JPH0316398B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention is applicable to metallurgical furnaces, ceramic furnaces, metal heating furnaces, etc.
This article relates to paste-like refractories (hereinafter referred to as press-in materials) that are used to fill the gaps between the outer shell and lining bricks of various types of kilns, or between the lining bricks. (Prior Art) In recent years, with advances in metal melting and smelting technology, various types of kilns have been operated at increasingly higher operating temperatures or used under harsh conditions. For this reason, various types of furnaces have been developed by using refractories with high purity and high refractory properties, or by cooling the furnace body using refractories with high thermal conductivity to suppress wear and tear on the refractories and extend the life of the furnace. It has been adopted. The present invention relates to the latter. For example, a blast furnace is equipped with a cooling mechanism for the purpose of protecting the steel shell, suppressing erosion of the lining bricks, etc., and the furnace wall is cooled by spraying water on the steel shell or the like. In order to promote this cooling effect, when constructing the furnace wall, a high thermal conductivity material mainly made of carbon powder is used between the lining brick and the iron skin or between the lining brick to prevent the thermal expansion of the surrounding bricks and water cooling box. Filling a plastic monolithic refractory that can absorb and exhibit cushioning properties, or filling a large gap up to 100 mm between an iron shell and a brick or between a water cooling box and a brick with the plastic monolithic refractory. This was proposed in Japanese Patent Application Laid-open Nos. 54-8611 and 55-51767. During long-term operation of a blast furnace, gaps are formed between the steel shell and the lining bricks or between the lining bricks due to the effects of deformation of the steel shell, expansion and contraction of the lining bricks, and gas pressure within the furnace. For this reason, as mentioned above, even if a monolithic refractory with high thermal conductivity is filled, the cooling effect is significantly reduced due to the gaps created between the steel shell and the lining bricks, or between the lining bricks. The gap rapidly expanded due to the intrusion of high-temperature gas, etc., causing the steel shell to become red-hot, which could lead to an accident. In this way, the occurrence of gaps promotes damage to the steel shell and lining bricks, so it is necessary to prevent the gaps by filling them with monolithic refractories when they are small.
Considering the above, it is considered effective to fill the gap to about 0.3 to 10 mm, preferably about 0.5 to 5 mm.
With the filler made of plastic molded material or ramming material shown in No. 1, it was more difficult to fill the gap as the gap became narrower. (Problems to be Solved by the Invention) In view of the above, the present inventors focused on a press-fit material that is relatively easy to fill into small gaps as a filler, and the characteristics of this press-fit material are as follows: It has good fluidity even when the gap is mixed, and it is easy to fill even the slightest gap. Press-fitting work often requires a long time from mixing the press-fitting materials to starting press-fitting due to timing issues with blast furnace operations. Even in such cases, the material must not deteriorate over time. In blast furnaces, the distance for press-in material to be pumped is long, and it takes a long time to pump it, so separation and solidification should not occur during operation. As a result of various research and examinations to satisfy these requirements, such as increasing the cooling effect of the steel shell and making it a material with high thermal conductivity after press-fitting, we have developed a material with high heat conductivity to the inside of the blast furnace shell or the narrow gap between the lining bricks. We have discovered that the above problems can be solved at once by using a carbonaceous monolithic refractory with a specific particle size composition as an injection material as a material that has properties, does not change over time, and can be filled efficiently. The present invention has now been completed. (Means for Solving the Problems) That is, the gist of the present invention is to consist of a mixture of carbon powder and a thermosetting resin, with a room temperature curing agent added if necessary, and the carbon powder has a maximum particle size of 1.
This is a press-fitting material for filling gaps that has a particle size of 15 to 45 wt% of particles of 44 μm or less. The type of carbon powder used in the present invention is not particularly limited, and for example, one or more types selected from natural graphite, artificial graphite, electrode scrap, petroleum coke, foundry coke, carbon black, etc. can be used. Preferably, artificial graphite with a high degree of crystallinity is most desirable in terms of thermal conductivity and compactness. The reason why the particle size of the carbon powder is limited to 1 mm or less, preferably 0.7 mm or less is because if it exceeds 1 mm, it is not easy to press fit into a minute place, and the press-fit material tends to separate. Furthermore, 1mm or less and 44μ or less
The content is 45wt%, preferably 18 to 40wt%.
This is because if it is less than 15 wt% or more than 45 wt%, the stability of uniform dispersion of particle size and thermal conductivity will be significantly reduced, as shown in FIGS. 1 to 3, and the pumping efficiency of the press-fit material will be sharply reduced. Thermosetting resins are used as binders, but it is better to avoid phenolic resins that contain condensed water.
It is most desirable to use furan resin, which has a low viscosity and a relatively large amount of fixed carbon. The amount of thermosetting resin added is 7:3 to 3: by weight.
7, preferably 6:4 to 4:6. Furan resins include furfural resins and furfuryl alcohol resins, and solvents such as alcohols and ethers can also be used if necessary. It is possible to add an appropriate amount of a room temperature curing agent to the furan resin. For example, when filling a gap formed in the bottom of a blast furnace with press-in material, if the press-in material does not harden quickly, it will sink under the weight of the bottom bricks, making it impossible to lay bricks accurately. Room temperature curing agents include P-toluenesulfonic acid, P-toluenesulfonyl chloride, etc.
The addition ratio is 0.03 to 8 wt% based on the furan resin. If it is less than 0.03wt%, rapid room temperature curing cannot be expected. On the other hand, if it exceeds 8 wt%, the curing speed becomes too fast, and the press-fitting material is likely to harden while being pumped, making it difficult to supply the material stably. (Function) Press-in material is constructed by adding carbon powder, thermosetting resin, and room temperature curing agent if necessary at the construction site, for example, in front of a furnace, and kneading the press-in material in a mixer using a squeeze method or piston method. It can be easily press-fitted into a predetermined gap. (Example) Examples will be described below. As shown in Table 1, in Examples Nos. 1 to 5, the maximum particle size of the carbon powder was 1.0, 0.5, and 0.3 mm, respectively, and
Stable viscosity and uniform dispersion of carbon powder of press-fit material containing 50 wt% of carbon powder of one or more types of artificial graphite, pitch coke, and scale graphite with 15 to 45 wt% of 44 μ or less and 50 wt% of furan resin. The properties, press-fit thermal conductivity, and oxidation resistance were measured. In addition, in Example Nos. 6 and 7, the maximum particle size of the carbon powder was 0.3 mm, and 30.5 wt% of the artificial graphite powder was 44 μ or less.
The viscosity, uniform dispersion stability of carbon powder, press-fitability, thermal conductivity, and fire resistance of the press-fit material containing 40 or 60 wt% and 60 or 40 wt% furan resin were measured. Furthermore, in Example No. 8, 0.5 wt% of P-toluenesulfonic acid was added to the mixture of No. 2 to improve the viscosity, uniform dispersion stability of carbon powder, press-fitability, thermal conductivity, and oxidation resistance of the press-fit material. was measured. Comparative Examples Nos. 9 to 12 were ones that deviated from the range of 44 μm or less in the carbon powder defined by the present invention, and the same property values as in the Examples were measured. Furthermore, in the conventional example, a petroleum-based pyrolysis product or a conditioning liquid was added to carbon powder, and the property values thereof were measured. The results show that, as is clear from Table 1, the viscosity, uniform dispersion of particle size, press-fitting properties, oxidation resistance, and thermal conductivity of the injected material of the inventive example were better than the comparative example and the conventional example. It showed extremely good property values as a press-fit material.

【table】

[Table] (Effects of the invention) As described above, the press-fitting material of the present invention has good fluidity and is easy to fill into minute gaps, and does not cause material separation, agglomeration, or change over time during the press-feeding operation. It has high efficiency because it has high thermal conductivity and can continuously pump the press-fitting material, and its industrial value is remarkable.

[Brief explanation of the drawing]

Figure 1 is a relationship between the proportion of 44μ or less contained in the press-fit material and viscosity, Figure 2 is a relationship between the proportion of 44μ or less and thermal conductivity, and Figure 3 is a relationship between the proportion of 44μ or less and settlement. It is a relationship diagram with quantity.

Claims (1)

[Scope of Claims] 1. A gap comprising a blend of carbon powder and a thermosetting resin, characterized in that the carbon powder has a maximum particle size of 1 mm and a particle size containing 15 to 45 wt% of 44μ or less. Press-fit material for filling parts. 2. A press-fitting material for filling a gap according to claim 1, wherein the thermosetting resin is a furan resin.