JPH09202645A - Rock wool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a rock wool which mainly comprises SiO2 , Al2 O3 and alkaline earth metal oxides and has a high level of heat resistance comparable to that of ceramic fiber. SOLUTION: This rock wool contains a sufficient amount of diopside particularly containing Al, Fe<+3> -substituted diopside to keep its fiber form even at 1050 deg.C without softening and melting, when it is heated at elevated temperature, and converting to crystalline fiber. This rock wool contains 30-45wt.% of SiO2 , 10-16wt.% of Al2 O3 , 25-35wt.% of CaO, 3-10wt.% of MgO and 3-10wt.% of FeO as essential components, totaling to >=90wt.%. In other words, the FeO content of 3-10% is important in this composition.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to rockwool having good heat resistance.

[0002]

2. Description of the Related Art Rockwool is a molten product obtained by melting a mixture of iron and steel slag and various raw materials for minerals with silica stone, dolomite, etc. added as a component ratio adjusting material and heating it in a cupola or electric furnace. It is a glassy inorganic fiber obtained by fiberizing by blowing air with compressed air (blowing method) or by colliding it with a high-speed rotating body (rotor method). Its chemical composition is generally SiO ₂ 35-50.
% (Weight; the same applies hereinafter), Al ₂ O ₃ 10-20%, CaO
30-40%, MgO 3-6%, FeO + Fe ₂ O ₃ 0.1
In addition, the other trace components contained in the total amount of about 5% are TiO ₂ , MnO, Cr ₂ O ₃ , BaO and Na.
₂ O, K ₂ O, S and the like.

Rock wool, which is a relatively inexpensive incombustible fiber, is widely used in bulk fiber as a fireproof covering material or a high-temperature heat insulating material, and as a heat insulating material in the form of blankets, mats, felts, boards and the like. ing. However, the conventional rockwool product has an upper limit of usable temperature of 750 ° C. at most, and at a higher temperature than that, it softens and melts to cause remarkable shrinkage and deformation.

Although silica-alumina ceramic fibers can be used at higher temperatures, it is becoming difficult to use them in fireproof coating materials and the like because of their high cost and environmental hygiene.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a ceramic in terms of heat resistance while having the advantage that it can be manufactured at a low cost similarly to the conventional rock wool and is also highly flexible. It is intended to provide rock wool having a high degree of heat resistance, which can be used at around 1000 ° C. like a fiber.

[0006]

The heat-resistant rock wool that has been successfully provided by the present invention is a rock wool containing SiO ₂ , Al ₂ O ₃ and an alkaline earth metal oxide as a main component, and is resistant to high temperatures. When heated, it is characterized by being transformed into a crystalline fiber containing a sufficient amount of diopside, particularly Al, Fe ⁺³ substituted diopside, to maintain the fiber morphology at 1050 ° C without softening and melting. It is a thing.

[0007] Jiopusaido is a basic composition of CaO · MgO · 2SiO _2, the mineralogy is monoclinic crystals called diopside. Usually, some of Ca, Mg, and Si in the above basic composition are A while retaining common crystallographic properties.
It exists in a state in which it is substituted with metal elements such as l, Mn, Cr, Zn, Fe and the like. In this specification, a diopside in which some of the metal elements are substituted has Al and Fe ⁺³ as essential components, which is referred to as Al, Fe ⁺³ substituted diopside.

A typical rockwool having the above characteristics, which produces Al, Fe ⁺³ substituted diopside when heated to a high temperature, has a chemical composition of 30 to 45% by weight of SiO ₂ and 10 of Al ₂ O ₃ . ~ 16 wt%, CaO 25-35 wt%, MgO 3-10 wt%, FeO 3-10 wt%
It is characterized in that the total content of these essential components is 90% by weight or more.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION As described above, when the rock wool of the present invention is heated to a high temperature, it produces diopside in the rock wool before it softens and melts. The temperature at which the formation of diopside becomes particularly remarkable is about 830 to 850 ° C., although it varies somewhat depending on the composition of rock wool. Due to the rapid and prominent formation of diopside (simultaneous formation of crystals other than diopside at the same time), the rockwool of the present invention turns into a crystalline fiber when exposed to a high temperature atmosphere. , The amorphous portion is probably reduced to about 5-10% by weight or less.

As a result, this conventional rock wool is completely softened and melted by the conventional ordinary rock wool.
It is quite stable even at around 50 ° C. Moreover, since the produced diopside does not change its crystal form even when the temperature further rises, this rockwool maintains the fiber form up to around 1050 ° C., and the cotton collected molded product is heated at 1050 ° C. for 3 hours. The linear shrinkage ratio does not exceed 5% (Although the conventional rockwool composition also crystallizes at around 850 ° C and crystallizes melilite, it softens and melts before that, so rock wool cotton molding Objects will undergo significant shrinkage and deformation.)

Rock wool containing about 3 to 10% by weight of FeO so as to produce Al, Fe ⁺³ -substituted diopside when heated to a high temperature is particularly preferable because the crystallization before the softening and melting is sure.

The physical properties of the rockwool as fibers naturally change with the crystallization of the glassy constituents, and there are disadvantageous changes such as a decrease in flexibility, but such changes after being put into use. Since there is little inconvenience, it becomes possible to use at a high temperature, which exceeds the conventional wisdom about rock wool.

It is noted that diopside occurs in rock wool before it softens and melts when heated to a high temperature.
It can be confirmed as follows. 200 ° C /
The sample is heated at a heating rate of about Hr, and when the temperature reaches 850 ° C., the temperature is maintained for 3 hours. Then, it is cooled to room temperature and the appearance is observed. Unless the fiber morphology before heating such as contraction and lump formation is maintained, it cannot be said to be the rock wool of the present invention without confirming generation of diopside.
The presence or absence of diopside in the sample maintaining the fiber form is confirmed by the following powder X-ray diffraction analysis.

Powder X-ray diffraction analysis method: A sample was crushed in an agate mortar to obtain a fine powder having a particle size of 44 μm or less (passing 250 mesh), which was then put into a sample holder (35 × 50 mm ² , aluminum with a thickness of 1.5 mm). The plate is filled with 20 x 18 mm ² holes), set in the X-ray diffractometer, and the tube voltage is set to 30.
Measure KV, tube current 15 mA, and scan each 2θ = 5 to 70 °. The crystal component is identified by comparing the d value of each diffraction peak of the obtained X-ray diffraction peak pattern with the JCPDS data (see Example 1 below).

Accurate quantitative analysis of diopside in a sample in which the presence of diopside was confirmed is difficult, but when various analysis results are combined, the amount of diopside in the rock wool 850 ° C. heat-treated product of the present invention is: It is estimated to be at least 50% by weight, usually about 90% by weight or more.

The chemical composition of the rockwool of the present invention is not limited as long as it can generate diopside before it is softened and melted when heated to a high temperature, and is not limited, but preferably. , Al, Fe ⁺³ substituted diopside can be produced at a high rate, that is, SiO ₂ of 30 to 45
% By weight, 10 to 16% by weight of Al ₂ O ₃ and 25 to ₃ of CaO.
5% by weight, 3 to 10% by weight of MgO and 3 to 10% by weight of FeO are contained, and the total amount of these essential components is 90% by weight or more.

The above-mentioned preferable component ratio is "a crystalline material containing a sufficient amount of Al, Fe ⁺³ substituted diopside to maintain the fiber morphology even at 1050 ° C. without softening and melting when heated to a high temperature. Rock wool that transforms into fibers ”
It was confirmed based on the compositional analysis values before and after the high-temperature heat treatment of several cases and the compositional analysis results of Al, Fe ⁺³ substituted diopside generated in the rock wool.
The composition of ⁺³ substituted diopside (however Fe ₂ O ₃ is converted to FeO) is included as an optimum value (Al, Fe ⁺³ substituted diopside composition is such that the heat treated rockwool product of the diopside is treated with hydrochloric acid. It was confirmed by analyzing the diopside separated by the method described in Example 1 below.

The inclusion of FeO is of particular importance in order to be able to give Al, Fe ⁺³ -substituted diopsides when heated to high temperatures, and the amount must be above 3% by weight. However, if the content of FeO is too high, the flexibility is insufficient, so the upper limit content is about 10% by weight. (In the case of the conventional rock wool containing mainly Fe ₂ O ₃ even with the same iron content, the high temperature is not When heated, the formation of Al, Fe ⁺³ substituted diopside is not remarkable, and the rock wool softens and melts before being stabilized by crystallization.
It is considered that the process in which Fe ⁺² of FeO in rockwool is oxidized to Fe ⁺³ is involved in the process of producing l, Fe ⁺³ substituted diopside. ).

Fe ₂ O ₃ does not interfere with the formation of Al, Fe ⁺³ -substituted diopside in the presence of an appropriate amount of FeO, but a large amount of Fe ₂ O ₃ results in the same amount of fibers as when the amount of FeO is too large. Since the physical properties are deteriorated, it is desirable that the upper limit content of the total amount of FeO and Fe ₂ O _{3 be} about 10% by weight.

The total content of the above-mentioned essential components is preferably as high as possible, and Fe ₂ O ₃ , TiO ₂ , MnO, Cr ₂ O ₃ and Ba are contained.
It is desirable that the total amount of trace components such as O, Na ₂ O, K ₂ O, and S, which originate from the raw materials and are inevitably mixed, is less than 10% by weight.

Rockwool having the above composition and capable of producing Al, Fe ⁺³ substituted diopside is produced in exactly the same manner as conventional rockwool except that the raw material composition is selected so that the chemical composition is within the above range. can do. That is, blast furnace slag, converter slag, basalt, amphibolite, diorite, silica stone, dolomite, wax stone, feldspar, otolith, etc.
Appropriately blended (among these raw materials, FeO sources can be converter slag, basalt, amphibolite, diabase, etc.),
It can be manufactured without difficulty by heating and melting in a cupola furnace and fibrillating by a known method such as a rotor method.

The obtained rock wool can be collected by a conventional method, laminated, bound with a binder and cured to be molded into a board or other shape, and can be used as a heat insulating material or the like.

[0023]

【Example】

Example 1 Blast-furnace slag, converter slag, basalt, amphibolite, etc. are used as raw materials, and a mixture of these is heated and melted in a cupola furnace, fiberized by a rotor system, and then collected and laminated, and further a phenol resin binder. And then heated to cure the binder to produce a board having a bulk density of 150 kg / m ³ .

Three types of rock wool having different compositions were produced by changing the raw material mixture ratio in the above production method, and the test pieces of the boards (length 150 mm, width 50 mm, thickness 25 mm) made of them were heated. The test was conducted.
For comparison, the same test was performed on standard conventional rock wool (two commercial products). The test method is as follows.

Test method: A test piece is placed in an electric furnace, heated from room temperature to 850 ° C., 950 ° C., or 1050 ° C. at a heating rate of 200 ° C./Hr. Hold for 3 hours. Then, the test piece is taken out of the electric furnace, cooled to room temperature, the shrinkage rates in the length direction and the width direction are measured, and the average value of both shrinkage rates is taken as the linear shrinkage rate. The number of tests is 3 for each condition, and the measurement results are displayed as an average value.
The results are shown in Table 1. Comparative Examples 1 and 2 are commercial products.

[0026]

Table 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 Example 1 Example 2 Chemical composition (wt%) SiO ₂ 46.9 39.4 40.0 34.8 38.5 Al ₂ O ₃ 12.4 15 .2 13.0 12.9 13.0 CaO 32.7 33.1 29.1 33.2 25.5 MgO 3.8 5.8 6.9 6.2 6.2 6.2 FeO 0.2 1.7 2.6 5.7 7.6 Fe ₂ O ₃ 0.0 0.1 0.4 0.8 0.8 TiO ₂ 1.1 0.6 0.6 1.5 1.1 1.0 MnO 0.4 0 .3 0.4 1.6 0.9 0.9 Na ₂ O Traces 1.0 2.7 1.9 3.8 K ₂ O 0.6 0.9 1.4 1.4 0.2 0.8 Others 1.9 1 .9 2.0 1.3 1.9 Linear shrinkage of board (%) After heating at 850 ° C ※※ 8.3 2.1 3.1 After heating at 950 ° C ※※ 10.5 2.5 3.4 1050 After heating at ℃ ※※ 15.4 3.9 4.3 (※ Significant shrinkage and deformation at 850 ℃, the fiber lost its original shape.)

Table 2 shows the results of examining the crystallization state of the test pieces of each example after the heating test by powder X-ray diffraction analysis.

[0028]

[Table 2] After heating at 850 ° C for 3 hours After heating at 950 ° C for 3 hours After heating at 1050 ° C for 3 hours Comparative Example 1 Melilite (S) Melilite (S) Same as left Anorthite (M) Diopside (W) Comparative Example 2 Melilite (S) Melilite (S) Same as left Anorthite (M) Diopside (W) Comparative Example 3 Melilite (S) Melilite (S) Same as left Diopside (M) Diopside (M) Anorthite (W) Example 1 Diopside (S) Same as left Same as left Merrilite (S) Example 2 Diopside (S) Diopside (S) Same as left Merrilite (W) Melilite (W) Wollastonite (VW) Anorthite (VW) (Note) S: Large amount M: Medium amount W: Small amount VW: Trace amount

From Tables 1 and 2, in the conventional rock wool (Comparative Examples 1 and 2), melilite was crystallized by heating at 850 ° C., but a considerable portion remained in a vitreous state, which was 95%.
It can be seen that heating at 0 ° C. gives a medium amount of anorthite and a small amount of diopside, and during that time the fiber softens or melts. Comparative Example 3 in which the FeO content is 2.6% by weight produces moderate diopside upon heating at 850 ° C., but shows a crystallization tendency similar to that of conventional rockwool.

On the other hand, the rock wool of the present invention has a temperature of 850 ° C.
High degree of crystallization that mainly produces diopside upon heating, and the formed crystalline state is 950 ° C and 10 ° C.
It can be seen that there is almost no change even by heating at 50 ° C.

Next, 8 of Examples 1 and 2 in the above test
The composition of the generated diopside was examined for the 50 ° C. heat-treated product. That is, the 850 ° C. heat-treated product was made into a powder of 200 mesh or less and put into 0.2N-hydrochloric acid at room temperature.
The mixture is stirred for 0 minutes to dissolve crystals other than glass and diopside, filtered and washed with water to obtain diopside as a residue. The diopside residue GS-1 (of Example 1)
And GS-2 (of Example 2) were subjected to chemical analysis, and GS-1 was subjected to powder X-ray diffraction analysis. The results are shown in Tables 3 and 4. 1 to 3 are charts showing the data of Table 4.

The result of the X-ray diffraction analysis is JCPDS (Joint
comittee of Powder Diffraction Standard) Two types of diopside No. 11-654 and N listed on the card
It showed good agreement with the powder X-ray diffraction data of o.41-1370.

[0033]

[Table 3]

[0034]

[Table 4]

The above diopside residue GS-1 and G
For S-2, using the data in Table 3, the basic composition CaMgS
The rational formula obtained by calculating the number of O based on i ₂ O ₆ as 6 was as follows. GS-1: Ca _0.98 (Mg _0.44 Al _0.07 Fe ⁺³ _0.38 Ti _0.09 Mn _0.11 ).
_1.09 (Si _1.43 Al _0.57 ) ₂ O ₆ GS-2: Ca _1.04 (Mg _0.45 Al _0.13 Fe ⁺³ _0.28 Ti _0.04 Mn _0.04 N
a _0.03 K _0.03 ) _1.00 (Si _1.56 Al _0.44 ) ₂ O ₆

Test Example For the plate-like refractory material (thickness 50 mm, bulk density 150 kg / m ³ ) made of rock wool of Examples 1 and 2 and Comparative Example 2, “Fireproof test method for building structure part” (JIS A1304).
The fire resistance performance was tested according to the following method.

Test method: A steel material (H-300 × 300 × 10 × 15 × 2400Hmm) with thermocouples attached at 18 places on the surface is surrounded by 300 ×
Cover with a 500 mm (partly 300 x 400 mm) refractory material, raise the ambient temperature under the conditions specified by JIS, and track the change in steel material temperature (average value). Table 5 shows the test results.

[0038]

Table 5 Comparative Example 2 Example 1 Example 2 Time to reach 350 ° C. (min) 60 107 95

After the test, the refractory material of Comparative Example 2 had a blackish-melt surface. On the other hand, the refractory materials of Examples 1 and 2 are
Although the surface was discolored to dark brown, the shrinkage and the opening of the joint were slight, and the skin of Example 1 was particularly thin.

[0040]

As described above, according to the present invention, it has a high heat resistance which exceeds the conventional wisdom of rock wool and is 1000
° Rock wool that can be used before and after is provided. It is also a feature of the present invention that this rock wool does not require any special raw material or manufacturing method and can be manufactured at a low cost like conventional rock wool.

[Brief description of drawings]

FIG. 1 Powder X-ray diffraction chart of Diopside No. 11-654 described in JCPDS card

FIG. 2 is a powder X-ray diffraction chart of diopside No. 41-1370 described on the JCPDS card.

FIG. 3 is a powder X-ray diffraction chart of Al, Fe ⁺³ substituted diopside in the heat-treated 850 ° C. rock wool of Example 1.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shiro Kamiko 26 Kurita, Kanagawa-ku, Yokohama

Claims (4)

[Claims] 1. A rockwool containing SiO ₂ , Al ₂ O ₃ and an alkaline earth metal oxide as a main component, when heated to a high temperature, does not soften and melt at 1050 ° C.
The rock wool is characterized by being transformed into a crystalline fiber containing diopside in an amount sufficient to maintain the fiber morphology. 2. A rockwool containing SiO ₂ , Al ₂ O ₃ and an alkaline earth metal oxide as a main component, when heated to a high temperature, does not soften and melt at 1050 ° C.
Sufficient amount of Al, Fe to maintain fiber morphology
Rock wool characterized by being transformed into crystalline fibers containing ⁺³ substituted diopside. 3. A rockwool containing SiO ₂ , Al ₂ O ₃ and an alkaline earth metal oxide as a main component, wherein Fe
A crystalline material containing ³ to 10% by weight of O and containing Al, Fe ⁺³ substituted diopside in an amount sufficient to maintain the fiber morphology even at 1050 ° C. without softening and melting when heated to a high temperature. Rock wool characterized by being transformed into fibers. 4. As an essential component, SiO ₂ is 30 to 45% by weight, Al ₂ O ₃ is 10 to 16% by weight, CaO is 25 to 35% by weight, MgO is 3 to 10% by weight, and FeO is 3 to 10% by weight. %
Rockwool contained, wherein the total amount of these essential components is 90% by weight or more.