JPH0665626B2 - Carbon-containing refractory - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a carbon-containing refractory material, and more particularly to a carbon-containing refractory material using a new graphite / carbon fiber composite material dough as a graphite raw material.

[Prior Art] Carbon-containing refractory is composed of an aggregate made of refractory inorganic oxide, graphite, metal powder, etc., and is used as a refractory for various purposes. For example, a lining material for a metal refining furnace or the like is mainly composed of a basic refractory aggregate, and a lining material for a hot metal wheel or the like is mainly composed of a non-basic refractory aggregate.

Conventionally, natural graphite such as scaly graphite has been widely used as a graphite raw material for these carbon-containing refractories.

Further, as a carbon-containing refractory material containing carbon fibers, for example, JP-A-59-207871 discloses magnesia clinker 5.
Mixture 1 of 0 to 90% by weight and scaly graphite 50 to 10% by weight
Metal magnesium powder 0.5 to 10 parts by weight
Disclosed is a magnesia carbon brick obtained by adding 0.1 to 10 parts by weight of carbon fiber having a weight part and a length of 1 to 70 mm and a diameter of 3 to 100 μm.

[Problems to be Solved by the Invention] However, in the magnesia-carbon brick described in JP-A-59-207871, as a method of dispersing carbon fibers, fine powder of magnesia clinker, scaly graphite, metallic magnesium, and carbon fibers are used. Since they are mixed together in a Henschel mixer and then mixed with coarse kneaders in a kneader, the fibers are crushed and fiberized in the Henschel mixer, and the kneader leads to complete crushing. The carbon fibers are shredded and become useless. This is mainly because the magnesium particles cut the fibers.

Therefore, the present invention is a novel carbon-containing refractory material in which the graphite / carbon fiber composite material kneaded clay (hereinafter referred to as C / C composite) in which carbon fibers are composited into graphite is used as a graphite-containing refractory material. To provide.

[Means for Solving the Problem] That is, the present invention relates to a carbon-containing refractory containing graphite,
As a graphite raw material, an average diameter of 3 to 30 μm and a length of 0.1 to 80 parts by weight relative to 100 parts by weight of a graphite matrix are used.
The carbon fiber / liquid volume ratio 1 / (1
00 or more), the carbon fibers are uniformly dispersed in the liquid by mixing under a shearing force, and the graphite matrix is added to the obtained dispersion and further mixed.
The carbon-containing refractory material is characterized by using a clay of graphite / carbon fiber composite material in which the carbon fibers are randomly dispersed in the graphite matrix.

[Function] The carbon-containing refractory material of the present invention is characterized in that the C / C composite dough is used as the graphite raw material.

The carbon fibers used in the C / C composite dough used in the present invention have an average diameter of 3 to 30 μm and a length of 0.1 to 10 μm.
It has a size of 0 mm.

The graphite that can be used for the C / C composite dough may be either natural graphite or artificial graphite, and examples thereof include scaly graphite, earth graphite, carbon bratz, and pyrolytic carbon. The particle size of the graphite used may be arbitrary.

The C / C composite dough has the above-mentioned graphite as a matrix, and 1 to 80 parts by weight of carbon fibers per 100 parts by weight of the graphite are randomly dispersed in the matrix. If the amount of carbon fiber added is less than 1 part by weight, the effect of fiber addition does not appear, and if it exceeds 80 parts by weight, it is not preferable because the amount of overlapping of fibers increases and peeling easily occurs. .

The C / C composite dough may contain metallic silicon for the purpose of strengthening interfacial bonding. The addition amount of metallic silicon is 1 to 10 per 100 parts by weight of graphite.
Within the range of parts by weight. Addition amount of metallic silicon is 1
If it is less than 1 part by weight, it is not preferable because it has no effect of addition.
If it exceeds 0 parts by weight, the compound of the metallic silicon and the fiber becomes large, and the fiber is cut, which is not preferable.

Next, a method for producing a C / C composite dough will be described.

First, 1 to 80 parts by weight of carbon fiber as described above per 100 parts by weight of graphite, and a liquid having a viscosity of 0.1 Pascal · sec or less are applied with a shearing force at the fiber / liquid volume ratio 1 / (100 or more). To uniformly disperse the carbon fibers in the liquid.

It is not necessary when the carbon fiber to be used can be used as it is as a short fiber, but when it is in the form of chopped strand or fiber ball, it is necessary to use the carbon fiber after defibrating treatment. The defibration treatment can be performed using a conventional defibration machine, a high speed mixer or the like.

Examples of the liquid having a viscosity of 0.1 Pascal · second or less used in this dispersion operation include water, alcohol, ether,
Acetone or a phenol resin, an epoxy resin or the like whose viscosity is reduced by diluting with acetone can be used. The amount of these liquids used is the carbon fiber / liquid volume ratio 1 / (1
00 or more). When the volume ratio of the liquid is a carbon fiber / liquid volume ratio of 1 / (less than 100), the shearing force of the liquid does not work effectively, which is not preferable.

The dispersing operation can be carried out by applying a shearing force to the mixture of carbon fibers and liquid. An omni mixer or the like can be used for the operation of applying the shearing force. The carbon fiber can be uniformly dispersed in the liquid by loading the mixture into an omni-mixer and treating the mixture under shearing force.

Next, the above-obtained graphite 10 was added to the dispersion obtained as described above.
0 part by weight is added and further mixed to obtain a mixture. This operation can be carried out in an omni mixer subsequent to the dispersing operation. Note that it is preferable to add a small amount of a surfactant to the dispersion before adding graphite. As the surfactant, it is preferable to use soaps or dispersants having a low foaming property. By this operation, carbon fibers can be randomly dispersed in graphite.

Next, the liquid content is removed from the resulting mixture and / or
Alternatively, it can be removed by drying at a temperature of about 150 to 200 ° C. to obtain the C / C composite dough of the present invention.

The carbon-containing refractory of the present invention uses the above-mentioned C / C composite dough as a graphite raw material.
The addition amount thereof may be an ordinary addition amount of graphite, for example, about 95 to 60% by weight of the refractory raw material and about 5 to 40% by weight of the C / C composite dough.

It is preferable to coat the C / C composite dough with a binder before mixing the C / C composite dough with the refractory material.

Coating of the C / C composite dough with a binder can be performed by the following method.

First, the C / C composite dough obtained as described above is put into a mixing type mixer, and then a binder diluted with a diluent such as alcohol such as a phenol resin is added and mixed, and then naturally dried. Can be carried out by removing the diluent.

When metallic silicon or the like is added to the C / C composite, it can be added simultaneously with the diluted binder.

Further, for mixing the refractory raw material and the C / C composite dough, it is preferable to use a mixer capable of soft mixing such as a V-type mixer. For example, using a kneader mixer is not preferable because the fibers are mainly cut into pieces by the refractory raw material and lose their traces.When using a high speed mixer, the carbon fibers dispersed in the graphite form fiber balls. Not preferred to form.

Further, the refractory raw material used for the carbon-containing refractory of the present invention is not particularly limited, and all conventional refractory raw materials from basic refractory raw materials to non-basic refractory raw materials can be used.

Furthermore, to the carbon-containing refractory material of the present invention, a metal powder, a metal nitride, a metal boride, or the like which is commonly used as a carbon antioxidant can be appropriately added.

[Examples] The present invention will be further described with reference to Examples.

Example A C / C composite dough for use in the carbon-containing refractory material of the present invention was prepared in the mixing ratios shown in Table 1 below.

First, a certain amount of defibrated carbon fiber and water 6
(About 1000 times the volume of carbon fiber) was loaded into an omni mixer and treated under the condition of a rotation speed of 6 Hz to uniformly disperse the carbon fiber in water.

Next, the obtained dispersion was mixed with Miranol HM as a surfactant.
1 ml and a few drops of silicone oil were added, a predetermined amount of graphite raw material was added, and the mixture was further treated at a rotation speed of 6 Hz to obtain a dispersion in which carbon fibers were randomly dispersed in graphite. It was

Next, water was removed from the dispersion by filtration, and the dispersion was dried at a temperature of 150 ° C. for 5 hours to obtain a C / C composite dough of the present invention.

The graphite 1 shown in Table 1 is a flake-shaped natural graphite,
Graphite 2 is artificial graphite. The carbon fiber 1 has an average diameter of 7 μm and a length of about 12 mm.
Has an average diameter of 18 μm and a length of about 10 mm.

Next, 6 parts by weight of the binder of alcohol: phenol resin weight ratio = 2: 1 was added to the obtained C / C composite dough in an amount of phenol resin equivalent to 100 parts by weight of the graphite raw material, and no pressure was applied. The alcohol was removed by mixing in a kneader mixer and then air drying at 20 ° C. for 24 hours. Incidentally, metallic silicon can be appropriately added together with the diluted phenol resin during this step.

Next, the C / C composite 2 obtained as described above
0 parts by weight and 80 parts by weight of refractory raw material (magnesia) previously treated with a binder were mixed softly with a V-type mixer, and at that time, 2 parts by weight of aluminum metal was added as an antioxidant to contain carbon of the present invention. I got a refractory.

The characteristic values of the obtained carbon-containing refractory are also shown in Table 1.

[Advantages of the Invention] Since the carbon-containing refractory of the present invention uses the C / C composite dough as a graphite raw material, the carbon fibers can be dispersed in the carbon-containing refractory in a good state.

Claims (1)

[Claims] 1. In a carbon-containing refractory material containing graphite, 1 is used as a graphite raw material per 100 parts by weight of a graphite matrix.
-80 parts by weight average diameter 3 to 30 μm, length 0.1 to 10
A carbon fiber of 0 mm and a liquid having a viscosity of 0.1 Pascal · sec or less are added to the carbon fiber / liquid volume ratio 1 / (100
The above), the carbon fibers are uniformly dispersed in the liquid by mixing under the application of shearing force, the graphite matrix is added to the obtained dispersion, and the carbon fibers are obtained by further mixing. A carbon-containing refractory characterized by using a clay / graphite / carbon fiber composite dough which is randomly dispersed in a matrix.