BINDER FOR MONOLITHIC REFRACTORIES, MONOLITHIC REFRACTORY,
AND CONSTRUCTION METHOD OF MONOLITHIC REFRACTORIES
5
Field of the Invention
[0001]
The present invention relates to a binder for monolithic refractories, which is
used for the lining or repair of furnaces, a monolithic refractory, and a construction
10 method of monolithic refractories.
Priority is claimed on Japanese Patent Application No. 2010104559, filed April
28, 2010, the content of which is incorporated herein by reference.
Related Art
15 [0002]
As a binder for the lining refractories of furnaces used for a variety of high
temperature processes, best exemplified by steel processes, a number of organic and
inorganic compounds, such as sodium phosphate, sodium silicate, a fiaran resin, a. phenol
resin, pitch, aluminum lactate, sodium aluminate, silica sot, alumina sot, polyvinyl
20 alcohol, methylcellulose, carboxymethylcellulose, ethylsilicate, alumina cement,
hydraulic alumina, or the like, are used.
[0003]
In recent years, refractories have become unshaped for improvement in
constructability, ease of repair, or the like, and monolithic refractories have become
25 widely used even in parts that come into contact with molten iron or high temperature
2
slag, for which shaped bricks were used in the past.
[0004]
The manufacture of monolithic refractories does not include a high pressure
press, which is performed in the manufacture of shaped refractories. Therefore, the
5 characteristics of raw materials or binders for a filling property, firmness, and
development of strength are particularly important. Among them, alumina cement
(major chemical compounds: CaO•Al2O3, CaO.2Al2O3, l2CaO.7Al2O3) is used for a
wide range of uses as a binder for refractories of degassing and secondary refining
facilities such as a blast furnace runner, a molten steel ladle, or RH; a tundish; a heating
10 furnace; heat treatment furnace; and the like.
[0005]
Furthermore, investigations are also ongoing with alumina- based binders
including chemical components other than CaO-Al2O3.
[0006]
15 For examples, Patent Documents 1 and 2 disclose mixtures of raw materials for
the manufacture of refractory alumina cement including barium or strontium and alumina
as the main chemical components. Specifically, the mixtures of raw materials for the
manufacture of cement are obtained by appropriately performing a thermal treatment on
mixtures of carbonates and chlorides.
20 [0007]
Non-Patent Document 1 discloses a material produced by adding a commercial
high-purity reagent to CaO-SrO-A12O3-based cement and then blending and firing the
mixture, which shows a property of being hardened with an addition of water.
[0008]
25 In addition, Patent Document 3 discloses a binder for monolithic refractories
3
using mixtures of raw materials for the manufacture of cement having CaOtSrO-Al2O3
composition, which shows improved high temperature slag resistance, compared to
binders with CaO-Al2O3 composition.
5 Reference Documents
Patent Documents
[0009]
[Patent Document 1] Japanese Unexamined Patent Application, First
Publication No. 552148524
10 [Patent Document 2] Japanese Unexamined Patent Application, First
Publication No. S58-26079
[Patent Document 3] Japanese Unexamined Patent Application, First
Publication No. 2008-290934
Non-Patent Documents
15 [0010]
[Non-Patent Document 1] Ito, Mizuno, Kawano, Suzuki: Journal of the
Ceramic Society of Japan, 89, 10, P. 572-577, 1981
[Non=Patent Document 2] Prodjosantoso, A.K. and B.J. Kennedy, Journal of
Solid State Chemistry, 2002, Vol.168, No.1, pp.229-236
20
Disclosure of the Invention
Problems to be Solved by the Invention
[0011]
However, the demand for improvement in steel quality tends to make conditions,
25 such as operation temperature, or the like, more severe and thus high temperature
4
corrosion resistance, or the like is continuously becoming insufficient in conventional
binders. Compared to chemical components in refractory aggregates for monolithic
refractories, binders including alumina cement, which are generally used, have problems
in that they are liable to form low melting point materials due to ferric oxides in molten
5 iron or slag, and wear or infiltration proceeds from binder portions in refractories, which
makes it impossible to sufficiently develop the intrinsic tolerance of chemical
components in the refractory aggregates.
[0012]
That is, patent Document 1 supplies the mixtures of raw materials for the
10 manufacture of refractory alumina cement including barium or strontium and alumina as
the main chemical components, and studies the strength, or the like of clinker binders
using the mixtures of raw materials. However, the compressive strength is not
sufficiently developed 3 days and' days after the manufacture and eventually reaches the
maximum on the 28 days after the manufacture.
15 [0013]
Generally, monolithic refractories are subjected to drying and heating 1 day after
the manufacture and are often placed under the operating environment. From such a
viewpoint, development of the maximum strength within 24 hours is strongly required.
As a result, binders whose maximum strength is eventually developed on the 28 days
20 after manufacture cannot be adopted for monolithic refractories.
[0014]
In addition, Patent Document 1 discloses nothing about high temperature
characteristics of higher than 1000°C and furthermore is not clear about corrosion
resistance with respect to high temperature molten iron or slag and discloses nothing
25 about methods for the application to monolithic refractories with excellent high
temperature corrosion resistance.
[0015]
In addition, Patent Document 2 supplies heat-insulating castable mixtures using
strontium aluminate as a binder, with which heat-insulating materials with high
5 temperature strength can be obtained. However, the document is about heat-insulating
uses for which the mixtures are lined on the rear surface of furnaces, and therefore is not
clear about corrosion resistance with respect to high temperature molten iron or slag,
which is an essential characteristic for the wear lining of furnaces. In addition, when
strontium aluminate is used as a binder, strontium ions are liable to be eluted during
10 mixing, which easily leads to agglomeration. Accordingly, it becomes clear that there
are cases where the construction of the heat insulating castable mixtures using strontium
aluminate as a. binder is difficult.
[0016]
In addition, Non-Patent Document 1 shows that CaO-SrO-Al2O3-based cement
15 is produced and the strength of hardened bodies becomes extremely great at an amount of
Sr-substitution of from 0.3 mot to 0.4 mot. However, the document discloses nothing
about high temperature characteristics of higher than 1000°C, and also shows nothing
about methods for the application to monolithic refractories with excellent high
temperature corrosion resistance.
20 [0017]
Due to the above limitations, as binders for monolithic refractories in actual
industrial uses, alumina cement including CaO-Al2O3, as the major chemical component,
a-A1203 or CaO.2A12O3, I2CaO.7Al2O3 and a variety of additives are used.
[0018]
25 In addition, Non-Patent Document 2 shows that a crystal structure of a
6
CaA12O4 SrA12O4 solid solution varies depending on the amount of Ca or Sr solidified.
The Introduction thereof shows that CaA12Oa is the major chemical component of high
alumina cement used for a heat-resistant castable in the steel industry. However, the
document discloses or suggests nothing relating to performance, for example, the
5 strength or corrosion resistance of monolithic refractories when the CaAl2O4-SrAl2O4
solid solution is used as a binder for monolithic refractories.
[0019]
That is, as of now, examples of alumina cement used as binders for monolithic
refractories include "high alumina cement ES", "high alumina cement VS-2", "high
10 alumina cement super 90", "high alumina cement super G", "high alumina cement super
2", "high alumina cement sup eer", or the like (all product names, manufactured by Denki
ICagaku Kogyo Kabushiki Kaisha); "SECAR 71 ", "SECAR 80", or the like (all product
names, manufactured by Kerneos Inc.); or the like. Any of the above includes
CaO•AI2O3, as the major chemical component, a-A1203 or CaO.2Al2O3, 12CaO.7A12O3,
15 and a small amount of additives depending on required characteristics.
[0020]
As a result, there has been a strong demand for the development of binders for
monolithic refractories with excellent corrosion resistance with respect to high
temperature molten iron or slag because conditions such as operation temperature
20 continuously become more severe.
[0021]
On the other hand, Patent Document 3 discloses CaxSru_xA12O4 as binders having
excellent corrosion resistance with respect to slag or molten iron, compared to alumina
cement in the conventional technology. However, in order for Ca,Srl _,A12O4 to be
25 widely used as binders of monolithic refractories of furnaces having various thicknesses
7
and shapes and the like, further improvement of hardened strength is required.
[0022]
An object of the present invention is to provide a binder for monolithic
refractories having excellent corrosion resistance with respect to slag or molten iron and
5 excellent characteristics in the early development of hardened strength and the stability
thereof, compared to binders such as alumina cement in the conventional technology; a
monolithic refractory using the binder; and a construction method of the monolithic
refractory.
10 Methods for Solving the Problem
[0023]
The inventors paid attention to substituting Ca in a binder for monolithic
refractories with a metal atom from the viewpoint of improving the refractoriness of a
monolithic refractory, and newly found that, by dissolving SrO in CaO•Al203 which is a
15 component of alumina cement in the conventional technology (in other words, by
dissolving Ca components in SrAl2O4 to obtain a solid solution), a composition has a
high melting point, corrosion resistance with respect to slag or molten iron is excellent,
and constructability and high temperature stability can be improved (refer to Patent
Document 3). In addition, the inventors also found that due to the solidification of SrO,
20 a time taken to develop strength of a monolithic refractory can be shortened and thus
high strength can be realized (refer to Patent Document 3).
[0024]
The inventors newly paid attention to a crystallite diameter of the
above-described solid solution and vigorously studied and discussed; and as a result,
25 found that, when the crystallite diameter is set to be a predetermined size or less smaller
8
than that in the conventional technology, corrosion resistance and a strength developing
property can be further improved and completed the present invention.
[0025]
Here, the solidification represents two or more kinds of elements (which may be
5 metal or non-metal) dissolving each other such that the entire mixture is uniformly solid.
In addition, the solid solution represents a phase of a crystalline material which is formed
by two or more kinds of elements becoming uniformly solid.
[0026]
The summary of the present invention is as follows.
10 (1) Ahinder for monolithic refractories including a solid solution obtained by
dissolving Ca components in a-SrAl2O4 or j3-SrAl2O4, wherein when the Ca components
are dissolved in the a-SrAl2O4, a crystallite diameter of the solid solution is from 40 nm
to 75 nm, and when the Ca components are dissolved in the R-SrAl2O4, a crystallite
diameter of the solid solution is from 35 ran to 70 nm.
15 (2) The binder for monolithic refractories according to (1) above, wherein an
amount of the solid solution obtained by dissolving Ca components in the a-SrAI2O4 or
the p-SrAl2O4 is from 10 mass% to 60 mass%, and 40 mass% to 90 mass% of A1203 is
blended thereinto.
(3) The binder for monolithic refractories according to (1) above, further
20 including, as a mixture, a solid solution obtained by dissolving Sr components in
CaA12O4, wherein a crystallite diameter of the solid solution is from 25 nm to 60 nm.
(4) The binder for monolithic refractories according to (3) above, wherein an
amount of the solid solution obtained by dissolving Ca components in the a-•SrAl2O4 or
the p-SrAl2O4 and the solid solution obtained by dissolving Sr components in the
9
CaA12O4 is from 10 mass% to 60 mass%, and 40 mass% to 90 mass% of A1203 is
blended thereinto.
(5) The binder for monolithic refractories according to (1) above, wherein both
of a solid solution obtained by dissolving Ca components in the a-SrAl2O4 and a solid
5 solution obtained by dissolving Ca components in the [3-SrAl2O4 are included as a
mixture.
(6) The binder for monolithic refractories according to (5) above, wherein a
total amount of both of the solid solution obtained by dissolving Ca components in the
a-SrAl2O4 and the solid solution obtained by dissolving Ca components in the R-SrAl2O4
10 is from 10 mass% to 60 mass%, and 40 mass% to 90 mass% of A12O3 is blended
thereinto.
('7) The binder for monolithic refractories according to (5) above, further
including, as a mixture the solid solution obtained by dissolving Sr components in the
CaAl2O4.
15 (8) The binder for monolithic refractories according to (7) above, wherein a
total amount of the solid solution obtained by dissolving Ca components in the
a-SrAl2O4, the solid solution obtained by dissolving Ca components in the (3-SrAl2O4,
and the solid solution obtained by dissolving Sr components in the CaA12O4 is from 10
mass% to 60 mass%, and 40 mass% to 90 mass% of A1203 is blended thereinto.
20 (9) The binder for monolithic refractories according to (1) above, wherein one
kind or two or more kinds selected from a group consisting of SiO2, TiO2, Fe2O3, MgO,
and BaO are included in the binder for monolithic refractories and an amount thereof is
12 mass% or less.
(10) The binder for monolithic refractories according to (1) above, wherein at
10
least one of a dispersant and a hardening retardant is blended into the binder for
monolithic refractories.
(11) A monolithic refractory obtained by blending the binder for monolithic
refractories according to any one of (1) to (10) above into a refractory aggregate.
5 (12) The monolithic refractory according to (11) above, wherein the refractory
aggregate includes an ultrafine alumina. powder with a particle diameter of from 0.8 nm
to 1 μm.
(13) The monolithic refractory according to (11) above, wherein an amount of
the binder for monolithic refractories is from 0.3 mass% to 20 mass% with respect to 100
10 mass% of a total amount of the binder for monolithic refractories and the refractory
aggregate.
(14) The monolithic refractory according to (13) above, wherein the amount of
the binder for monolithic refractories is from 0.5 mass% to 12 mass% with respect to 100
mass% of the total amount of the binder for monolithic refractories and the refractory
15 aggregate.
(15) The monolithic refractory according to (11) above, wherein further at
least one of a dispersant, a hardening retardant, and a hardening accelerator is added.
(16) The monolithic refractory according to (15) above, wherein the dispersant
is one kind or two or more kinds selected from a group consisting of a
20 polycarbonate-based dispersant, a phosphate=based dispersant, an oxycarboxylic acid, a
melamine-based dispersant, a naphthalene-based dispersant, and a lignin sulfonic
acid-based dispersant, the hardening accelerator is at least one of an alkali metal salt and
aluminate, and the hardening retardant is at least one of boric acid group and
silicofluoride,
25 (17) A construction method of monolithic refractories including: blending and
11
mixing the binder for monolithic refractories according to any one of (1.) to (10) above
and a refractory aggregate including an ultrafine alumina powder with a particle diameter
of 1 μm or less to obtain a monolithic refractory; and constructing the monolithic
refractory.
5
Effects of the Invention
[0027]
According to a binder for monolithic refractories of the present invention, since
a favorable strength developing property is developed within a shorter period of time
10 compared to that of the conventional technology, a time taken to remove a frame can be
reduced and construction efficiency can be improved. In addition, it is possible to
develop the effects of excellent corrosion resistance with respect to slag or molten iron,
and of expansion of the service life of monolithic refractories lined in furnaces used at a
high temperature.
15
Brief Description of the Drawings
[0028]
FIG. 1 is a perspective view showing a shape of an evaluation specimen.
FIG. 2 is a perspective view showing an external appearance of a rotary
20 corrosion furnace.
FIG. 3 is a cross--sectional view of the rotary corrosion furnace.
Embodiments of the Invention
[0029]
25 Hereinafter, some embodiments of the present invention will be described.
12
[0030]
According to a first embodiment of the present invention, a binder includes a
solid solution obtained by dissolving Ca components in SrA12O4 therein. At this time,
when SrA12O4 is a-SrAl2O4, a crystallite diameter of the solid solution is from 40 rim to
5 75 nm; or when SrAl2O4 is (3-SrAl2O4, a crystallite diameter of the solid solution is from
35 mn to '70 ran.
[0031]
A binder, which includes a solid solution having a crystallite diameter in the
above-described predetermined range, has a higher melting point than that of alumina
10 cement (major chemical component: CaO•Al2O3) in the conventional technology, and has
excellent high temperature stability when it reacts with water so as to form the hardened
body. In addition, in particular, when the crystallite diameter is in the above-described
predetermined range, by using the present binder, an appropriate operation time can be
secured when manufacturing monolithic refractories. Furthermore, since hardening rate
15 is improved compared to that in the conventional technology, corrosion resistance and
strength can be improved. Asa result, the present binder can be used for a wide range
of uses as a binder.
[0032]
However, in order to facilitate the effects, it is preferable that an amount of the
20 solid solution be 10 mass% or higher in the binder. In addition, the upper limit of the
amount maybe 100 mass%. The composition of a balance in the binder is typically
A12O3, and also includes examples of SiO2, TiO2, Fe2O3, MgO, BaO, or the like. With
regard to how they can intrude into the binders of the present invention, in the case of
A12O3, it may be intentionally added in order to impart a. high level of fireproofness
25 thereto. In the case of other components, a case in which they have already been
13
included in raw materials to be used or a case in which the binders are contaminated from
a crushing apparatus, a transportation apparatus, a firing apparatus, or the like of binder
raw materials or products during the manufacturing process can be considered. In
addition, a solid solution according to the following embodiment can be included in the
5 binder as a mixture.
[0033]
In a binder for monolithic refractories according to a second embodiment of the
present invention, a solid solution, obtained by dissolving SrO as Sr components in
CaO•Al203, is blended into a binder including the solid solution according to the first
10 embodiment obtained by dissolving Ca. components in a-SrA12O4 in which a crystallite
diameter of the solid solution is from 40 nm to 75 nm, or into a binder including the solid
solution according to the first embodiment obtained by dissolving Ca components in
(3-SrAl2O4 in which a crystallite diameter of the solid solution is from 35 nm to 70 rim.
In this case, a crystallite diameter of the solid solution obtained by dissolving SrO in
15 CaO-A12O3 is from 25 ran to 60 nm.
[0034]
With regard to the existence form of these solid solutions in the binder, they are
not present as a single solid solution obtained by being solidified with each other but are
present as independent solid solutions. The binder is present in the form of a mixture.
20 [0035]
A content ratio of the solid solution obtained by dissolving SrO in CaO•A1203
included in the binder is not limited. However, in order to facilitate the effects thereof,
it is preferable that an amount of a mixture of the solid solution in the binder be 10
mass% or higher. In addition, the upper limit of the amount may be 100 mass%. If
14
there is a balance in the binder, the composition of the balance is typically A12O3, and
also includes examples of SiO2, TiO2, Fe2O3, MgO, BaO, or the like. With regard to
how they can intrude into the binders of the present invention, as in the case of the first
embodiment, A12O3 may be intentionally added in order to impart a high level of
5 fireproofness thereto. In the case of other components, a case in which they have
already been included in raw materials to be used or a case in which the binders are
contaminated from a crushing apparatus, a transportation apparatus, a firing apparatus, or
the like of binder raw materials or products during the manufacturing process can be
considered.
10 [0036]
The solid solution obtained by dissolving SrO in CaO•A12O3 is hydraulic, has a
higher melting point than that of CaO•Al203 of alumina cement in the conventional
technology, and has excellent high temperature stability when it reacts with water so as to
form the hardened body. Therefore, it is possible to obtain a greater effect than that
15 with a binder in the conventional technology. In addition, the solid solution obtained by
dissolving SrO in CaO•A12O3 is more preferable because a crystallite diameter of the
solid solution is from 25 run to 60 nm and thus an appropriate operation time and
hardening rate can be obtained.
[0037]
20 According to a third embodiment of the present invention, both of the solid
solution according to the first embodiment obtained by dissolving Ca components in
a-SrAl2O4 which has a crystallite diameter in the predetermined range and the solid
solution according to the first embodiment obtained by dissolving Ca components in
(3=SrAl2O4 which has a crystallite diameter in the predetermined range, are included in a
15
binder. The third embodiment is different from the first embodiment in that both of the
solutions are included, not either of them. This binder may further include the solid
solution according to the second embodiment obtained by dissolving Sr components in
CaO•A1203. With regard to the existence form of these solid solutions in the binder,
5 they are not present as a single solid solution obtained by being solidified with each other
but are present as independent solid solutions. The binder is present in the form of a
mixture. In addition, according to the third embodiment, as in the cases of the first
embodiment and the second embodiment, it is possible to obtain a greater effect than that
with a binder in the conventional technology.
10 [0038]
A ratio of two or three kinds of solid solutions as a mixture in the binder is not
particularly limited. However, in order to facilitate the effects therec'f, it is preferable
that a total amount of a mixture of these solid solutions in the binder be 10 mass% or
higher. In addition, the upper limit of the amount maybe 100 mass%. The
15 composition of a balance in the binder is typically A12O3, and also includes examples of
SiO2, TiO2, Fe2O3, MgO, BaO, or the like. With regard to how they can intrude into the
binders of the present invention, as in the cases of the first and second embodiments,
A1203 may be intentionally added in order to impart a high level of fireproofness thereto.
In the case of other components, a case in which they have already been included in raw
20 materials to be used or a case in which the binders are contaminated from a crushing
apparatus, a transportation apparatus, a firing apparatus, or the like of binder raw
materials or products during the manufacturing process can be considered.
[0039]
By performing the maintenance and optimization of the selection and
25 manufacturing processes of industrially used raw materials, an amount of SiO2, TiO2,
16
Fe2O3, MgO, BaO, and the like, which are impurities in the binders of the first to third
embodiment, can be reduced to a level with no influence on the effects of the present
invention. The amount is preferably 12 mass% or less and more preferably 5 mass% or
less with respect to the total mass of the binders of the present invention in the total
5 amount of chemical components, which is the converted amount of the oxides of the
respective chemical components. If the amount is more than 12 mass%, there are cases
in which performance degradation, such as degradation of the strength developing
property and corrosion resistance of monolithic refractories using the binders, occurs.
In addition, when the amount of SiO2, TiO2, Fe2O3, MgO, and BaO is 12 mass%
10 or less, the cured strength of monolithic refractories may increase. The reason is
considered that minerals containing these components generate amorphous materials and
ions are liable to be eluted when it reacts with water. Strength increases greatly when
the amount is 5 mass% or less and the increase continues until 12 mass%. However,
when the amount exceeds 12 mass%, conversely, there are cases in which strength is
15 reduced maybe because the minerals containing the components generate crystalline
materials having a low solubility in water. In addition, there are cases where high
temperature corrosion resistance is degraded maybe because a melting point of impurities
is lowered.
[0040]
20 Furthermore, the present inventors also reviewed a case where no Ca
components are included in a solid solution of SrA12O4 in comparison, but found that
there were differences in the functions of a binder, from the case where Ca components
are included as in the present invention. Therefore, in order to study the functions of
the binders, an ion elution test was conducted to compare reaction processes with water
25 of both of the cases to each other. As a result, in a case where the composition of a
17
solid solution is represented by Ca,Srl. ,A12O4, it was found that the initial amount of ions
eluted of a solid solution in which XX0 and no Ca components were included was
extremely greater than that of a solid solution in which Ca components was included (for
example, X=0.15). Therefore, in the case where no Ca components were included, the
5 elution speed of ions was extremely fast. After a saturated solubility was reached,
hydration products were precipitated in a supersaturated solution. Across-linked
structure was generated between particles so as to contribute to binding and strength
development for hardening.
[0041]
10 In detail, the rate of Sr ions eluted from the SrAl2O4 composition, in which no
Ca components were included, into mixing water and the rate of Sr and Ca ions eluted
from the above-described various solid solutions according to the present invention were
compared. For the comparison, 200 g of a specimen was fed into 400 g of distilled
water and stirred for a predetermined period of time using a magnetic stirrer, and then the
15 solution was extracted and analyzed with inductively-coupled plasma (ICP) optical
emission spectrometry, thereby measuring the amount of elements in the solution. The
elements in the solution were presumed to be present in a variety of ion states. As a
result of comparing the amounts for the same stirring time, it was quantitatively found
that the rate of Sr ions eluted from SrA12O4i in which no Ca components were included,
20 into mixing water was greater than the rate of Sr and Ca ions eluted from the
above described various solid solutions according to the present invention.
[0042]
Therefore, when the solid solution in which X=0 is used for the binder for
monolithic refractories, agglomeration of materials occurs easily due to a large amount of
25 ions eluted. Asa result, the necessary time for hardening is shortened and an amount of
18
monolithic refractories to be constructed is large. For example, when an hour or longer
is necessary for construction, there is a possibility of problems such as the hardening of a
material during mixing and during pouring. To suppress this, it is necessary that a large
amount of additives which have an effect of sequestering initially eluted ions, that is, a
5 large amount of boric acid, borax, sodium gluconate, silicofluorides, or the like be added
as a hardening retardant compared to the case where Ca components are included (for
example, X=0.15). Still, when the function of the hardening retardant which suppresses
ion elution does not work, hardening proceeds immediately.
[0043]
10 Therefore, when a long period of time is necessary for construction, for example,
in furnace facilities where there is a large amount to be constructed, it was found that the
case where Ca components are included is preferable from the viewpoint of more stable
construction.
[0044]
15 Since a binder is usually used in the powder state, it is preferable that the
above-described solid solutions according to the present invention be present in the
powder state in the binders.
[0045]
In addition, crystallite diameters of all the solid solutions can be calculated by
20 the Scheirer method after obtaining the full-width at half maximum from the diffraction
peak obtained by powder X-ray diffractometry. The solid solutions according to the
present invention have a characteristic that a diffraction line thereof changes depending
on the blending ratio of Ca and Sr. The respective crystallite diameters can be
calculated by obtaining the frill-width at half maximum: from the diffaction peak of (-2
25 1 1) plane with 20 of about 28.4° in the case of the solid solution obtained by dissolving
19
Ca components in a-SrAl2O4; from the diffraction peak of (10 2) plane with 20 of about
29.5° in the case of the solid solution obtained by dissolving Ca components in
[S-SrAl2O4; and from the diffraction peak of (1 2 3) plane with 20 of about 30.0° in the
case of the solid solution obtained by dissolving Sr components in CaAI2O4.
5 [0046]
In detail, in the various solid solutions, for which a variety of raw materials are
prepared and synthesized by a firing method, when a batch furnace is used, samples are
taken from various places, such as the surface, interior, or the like of a fired body; and
when a continuous furnace such as a rotary kiln is used, samples are taken on a
10 predetermined time interval basis (for example, on a minute basis) to obtain average
evaluation samples. Then, the samples (for example, n=10) are sampled, divided, and
then crushed by a crusher so that the 50% average diameter becomes i 0 pm or less.
The samples are measured using a powder X-ray diffractometer (for example, JDX-3500,
trade name, manufactured by JEOL Ltd.), and it is possible to calculate the crystallite
15 diameter using JADE 6, a powder X-ray diffraction pattern analyzing software.
[0047]
The measurement of crystallite diameters using an X-ray diffractometer may be
performed under the conditions of an X-ray source of CuKa, a tube voltage of 40 IN, a
tube current of 300 mA, a step angle of 0.02°, and a spectroscopy with a measurement
20 condition of monochromator of 20 from 15° to 40°. With regard to the X-ray
diffractometer-derived full-width at half maximum used for the analysis of crystallite
diameter, it is possible to use values obtained by measuring silicon powder specimens
with the same diffractometer under the same conditions and then obtaining the full-width
at half maximum curves.
20
[0048]
Next, a manufacturing method of the binders according to the present invention
will be described.
[0049]
5 In the manufacture of the solid solution obtained by dissolving Ca components
in a-SrAl2O4, the solid solution obtained by dissolving Ca components in (3-SrAl2O4, and
the solid solution obtained by dissolving Sr components in CaAl2O4, these can be
respectively manufactured according to the firing temperature by changing the blending
ratio of starting materials so as to be a predetermined molar ratio.
10 [0050]
As the starting materials, any raw materials can be used as long as CaO, SrO,
and A1203 are used as the major chemical components. However, since there is a
possibility that CaO and SrO may be hydrated in the atmosphere, CaCO3, SrCO3, and
A1203 are preferably used. The kind of raw materials will be described in detail.
15 [0051]
The blending ratio of CaO:SrO:Al2O3 is set by weighing and blending the raw
materials so that Ca„Srl_,A12O4 has a predetermined X in terms of molar ratio.
[0052]
As the crystal phase obtained after firing the mixture at, for example 1450°C,
20 when X is equal to 1.0, CaAl2O4 is obtained; when X is from about 0.8 to 0.9, the solid
solution obtained by dissolving Sr components in CaAl2O4 is obtained; when X is from
about 0.5 to 0.7, a mixture of the solid solution obtained by dissolving Sr components in
CaAl2O4 and the solid solution obtained by dissolving Ca components in (3-SrAl2O4 is
obtained; when X is from about 0.3 to 0.4, the solid solution obtained by dissolving Ca
25 components in (3=SrAt2O4 is obtained; when Xis from about 0.1 to 0.2, a mixture of the
21
solid solution obtained by dissolving Ca components in (3-SrA12O4 and the solid solution
obtained by dissolving Ca components in a-SrAl2O4 is obtained; and when X is more
than 0 and equal to or less than 0.1, the solid solution obtained by dissolving Ca
components in a-SrA12O4 is obtained.
5 [0053]
At this time, along with the increase in the molar ratio of Sr, the lattice constants
of a-axis, b-axis, and c-axis increase. This is because of, for example, the ionic radii of
Ca and Sr. Referring to the ionic radii during pouring, the ionic radius of Ca is 0.099
nm and the ionic radius of Sr is 0.113 run and Sr has a larger ionic radius. It is
10 presumed that, due to the substitution with Sr having a larger ionic radius, the lattice
expands and the lattice spacing expands.
[0054]
Therefore, these crystal phases can be identified using the powder X-ray
diffractometry ()(RD) and can be respectively obtained while checking a desired solid
15 solution and a mixture thereof. As the device, for example, a RAD-13 system equipped
with a curved crystal monochromator (manufactured by Rigaku Corporation) can be used.
The XRD measurement is performed under the conditions of an anticathode of Cu
(CuKa), 20 from 15° to 70°, a tube voltage of 40 kV, a tube current of 20 mA, a scan
step of 0.010 deg, a scan speed of 4 °/min, a divergence slit of 1/2 deg, a receiving slit of
20 0.15 nm, and a scattering slit of 1/2 deg. However, the conditions for the XRD
measurement are not limited thereto. When the crystal phases are precisely measured, it
is preferable that silicon, aluminum, and magnesium be used as primary standards and an
internal standard method be used.
[0055]
22
In addition, the solid solutions and the mixtures of the solid solutions may be
further blended to obtain a desired mixture of the solid solutions.
[0056]
In addition, as a method of making a crystallite diameter a predetermined size, in
5 cases where the crystallite diameter of the solid solution obtained by dissolving Ca
components in a-SrAl2O4 is made to be from 40 our to 75 nm; where the crystallite
diameter of the solid solution obtained by dissolving Ca components in (3=SrAl2O4 is
made to be from 35 nni to 70 nm; and where the crystallite diameter of the solid solution
obtained by dissolving Sr components in CaAlzO4 is made to be from 25 Din to 60 nm,
10 firing is performed at a temperature of preferably from 1300°C to 1600°C and more
preferably from 1400°C to 1500°C using a firing apparatus, such as an electric furnace, a
reverberating furnace, an open-hearth furnace, a shaft furnace, a shuttle kiln, or a rotary
kiln.
[0057]
15 When the firing temperature is lower than 1300°C, um'eacted raw materials are
liable to remain and there are cases in which the amount of a target solid solution
generated is reduced. In addition, when the firing temperature is higher than 1600°C,
there are cases in which the crystal of a solid solution is excessively grown, the crystallite
diameter thereof becomes large beyond the predetermined range, and therefore the
20 strength developing property deteriorates. At a temperature of from 1400°C to 1500°C,
it is possible to shorten the firing time to obtain a predetermined crystallite diameter and
it becomes difficult for the crystallite diameter to be excessively increased due to
excessive firing. Therefore, this temperature range is preferable.
[0050]
24
refractories, there are cases in which it becomes difficult to develop a sufficient hardened
strength.
[0062]
On the other hand, with the amount of the solid solutions of higher than 60
5 mass%, depending on the chemical components or particle size distribution of the
aggregates in monolithic refractories, there are cases in which the hardening rate is too
fast and it becomes difficult to secure a sufficient usable life for construction.
[0063]
In addition, if the amount of AI2O3 in the binder is 40 mass% or higher, the
10 strength or refractoriness of hardened bodies increases sufficiently, which is preferable.
However, if the amount of A1203 to be blended thereinto is more than 90 mass%, the
amount of the solid solutions becomes relatively small, and thus it may become difficult
to he uniformly hardened. Therefore, the amount of A.12O3 to be blended thereinto is
preferably 90 mass% or less.
15 [0064]
Next, a monolithic refractory used for the binder for monolithic refractories
according to the present invention will be described. In the present invention, the
blending ratio of the binder and refractory aggregates in a monolithic refractory is not
particularly specified, and it has been confirmed that, even with an arbitrary blending
20 ratio, the effects of the present invention can be obtained.
[0065]
However, in a case in which the binder for monolithic refractories of the present
invention is used to manufacture actual monolithic refractories, with regard to the
blending ratio of the binder and refractory aggregates, it is suggested that the amount of
25 the binder is preferably from 0.3 mass% to 20 mass%, and further preferably from 0.5
25
mass% to 12 mass% with respect to 100 mass% of the total a
refractory aggregates.
[0066]
OUR of the binder and
This is because, with an amount of less than 0.3 mass%, there are cases in which
5 binding is not sufficient and therefore the strength is not sufficient even after the binder
has been hardened. In addition, it is because, with an amount of more than 20 mass%,
there are cases in which volume change, or the like generated during the hydration or
dehydration process of the binder adversely affects the entire monolithic refractories, and
therefore cracking, or the like occurs.
10 [0067]
As the refractory aggregates of monolithic refractories, fused alumina, fused
bauxite, sintered alumina, calcined alumina, fused mullite, synthesized mullite, melted
silica, fused zirconia, fused zirconia mullite, zircon, magnesia clinker, fused magnesia,
fused magnesite-chrome, sintered spinel, fused spinet, silicon nitride, silicon carbide,
15 squarnation graphite, earthy graphite, sillimanite, kyanite, andalusite, agalmatolite, shale,
dolomite clinker, silica rock, clay, chamotte, lime, chrome, melted quartz, calcium
aluminate, calcium silicate, or silica flower can be used. They may be used alone or in
combination of two or more kinds thereof.
[0068]
20 In a case in which the binder of the present invention is used as a binder for
monolithic refractories, the amount of water or water-containing solvent used for
construction is not particularly specified. However, the amount is dependent on the
particle size distribution of aggregates or the type and amount of dispersants, and
therefore it is preferable that the amount is roughly from about 2 mass% to 10 mass%
25 with respect to the refractory aggregates in outer percentage.
26
[0069]
This is because, if the amount is less than 2 mass%, it becomes difficult to
harden the binder. In addition, it is because, if the amount is more than 10 mass%, the
amount relating to the formation of hardened structures becomes relatively large, and
5 volume change, or the like during hardening reactions becomes liable to adversely affect
the quality of refractories.
[0070]
In addition, if the binder of the present invention is used as a binder for
monolithic refractories, in order to appropriately control the rate of the hydration and
10 hardening reactions according to the atmospheric temperature or humidity, it is preferable
to add a dispersant or a hardening adjuster.
[0071]
As the dispersant, carbonates, such as sodium carbonate, sodium hydrogen
carbonate, or the like; oxycarboxylic acids, such as citric acid, sodium citrate, tartaric
15 acid, sodium tartrate acid, or the like; polyacrylic acid or methacrylic acid and salts
thereof, condensed phosphates, such as sodium tripolyphosphate or sodium
hexametaphosphate, or the like, and/or alkali metals thereof, alkaline-earth metal salts, or
the like are mainly used.
[00'72]
20 As the hardening adjuster, a hardening retardant or a hardening accelerator can
be used. As the hardening retardant, it is possible to use boric acid, borax, sodium
gluconate, silicofluorides, or the like. On the other hand, as the hardening accelerator, it
is possible to use lithium salts, such as lithium carbonate or the like; slaked lime or the
like; and aluminates or the like.
25 [0073]
27
In addition, a method also can be used that increases the ventilation rate of
materials by adding an explosion preventer, such as an organic fiber, such as vinylon, or
the like, metallic aluminum powder, aluminum lactate, or the like.
[0074]
5 Furthermore, it is also possible to add ultrafine powder in order to achieve
improvement in the flow property, a filling property or sinterability. Examples of the
ultrafine powder include inorganic fine powder with a particle diameter of from about
0.01 μm to 100 pro, such as silica fume, colloidal silica, well-sinterable alumina,
amorphous silica, zirconia, silicon carbide, silicon nitride, chrome oxide, titanium oxide,
10 or the like.
[0075]
In a case in which a basic aggregate, such as magnesia, or the like, is blended
thereinto, there is a possibility of the generation of cracking caused by hydration swelling
of magnesia. In order to suppress such a phenomenon, it is preferable to add a highly
15 surface-active additive, such as filmed silica.
[0076]
Furthermore, since the monolithic refractories of the present invention are used
to manufacture dense hardened bodies, during mixing with water, it is possible to use
chemical admixtures, such as a water reducing agent, such as a polycarbonate-based
20 water reducing agent, a lignin-based water reducing agent, or the like, a high
performance water reducing agent, a. high performance AE water reducing agent, or the
like. The type and amount added of the above chemical admixtures can be properly
selected according to the type or amount of refractory aggregates to be blended thereinto
and conditions, such as the construction temperature, or the like.
25 [00771
28
As raw materials used for manufacturing the solid solution obtained by
dissolving Ca components in a-SrAl2O4, the solid solution obtained by dissolving Ca
components in (3-SrAl2O4, and the solid solution obtained by dissolving Sr components in
CaAl2O4, which are the binders for monolithic refractories according to the present
5 invention, lime stone (mainly CaCO3), calcined lime (mainly CaO), purified alumina
(a-A1203, Al(OH)3) or bauxite (a raw material of A12O3), strontianite (SrCO3) or celestite
(SrSO4) are preferably used. Before firing, it is preferable to crush the raw material
with a crusher so as to have a 50% average diameter (median diameter) of from about 0.5
μm to 15 μm. This is because, if the raw material includes particles coarser than the
10 above, there are cases in which a large number of unreacted parts remain or a
composition other than the solid solutions according to the present invention is partially
generated, and therefore there are cases in which the intrinsic effects of the present
invention become difficult to develop.
[0078]
15 As the composition other than the solid solutions according to the present
invention, there are cases in which, if alumina components are rich in the raw material, a
solid solution such as CaSrl_xA14O7 is generated, and if CaO components and SrO
components are rich in the raw material, a solid solution such as (Ca Sri_) I2AII4O33 or
(CaaSri_x)3A12O6 is generated. However, if the raw materials are prepared, crushed, and
20 blended as described above so as to obtain the target solid solution according to the
present invention, the amount of the above generation is small and has less effect on the
binder characteristics.
[0079]
Furthermore, the raw material to be used is preferably a high purity material
29
with 98 mass% or more of a total amount of CaO, A12O3 and SrO in the raw material.
Impurities included in bauxite, strontianite or celestite, such as Si02, TiO2, MgO, Fe2O3,
or the like, have a possibility of degrading high temperature properties, and it is
preferable to suppress these to an extremely small amount.
5 [0080]
Since the particle size of solid solution powder in the binders affects hydration
reaction or hardening rate, it is preferable to control particles to be from about 1 μm to 20
pm by a crusher after firing for manufacturing a solid solution. The particle size is a
measurement result by a particle size analyzer used for a laser diffractometry, a laser
10 scattering method, a sedimentation balance method, or the like and indicates the 50%
average diameter. The raw material can be uniformly blended using a mixer, such as an
Eirich mixer, a rotary drum, a cone blender, a V-shape blender, an omni mixer, a nauta
mixer, a pan-type mixer, or the like.
[0081]
15 As the crusher, it is possible to use an industrial crusher, such as an oscillating
mill, a tube mill, a ball mill, a roller mill, a jet mill or the like.
[0082]
The binders, in which from 10 mass% to 60 mass% of the solid solutions
according to the first to third embodiment are included and from 40 mass% to 90 mass%
20 of A12O3 is blended, can be manufactured by blending a.-alumina powder into the various
solid solutions obtained by the above-described method.
[0083]
a-alumina powder refers to high purity alumina including 90 mass% or more of
A1203, and generally alumina is manufactured by the Bayer process. in this method,
30
firstly, bauxite is washed in a hot solution of sodium hydroxide (NaOH) at 250°C. In
this process, alumina is transformed to aluminum hydroxide (Al(0H3)) and dissolved by
a reaction shown in the following formula (1).
A12O3 + 2011- + 31120 > 2[Al(Ox)4f (1)
5 [0084]
At this time, other chemical components in the bauxite are not dissolved and can
be removed through filtering as solid impurities. Subsequently, if the solution is cooled,
the dissolved aluminum hydroxide is precipitated as a. white fluffy solid. lithe solid is
subjected to a firing treatment at 1050°C or higher using a rotary kiln, or the like,
10 dehydration shown in the following formula (2) occurs and therefore alumina is
generated.
2A1(OH)3 > A12O3 + 31120 ... (2)
[0085]
Since binders are highly dependent on the specific surface area of a-A1203
15 blended into the binders in terms of the flow property, the BET specific surface area of
a-A1203 is preferably from about 0.1 m2/g to 20 m2/g.
[0086]
a-Al2O3 can be blended thereinto in a state of being made into fine particles or
by blending and crushing it with the various solid solutions.
20 [0087]
When a-A12O3 to be blended into the binder is crushed and then blended, it is
preferable that refinement be performed so that the 50% average diameter be from about
0.3 pm to 10 μm. In addition, fine alumina powder with the above-described particle
diameter can be blended. In addition, when the components of the solid solutions and
a-Al2O3 are crushed and blended, it is preferable to set crushing conditions so that the
50% average diameter ofaA-l2bO3e in the same range.
[0088]
When the 50% average diameter of a-A12O3 is in the above-described range,
5 sinterability with respect to aggregates to be blended into binders or monolithic
refractories is improved and a dense structure having excellent corrosion resistance can
be obtained.
[0089]
In addition, the higher the purity of A12O3, the superior the refractoriness.
10 Therefore, the purity of a-iAsl 2pOre3ferably 95 mass% or higher and more preferably
99 mass% or higher.
[0090]
This a-A1203 is uniformly blended with hydraulic components by blending it in
the binder in advance. When the resultant is blended into a monolithic refractory, the
15 hydraulic components can be more uniformly blended and it is possible to obtain a
structure of refractory having excellent strength developing property and corrosion
resistance of hardened bodies.
[0091]
In the present invention, the manner in which u,-A1203 is blended with the binder
20 and crushed is preferable since a-A1203 is uniformly blended into the binder composition
and therefore the microstructure of the hardened bodies is liable to become uniform when
used for monolithic refractories, and this manner has a tendency of improving
performance, such as corrosionresistance, or the like.
[0092]
32
In addition, in the monolithic refractory according to the present invention, a
construction method of refractories used for the lining or repair of furnaces may be the
same as a general construction method of monolithic refractories. However,
particularly when an aggregate including an ultrafine alumina powder with a particle
5 diameter of from 0.8 nm to 1 pro and the binders according to the present invention are
blended and mixed for construction, binding is further improved due to the synergistic
effect with the binders according to the present invention. As a result, a favorable
strength developing property is developed within a short period of time, construction
efficiency is improved, corrosion resistance with respect to slag and molten iron is
10 further improved, and the effect of service life expansion of furnaces can be more
strongly exhibited. Therefore, the above-described manner is preferable.
[0093]
It is preferable that the blending ratio of the ultrafine alumina powder with a
particle diameter of 1 μm or less in the monolithic refractory (other than moisture) be
15 from 2 mass% to 70 mass%
[Examples]
[0094]
Hereinafter, the present invention will be described in detail with examples, but
the present invention is not limited to the examples.
20 [0095]
In the following examples, as the raw materials, CaCO3 with a purity of 99
mass% (manufactured by Ube Material Co., Ltd.), SrC®3 with a purity of 98 mass%
(manufactured by Sakai Chemical Industry Co., Ltd.), and high purity a=alumina with a
purity of 99 mass% (manufactured by Nippon Light Metal Co., Ltd.) were used.
25 [0096]
33
Each of the raw materials was weighed with scales so as to have the chemical
compositions in the following tables, and then blended and crushed with a mortar. 15
mass% of water was added to the blended and crushed raw materials in outer percentage,
was granulated into spherical pellets, were fed into an alumina container, and then
5 subjected to a heating treatment at the maximum temperature in the air atmosphere using
an electric furnace (with a furnace volume of 130 L) while changing the holding time
thereof. After that, the resultant were cooled to room temperature and placed in the air,
and then crushed with a batch type ball mill so as to obtain various solid solutions and
binders shown in the examples.
10 [0097]
Furthermore, with regard to examples in which a-A1203 is blended, high purity
a-alumina (manufactured by Nippon Light Metal Co., Ltd.) was added to the obtained
solid solutions and binders so as to obtain a predetermined chemical component.
[0098]
15 In addition, in order to study the effects of impurities, barium oxide was used
which was obtained by heating at 1400°C a variety of reagents with a purity of 99 mass%,
such as silicon oxide, titanium oxide, magnesium oxide and ferric oxide and a. barium
carbonate reagent with a purity of 99%. The raw materials were blended according to
the contents of the respective following tables to prepare the binders in the same manner
20 described above.
[0099]
8 mass% of the binder, 92 mass% of refractory aggregates (50 mass% of
sintered alumina with a particle size by sieving of 1 μm or lower, 43 mass% of fused
alumina with a particle size of from 75 pin to 5 urn, 6 mass% of magnesia, 0.8 mass% of
34
silica flower, and 0.15 mass% of vinylon fiber), and 0.05 mass% of boric acid powder
were blended for 1 minute with an omni mixer, and, furthermore, 6.8 mass% of water
was added to 100 mass% of the mixture thereof in a constant temperature room of 20°C
and then blended and mixed with a mortar mixer for 3 minutes, thereby obtaining
5 monolithic refractory specimens.
[0100]
In order to evaluate the operability of the prepared monolithic refractory
specimens, the flow test was carried out according to JIS R2521, "Physical testing
methods of aluminous cement for refractories" to measure spreading diameters of
10 samples immediately after mixing and 2 hours after the start of blending, in which the
samples were subjected to falling motion 15 times.
[0101]
The flexural strength after curing was measured according to JIS R2553,
"Testing method for crushing strength and modulus of rupture of castable refractories"
15 after the monolithic refractory specimens were poured into a 40 x 40 x 160 mm mold
form and then cured in a constant temperature room at 20°C for a predetermined time.
In addition, the curing time was set to 6, 12, and 24 hours after the start of blending of
monolithic refractories.
[0102]
20 In addition, the monolithic refractory specimens were cured in a constant
temperature room at 20°C for a predetermined time to manufacture hardened bodies of
the refractories and provide specimens for a test for the evaluation of corrosion resistance
with respect to slag at a high temperature.
[0103]
35
The rotary corrosion method was used for the evaluation of corrosion resistance
with respect to slag at a high temperature. Specimens (refractory 1) cut out into the
shape as in FIG. I were manufactured, and, as shown in FIG. 2, 8 pieces of the refractory
1 were lined and embedded in a rotary furnace. The size thereof was a = 67 mm, b = 41
5 nun, c = 48 mm, and d = 114 min. In addition, a cylindrical protection plate 2 (with a
diameter of about 150 mm^) was embedded on the inner side on which 8 pieces of the
refractory I were lined.
[0104]
As shown in FIG. 3, the embedded refractory 1 was installed in the rotary
10 furnace, and the temperature was increased by the burning of a burner 3 from the inside
of the rotary furnace while rotating the refractory 1. As the burning gas, a gas with a
volume ratio of 1 LPG to 5 oxygen was used. Further, the reference number 4 indicates
slag, and the reference number 5 indicates a filling material.
[0105]
15 The wear amount of each specimen was obtained from the average value
obtained by measuring the remaining dimensions (which are the thicknesses of a
non-oxidation layer in the case of the thicknesses of a decarburized layer) at 5 points
every 20 mm and calculating the difference from the initial thickness (48 mm). The
composition of the slag 4 includes 50.5 mass% of CaO, 16.8 mass% of SiO2, 7 mass% of
20 MgO, 2 mass% of A12O3, 3.5 mass% of MnO, and 20.2 mass% of FeO, and, with the test
temperature of 1600°C and 1 charge of 25 minutes, 500 g of the slag 4 was subjected to 1
charge of the test for a replacement, and the test was performed for a total of 6 charges
for 2 horn's 30 minutes. The old charge of the slag 4 was replaced with anew charge of
the slag 4 by tilting a horizontal type drum.
25 [0106]
36
[1] Example relating to a binder for monolithic refractories including a solid
solution obtained by dissolving Ca components in a-SrAl2O4 in which a crystallite
diameter of the solid solution is from 40 nm to 75 nor or a solid solution obtained by
dissolving Ca components in (3-SrAl2O4 in which a crystallite diameter of the solid
5 solution is from 35 run to 70 nor
Measurement of the flow value and the flexural strength after curing and rotary
corrosion tests using slag were performed using monolithic refractories manufactured
with binders including a solid solution for which all the components of a binder had been
controlled so as to solidify Ca components in a-SrA12O4 and firing conditions had been
10 set so that a crystallite diameter thereof was a value in the tables in Examples 1 to 8 and
Reference Examples 1 to 6; monolithic refractories manufactured with binders including
a solid solution for which all the components of a binder had been controlled so as to
solidify Ca components in (3mSrAl2O4 and firing conditions had been set so that a
crystallite diameter thereof was a value in the tables in Examples 9 to 16 and Reference
15 Examples 7 to 12; monolithic refractories manufactured with binders including no Sr
components in Comparative Examples 1 to 3; and monolithic refractories manufactured
with binders including no Ca components in Reference Examples 13 to 16. Tables 1 to
3 show the composition of the raw materials of the binder, the crystallite diameter of the
solid solution, the firing conditions, and the measurement results of flow value and
20 flexural strength after curing and results of the rotary corrosion test of the monolithic
refractory in each of the examples.
[0107]
In addition, when the monolithic refractory manufactured with the binder
including no Ca components was used in Reference Example 15, the test results were
37
obtained after 0.3 mass% of boric acid powder to be blended into the monolithic
refractory was added with respect to the mass of castable in outer percentage so as to
obtain a predetermined flow property 2 hours after the start of mixing.
[0108]
5 [Table 1]
[0109]
[Table 2]
[0110]
[Table 3]
10 [0111]
The evaluation results are as shown in Tables 1 to 3. In Examples Ito 16, the
flow values suitable for pouring were obtained 2 hours after the start of mixing.
Therefore, it has been confirmed that Examples 1 to 16 can be applied to furnaces with a
large volume or the like. Furthermore, Examples I to 16 show larger values than
15 Comparative Examples Ito 3 in the flexural strength after curing of 6, 12, and 24 hours,
and therefore it has been clarified that Examples 1 to 16 are excellent in terms of cured
strength developing property. In particular, the flexural strength after curing of 6 hours
is remarkably greater compared to those of the Comparative Examples, and therefore it
has been confirmed that Examples 1 to 16 are excellent in terms of early strength
20 developing property. Furthermore, it has been clarified that, compared to Comparative
Examples, Examples 1 to 16 clearly show small wear amounts in the rotary corrosion test
using slag and are excellent in terms of slag resistance at a high temperature.
[0112]
In Reference Examples 1, 4, 7, and 10 in which the crystallite diameters of the
25 solid solution obtained by dissolving Ca. components in a-SrAl2O4 and the solid solution
38
obtained by dissolving Ca components in (3-SrAl2O4 are less than the range of the present
invention and in Reference Examples 13, 14, and 16 in which the binder including no Ca
components was used, a large amount of deterioration in the flow property after 2 hours
or the hardening of the monolithic refractories occurred, and therefore it has been
5 confirmed that it is difficult for Reference Examples 1, 4, 7, and 10 and Reference
Examples 13, 14, and 16 be applied to furnaces with a large volume or the like. As
described in Reference Example 15, by increasing the amount of boric acid powder as the
hardening retardant added, the flow property after 2 hours can be secured. However, it
is necessary that the amount of the hardening retardant added be increased to a large
10 degree, which leads to a rise in manufacturing costs. In addition, in Reference
Examples 2, 3, 5, 6, 8, 9, 11, and 12 in which the crystallite diameters are more than the
range of the present invention, it has been confirmed that, compared to the case where the
crystallite diameter is in the range of the present invention, the strength after curing
deteriorates, it is difficult for a frame to be removed early, and the risk of explosion
15 increases due to insufficient strength when the monolithic refractories are dried.
[0113]
From these test results, it has been clarified that, by using the binder including a
solid solution obtained by dissolving Ca components in a-SrAl2O4 in which a crystallite
diameter of the solid solution is from 40 nm to 75 ran or a solid solution obtained by
20 dissolving Ca components in (3-SrA1z®a in which a crystallite diameter of the solid
solution is from 35 mu to 70 nm, a monolithic refractory in which a favorable operability
is secured even after a long period of time has elapsed after pouring and blending water
thereinto, a favorable strength developing property is obtained early, and slag resistance
at a high temperature is superior compared to the conventional technique can be
25 obtained.
39
[0114]
[2] Examples relating to a binder for monolithic refractories including a solid
solution obtained by dissolving Ca components in a=SrAl2O4 in which a crystallite
diameter of the solid solution is from 40 nor to 75 nm or a solid solution obtained by
5 dissolving Ca components in [1-SrAl2O4 in which a crystallite diameter of the solid
solution is from 35 non to 70 nm, into which A1203 is blended
Measurement of the flow value and the flexural strength after curing and rotary
corrosion tests using slag were performed using monolithic refractories manufactured
with binders including a solid solution obtained by dissolving Ca components in
10 a-SrA12O4 in which a X value of Ca,Srl_,A12O4 is 0.05, into which a-A1203 was blended
with a predetermined ratio, in Examples 17 to 21; monolithic refractories manufactured
with binders including a solid solution obtained by dissolving Ca components in
p-SrAl2O4 in which a X value of Ca.,Sri_xA12O4 is 0.30, into which a-A12O3 was blended
with a predetermined ratio, in Examples 22 to 26; and monolithic refractories
15 manufactured with binders obtained by blending raw materials so that the composition of
a binder is CaA12O4 and blending the resultant and u,-A1203 with a predetermined ratio in
Comparative Examples 4 to 6. Tables 4 and 5 show the compositions of the solid
solutions, the crystallite diameters of the solid solutions, the blending ratio of the solid
solutions, CaAl2O4, and a-A1203, and the measurement results of flow value and flexural
20 strength after curing and results of the rotary corrosion test of the monolithic refractory in
each of the Examples. All of the solid solutions and the binders were subjected to firing
for 2 hours at the maximum temperature of 1500°C for manufacture.
[0115]
[Table 4]
40
[0116]
[Table 5]
[0117]
The evaluation results are as shown in Tables 4 and 5. In Examples 17 to 26,
5 the flow values of the monolithic refractories suitable for pouring were obtained 2 hours
after the start of mixing. Therefore, it has been confirmed that Examples 17 to 26 can
be applied to furnaces with a large volume or the like. Furthermore, Examples 17 to 26
show larger values than Comparative Examples I to 6 in the flexural strength after curing
of 6, 12, and 24 hours, and therefore it has been clarified that Examples 17 to 26 are
10 excellent in terms of cured strength developing property. In particular, the flexural
strength after curing of 6 hours is remarkably greater compared to those of the
Comparative Examples, and therefore it has been confirmed that Examples 17 to 26 are
excellent in terms of early strength developing property. Furthermore, it has been
clarified that, compared to Comparative Examples, Examples 17 to 26 clearly show small
15 wear amounts in the rotary corrosion test using slag and are excellent in terms of slag
resistance at a high temperature.
[0118]
In addition, in Examples 17 to 26, it is possible to further decrease the wear
amount in the rotary corrosion test using slag, compared to Examples 3 and 11 including
20 no A12O3, since Examples 17 to 26 include A1203, which clarifies that Examples 17 to 26
are superior in terms of slag resistance at a high temperature.
[0119]
From these test results, it has been clarified that, by using the binder for
monolithic refractories including a solid solution obtained by dissolving Ca components
25 in a-SrAl2O4 in which a crystallite diameter of the solid solution is from 40 nm to 75 ram
41
or a solid solution obtained by dissolving Ca components in (3-SrAl2O4 in which a
crystallite diameter of the solid solution is from 35 nm to 70 ran, into which A1203 is
blended, a monolithic refractory in which a favorable operability is secured even after a
long period of time has elapsed after pouring and blending water thereinto, a favorable
5 strength developing property is obtained early, and slag resistance at a high temperature
is superior compared to the conventional technique can be obtained.
[0120]
[3] Examples relating to a binder for monolithic refractories including a mixture
of a solid solution obtained by dissolving Ca components in a-SrA12O4 or a solid solution
10 obtained by dissolving Ca components in (3-SrAl2O4; and a solid solution obtained by
dissolving Sr components in CaAl2O4 in which a crystallite diameter of the solid solution
is from 25 nm to 60 nm,.
Measurement of the flow value and the flexural strength after curing and rotary
corrosion tests using slag were performed using monolithic refractories manufactured
15 with binders including a mixture of a solid solution for which all the components of a
binder had been controlled so as to solidify Ca components in a-SrAl2O4 and a solid
solution for which all the components of a binder had been controlled so as to solidify Sr
components in CaA12O4, in which firing conditions had been set so that a crystallite
diameter thereof was a value in the tables in Examples 27 to 37 and Reference Examples
20 17 to 19; and monolithic refractories manufactured with binders including a mixture of a
solid solution for which all the components of a binder had been controlled so as to
solidify Ca components in (3-SrAI2O4 and a solid solution for which all the components
of a binder had been controlled so as to solidify Sr components in CaAI2O4, in which
firing conditions had been set so that a crystallite diameter thereof was a value in the
42
tables in Examples 38 to 48 and Reference Examples 20 to 22. The solid solution
obtained by dissolving Ca components in u. SrAl2O4 and the solid solution obtained by
dissolving Ca components in (3-SrAl2O4 were subjected to firing for 2 hours at the
maximum temperature of 1500°C for manufacture. Tables 6 to 8 show the composition
5 of the raw materials, the firing conditions, the crystallite diameters of the solid solutions,
and the measurement results of flow value and flexural strength after curing and results
of the rotary corrosion test of the monolithic refractory in each of the Examples.
[0121]
[Table 6]
10 [0122]
[Table 7]
[0123]
[Table 8]
[0124]
15 The evaluation results are as shown in Tables 6 to 8. In Examples 27 to 48, the
flow values of the monolithic refractories suitable for pouring were obtained 2 hours after
the start of mixing. Therefore, it has been confirmed that Examples 27 to 48 can be
applied to furnaces with a large volume or the like. Furthermore, Examples 27 to 48
show larger values than Comparative Examples 1 to 3 in the flexural strength after curing
20 of 6, 12, and 24 hours, and therefore it has been clarified that Examples 27 to 48 are
excellent in terms of cured strength developing property. In particular, the flexural
strength after curing of 6 hours is remarkably greater compared to those of Comparative
Examples 1 to 3, and therefore it has been confirmed that Examples 27 to 48 are
excellent in terms of early strength developing property. Furthermore, it has been
25 clarified that, compared to Comparative Examples 1 to 3, Examples 27 to 48 clearly
43
show small wear amounts in the rotary corrosion test using slag and are excellent in
terms of slag resistance at a high temperature.
[0125]
In Reference Examples 17, 19, 20, and 22 in which the crystallite diameter of
5 the solid solution obtained by dissolving Sr components in CaAl2O4 is less than the range
of the present invention, a large amount of deterioration in the flow property after 2 hours
occurred, and therefore it has been confirmed that it is difficult for Reference Examples
17, 19, 20, and 22 to be applied to furnaces with a large volume or the like. In addition,
in Reference Examples 18 and 21 in which the crystallite diameters are more than the
10 range of the present invention, it has been confirmed that, compared to the case where the
crystallite diameter is in the range of the present invention, the flexural strength after
curing deteriorates, it is difficult for a frame to be removed early, and the risk of
explosion increases due to insufficient strength when the monolithic refractories are
dried.
15 [0126]
From these test results, it has been clarified that, by using the binder including a
mixture of a solid solution obtained by dissolving Ca components in a-SrAl2O4 in which
a crystallite diameter of the solid solution is from 40 nm to 75 nm or a solid solution
obtained by dissolving Ca components in [3-SrAl2O4 in which a crystallite diameter of the
20 solid solution is from 35 nm to 70 nm; and a solid solution obtained by dissolving Sr
components in CaAl2O4 in which a crystallite diameter of the solid solution is from 25
nm to 60 nm, a monolithic refractory in which a favorable operability is secured even
after a long period of time has elapsed after pouring and blending water thereinto, a
favorable strength developing property is obtained early, and slag resistance at a high
25 temperature is superior compared to the conventional technique can be obtained.
44
[0127]
[4] Examples relating to a binder for monolithic refractories including a mixture
of a solid solution obtained by dissolving Ca components in a-SrAI2O4 or (3-SrA12O4 and
a solid solution obtained by dissolving Sr components in CaAl2O4, into which A1203 is
5 blended
Measurement of the flow value and the flexural strength after curing and rotary
corrosion tests using slag were performed using monolithic refractories manufactured
with binders including a mixture of a solid solution obtained by dissolving Ca
components in a-SrAl2O4 in which a X value of Ca Sri_„A12O4 is 0.05 and a solid
10 solution obtained by dissolving Sr components in CaAl2O4 in which a X value of
Ca,Sri,,A12O4 is 0.95, into which a-wAla2Os 3blended with a predetermined ratio, in
Examples 49 to 53; and monolithic refractories manufactured with binders obtained
including a mixture of a solid solution obtained by dissolving Ca components in
(3-SrA12O4 in which a X value of Ca,,Sri_,A12O4 is 0.30 and a solid solution obtained by
15 dissolving Sr components in CaAl2O4 in which a X value of Ca,Sri_,A12O4 is 0.95, into
which a-A1203 was blended with a predetermined ratio, in Examples 54 to 58. Table 9
shows the compositions of the solid solutions, the crystallite diameters, the blending ratio
of the solid solutions and u.-A1203, and the measurement results of flow value and
flexural strength after curing and results of the rotary corrosion test of the monolithic
20 refractory in each of the Examples. All of the solid solutions were subjected to firing
for 2 hours at the maximum temperature of 1500°C for manufacture.
[0128]
[Table 9]
[0129]
45
The evaluation results areas shown in Table 9. In Examples 49 to 58, the flow
values of the monolithic refractories suitable for pouring were obtained 2 hours after the
start of mixing. Therefore, it has been confirmed that Examples 49 to 58 can be applied
to furnaces with a large volume or the like. Furthermore, Examples 49 to 58 show
5 larger values than Comparative Examples 1 to 6 in the flexural strength after curing of 6,
12, and 24 hours, and therefore it has been clarified that Examples 49 to 58 are excellent
in terms of cured strength developing property. In particular, the flexural strength after
curing of 6 hours is remarkably greater compared to those of the Comparative Examples,
and therefore it has been confirmed that Examples 49 to 58 are excellent in terms of early
10 strength developing property. Furthermore, it has been clarified that, compared to
Comparative Examples, Examples 49 to 58 clearly show small wear amounts in the
rotary corrosion test using slag and are excellent in terms of slag resistance at a high
temperature.
[0130]
15 In addition, in Examples 49 to 58, it is possible to further decrease the wear
amount in the rotary corrosion test using slag, compared to Examples 34 and 45
including no A1203, since Examples 49 to 58 include A1203, which clarifies that
Examples 49 to 58 are superior in terms of slag resistance at a high temperature.
[0131]
20 From these test results, it has been clarified that, by using the binder for
monolithic refractories including a mixture of a solid solution obtained by dissolving Ca
components in a-SrAl2O4 in which a crystallite diameter of the solid solution is from 40
nor to 75 am or a solid solution obtained by dissolving Ca components in (3=SrAl2O4 in
which a crystallite diameter of the solid solution is from 35 ran to 70 am; and a solid
25 solution obtained by dissolving Sr components in CaAl2O4 in which a crystallite diameter
46
of the solid solution is from 25 urn to 60 rim, into which A1203 is blended, a monolithic
refractory in which a favorable operability is secured even after a long period of time has
elapsed after pouring and blending water thereinto, a favorable strength developing
property is obtained early, and slag resistance at a high temperature is superior compared
5 to the conventional technique can be obtained.
[0132]
[5] Examples relating to a binder for monolithic refractories including a mixture
of both of a. solid solution obtained by dissolving Ca components in a--SrA12O4 in which
a crystallite diameter of the solid solution is from 40 nor to 75 nm and a solid solution
10 obtained by dissolving Ca components in (3-SrAl2O4 in which a crystallite diameter of the
solid solution is from 35 nm to 70 run
Measurement of the flow value and the flexural strength after curing and rotary
corrosion tests using slag were performed using monolithic refractories manufactured
with binders including a mixture of both of a solid solution obtained by dissolving Ca
15 components in a-SrAl2O4 in which a X value of CaxSri,Al2O4 is 0.05 or 0.15 and a
crystallite diameter of the solid solution is from 40 nm to 75 nm and a solid solution
obtained by dissolving Ca components in (3-SrAl2O4 in which a X value of Ca,,Sri_,A12O4
is 0.30 or 0.55 and a crystallite diameter of the solid solution is from 35 nni to 70 nor in
Examples 59 to 94. Tables 10 to 13 show the compositions of the solid solutions, the
20 crystallite diameters of the solid solutions, the firing conditions, the blending ratio of the
solid solutions, and the measurement results of flow value and flexural strength after
curing and results of the rotary corrosion test of the monolithic refractory in each of the
Examples. In each solid solution, firing conditions had been set so that a crystallite
diameter thereof was a value in the tables.
47
[0133]
[Table 10]
[0134]
[Table 11]
5 [0135]
[Table 12]
[0136]
[Table 13]
[0137]
10 The evaluation results areas shown in Tables 10 to 13. In Examples 59 to 94,
the flow values of the monolithic refractories suitable for pouring were obtained 2 hours
after the start of mixing. Therefore, it has been confirmed that Examples 59 to 94 can
be applied to furnaces with a large volume or the like. Furthermore, Examples 59 to 94
show larger values than Comparative Examples 1 to 3 in the flexural strength after curing
15 of 6, 12, and 24 hours, and therefore it has been clarified that Examples 59 to 94 are
excellent in terms of cured strength developing property. In particular, the flexural
strength after curing of 6 hours is remarkably greater compared to those of the
Comparative Examples, and therefore it has been confirmed that Examples 59 to 94 are
excellent in terms of early strength developing property. Furthermore, it has been
20 clarified that, compared to Comparative Examples I to 3, Examples 59 to 94 clearly
show small wear amounts in the rotary corrosion test using stag and are excellent in
terms of slag resistance at a high temperature.
[0138]
From these test results, it has been clarified that, by using the binder for
25 monolithic refractories including a mixture of both of a solid solution obtained by
48
dissolving Ca components in a=SrAl2O4 in which a crystallite diameter of the solid
solution is from 40 nm to 75 nor and a solid solution obtained by dissolving Ca
components in (3-SrAl2O4 in which a crystallite diameter of the solid solution is from 35
nun to 70 run, a. monolithic refractory in which a favorable operability is secured even
5 after a long period of time has elapsed after pouring and blending water thereinto, a
favorable strength developing property is obtained early, and slag resistance at a high
temperature is superior compared to the conventional technique can be obtained.
[0139]
[6] Examples relating to a binder for monolithic refractories including a mixture
10 of a solid solution obtained by dissolving Ca components in a-SrAl2O4 and a solid
solution obtained by dissolving Ca components in (3-SrAl2O4, into which A12O3 is
blended
Measurement of the flow value and the flexural strength after curing and rotary
corrosion tests using slag were performed using monolithic refractories manufactured
15 with binders including a mixture of a solid solution obtained by dissolving Ca
components in a-SrAl2O4 in which a X value of CaSrl-,Al2O4 is 0.05 and a solid
solution obtained by dissolving Ca components in (3-SrAl2O,G in which a X value of
Ca,Srl-,Al2O4 is 0.30, into which a-A1203 was blended with a predetermined ratio, in
Examples 95 to 99. Table 14 shows the compositions of the solid solutions, the
20 crystallite diameters of the solid solutions, the blending ratio of the solid solutions, the
binder, and a-A1203, and the measurement results of flow value and flexural strength
after curing and results of the rotary corrosion test of the monolithic refractory in each of
the Examples. All of the solid solutions were subjected to firing for 2 hours at the
maximum temperature of 1500°C for manufacture.
50
urn to 75 nm and a solid solution obtained by dissolving Ca components in (3-SrA12O4 in
which a crystallite diameter of the solid solution is from 35 rim to 70 nun, into which
A12O3 is blended, a monolithic refractory in which a favorable operability is secured even
after a long period of time has elapsed after pouring and blending water thereinto, a
5 favorable strength developing property is obtained early, and slag resistance at a high
temperature is superior compared to the conventional technique can be obtained.
[0144]
[7] Examples relating to a binder for monolithic refractories including a mixture
of a solid solution obtained by dissolving Ca components in a=SrAl2O4, a solid solution
10 obtained by dissolving Ca components in (3-SrAl2O4, and a solid solution obtained by
dissolving Sr components in CaAl2O4
Measurement of the flow value and the flexural strength after curing and rotary
corrosion tests using slag were performed using monolithic refractories manufactured
with binders including a mixture of a solid solution obtained by dissolving Ca
15 components in a-SrA12O4 in which a X value of Ca,Srl_,A12O4A12O4 is 0.05, a solid
solution obtained by dissolving Ca components in (3=SrAl2O4 in which a X value of
Ca,Srl_,A12O4 is 0.30, and a solid solution obtained by dissolving Sr components in
CaAl2O4 in which a X value of CaSrl.,Al2O4 is 0.95 in Examples 100 to 104. Table 15
shows the compositions of the solid solutions, the crystallite diameters of the solid
20 solutions, the blending ratio of the solid solutions, and the measurement results of flow
value and flexural strength after curing and results of the rotary corrosion test of the
monolithic refractory in each of the Examples. All of the solid solutions were subjected
to firing for 2 hours at the maximum temperature of 1500°C for manufacture.
[0145]
51
[Table 15]
[0146]
The evaluation results are as shown in Table 15. In Examples 100 to 104, the
flow values of the monolithic refractories suitable for pouring were obtained 2 hours after
5 the start of mixing. Therefore, it has been confirmed that Examples 100 to 104 can be
applied to furnaces with a large volume or the like. Furthermore, Examples 100 to 104
show larger values than Comparative Examples 1 to 6 in the flexural strength after curing
of 6, 12, and 24 hours, and therefore it has been clarified that Examples 100 to 104 are
excellent in terms of cured strength developing property. In particular, the flexural
10 strength after curing of 6 hours is remarkably greater compared to those of the
Comparative Examples, and therefore it has been confirmed that Examples 100 to 104
are excellent in terms of early strength developing property. Furthermore, it has been
clarified that, compared to Comparative Examples, Examples 100 to 104 clearly show
small wear amounts in the rotary corrosion test using slag and are excellent in terms of
15 slag resistance at a high temperature.
[0147]
From these test results, it has been clarified that, by using the binder for
monolithic refractories including a mixture of a solid solution obtained by dissolving Ca
components in a-SrAl2O4 in which a crystallite diameter of the solid solution is from 40
20 nm to 75 nm, a solid solution obtained by dissolving Ca components in p-SrAl2O4 in
which a crystallite diameter of the solid solution is from 35 run to 70 am, and a solid
solution obtained by dissolving Sr components in CaA12O4 in which a crystallite diameter
of the solid solution is from 25 rrrn to 60 rim, a monolithic refractory in which a favorable
operability is secured even after a long period of time has elapsed after pouring and
25 blending water thereinto, a favorable strength developing property is obtained early, and
52
slag resistance at a high temperature is superior compared to the conventional technique
can be obtained.
[0148]
[8] Examples relating to a binder for monolithic refractories including a mixture
5 of a solid solution obtained by dissolving Ca components in a=SrAl2O4, a solid solution
obtained by dissolving Ca components in P=SrAl2O4, and a solid solution obtained by
dissolving Sr components in CaAl2O4, into which A12O3 is blended
Measurement of the flow value and the flexural strength after curing and rotary
corrosion tests using slag were performed using monolithic refractories manufactured
10 with binders including a mixture of a solid solution obtained by dissolving Ca
components in a=SrAl2Or in which an X value of CaXSrr_,A1204 is 0.05, a solid solution
obtained by dissolving Ca components in (3-SrAl2O4 in which an X value of
Ca,Sr1_,A12O4 is 0.30, and a solid solution obtained by dissolving Sr components in
CaAl2O4 in which an X value of CaxSrr,xA12O4 is 0.95, into which a-A1203 is blended, in
15 Examples 105 to 109. Table 16 shows the compositions of the solid solutions, the
crystallite diameters of the solid solutions, the blending ratio of the solid solutions and
a-A1203, and the measurement results of flow value and flexural strength after curing and
results of the rotary corrosion test of the monolithic refractory in each of the Examples.
All of the solid solutions were subjected to firing for 2 hours at the maximum
20 temperature of 1500°C for manufacture.
[0149]
[Table 16]
[0150]
The evaluation results are as shown in Table 16. In Examples 105 to 109, the
53
flow values of the monolithic refractories suitable for pouring were obtained 2 hours after
the start of mixing. Therefore, it has been confirmed that Examples 105 to 109 can be
applied to furnaces with a large volume or the like. Furthermore, Examples 105 to 109
show larger values than Comparative Examples 1 to 6 in the flexural strength after curing
5 of 6, 12, and 24 hours, and therefore it has been clarified that Examples 105 to 109 are
excellent in terms of cured strength developing property. In particular, the flexural
strength after curing of 6 hours is remarkably greater compared to those of the
Comparative Examples, and therefore it has been confirmed that Examples 105 to 109
are excellent in terms of early strength developing property. Furthermore, it has been
10 clarified that, compared to Comparative Examples, Examples 105 to 109 clearly show
small wear amounts in the rotary corrosion test using slag and are excellent in terms of
slag resistance at a high temperature.
[0151]
In addition, in Examples 105 to 109 it is possible to further decrease the wear
15 amount in the rotary corrosion test using slag, compared to Example 101 including no
A12O3, since Examples 105 to 109 include A12O3, which clarifies that Examples 105 to
109 are superior in terms of slag resistance at a high temperature.
[0152]
From these test results, it has been clarified that, by using the binder for
20 monolithic refractories including a mixture of a solid solution obtained by dissolving Ca
components in a-SrAl2O4 in which a crystallite diameter of the solid solution is from 40
ran to 75 nm, a solid solution obtained by dissolving Ca components in R-SrAl2O4 in
which a crystallite diameter of the solid solution is from 35 nm to 70 ran, and a solid
solution obtained by dissolving Sr components in CaA12O4 in which a crystallite diameter
25 of the solid solution is from 25 run to 60 nm, into which A12O3 is blended, a monolithic
55
including a mixture of two or three kinds selected from a group consisting of a solid
solution for which the chemical components of a binder had been controlled to solidify
Ca components in a-SrAl2O4, a solid solution for which the chemical components of a
binder had been controlled to solidify Ca components in (3-SrAl2O4, and a solid solution
5 for which the chemical components of a binder had been controlled to solidify Sr
components in CaAl2O4 in Examples 150 to 197 and Comparative Examples 15 to 30;
and monolithic refractories manufactured with binders including a mixture of two or
three kinds selected from a group consisting of a solid solution for which the chemical
components of a binder had been controlled to solidify Ca components in a-SrAl2O4, a
10 solid solution for which the chemical components of a binder had been controlled to
solidify Ca components in (3 SrA12O4, and a solid solution for which the chemical
components of a binder had been controlled to solidify Sr components in CaAl2O4, into
which A1203 was blended, in Examples 198 to 221.
Tables 17 to 43 show the chemical composition and chemical components, and
15 the measurement results of flow value and flexural strength after curing and results of the
rotary corrosion test of the monolithic refractory in each of Examples and Comparative
Examples. All of the solid solutions were subjected to firing for 2 hours at the
maximum temperature of 1500°C for manufacture. In addition, the chemical
components of the manufactured binders were measured using X-ray fluorescence
20 analysis ("ZSX-Primus 1I", a scanning X-ray fluorescence analyzer manufactured by
Rigaku Corporation).
[0154]
[Table 17]
[0155]
56
[Table 18]
[0156]
[Table 19]
[01571
5 [Table 20]
[0158]
[Table 21]
[0159]
[Table 22]
10 [0160]
[Table 23]
[0161]
[Table 24]
[0162]
15 [Table 25]
[0163]
[Table 26]
[0164]
[Table 27]
20 [0165]
[Table 28]
[0166]
[Table 29]
[0167]
25 [Table 30]
57
[0168]
[Table 31]
[0169]
[Table 32]
5 [0170]
[Table 33]
[0171]
[Table 34]
[0172]
10 [Table 35]
[0173]
[Table 36]
[0174]
[Table 37]
15 [0175]
[Table 38]
[0176]
[Table 39]
[0177]
20 [Table 40]
[0178]
[Table 41]
[0179]
[Table 42]
25 [0180]
58
[Table 43]
[0181]
The evaluation results are as shown in Tables 17 to 43. Comparative Examples
7 to 30 show degradation in the cured flexural strength and an increase in the wear
5 amount in the rotary corrosion test using slag since they include from 14.8 mass% to 23.8
mass% of one kind or two or more kinds of components selected from a group consisting
of SiO2., TiO2, Fe2O3, MgO, and BaO other than SrO, CaO, and A12O3 in the binders of
the present invention. Examples 110 to 221 show a superior strength developing
property compared to a case not including the above-described components and superior
10 high temperature slag resistance compared to CaO-A12O3-based binders of the
conventional technique, which clarifies that favorable characteristics can be obtained by
including preferably 12 mass% or less and more preferably 5 mass% or less of one kind
or two or more kinds of components selected from a group consisting of SiO2, TiO2,
Fe2O3, MgO, and BaO in the binders.
15 [0182]
From these test results, it has been clarified that, by using the binder for
monolithic refractories according to the present invention including a solid solution
including one kind or two or more kinds selected from a group consisting of SiO2, TiO2,
Fe2O3, MgO, and BaO in which an amount thereof is 12 mass% or less, a monolithic
20 refractory in which a favorable operability is secured even after a long period of time has
elapsed after pouring and blending water thereinto, a favorable strength developing
property is obtained early, and slag resistance at a high temperature is superior compared
to the conventional technique can be obtained. Therefore, in the binder for monolithic
refractories according to the present invention, when low purity raw materials including
25 impurities such as SiO2, T1O2, Fe2O3, MgO, and BaO are used or when various
59
contaminations of impurities are generated during the manufacturing process, by
adjusting an amount thereof to be 12 mass% or less in a binder, superior characteristics
can be obtained compared to CaO-A12O3-based binders of the conventional technique.
[0183]
5 [10] Examples relating to a monolithic refractory obtained by blending at least
either a dispersant or a hardening retardant in the binders according to the present
invention
Measurement of the flow value and the flexural strength after curing and rotary
corrosion tests using slag were performed using monolithic refractories manufactured
10 with binders including various solid solutions for which raw materials had been
controlled to obtain an X value of CaxSri_,A12O4 of 0.05, 0.30, or 0.95 and firing had
been performed for 2 hours at the maximum temperature of 1500°C for manufacture, into
which a-A1203 was blended with a predetermined ratio and one or two kinds of either a
dispersant or a hardening retardant were blended, in Examples 222 to 257. In addition,
15 the same tests were performed using monolithic refractories manufactured with binders
including a solid solution for which raw materials had been controlled to obtain a
composition of CaA12O4 and firing had been performed for 2 hours at the maximum
temperature of 1500°C for manufacture, into which a,-A1203 was blended with a
predetermined ratio, in Comparative Examples 31 to 36. Monolithic refractories were
20 manufactured with an amount of water added reduced to 6.2 mass% with respect to 100
mass% of a mixture of the binder and refractory aggregates. Tables 44 to 47 show the
compositions of the solid solutions, the crystallite diameters of the solid solutions, the
blending ratio of the solid solutions, CaAl2O4, a=Al2O3, the dispersant, and the hardening
retardant, and the measurement results of flow value and flexural strength after curing
60
and results of the rotary corrosion test of the monolithic refractory in each of the
Examples. In the tables, the amounts of the dispersant and the hardening retardant
blended are represented by the ratio (mass ratio) to the binders.
[0184]
5 A commercially available powder polycarboxylic acid-based dispersant was
used as the dispersant, and boric acid (primary reagent) was crushed to 200 mesh or
lower and used as the hardening retardant.
[0185]
[Table 44]
10 [0186]
[Table 45]
[0187]
[Table 46]
[0188]
15 [Table 47]
[0189]
The evaluation results are as shown in Tables 44 to 47. In Examples 222 to
257, regardless of the reduced amount of water added to monolithic refractories, the flow
values suitable for pouring were obtained 2 hours after the start of mixing. Therefore, it
20 has been confirmed that Examples 222 to 257 can be applied to furnaces with a large
volume or the like. Furthermore, Examples 222 to 257 show larger values than
Comparative Examples 31 to 36 in the flexural strength after curing of 6, 12, and 24
hours, and therefore it has been clarified that Examples 222 to 257 are excellent in terms
of cured strength developing property. In particular, the flexural strength after curing of
25 6 hours is remarkably greater compared to those of the Comparative Examples, and
61
therefore it has been confirmed that Examples 222 to 257 are excellent in terms of early
strength developing property. Furthermore, it has been clarified that, compared to
Comparative Examples, Examples 222 to 257 clearly show small wear amounts in the
rotary corrosion test using slag and are excellent in terms of slag resistance at a high
5 temperature.
[0190]
In addition, since monolithic refractories were manufactured with a reduced
amount of water added, a decrease in the wear amount in the rotary corrosion test using
slag could be obtained compared to a. case where monolithic refractories were
10 manufactured with the same composition of binder.
[0191]
From these test results, it has been clarified that, by using the dispersant and the
hardening retardant in the binder for monolithic refractories according to the present
invention, a monolithic refractory in which a favorable operability is secured even after a
15 long period of time has elapsed after pouring and blending water thereinto, a favorable
strength developing property is obtained early, and slag resistance at a high temperature
is superior compared to the conventional technique can be obtained.
[0192]
[11] Examples relating to a monolithic refractory including a mixture of the
20 binder for monolithic refractories according to the present invention and a. refractory
aggregate including an ultrafine alumina powder with a particle diameter of 1 μm or less
The same tests were performed using monolithic refractories manufactured from
aggregates in which amounts of the ultrafine alumina powder with a. particle diameter of
1 I-,m or less in the monolithic refractories were varied in a range of 0 to 80 mass% and
25 the binder according to the present invention in Examples 258 to 293 and Reference
62
Examples 23 to 34. In all tests, a binder including 40 mass% of various solid solutions
and their mixture and 60 mass% of a-A1203 were used, wherein the solid solutions
prepared such that raw materials had been controlled to obtain an X value of
Ca,Srl_,A12O4 of 0.05, 0.30, or 0.95 and firing had been performed for 2 hours at the
5 maximum temperature of 1500°C. The amount of fused alumina of from 75 μm to 5
mm was adjusted to cover a changed amount of the ultrafine alumina powder of 1 μm or
less so as to manufacture monolithic refractories with the same total mass of alumina
refractory aggregates. Further, the blending ratio of the binder, magnesia, silica flower,
vinylon fiber and the amount of water added was not varied. Tables 48 to 52 show the
10 compositions of the solid solutions, the crystallite diameters of the solid solutions, the
blending ratio of the various solid solutions and a=Al2O3, the amount of sintered alumina
of 1 pm or less, the amount of fused alumina of from 75 pin to 5 mm, and the
measurement results of flow value and flexural strength after curing and results of the
rotary corrosion test of the monolithic refractory in each of the Examples.
15 [0193]
[Table 48]
[0194]
[Table 49]
[0195]
20 [Table 50]
[0196]
[Table 51]
[0197]
[Table 52]
64
in which an amount of the ultrafinc alumina powder with a particle diameter of 1 μm or
less is from 2 mass% to 70 mass%.
[0201]
[12] Examples relating to a monolithic refractory using a varied amount of the
5 binder for monolithic refractories according to the present invention
In Examples 294 to 337 and Reference Examples 35 to 44, in monolithic
refractories manufactured using the binder according to the present invention, the same
tests were performed with a varied amount of the binder in a case in which the total of
the binder and refractory aggregates was made to be 100 mass%. In all tests, a binder
10 including 40 mass% of various solid solutions and their mixture and 60 mass% of
a-A1203 were used, wherein the solid solutions prepared such that raw materials had
been controlled to obtain an X value of CaSrr_,A12O4 of 0.05, 0.30, or 0.95 and firing
had been performed for 2 hours at the maximum temperature of 1500°C. Tables 53 to
58 show the compositions of the solid solutions, the crystallite diameters of the solid
15 solutions, the blending ratio of the various solid solutions and a--A1203, the amount of the
binder added, and the measurement results of flow value and flexural strength after
curing and results of the rotary corrosion test of the monolithic refractory in each of the
Examples.
[0202]
20 [Table 53]
[0203]
[Table 54]
[0204]
[Table 55]
65
[0205]
[Table 56]
[0206]
[Table 57]
5 [0207]
[Table 58]
[0208]
The evaluation results are as shown in Tables 53 to 58. In Examples 294 to
337, the flow values suitable for pouring were obtained 2 hours after the start of mixing.
10 Therefore, it has been confirmed that Examples 294 to 33'7 can be applied to furnaces
with a large volume or the like. Furthermore, Examples 294 to 337 show favorable
values in the flexural strength after curing of 6, 12, and 24 hours. Inparticular,
Examples 294 to 337 show larger values in the flexural strength after curing of 6 hours,
and therefore it has been clarified that Examples 294 to 337 are excellent in terms of
15 early strength developing property. Furthermore, it has been clarified that, Examples
294 to 337 show small wear amounts in the rotary corrosion test using slag and are
excellent in terms of slag resistance at a high temperature.
[0209]
On the other hand, in Reference Examples 36, 38, 40, and 43 in which an
20 amount of the binder added was 0.2 mass%, it has been confirmed that the flexural
strength after curing of 6 hours is low, it is difficult for a frame to be removed early, and
the risk of explosion increases due to insufficient strength when the monolithic
refractories are dried. In Reference Examples 35, 37, 39, 41, 42, and 44 in which an
amount of the binder added was 25 mass%, it has been confirmed that, compared to other
25 cases, Reference Examples 35, 37, 39, 41, 42, and 44 show an increase in the wear
66
amount in the rotary corrosion test using slag and degradation in the slag resistance at a
high temperature.
[0210]
In Examples in which an amount of the binder added was from 0.5 mass% to 12
5 mass%, it has been confirmed that Examples are excellent in terms of both of the cured
strength and the wear amount in the rotary corrosion test using slag.
[0211]
From these test results, it has been confirmed that the amount of the binder for
monolithic refractories according to the present invention is preferably from 0.3 mass%
10 to 20 mass%, and further preferably from 0.5 mass% to 12 mass% with respect to 100
mass% of the total amount of the binder for monolithic refractories and the refractory
aggregates.
[0212]
[13] Examples relating to a monolithic refractory into which at least one of a
15 dispersant, a hardening retardant, and a hardening accelerator is added
In Examples 338 to 515, monolithic refractories were manufactured by using a
binder including 40 mass% of various solid solutions and their mixture and 60 mass% of
a-A1203, wherein the solid solutions prepared such that raw materials had been controlled
to obtain an X value of Ca,Sr1_xA12O4 of 0.05, 0.30, or 0.95 and firing had been
20 performed for 2 hours at the maximum temperature of 1500°C, and blending a
predetermined amount of at least one kind of a variety of dispersants, hardening
retardants and hardening accelerators in outer percentage, and then the tests were
performed. In addition, in Comparative Examples 31 to 47, monolithic refractories
were manufactured by using a binder including no Sr components and blending at least
25 one kind of a dispersant, a hardening retardant and a hardening accelerator in the same
67
manner, and then the tests were performed. Further, when blending a dispersant, a
hardening retardant, or a dispersant and a hardening retardant, the amount of water added
was reduced to 6.2 mass% with respect to 100 mass% of the mixture of the binder and
refractory aggregates, and then the test was performed. In addition, when blending only
5 a hardening accelerator, as usual, 6.8 mass% of water was added and the test was
performed. A powder dispersant, a hardening retardant, and a hardening accelerator
were used after being blended with the binder and refractory aggregate using an omni
mixer. For liquid dispersants, the mass of solid components included was considered as
the amount added, and adjustment was performed so as to obtain a predetermined amount
10 of water by reducing from the amount of water to be added by the mass portion of the
solvent parts. In addition, liquid dispersants were used after being blended with mixing
water.
[0213]
Meanwhile, in the embodiments, a sodium polyacrylate reagent, which is a
15 polycarboxylic acid-based dispersant, was used as the dispersant A; "TIGHTLOCK"
(trade name, manufactured by Kao Corporation), which is a. polyether-based dispersant,
was used as the dispersant B; sodium tripolyphosphate (primary reagent), which is a
phosphate-based dispersant, was used as the dispersant C; trisodium citrate dihydrate
(primary reagent), which is an oxycarboxylic acid, was used as the dispersant D; "FT-3 S"
20 (with a solid content of 33 mass%) (trade name, manufactured by Grace Chemical Co.,
Ltd.), which is a melamine-based dispersant, was used as the dispersant E; "MIGHTY
150" (with a solid content of 40 mass%) (trade name, manufactured by Kao Corporation),
which is a naphthalene-based dispersant, was used as the dispersant F; "VANILLEX
HW" (trade name, manufactured by Nippon Paper Chemicals Co., Ltd.), which is a
25 lignin-based dispersant, was used as the dispersant G; boric acid (special grade chemical),
68
which is one of boric acid groups, was used as the hardening retardant a; sodium
silicofluoride (special grade chemical), which is a silicofluoride, was used as the
hardening retardant b; lithium citrate (primary reagent), which is one of salts of alkaline
metals, was used as the hardening accelerator a; and sodium aluminate (primary reagent),
5 which is one of aluminates, was used as the hardening accelerator (3.
[0214]
Tables 59 to 78 show the compositions of the solid solutions, the crystallite
diameters of the solid solutions, the blending ratio of the various solid solutions and
CaA11O4 and a-A1203 for comparison, the type and amount added of the dispersant, the
10 type and amount added of the hardening retardant, the type and amount added of the
hardening accelerator, and the measurement results of flow value and flexural strength
after curing and results of the rotary corrosion test of the monolithic refractory in each of
the Examples. In the tables, the amounts of the dispersant, the hardening retardant, and
the hardening accelerator used are represented by the ratio to the total amount of the
15 binders and the refractory aggregates.
[0215]
[Table 59]
[0216]
[Table 60]
20 [0217]
[Table 61]
[0218]
[Table 62]
[0219]
25 [Table 63]
69
[0220]
[Table 64]
[0221]
[Table 65]
5 [0222]
[Table 66]
[0223]
[Table 67]
[0224]
10 [Table 68]
[0225]
[Table 69]
[0226]
[Table 70]
15 [0227]
[Table 71]
[0228]
[Table'72]
[0229]
20 [Table 73]
[0230]
[Table 74]
[02311
[Table 75]
25 [0232]
70
[Table 76]
[0233]
[Table 77]
[0234]
5 [Table 78]
[0235]
The evaluation results are as shown in Tables 59 to 78. In the cases of
Examples 338 to 364, 371 to 376, 391 to 417, 424 to 429, 444 to 452, 455, 456, 462 to
470, 473, 474, 480 to 488, 491, 492, 498 to 506, 505, and 506 in which a dispersant
10 and/or a hardening retardant were used, regardless of the reduced amount of water added
to monolithic refractories, the flow values of the monolithic refractories suitable for
pouring were obtained 2 hours after the start of mixing. Therefore, it has been
confirmed that Examples 338 to 364, 371 to 376, 391 to 417, 424 to 429, 444 to 452, 455,
456, 462 to 470, 473, 474, 480 to 488, 491, 492, 498 to 506, 505, and 506 can be applied
15 to furnaces with a large volume or the like. Furthermore, Examples 338 to 364, 371 to
376, 391 to 417, 424 to 429, 444 to 452, 455, 456, 462 to 470, 473, 474, 480 to 488, 491,
492, 498 to 506, 505, and 506 show larger values than Comparative Examples 31 to 39,
42, and 43 in the flexural strength after curing of 6, 12, and 24 hours, and therefore it has
been clarified that Examples 338 to 364, 371 to 376, 391 to 417, 424 to 429, 444 to 452,
20 455, 456 , 462 to 470, 473 , 474, 480 to 488, 491, 492 , 498 to 506, 505, and 506 are
excellent in terms of cured strength developing property. In particular, the flexural
strength after curing of 6 hours is remarkably greater compared to those of the
Comparative Examples, and therefore it has been confirmed that Examples 338 to 364,
371 to 376, 391 to 417, 424 to 429, 444 to 452, 455, 456, 462 to 470, 473, 474, 480 to
25 488, 491, 492, 498 to 506, 505, and 506 are excellent in terms of early strength
71
developing property. Furthermore, it has been clarified that, compared to Comparative
Examples, Examples 338 to 364, 371 to 376, 391 to 417, 424 to 429, 444 to 452, 455,
456, 462 to 470, 473, 474, 480 to 488, 491, 492, 498 to 506, 505, and 506 clearly show
small wear amounts in the rotary corrosion test using slag and are excellent in terms of
5 slag resistance at a high temperature.
[0236]
In addition, by reducing the amount of water added, compared to Examples in
which the same binder was used with the ordinary amount of water added, Examples 338
to 364, 371 to 376, 391 to 417, 424 to 429, 444 to 452, 455, 456, 462 to 470, 473, 474,
10 480 to 488, 491, 492, 498 to 506, 505, and 506 show an increase in the cured flexural
strength and degradation in the wear amount in the rotary corrosion test using slag.
[0237]
In Examples 365 to 370, 418 to 423, 453, 454, 471, 472, 489, 490, 507, and 508
using only a hardening accelerator, the flow values of the monolithic refractories suitable
15 for pouring were obtained 2 hours after the start of mixing. Therefore, it has been
confirmed that Examples 365 to 370, 418 to 423, 453, 454, 471, 472, 489, 490, 507, and
508 can be applied to fin uaces with a large volume or the like. Furthermore, Examples
365 to 370, 418 to 423, 453, 454, 471, 472, 489, 490, 507, and 508 show larger values
than Comparative Examples 40 and 41 in the flexural strength after curing of 6, 12, and
20 24 hours, and therefore it has been clarified that Examples 365 to 370, 418 to 423, 453,
454, 471, 472, 489, 490, 507, and 508 are excellent in terms of cured strength developing
property. In particular, the flexural strength after curing of 6 hours is remarkably
greater compared to those of the Comparative Examples, and therefore it has been
confirmed that Examples 365 to 370, 418 to 423, 453, 454, 471, 472, 489, 490, 507, and
25 508 are excellent in terms of early strength developing property. Furthermore, it has
72
been clarified that, compared to Comparative Examples, Examples 365 to 370, 418 to
423, 453, 454, 471, 472, 489, 490, 507, and 508 clearly show small wear amounts in the
rotary corrosion test using slag and are excellent in terms of slag resistance at a high
temperature.
5 [0238]
In Examples 365 to 370, 418 to 423, 453, 454, 471, 472, 489, 490, 507, and 508
including a hardening accelerator added, the cured flexural strength was further increased
after 6 hours and 12 hours compared to Examples including no hardening accelerator
added, which clarified that Examples 365 to 370, 418 to 423, 453, 454, 471, 472, 489,
10 490, 507, and 508 are superior in terms of early strength developing property. In
addition, the wear amount became almost the same as that of cases including no additive
in the rotary corrosion test using slag, which clarified that Examples 365 to 370, 418 to
423, 453, 454, 471, 472, 489, 490, 507, and 508 are excellent in terms of slag resistance
at a high temperature.
15 [0239]
In Examples 377 to 390, 430 to 443, 457 to 461, 475 to 479, 493 to 497, and 511
to 515 using a hardening accelerator and furthermore at least either a dispersant or a
hardening retardant, regardless of the reduced amount of water added to monolithic
refractories, the flow values of the monolithic refractories suitable for pouring were
20 obtained 2 hours after the start of mixing. Therefore, it has been confirmed that
Examples 377 to 390, 430 to 443, 457 to 461, 475 to 479, 493 to 497, and 511 to 515 can
be applied to furnaces with a large volume or the like. Furthermore, Examples 377 to
390, 430 to 443, 457 to 461, 475 to 479, 493 to 497, and 511 to 515 show larger values
than Comparative Examples 44 to 47 in the flexural strength after curing of 6, 12, and 24
25 hours, and therefore it has been clarified that Examples 377 to 390, 430 to 443, 457 to
74
satisfactory slag resistance at 1600°C than the Comparative Examples, which clarified
that the tolerance at places that come into contact with molten iron or slag are improved.
Industrial Applicability
5 [0242]
According to the prevention, a binder for monolithic refractories having
excellent corrosion resistance with respect to slag or molten iron and excellent
characteristics in the early development of hardened strength and the stability thereof
compared to binders such as alumina cement in the conventional technology; a
10 monolithic refractory using the binder; and a construction method of the monolithic
refractory, can be provided.
15
Reference Symbol List
[0243]
1: REFRACTORY (TEST SPECIMEN)
2: PROTECTION PLATE
3: BURNER
4: SLAG
5: FILLING MATERIAL

CLAIMS
1. A binder for monolithic refractories comprising
a solid solution obtained by dissolving Ca components in a-SrAl2O4 or
5 (3-SrAl2O4,
wherein when the Ca components are dissolved in the a-SrAl2O4, a crystallite
diameter of the solid solution is from 40 nm to 75 ran, and
when the Ca components are dissolved in the (3-SrAl2O4, a crystallite diameter
of the solid solution is from 35 our to 70 nm.
10
2. The binder for monolithic refractories according to claim 1,
wherein an amount of the solid solution obtained by dissolving Ca components
in the a-SrAl2O4 or the (3-SrAl2O4 is from 10 mass% to 60 mass%, and
40 mass% to 90 mass% of A1203 is blended thereinto.
15
3. The binder for monolithic refractories according to claim 1, further
comprising, as a mixture,
a solid solution obtained by dissolving Sr components in CaAl2O4,
wherein a crystallite diameter of the solid solution is from 25 nor to 60 ran.
20
4. The binder for monolithic refractories according to claim 3,
wherein an amount of the solid solution obtained by dissolving Ca components
in the a-SrA12O4 Qr the (3-SrA12O4 and the solid solution obtained by dissolving Sr
components iri the CaAl2O4 is from 10 mass% to 60 mass%, and
40 mass% to 90 mass% of A1203 is blended thereinto.
5. The binder for monolithic refractories according to claim 1,
wherein both of a solid solution obtained by dissolving Ca components in the
a-SrAl2O4 and a solid solution obtained by dissolving Ca components in the (3-SrAl2O4
are included as a mixture.
6. The binder for monolithic refractories according to claim 5,
wherein a total amount of both of the solid solution obtained by dissolving Ca
10 components in the a-SrAl2O4 and the solid solution obtained by dissolving Ca
components in the P-SrAl2O4 is from 10 mass% to 60 mass%, and
40 mass% to 90 mass% of A1203 is blended thereinto.
7. The binder for monolithic refractories according to claim 5, further
15 comprising, as a mixture
the solid solution obtained by dissolving Sr components in the CaA12O4.
8. The binder for monolithic refractories according to claim 7,
wherein a total amount of the solid solution obtained by dissolving Ca
20 components in the a=SrAl2O4, the solid solution obtained by dissolving Ca components
in the G3-SrAl2O4, and the solid solution obtained by dissolving Sr components in the
CaAl2O4 is from 10 mass% to 60 mass%, and
40 mass% to 90 mass% of A12O3 is blended thereinto.
9. The binder for monolithic refractories according to claim 1,
wherein one kind or two or more kinds selected from a group consisting of SiO2,
Ti02, Fe2O3, MgO, and BaO are included in the binder for monolithic refractories and an
amount thereof is 12 mass% or less.
5
10. The binder for monolithic refractories according to claim 1,
wherein at least one of a dispersant and a hardening retardant is blended into the
binder for monolithic refractories.
10 11. A. monolithic refractory obtained by blending the binder for monolithic
refractories according to any one of claims 1 to 10 into a refractory aggregate.
12. The monolithic refractory according to claim 11,
wherein the refractory aggregate includes an ultrafine alumina powder with a
15 particle diameter of from 0.8 am to 1 μm.
13. The monolithic refractory according to claim 11,
wherein an amount of the binder for monolithic refractories is from 0.3 mass%
to 20 mass% with respect to 100 mass% of a total amount of the binder for monolithic
20 refractories and the refractory aggregate.
14. The monolithic refractory according to claim 13,
wherein the amount of the binder for monolithic refractories is from 0.5 mass%
to 12 mass% with respect to 100 mass% of the total amount of the binder for monolithic
25 refractories and the refractory aggregate.
78 }
15. The monolithic refractory according to claim 11,
wherein further at least one of a dispersant, a hardening retardant, and a
hardening accelerator is added.
5
16. The monolithic refractory according to claim 15,
wherein the dispersant is one kind or two or more kinds selected from a group
consisting of a polycarbonate-based dispersant, a phosphate-based dispersant, an
oxycarboxylic acid, a melamine-based dispersant, a naphthalene-based dispersant, and a lignin snlfonic acid-based dispersant,
the hardening accelerator is at least one of an alkali metal salt and aluminate,
and
the hardening retardant is at least one of boric acid group and silicofluoride.
15 17. A construction method of monolithic refractories comprising:
blending and mixing the binder for monolithic refractories according to any one
of claims 1 to 10 and a refractory aggregate including an ultrafine alumina powder with a
particle diameter of 1 μm or less to obtain a. monolithic refractory; and
constructing the monolithic refractory.