sampling width: 0.02 °, scan speed 2.0 ° / min

Experimental example 2 (comparative example)
Except for using RCF1, HS2, HS3, HS4, and LS1 having the composition shown in Table 1, a board was manufactured and observed for cracks in the same manner as in Experimental Example 1 (1). The results are shown in Table 2. The board using HS2, HS3, HS4 was cracked by one-side heating at 1100 ° C. for 24 hours, the board using LS1 had no or few cracks, and the board using RCF1 had no cracks.
Further, XRD measurement was performed on each board that was heated for 8 hours at 800, 900, 1000, 1100, 1200, and 1300 ° C. in the same manner as in Experimental Example 1 (2). The results are shown in Table 2. From the table, it can be seen that there is a correlation between the generation of cristobalite and the occurrence of cracks.

Experimental Example 3 (Example and Comparative Example)
(1) Production of board A board was produced in the same manner as in Experimental Example 1 (1) except that only HS1, only LS2, and a mixture of HS1 and LS2 were used. The mixing ratio (weight ratio) was changed as shown in Table 3.
(2) Evaluation of crack and crystal About the board manufactured by (1), the presence or absence of the crack was observed like Experimental example 1 (1). The results are shown in Table 3. In the board using the mixed fiber, it can be seen that there is little or no cracking even by single-sided heating at 1200 ° C., and the occurrence of cracking is suppressed.
Further, XRD measurement was performed on each board that was heated at 1000, 1100, 1200, and 1300 ° C. for 8 hours in the same manner as in Experimental Example 1 (2). The results are shown in Table 3. FIG. 3 shows an XRD chart of the board heated at 1100 ° C. over the entire surface. FIG. 3 shows that the generation of cristobalite decreases as the mixing ratio of LS2 increases.

(3) Heat Shrinkage Ratio and Alumina Resistant Resistance With respect to the board manufactured in (1), the heat shrinkage ratio and the alumina resistance resistance were measured by the following methods.
(I) Heat shrinkage rate (heat resistance)
Two or more platinum pins were driven into the surface of the manufactured board, the distance between the platinum pins was measured before and after heating, and the dimensional change rate was defined as the heat shrinkage rate. The results are shown in FIG. When the mixing ratio of LS2 was about 30 to 50% by weight, the heat shrinkage rate at 1300 ° C. was reduced as compared with the case of HS1 100%.

(Ii) Alumina resistance About 1 g of alumina powder having a purity of 99% or more was press-molded with a mold having a diameter of 17 mm to form pellets. This pellet was placed on a board and the reactivity after heating at 1100-1300 ° C. for 8 hours was confirmed. The case where it did not react with the pellet at all was marked with ◯, the case where it was lightly attached to the board, and the case where the hole was opened when the board melted and the pellet was removed. The results are shown in Table 4. As LS2 increases, the alumina reactivity decreases.

(4) Excess silica Excess silica was calculated for the board produced in (1) (see paragraph 0036). The results are shown in Table 5. For reference, the crystal phase at 1100 and 1200 ° C. and the data on cracking during single-sided heating are also shown. It turns out that there are few cracks, when there is little surplus silica.

  HS1 has better heat resistance and alumina reactivity than LS2, but cracking occurred when heated on one side at 1100 ° C or higher. However, when LS2 was mixed, cracking due to single-sided heating at 1100 ° C. or higher could be suppressed while substantially maintaining heat resistance and alumina reactivity.

  The inorganic fibrous molded body of the present invention can be used in various applications as a general high-temperature heat insulating material, a furnace furnace ceiling, a furnace wall heat insulating material lining material, a heat insulating material, and a backup material.

1 Single-sided heating evaluation furnace 11 HS1 board 12, 13, 14 RCF1 board 20 Panel heater

Claims (10)

One or more metal oxides selected from calcia and magnesia, silica, a first inorganic fiber containing 18-30 wt% of the metal oxide and 70-82 wt% of the silica;
One or more metal oxides selected from calcia and magnesia, and containing silica, 18 to 50% by weight of the metal oxide, and a second inorganic fiber containing 50 to 70% by weight of the silica. Inorganic fiber molded body (excluding mats) . One or more metal oxides selected from calcia and magnesia 18-30 wt%, by silica 70 to 82 _{wt%, Al 2 O 3, TiO} 2 and 0% by weight of one or more selected from ZrO ₂ ~ A first inorganic fiber comprising a content of 6% by weight ;
One or more metal oxides selected from calcia and magnesia 30 wt% to 43 wt%, shea silica less than 70 wt% 57 wt% or more, _Al 2 _O 3, TiO ₂ and one or more selected from ZrO ₂ And an inorganic fiber molded body containing a second inorganic fiber containing 0 to 3% by weight . The inorganic fiber molding according to claim 1 or 2 , wherein a weight ratio of the first inorganic fiber to the second inorganic fiber is first inorganic fiber: second inorganic fiber = 5 to 95: 95-5. body. The first inorganic fiber includes 90% by weight or more of the metal oxide and silica,
The inorganic fiber molded body according to any one of claims 1 to 3, wherein the second inorganic fiber includes 90% by weight or more of the metal oxide and silica. The inorganic fiber molded body according to any one of claims 1 to 4, wherein the first inorganic fiber includes the following components in the following content.
SiO _2: 72 wt% to 82 wt%
MgO: 8 to 22% by weight
CaO: 4 to 14% by weight
Al ₂ O _3: 0 wt% to 3 wt%
Mainly composed of three components of SiO ₂ , MgO and CaO The inorganic fiber molded body according to any one of claims 1 to 5 , wherein the second inorganic fiber includes the following components in the following content.
SiO ₂ 58 wt% or more and less than 70 wt% CaO 25 to 38 wt%
MgO 2 to 10% by weight
Al ₂ O ₃ 0% by weight to 3% by weight Si, Ca, Mg and Al, claim diopside, wollastonite, the amount of excess silica when enstatite and mullite crystals was assumed to have maximally generated is not more than 50 mol% 1-6 An inorganic fibrous molded article according to any one of the above. The inorganic fibrous molded body according to any one of claims 1 to 7 , wherein the content of silica is 75% by weight or less. The inorganic fiber molded body according to any one of claims 1 to 8 , wherein no cracks are produced when one side is heated at 1100 ° C for 24 hours. The inorganic fibrous molded body according to any one of claims 1 to 9 , wherein when one side is heated at 1200 ° C for 24 hours, no crack is generated.